Stanford's Clinical Pre

Question 1

According to ASA Standard I, what is the minimum requirement for anesthesia personnel?

A) Presence during induction only
B) Presence throughout the conduct of all anesthetics
C) Availability for consultation by phone
D) Presence only for general anesthesia cases

Answer 1

Answer: B

Rationale: ASA Standard I specifies that qualified anesthesia personnel must be present throughout the conduct of all types of anesthesia to ensure patient safety.

Question 2

Which of the following is evaluated continually according to ASA Standard II?

A) Patient’s oxygenation, ventilation, circulation, and temperature
B) Only oxygenation and ventilation
C) Only circulation
D) Patient’s comfort and pain levels

Answer 2

Answer: A

Rationale: ASA Standard II requires continual evaluation of oxygenation, ventilation, circulation, and temperature during anesthesia.

Question 3

or oxygenation monitoring, which of the following devices is used to assess inspired gas in an anesthesia machine?

A) EKG
B) Capnograph
C) FiO2 analyzer
D) Thermometer

Answer 3

Answer: C

Rationale: The FiO2 analyzer monitors inspired gas and oxygen concentration levels during anesthesia.

Question 4

When using mechanical ventilation, what alarm setting must be activated according to ASA standards (select 2)?

A) Heart rate alarm
B) Low Oxygen saturation alarm
C) Disconnection alarm
D) Blood pressure alarm

Answer 4

Answer: B & C

Rationale: The disconnection and low Oxygen Sat alarms must be activated when the patient is mechanically ventilated to detect accidental disconnections.

Question 5

Which of the following circulatory monitoring techniques is NOT part of the continuous circulatory assessment requirement?

A) Pulse oximetry
B) Pulse tracing
C) A line tracing
D) Blood pressure every 15 minutes

Answer 5

Answer: D

Rationale: Blood pressure should be checked at a minimum of every 5 minutes, not 15, as part of circulatory assessment.

Question 6

The fractional oxygen saturation (S𝑝𝑂2) includes which of the following?

A) Only oxyhemoglobin (O2Hb)
B) O2Hb, deoxyhemoglobin (Hb), MetHb, and COHb
C) Only MetHb and COHb
D) Only deoxyhemoglobin (Hb)

Answer 6

Answer: B
Rationale: Fractional oxygen saturation accounts for all forms of hemoglobin including O2Hb, deoxyhemoglobin (Hb), MetHb, and COHb

Question 7

In pulse oximetry, light absorption at 660 nm predominantly measures which type of hemoglobin select 2?

A) Oxyhemoglobin
B) Carboxyhemoglobin
C) Deoxyhemoglobin
D) Methemoglobin

Answer 7

Answer: C & D

Rationale: Light at 660 nm (red light) is primarily absorbed by deoxyhemoglobin.

Question 8

he AC component of the pulse oximeter measures:

A) Venous blood flow
B) Pulsatile arterial blood
C) Capillary blood
D) Non-pulsatile tissue absorption

Answer 8

Answer: B

Rationale: The AC (alternating current) component corresponds to the pulsatile arterial blood, which changes with each heartbeat.

Question 9

Which of the following can cause falsely elevated SpO2 readings? (Select 2)

A) Anemia
B) Carboxyhemoglobin
C) Methemoglobinemia
D) Cyanide poisoning

Answer 9

Answers: B, D
Rationale: Carboxyhemoglobin and cyanide poisoning can both lead to falsely high SpO2 readings. Anemia affects the amount of hemoglobin but does not directly alter the SpO2
reading.

Question 10

Methemoglobinemia typically results in what change to the SpO2reading when MetHb levels are high?

A) SpO2 approaches 100%
B) SpO2 approaches 0%
C) SpO2 remains around 85%
D) SpO2 shows extreme variability

Answer 10

Answer: C
Rationale: High levels of methemoglobin cause the SpO2
reading to approximate 85%, regardless of true oxygenation.

Question 11

What are the recommended treatments for methemoglobinemia? (Select 2)

A) Methylene blue
B) Vitamin C
C) Epinephrine
D) Albuterol

Answer 11

Answers: A, B

Rationale: Methylene blue is the primary treatment. Vitamin C may also help, particularly in patients with G6PD deficiency who cannot tolerate methylene blue.

Question 12

What abnormality is commonly seen on an arterial blood gas (ABG) in patients suffering from cyanide poisoning? (Select 2)

A) Low partial pressure of oxygen (PaO2)
B) Normal partial pressure of oxygen with falsely elevated oxygen saturation readings
C) High lactate levels indicating lactic acidosis
D) Low bicarbonate levels

Answer 12

Answers: B, C

Rationale: Cyanide poisoning disrupts cellular respiration, leading to tissue hypoxia. This can result in normal oxygen levels in the blood despite a falsely high oxygen saturation reading. High lactate levels are common due to impaired aerobic metabolism.

Question 13

A patient undergoing surgery has a stable oxygen saturation reading of 85% despite increasing the fraction of inspired oxygen. An arterial blood gas shows a normal partial pressure of oxygen. What is the most likely diagnosis?

A) Low blood volume (hypovolemia)
B) High levels of methemoglobin in the blood (methemoglobinemia)
C) Blockage of a lung artery (pulmonary embolism)
D) Carbon monoxide poisoning

Answer 13

Answer: B

Rationale: Methemoglobinemia causes a constant oxygen saturation reading of around 85%, regardless of actual oxygenation levels, due to altered hemoglobin that cannot carry oxygen effectively.

Question 14

During a house fire, a patient is brought to the hospital with an oxygen saturation reading of 99% but is showing severe signs of respiratory distress. Which conditions should be considered in this patient? (Select 2)

A) High levels of methemoglobin (methemoglobinemia)
B) High levels of carboxyhemoglobin (carboxyhemoglobinemia)
C) Cyanide poisoning from smoke inhalation
D) Severe asthma attack

Answer 14

Answers: B, C

Rationale: Carboxyhemoglobin can falsely elevate the oxygen saturation reading, giving a misleading impression of good oxygenation. Cyanide poisoning is also a risk in smoke inhalation cases and can cause severe tissue hypoxia despite normal blood oxygen readings.

Question 15

What is the first-line treatment for a patient diagnosed with cyanide poisoning?
A) Methylene blue
B) Atropine
C) Hydroxocobalamin (Vitamin B12a)
D) Sodium bicarbonate

Answer 15

Answer: C

Rationale: Hydroxocobalamin is the preferred treatment for cyanide poisoning. It binds to cyanide to form cyanocobalamin, which is then excreted by the body.

Question 16

A patient shows an oxygen saturation reading of 100% after being resuscitated from smoke inhalation, but they continue to have symptoms of severe hypoxia, such as confusion and low blood pressure. What is the most likely cause of the discrepancy between the oxygen saturation reading and the patient’s clinical presentation?

A) Methemoglobinemia
B) Carboxyhemoglobinemia
C) Cyanide toxicity
D) Pulmonary embolism

Answer 16

Answer: B

Rationale: Carboxyhemoglobin, which forms from carbon monoxide exposure during smoke inhalation, can falsely elevate oxygen saturation readings, masking the true hypoxic state of the patient.

Question 17

Which two wavelengths of light are primarily used in pulse oximetry to determine oxygen saturation? (Select 2)

A) 450 nm
B) 660 nm
C) 850 nm
D) 940 nm

Answer 17

nswers: B, D

Rationale: Pulse oximeters use red light at 660 nm and infrared light at 940 nm to differentiate between oxyhemoglobin and deoxyhemoglobin.

Question 18

What does it mean if a pulse oximeter shows a reading of 85% when the patient is not connected to the device?

A) The patient is severely hypoxic
B) The ratio of light absorption at 660 nm and 940 nm is equal (1:1)
C) The device is malfunctioning
D) The patient’s hemoglobin is fully saturated

Answer 18

Answer: B

Rationale: When the ratio of light absorption at 660 nm and 940 nm is equal (1:1), the pulse oximeter defaults to a reading of 85%. This can happen when the sensor is disconnected or when there is interference from certain types of hemoglobin (e.g., methemoglobin).

Question 19

Which of the following factors can cause a falsely low oxygen saturation reading on a pulse oximeter? (Select 2)

A) Blue nail polish
B) Anemia
C) Methylene blue dye
D) High ambient light

Answer 19

Answers: A, C

Rationale: Blue nail polish and methylene blue dye can interfere with the light absorption used by pulse oximeters, leading to falsely low readings. Anemia typically does not affect the oxygen saturation measurement directly.

Question 20

What condition is often clinically apparent when a patient has 5 grams per deciliter of desaturated hemoglobin?

A) Hypothermia
B) Hypovolemia
C) Cyanosis
D) Hypoglycemia

Answer 20

Answer: C

Rationale: Cyanosis becomes visible when there is approximately 5 grams per deciliter of desaturated hemoglobin, resulting in a bluish discoloration of the skin.

Question 21

What is an advantage of using a modified 3-electrode EKG system?

A) Provides better detection of atrial dysrhythmias
B) Allows monitoring of anterior wall ischemia
C) Offers full 12-lead analysis
D) Reduces sensitivity for ischemic changes

Answer 21

Answer: B

Rationale: The modified 3-electrode system places the left arm lead in the V5 position to better detect anterior wall ischemia.

Question 22

Which EKG lead is considered the best for detecting P waves and sinus rhythm?

A) Lead I
B) Lead II
C) Lead III
D) aVR

Answer 22

Answer: B

Rationale: Lead II is most commonly used to detect P waves and assess sinus rhythm due to its alignment with the heart’s electrical axis.

Question 23

In a 5-electrode EKG system, which combination of leads is most sensitive for detecting ischemic changes?

A) Lead I and Lead III
B) Lead II and aVR
C) V1 and V4
D) V4 and V5

Answer 23

Answers: D

Rationale: The addition of V4 and V5 leads in a 5-electrode system improves sensitivity for detecting ischemic changes.

Question 24

What is the main measurement derived by automated noninvasive blood pressure (NIBP) devices?

A) Systolic blood pressure (SBP)
B) Mean arterial pressure (MAP)
C) Diastolic blood pressure (DBP)
D) Pulse pressure

Answer 24

Answer: B

Rationale: Automated NIBP devices primarily measure mean arterial pressure (MAP) and then calculate systolic and diastolic pressures using algorithms.

Question 25

Which of the following could result from using a blood pressure cuff that is too small for the patient's arm? A) Falsely low blood pressure reading B) Falsely high blood pressure reading C) Accurate blood pressure measurement D) Inability to detect diastolic pressure

Answer 25

Answer: B Rationale: Using a cuff that is too small can result in a falsely high blood pressure reading because the cuff exerts more pressure than necessary.

Question 26

Which of the following is an indication for invasive blood pressure monitoring? (Select 2) A) Routine outpatient surgery B) Rapid blood sampling requirements C) Hemodynamic instability D) Low-risk procedures

Answer 26

Answers: B, C Rationale: Invasive blood pressure monitoring is indicated when frequent blood sampling is needed or when the patient is hemodynamically unstable.

Question 27

How does blood pressure change when the patient’s head is elevated by 10 centimeters? A) Increases by 10 mm Hg B) Decreases by 7.4 mm Hg C) Increases by 7.4 mm Hg D) Remains unchanged

Answer 27

Answer: B Rationale: According to the mnemonic provided (pH 7.410), elevating the head by 10 centimeters results in a decrease of blood pressure by approximately 7.4 mm Hg.

Question 28

Which mnemonic can help remember the relationship between changes in height and changes in blood pressure? A) pH 7.410 B) ABG 7.250 C) MAP 65.00 D) O2 Sat 98%

Answer 28

Answer: A Rationale: The mnemonic "pH 7.410" is used to remember that a pressure change of 7.4 mm Hg corresponds to a height change of 10 centimeters.

Question 29

In a patient positioned in the Beach chair (sitting) position with a blood pressure reading of 120/80 mm Hg on the leg, what would be the approximate blood pressure at the level of the brain if the brain is 60 cm higher than the cuff? A) 90/60 mm Hg B) 110/70 mm Hg C) 75/35 mm Hg D) 130/85 mm Hg

Answer 29

Answer: C Rationale: For every 10 cm height difference, blood pressure decreases by approximately 7.4 mm Hg. A 60 cm difference results in a substantial decrease in pressure, bringing the brain's blood pressure closer to 75/35 mm Hg.

Question 30

When positioning an arterial line transducer for a neurosurgical procedure, where should the transducer be leveled? A) At the level of the patient’s heart (phlebostatic axis) B) At the level of the patient’s knees C) At the level of the patient’s head (circle of Willis) D) At the level of the patient’s feet

Answer 30

Answer: C Rationale: In neurosurgical cases, the transducer should be leveled at the patient’s head (circle of Willis) to accurately reflect cerebral perfusion pressure.

Question 31

What effect does lowering the arterial line transducer below the level of the patient’s heart have on the blood pressure reading? A) It decreases the reading B) It does not change the reading C) It increases the reading D) It measures venous pressure instead

Answer 31

Answer: C Rationale: Lowering the transducer below the heart level results in a falsely elevated blood pressure reading due to hydrostatic pressure.

Question 32

As you move further from the aorta, which of the following changes can be observed in arterial line tracings? (Select 2) A) Increased systolic pressure B) Decreased dicrotic notch C) Narrower pulse pressure D) Higher dicrotic notch

Answer 32

Answers: A, B Rationale: Moving further from the aorta results in an increased systolic pressure (Amplification) and a later (lower) dicrotic notch. Pulse pressure widens, not narrows, with distance from the aorta.

Question 33

What is the clinical significance of the delayed dicrotic notch in arterial line tracings seen further from the aorta? A) It indicates reduced cardiac output B) It is caused by reflected pressure waves C) It signifies valve dysfunction D) It indicates venous congestion

Answer 33

Answer: B Rationale: The delayed dicrotic notch is due to reflected pressure waves as the pulse wave travels further from the central aorta.

Question 34

Which of the following can be used as a reliable indicator of fluid responsiveness in a mechanically ventilated patient? A) Mean arterial pressure B) Pulse pressure variation C) Capillary refill time D) Systolic blood pressure

Answer 34

Answer: B Rationale: Pulse pressure variation is a dynamic indicator of fluid responsiveness, particularly in patients who are mechanically ventilated.

Question 35

What effect does deep inspiration have on pulse pressure and stroke volume in a healthy patient? A) It decreases pulse pressure and stroke volume B) It increases pulse pressure but decreases stroke volume C) It decreases stroke volume and increases pulse pressure D) It has no effect on pulse pressure or stroke volume

Answer 35

Answer: A Rationale: Deep inspiration reduces venous return to the heart, leading to decreased stroke volume and, consequently, a decrease in pulse pressure.

Question 36

Which phase of the capnography waveform corresponds to the alveolar plateau, where the carbon dioxide concentration represents the patient’s maximal alveolar CO2 level? A) Phase I B) Phase II C) Phase III D) Phase IV

Answer 36

Answer: C Rationale: Phase III of the capnography waveform is the alveolar plateau, reflecting the maximal alveolar carbon dioxide concentration (End-tidal CO2).

Question 37

Which of the following can lead to an increased end-tidal carbon dioxide (ETCO2) reading? (Select 2) A) Hyperventilation B) Hypoventilation C) Increased metabolic rate D) Decreased cardiac output

Answer 37

Answers: B, C Rationale: Hypoventilation and an increased metabolic rate can lead to elevated end-tidal CO2 levels due to reduced CO2 elimination and increased production, respectively.

Question 38

What is a common cause of a sudden drop to near-zero in the end-tidal carbon dioxide reading during surgery? A) Hyperthermia B) Disconnection of the breathing circuit C) Increased dead space D) Excessive sedation

Answer 38

Answer: B Rationale: A sudden drop to near-zero ETCO2 is commonly caused by a disconnection in the breathing circuit, interrupting CO2 detection.

Question 39

Which of the following conditions can cause an upward sloping capnography waveform (upsloping phase)? A) Hyperventilation B) Bronchospasm C) Hypotension D) Pulmonary embolism

Answer 39

Answer: B Rationale: An upward sloping capnography waveform suggests airway obstruction, commonly seen in conditions like bronchospasm or chronic obstructive pulmonary disease (COPD). Larger alpha angle.

Question 40

What is a likely cause of a sudden drop to near-zero in end-tidal CO₂ (ETCO₂) during cardiopulmonary resuscitation (CPR)? A) High-quality chest compressions B) Recovery of spontaneous circulation (ROSC) C) Esophageal intubation D) Increased ventilation rate

Answer 40

Answer: C Rationale: A sudden drop in ETCO₂ to near-zero often indicates esophageal intubation, as the carbon dioxide from the lungs is not being detected.

Question 41

During CPR, a sudden increase in ETCO₂ from 10 mm Hg to 35 mm Hg is most indicative of what event? A) Ineffective chest compressions B) Hyperventilation C) Recovery of spontaneous circulation (ROSC) D) Massive pulmonary embolism

Answer 41

Answer: C Rationale: A sudden increase in ETCO₂ during CPR is a strong indicator of ROSC, as effective circulation returns carbon dioxide to the lungs.

Question 42

Which of the following can cause a decrease in ETCO₂ due to reduced carbon dioxide production? (Select 2) A) Hyperthyroidism B) Hypothyroidism C) Neuromuscular blockade D) Increased metabolic rate

Answer 42

Answers: B, C Rationale: Both hypothyroidism and neuromuscular blockade can lead to decreased carbon dioxide production, resulting in lower ETCO₂ readings.

Question 43

A patient experiences a sudden drop in ETCO₂ during surgery. Which of the following should be considered first as a potential cause? A) Circuit sampling line disconnect B) Hyperventilation C) Malignant hyperthermia D) Cardiac tamponade

Answer 43

Answer: A Rationale: A sudden drop in ETCO₂ often points to a mechanical issue such as disconnection of the sampling line.

Question 44

During laparoscopic surgery, an intubated patient in Trendelenburg position shows a decrease in oxygen saturation from 100% to 95% and an increase in ETCO₂ from 35 to 40 mm Hg. What is the most likely cause? A) Decreased diaphragmatic excursion B) Pneumothorax C) Carbon dioxide embolism D) Compression of the vena cava

Answer 44

Answer: A Rationale: In Trendelenburg position, the diaphragm is pushed upward, reducing lung capacity and causing decreased diaphragmatic excursion, leading to an increase in ETCO₂.

Question 45

Which capnography waveform pattern is most consistent with a sample line leak? A) Gradual upsloping trace B) Sudden drop to baseline C) Prolonged expiratory phase D) Oscillating baseline

Answer 45

Answer: B Rationale: A sudden drop in the capnography trace to baseline suggests a sampling line disconnect or leak, interrupting the detection of exhaled carbon dioxide.

Question 46

Which of the following conditions is suggested by a capnography waveform with a prolonged expiratory plateau (Phase III)? A) Normal ventilation B) Emphysema C) Hyperventilation D) Sample line obstruction

Answer 46

Answer: B Rationale: A prolonged expiratory plateau is commonly seen in patients with obstructive lung disease, such as emphysema, due to delayed exhalation. Make sure to increase the expiratory time or you might start to see the baseline start to climb, ie not reaching zero.

Question 47

Which temperature monitoring site provides the most accurate reflection of the patient’s core temperature? A) Axillary B) Tympanic membrane C) Pulmonary artery D) Skin

Answer 47

Answer: C Rationale: The pulmonary artery temperature is considered the gold standard for core temperature measurement, closely reflecting the body’s true core temperature. Tympanic membrane is a decent estimation of core body temp and can be used as well.

Question 48

What is a potential consequence of using a rectal temperature probe in a patient with reduced lower extremity blood flow? A) Overestimation of core temperature B) Underestimation of core temperature C) Accurate temperature reading D) Increased risk of infection

Answer 48

Answer: B Rationale: Reduced blood flow to the lower extremities may cause underestimation of core temperature when using a rectal probe due to poor perfusion.

Question 49

According to the capnography clinical pearl, how much should the end-tidal carbon dioxide level increase per minute during apnea? A) 1 mm Hg B) 2 mm Hg C) 3 mm Hg D) 6 mm Hg

Answer 49

Answer: D Rationale: The clinical pearl states that during apnea, ETCO₂ is expected to increase by 6 mm Hg after the first minute and by approximately 3 mm Hg every minute thereafter.

Question 50

Which monitoring device is used to assess the depth of anesthesia? A) Central venous pressure (CVP) monitor B) Intracranial pressure (ICP) monitor C) BIS monitor or Sedline D) Foley catheter

Answer 50

Answer: C Rationale: The BIS monitor or Sedline is used to monitor the depth of anesthesia by assessing the patient’s brain activity.

Question 51

What is a primary indication for using a pulmonary artery (PA) catheter during surgery? A) Assessing intracranial pressure B) Monitoring central venous pressure only C) Measuring continuous cardiac output and hemodynamic status D) Detecting air embolism

Answer 51

Answer: C Rationale: The PA catheter is used for advanced hemodynamic monitoring, including continuous cardiac output measurement.

Question 52

Which of the following is the best choice for monitoring if there is a high risk of air embolism during surgery? A) Esophageal stethoscope B) Precordial Doppler C) Foley catheter D) Sedline

Answer 52

Answer: B Rationale: The precordial Doppler is highly sensitive for detecting air embolisms, making it the preferred monitoring device in high-risk cases. A precordial Doppler ultrasound detects air embolisms by producing a distinctive sound pattern that changes when air enters the body: Small air embolisms: A brief "chirp" sound Large air embolisms: A persistent "static" sound, similar to a gramophone needle on a record

Question 53

What monitoring adjunct is commonly used in neurosurgical procedures to assess cerebral oxygenation? A) Transesophageal echocardiogram (TEE) B) Cerebral oximetry (NIRS) C) Central venous pressure (CVP) monitor D) Foley catheter

Answer 53

Answer: B Rationale: Near-infrared spectroscopy (NIRS) is used for cerebral oximetry to monitor brain oxygen levels, especially in neurosurgical cases. Near-infrared spectroscopy (NIRS) is a non-invasive technique that measures cerebral oxygenation by using infrared light to penetrate the head and scalp and measuring the absorption of light by tissue chromophores: 1. Light penetration NIRS uses light in the near-infrared range of 700–1000 nanometers (nm) that can pass through skin, bone, and other tissues. 2. Light absorption The amount of infrared light absorbed by tissue depends on the concentration of oxygenated and deoxygenated hemoglobin (HbO2 and HbR). 3. Data analysis The device uses a modified version of the Beer-Lambert law to calculate the concentration of hemoglobin species from the relative absorption of light at different wavelengths. NIRS can be used to monitor cerebral oxygenation during surgery and in the hospital bed. It can help detect oxygen deficiency in the brain, and can be used to guide therapy to reverse oxygenation issues. NIRS can also be used to monitor cerebral blood flow (CBF) and volume, and cerebral venous oxygen saturation.

Question 54

Which of the following phases is NOT typically a part of the pharmacokinetics of inhalational anesthetic agents? A) Uptake B) Distribution C) Filtration D) Elimination

Answer 54

Answer: C Rationale: The four main phases of pharmacokinetics for inhalational anesthetics are uptake (absorption into the bloodstream), distribution (to the site of action like the CNS), minimal metabolism, and elimination (primarily via exhalation). Filtration is not a phase in this context.

Question 55

What is the primary goal of administering an inhalational anesthetic agent? A) To achieve high blood concentration B) To achieve a partial pressure of the agent in the alveoli that equilibrates with the CNS C) To maximize metabolism in the liver D) To maintain constant heart rate

Answer 55

Answer: B Rationale: The goal is to produce a partial pressure of the anesthetic gas in the alveoli that equilibrates with the central nervous system (CNS), allowing the gas to exert its anesthetic effect. Partial pressure, not concentration, determines the anesthetic’s effect.

Question 56

Which factor increases the inspired concentration (Fi) of an inhalational anesthetic? A) High circuit absorption B) Low fresh gas flow C) Increased fresh gas flow D) Decreased ventilation

Answer 56

Answer: C When the fresh gas flow is increased, more of the anesthetic gas is delivered to the patient, directly increasing the inspired concentration (Fi).

Question 57

What determines the alveolar concentration (FA) of an inhalational anesthetic agent? (Select 2) A) Uptake into the blood B) Blood solubility of the agent C) Volume of breathing system D) Metabolism by the liver

Answer 57

Answers: A, B Rationale: The alveolar concentration (Fa) is influenced by the uptake of the gas into the blood and its solubility. Highly soluble agents are taken up by the blood more readily, reducing FA. Metabolism plays a minimal role for most inhalational anesthetics.

Question 58

Which anesthetic agent would likely have the fastest rise in the ratio of alveolar concentration to inspired concentration (Fa/Fi)? A) Halothane B) Isoflurane C) Desflurane D) Nitrous oxide

Answer 58

Answer: C Rationale: Desflurane has low blood solubility, allowing it to equilibrate quickly between the alveoli and blood. This results in a rapid rise in the Fa/Fi ratio, indicating faster onset.

Question 59

How does increased cardiac output affect the induction speed of an inhalational anesthetic agent? A) It speeds up induction B) It has no effect on induction C) It slows down induction D) It only affects intravenous agents

Answer 59

Answer: C Rationale: Increased cardiac output increases the amount of anesthetic taken up by the blood, effectively "removing" the agent from the alveoli and slowing the rise of Fa. This delays the onset of the anesthetic effect, particularly for more soluble agents.

Question 60

Which type of shunt delays the onset of poorly soluble inhalational agents the most? A) Left-to-right shunt B) Right-to-left shunt C) Atrial septal defect D) Patent ductus arteriosus

Answer 60

Answer: B Rationale: A right-to-left (mainstem intubation) shunt bypasses the alveoli, reducing the effective delivery of inhalational agents. This has a more significant impact on poorly soluble agents, which rely on alveolar ventilation for rapid uptake. A mainstem intubation can cause a right-to-left shunt because the endotracheal tube is positioned beyond the carina, only oxygenating one lung. This results in oxygen-poor blood from the non-ventilated lung diluting the oxygen levels of blood returning to the left ventricle.

Question 61

Why does low cardiac output predispose patients to overdose of inhalational anesthetics, especially with soluble agents? A) It decreases alveolar ventilation B) It increases blood solubility of the agent C) It results in a faster rise in the Fa/Fi ratio D) It enhances the metabolism of the agent

Answer 61

Answer: C Rationale: Low cardiac output reduces the amount of anesthetic taken up by the blood, allowing the alveolar concentration (Fa) to rise rapidly, especially for soluble agents. This can lead to faster onset and potential overdose. Soluble Agents: Soluble agents (e.g., halothane, isoflurane) have high blood solubility, meaning a larger amount of the agent is absorbed into the blood. This normally slows the rise of the alveolar concentration (Fa) because the gas is "taken up" by the blood rather than staying in the alveoli. Impact of Cardiac Output on Soluble Agents: Low Cardiac Output: When cardiac output is low, blood flow is reduced, so there is less blood available to take up the anesthetic agent, especially if the agent is highly soluble. This means that even soluble agents, which normally are absorbed extensively into the blood, will stay in the alveoli longer. As a result, the alveolar concentration (Fa) rises more quickly because there is less "sink effect" from the blood. This can lead to a faster onset and potentially an overdose, especially if the patient cannot compensate for the rapid rise in the agent’s effect.

Question 62

What is the primary effect of the second gas phenomenon when using nitrous oxide with a volatile anesthetic agent? A) It decreases the uptake of the second gas B) It delays the onset of the second gas C) It accelerates the onset of the second gas D) It has no impact on the second gas

Answer 62

Answer: C Rationale: The second gas effect refers to the ability of a rapidly absorbed gas like nitrous oxide to increase the concentration of a co-administered volatile agent in the alveoli, accelerating its onset.

Question 63

What does a slower rise in the ratio of alveolar concentration to inspired concentration (Fa/Fi) indicate about an anesthetic agent? A) High blood solubility B) Low potency C) Fast induction D) Low tissue uptake

Answer 63

Answer: A Rationale: A slower rise in the Fa/Fi ratio indicates high blood solubility, meaning the anesthetic is being absorbed into the blood more extensively, reducing the alveolar concentration and slowing induction.

Question 64

At equilibrium, which of the following statements is true regarding partial pressures of an inhalational anesthetic agent? A) Partial pressure in the alveoli is greater than in the blood B) Partial pressure in the blood is less than in the CNS C) Partial pressures in the alveoli, blood, and CNS are equal D) Partial pressure in the CNS is higher than in the alveoli

Answer 64

Answer: C Rationale: At equilibrium, the partial pressures of the anesthetic gas are equal across the alveoli, blood, and CNS, allowing the agent to exert its clinical effect consistently.

Question 65

Which inhalational agent has the lowest blood-gas partition coefficient, indicating the fastest onset and recovery? A) Isoflurane B) Halothane C) Desflurane D) Sevoflurane

Answer 65

Answer: C Rationale: Desflurane has the lowest blood-gas partition coefficient (0.42), meaning it is less soluble in blood. This results in a rapid rise in alveolar concentration (Fa) and faster onset and recovery.

Question 66

What does the minimum alveolar concentration (MAC) of an inhalational anesthetic represent? A) The concentration needed to achieve half-maximal metabolism B) The concentration required to prevent movement in 50% of patients in response to a surgical stimulus C) The concentration at which the anesthetic reaches equilibrium in the brain D) The concentration that produces cardiovascular depression

Answer 66

Answer: B Rationale: MAC is the concentration of an inhalational anesthetic that prevents movement in response to a surgical incision in 50% of patients. It is a measure of the anesthetic's potency.

Question 67

Which of the following factors would increase the rate of rise in the alveolar concentration to inspired concentration ratio (Fa/Fi) for an inhalational agent? (Select 2) A) High cardiac output B) Low blood-gas partition coefficient C) Low fresh gas flow D) Low cardiac output

Answer 67

Answers: B, D Rationale: A low blood-gas partition coefficient (indicating low solubility) leads to a faster rise in Fa/Fi. Additionally, low cardiac output reduces uptake by the blood, allowing the alveolar concentration to rise more quickly.

Question 68

How does increased cardiac output affect the onset of anesthesia for relatively soluble agents like isoflurane? A) It speeds up induction B) It has no effect on induction C) It slows down induction D) It only affects intravenous agents

Answer 68

Answer: C Rationale: Increased cardiac output increases the uptake of soluble agents like isoflurane by the blood, slowing the rise of alveolar concentration (Fa) and delaying the onset of anesthesia.

Question 69

f a patient has a high-fat content, how might this affect the pharmacokinetics of inhalational anesthetic agents? A) It speeds up induction B) It slows down induction C) It decreases the minimum alveolar concentration (MAC) D) It has no impact on pharmacokinetics

Answer 69

Answer: B Rationale: High fat content increases the overall blood-gas partition coefficient, meaning more of the agent is taken up by adipose tissue. This reduces the amount available in the alveoli, slowing induction.

Question 70

Which neurotransmitter receptor is most commonly associated with the action of inhalational anesthetics? A) Dopamine receptors B) GABA receptors C) Serotonin receptors D) Acetylcholine receptors

Answer 70

Answer: B Rationale:GABA, NMDA, glycine receptor subunits have all been shown to be affected

Question 71

How does sevoflurane at 1 MAC affect cerebral metabolic rate of oxygen (CMRO₂) and cerebral blood flow (CBF)? A) Increases CMRO₂ and decreases CBF B) Decreases CMRO₂ and increases CBF C) Increases both CMRO₂ and CBF D) Has no effect on CMRO₂ or CBF

Answer 71

Answer: B Rationale: At 1 MAC, sevoflurane decreases the cerebral metabolic rate of oxygen (CMRO₂), while the vasodilatory effects increase cerebral blood flow (CBF).

Question 73

What is the effect of inhalational anesthetics on the renal system? A) Increase renal blood flow and glomerular filtration rate (GFR) B) Decrease renal blood flow and GFR C) Increase GFR but decrease renal blood flow D) Have no effect on renal function

Answer 73

Answer: B Rationale: Inhalational anesthetics generally decrease renal blood flow and glomerular filtration rate .

Question 74

How does a dose-dependent increase in ventilatory response to hypercapnia and hypoxemia manifest with the use of inhalational anesthetics? A) Decreased tidal volume with preserved respiratory rate B) Increased tidal volume with decreased respiratory rate C) Complete abolition of the hypoxic ventilatory drive D) Enhanced respiratory drive

Answer 74

Answer: A Rationale: Inhalational anesthetics typically cause a dose-dependent decrease in tidal volume while preserving respiratory rate, leading to an overall reduction in minute ventilation.

Question 75

Which of the following best describes the cardiovascular effects of halothane compared to other volatile anesthetics? A) Halothane increases heart rate and cardiac output B) Halothane decreases cardiac output, while others may increase heart rate C) Halothane has no effect on the heart D) Halothane increases cardiac output but decreases heart rate

Answer 75

Answer: B Rationale: Halothane is known to decrease cardiac output, whereas other volatile anesthetics can compensate by increasing heart rate.

Question 76

Which inhalational agent is more likely to maintain cerebral blood flow (CBF) without significant change at 0.5 MAC? A) Desflurane B) Isoflurane C) Sevoflurane D) Halothane

Answer 76

Answer: B Rationale: Isoflurane at 0.5 MAC can counteract cerebral vasodilation, maintaining cerebral blood flow (CBF) relatively unchanged. Least cerebral Vasodilation
DOC FOR ↑ICP CASES
Suppresses Lidocaine induced seizure activity 


Question 77

How does a high fat-blood partition coefficient affect the onset of inhalational anesthetics in obese patients? A) It speeds up induction B) It has no impact on onset C) It slows down induction D) It decreases MAC

Answer 77

Answer: C Rationale: A higher fat-blood partition coefficient leads to increased uptake of the anesthetic into adipose tissue, reducing its availability in the alveoli and slowing induction.

Question 78

Which property of inhalational anesthetics primarily determines their potency? A) Blood-gas partition coefficient B) Oil-gas partition coefficient C) Minimum alveolar concentration (MAC) D) Rate of metabolism

Answer 78

Answer: B Rationale: The oil-gas partition coefficient is closely related to the potency of inhalational anesthetics; higher lipid solubility generally indicates greater potency.

Question 79

Which of the following is a primary reason why nitrous oxide cannot achieve 1 MAC in clinical practice? A) High lipid solubility B) High potency C) Low potency (MAC 104%) D) Strong muscle relaxation properties

Answer 79

Answer: C Rationale: Nitrous oxide has a MAC of 104%, indicating low potency. It cannot reach 1 MAC because it would require a concentration above 100%, which is not possible.

Question 80

What is a potential complication of using nitrous oxide in patients with a pneumothorax or bowel obstruction? A) Hypothermia B) Diffusion into air-filled cavities, causing expansion C) Increased cardiac output D) Muscle relaxation

Answer 80

Answer: B Rationale: Nitrous oxide can rapidly diffuse into air-filled cavities faster than it can leave, leading to expansion of spaces like pneumothorax or bowel, worsening the condition.

Question 81

Why is nitrous oxide often contraindicated in patients with a risk of middle ear surgery or recent eye surgery involving a gas bubble? A) It triggers malignant hyperthermia B) It provides inadequate analgesia C) It diffuses into gas-filled spaces, causing expansion D) It has a high risk of nephrotoxicity

Answer 81

Answer: C Rationale: Nitrous oxide diffuses into closed gas-filled spaces, such as the middle ear or eye, and can expand these spaces, leading to increased pressure and potential damage.

Question 82

What is the primary mechanism by which nitrous oxide may provide analgesic effects? A) GABA receptor activation B) NMDA receptor antagonism C) Serotonin receptor blockade D) Opioid receptor activation

Answer 82

Answer: B Rationale: Nitrous oxide acts as an NMDA receptor antagonist, which contributes to its analgesic properties.

Question 83

Which of the following statements is true regarding nitrous oxide and malignant hyperthermia (MH)? A) Nitrous oxide is a potent trigger of MH B) Nitrous oxide should be avoided in all patients due to MH risk C) Nitrous oxide does not trigger MH, unlike volatile anesthetics D) Nitrous oxide is only a mild trigger of MH

Answer 83

Answer: C Rationale: Nitrous oxide is not a trigger for malignant hyperthermia, unlike other volatile anesthetics.

Question 84

What is a major concern when using isoflurane related to coronary artery blood flow? A) Coronary artery vasospasm B) Coronary steal phenomenon C) Myocardial infarction D) Cardiac arrhythmia

Answer 84

Answer: B Rationale: Isoflurane has been implicated in the "coronary steal" phenomenon, where dilation of normal coronary arteries diverts blood away from stenotic vessels, potentially worsening ischemia.

Question 85

Which of the following effects is typically seen with isoflurane at 1 MAC? A) Increased intracranial pressure (ICP) B) Decreased cerebral blood flow (CBF) C) Electrically silent EEG D) Profound myocardial depression

Answer 85

Answer: A Rationale: Isoflurane can increase CBF, especially at higher MAC levels, and may increase ICP as a result. (usually short lived and less pronounced than other agents) EEG silent at 2 MAC

Question 86

What is the most common cardiovascular effect of isoflurane? A) Bradycardia B) Decreased blood pressure due to vasodilation C) Increased myocardial contractility D) Hypertension

Answer 86

Answer: B Rationale: Isoflurane commonly causes vasodilation, leading to a decrease in blood pressure.

Question 87

Why is sevoflurane a preferred agent for inhalational induction, especially in pediatric patients? A) High pungency B) Sweet smell and non-pungency C) Slow onset D) High lipid solubility

Answer 87

Answer: B Rationale: Sevoflurane is sweet-smelling and non-pungent, making it well-tolerated for inhalational induction, particularly in children.

Question 88

What potential complication can arise from using sevoflurane with a desiccated CO₂ absorbent? A) Formation of Compound A B) Triggering of malignant hyperthermia C) Increased cerebral blood flow D) Coronary steal phenomenon

Answer 88

Answer: A Rationale: Sevoflurane can form Compound A in the presence of desiccated CO₂ absorbent, which has shown nephrotoxic effects in animal studies.

Question 89

How can the formation of Compound A be minimized during sevoflurane use? A) Use of calcium hydroxide absorbent instead of barium hydroxide B) Increasing inspired concentration C) Decreasing fresh gas flow to less than 2 L/min D) Avoiding volatile anesthetics

Answer 89

Answer: A Rationale: Compound A formation can be minimized by using CO₂ absorbents that do not contain strong bases like barium hydroxide, opting for calcium hydroxide instead.

Question 90

Which characteristic of desflurane requires it to be delivered via a specialized vaporizer? A) Low MAC B) High solubility C) High vapor pressure and boiling point close to room temperature D) Low cost

Answer 90

Answer: C Rationale: Desflurane has a high vapor pressure and a boiling point close to room temperature, necessitating a heated, pressurized vaporizer to ensure consistent delivery.

Question 91

What respiratory side effect is common when desflurane is administered to an awake patient? A) Hypoventilation B) Bronchodilation C) Breath-holding and laryngospasm D) Sedation

Answer 91

Answer: C Rationale: Desflurane is very pungent and can cause airway irritation, leading to breath-holding, coughing, and laryngospasm in awake patients.

Question 92

What cardiovascular response can occur with a rapid increase in desflurane concentration? A) Hypotension B) Bradycardia C) Tachycardia and hypertension D) Myocardial depression

Answer 92

Answer: C Rationale: Rapid increases in desflurane concentration can trigger a sympathetic response, resulting in tachycardia and hypertension. Blunt with some fent

Question 93

Here’s a Select 2 question incorporating the provided answer choices: Question: Which of the following strategies or mechanisms are related to heat loss and temperature management during general anesthesia? (Select 2) A) Redistribution of heat as vasodilation causes blood to shift from core to periphery, followed by radiation as a major form of heat loss B) Use of desiccated CO₂ absorbents to minimize heat loss C) Using low fresh gas flows during anesthesia to help maintain body temperature and reduce water loss D) Avoiding volatile anesthetics to preserve thermoregulation E) Increasing inspired oxygen concentration to reduce convection heat loss

Answer 93

Answers: A, C Rationale: A: Redistribution of heat is a major mechanism of heat loss under general anesthesia, as vasodilation causes blood to move from the core to the periphery. Radiation is the primary form of heat loss after redistribution, with conduction, convection, and evaporation also contributing. C: Using low fresh gas flows minimizes heat and water loss, helping to maintain the patient’s body temperature during general anesthesia. B, D, E: These options do not directly relate to the key mechanisms or strategies for managing temperature during general anesthesia.

Question 94

What is the primary purpose of assessing "Anesthesia" immediately after intubation? A) To confirm endotracheal tube placement B) To set ventilation parameters and verify volatile anesthetic delivery C) To assess the patient’s position for surgery D) To administer additional analgesics

Answer 94

Answer: B Rationale: After intubation, it is critical to confirm proper ventilator settings and ensure the delivery of volatile anesthetics for anesthesia maintenance.

Question 95

Which intervention is used to maintain patient body temperature during surgery? A) Administering warm IV fluids B) Applying forced-air warming devices (e.g., Bair Hugger) and using a temperature probe C) Decreasing fresh gas flows D) Performing ABG analysis

Answer 95

Answer: B Rationale: Forced-air warming devices and temperature monitoring help prevent hypothermia during surgery.

Question 96

What is the purpose of placing an orogastric (OG) tube after intubation? A) To secure the endotracheal tube B) To prevent airway obstruction C) To decompress the stomach and prevent aspiration D) To deliver volatile anesthetics

Answer 96

Answer: C Rationale: An OG tube is placed to decompress the stomach and reduce the risk of regurgitation and aspiration, especially in patients undergoing prolonged procedures.

Question 97

Why should a bite block be considered after intubation? A) To prevent dental damage and protect the endotracheal tube B) To ensure airway patency C) To facilitate OG tube placement D) To reduce the risk of tongue injury

Answer 97

Answer: A Rationale: A bite block prevents the patient from biting down on the endotracheal tube, which could cause dental injury or damage to the tube.

Question 98

Why should analgesics be redosed prior to surgical incision? A) To maintain hemodynamic stability during intubation B) To optimize postoperative pain control C) To ensure adequate pain management during the surgical stimulus D) To prevent respiratory depression

Answer 98

Answer: C Rationale: Redosing analgesics before the surgical incision ensures adequate pain control during the surgical stimulus, reducing the risk of intraoperative hemodynamic instability.

Question 99

When should antibiotics be administered in relation to surgical incision? A) After the incision is made B) Immediately after intubation C) Within one hour before the incision D) During emergence from anesthesia

Answer 99

Answer: C Rationale: Administering antibiotics within one hour before the incision is critical for preventing surgical site infections.

Question 100

What should be assessed regarding "Access" after intubation? (Select 2) A) Whether there is adequate IV access for the procedure B) Placement of an arterial line if required for hemodynamic monitoring C) Bilateral breath sounds for tube placement confirmation D) Positioning of the patient's arms and legs

Answer 100

Answers: A, B Rationale: Ensuring adequate IV access and placing an arterial line (if indicated) are key steps to prepare for medication administration and advanced hemodynamic monitoring during surgery.

Question 101

Why is it important to reassess the positioning of the patient’s arms and legs after intubation? A) To confirm endotracheal tube placement B) To prevent nerve injuries and ensure comfort during the procedure C) To reduce the risk of hypothermia D) To allow better ventilation

Answer 101

Answer: B Rationale: Proper positioning helps prevent nerve injuries (e.g., brachial plexus or ulnar nerve compression) and ensures patient safety during long surgical procedures.

Question 102

Under what circumstances should a baseline arterial blood gas (ABG) analysis be performed after intubation? A) For all patients undergoing surgery B) Only for patients with suspected acid-base disturbances or critical illness C) For patients receiving volatile anesthetics D) To verify oxygen saturation

Answer 102

Answer: B Rationale: ABG analysis is typically reserved for patients with suspected acid-base disturbances, respiratory failure, or other critical conditions where baseline values are clinically relevant

Question 103

What key information does a baseline ABG provide in a post-intubation scenario? A) Cerebral oxygenation B) Confirmation of volatile anesthetic delivery C) Acid-base status and adequacy of ventilation D) Electrolyte concentrations

Answer 103

Answer: C Rationale: A baseline ABG provides critical information about the patient’s acid-base status and adequacy of ventilation, ensuring proper respiratory management.

Question 104

What is the primary function of a vaporizer in modern anesthetic machines? A) To cool the anesthetic agent B) To mix fresh gas flow with liquid anesthetic C) To create a saturated vapor in equilibrium with the liquid anesthetic D) To humidify the gas delivered to the patient

Answer 104

Answer: C Rationale: Vaporizers create a saturated vapor by allowing liquid anesthetic to evaporate until it reaches equilibrium. This vapor is then mixed with fresh gas flow and delivered to the patient.

Question 105

How does fresh gas flow interact with the vaporizer in an anesthetic machine? A) It absorbs the anesthetic vapor, becoming saturated with anesthetic gas B) It cools the vaporizer chamber C) It directly delivers the liquid anesthetic to the patient D) It removes excess anesthetic vapor from the chamber

Answer 105

Answer: A Rationale: Fresh gas flow passes through the vaporizer, absorbing anesthetic vapor to create a mixture that is delivered to the patient.

Question 106

What is the definition of saturated vapor pressure (SVP)? A) The pressure at which the anesthetic agent becomes solid B) The maximum partial pressure of a vapor at a given temperature when the liquid and vapor phases are in equilibrium C) The total pressure of the carrier gas and anesthetic vapor D) The pressure required to evaporate the anesthetic agent

Answer 106

Answer: B Rationale: SVP is the maximum pressure exerted by a vapor in equilibrium with its liquid phase at a given temperature.

Question 107

Why is SVP important in the delivery of volatile anesthetics? A) It determines the solubility of the anesthetic in blood B) It influences the partial pressure of the anesthetic in the carrier gas C) It affects the metabolism of the anesthetic D) It regulates the temperature of the vaporizer

Answer 107

Answer: B Rationale: The SVP dictates the partial pressure of the anesthetic gas in the carrier gas, which is essential for achieving the desired anesthetic concentration delivered to the patient.

Question 108

What happens to the concentration of anesthetic vapor delivered to the patient when the concentration control dial is increased? A) It decreases the fresh gas flow B) It increases the volume of vapor entering the carrier gas C) It decreases the volume of vapor entering the carrier gas D) It bypasses the vaporizer completely

Answer 108

Answer: B Rationale: Increasing the concentration control dial increases the amount of anesthetic vapor mixed with the fresh gas flow, raising the concentration delivered to the patient.

Question 109

What effect would a sudden decrease in room temperature have on the SVP of a volatile anesthetic? A) SVP would increase, delivering more anesthetic to the patient B) SVP would decrease, delivering less anesthetic to the patient C) SVP would remain unchanged D) The vaporizer would stop functioning

Answer 109

Answer: B Rationale: SVP is temperature-dependent. A decrease in room temperature lowers the SVP, reducing the partial pressure of anesthetic vapor delivered to the patient.

Question 110

What is the purpose of the bypass chamber in a vaporizer? A) To heat the anesthetic vapor B) To prevent over-saturation of the carrier gas C) To allow a portion of the fresh gas to bypass the vaporizing chamber D) To store excess anesthetic vapor

Answer 110

Answer: C Rationale: The bypass chamber ensures that a portion of the fresh gas bypasses the vaporizing chamber, mixing with saturated vapor to achieve the desired anesthetic concentration.

Question 111

What could happen if a vaporizer designed for one agent is used with a different volatile anesthetic? A) The anesthetic concentration would be delivered accurately B) The vaporizer would automatically adjust for the different SVP C) The delivered anesthetic concentration could be inaccurate, leading to overdose or underdose D) The vaporizer would stop functioning

Answer 111

Answer: C Rationale: Vaporizers are calibrated for specific agents based on their SVP. Using the wrong agent can lead to significant errors in the concentration delivered to the patient.

Question 112

Answer 112

Answer: B Rationale: This equation calculates the volume of anesthetic gas (VA) delivered by the vaporizer into the fresh gas flow.

Question 113

Answer 113

Answer: B Rationale: This equation calculates the total percentage concentration of volatile anesthetic delivered to the patient relative to the combined flow of fresh gas and anesthetic vapor.

Question 114

How does increasing fresh gas flow (FGF) affect the percentage of volatile anesthetic delivered? A) It increases the percentage of anesthetic delivered B) It decreases the percentage of anesthetic delivered C) It has no effect on the percentage of anesthetic delivered D) It directly increases the patient’s uptake of anesthetic

Answer 114

Answer: B Rationale: Increasing FGF dilutes the anesthetic vapor in the carrier gas, reducing the overall percentage of volatile anesthetic delivered to the patient.

Question 115

Given an SVP of 240 mmHg for sevoflurane, a total pressure (PT) of 760 mmHg, and a carrier gas volume (VC) of 1 L, what is the calculated volume of anesthetic gas (VA)? A) 0.316 L B) 0.240 L C) 1.000 L D) 0.760 L

Answer 115

Question 116

Why does the vaporizer dial for sevoflurane or isoflurane remain the same (e.g., 2% for 1 MAC) when used at higher altitudes like Denver? A) The vaporizer automatically compensates by increasing the partial pressure of the anesthetic gas. B) The vaporizer automatically increases the output volume to maintain the same partial pressure of the anesthetic gas. C) Partial pressure is unaffected by altitude, so no compensation is needed. D) Higher altitudes require a fixed percent concentration output, which modern vaporizers cannot adjust.

Answer 116

Answer: B Rationale: Modern vaporizers adjust their output in proportion to the drop in atmospheric pressure at higher altitudes. While the volume of anesthetic vapor output increases, the partial pressure remains the same to maintain the desired anesthetic effect.

Question 117

Question 2: Desflurane at High Altitudes What must be done to adjust the desflurane vaporizer setting at higher altitudes? A) The dial must be increased because the vaporizer delivers a fixed partial pressure. B) The dial setting remains unchanged because the vaporizer automatically adjusts for altitude. C) The dial must be increased because desflurane vaporizers deliver a fixed percent concentration, not a fixed partial pressure. D) The dial must be decreased to compensate for the reduced partial pressure at altitude.

Answer 117

Answer: C Rationale: Desflurane vaporizers deliver anesthetic based on a fixed percent concentration, unlike sevoflurane and isoflurane, which deliver a fixed partial pressure. At higher altitudes, the lower atmospheric pressure requires increasing the dial setting to maintain the desired partial pressure of desflurane in the alveoli. Like 12% in Denver

Question 118

What does the minimum alveolar concentration (MAC) represent? A) The concentration of anesthetic in the blood required to induce unconsciousness B) The alveolar concentration of an anesthetic that prevents movement in 50% of patients in response to surgical incision C) The maximum concentration of anesthetic tolerated by the patient D) The concentration needed to prevent hemodynamic changes during surgery

Answer 118

Answer: B Rationale: MAC is the alveolar concentration of an anesthetic at 1 atmosphere that prevents movement in 50% of subjects exposed to surgical incision, making it a measure of anesthetic potency.

Question 119

Which property of an inhalational agent is MAC inversely related to? A) Blood-gas partition coefficient B) Oil-gas partition coefficient C) Vapor pressure D) Fresh gas flow rate

Answer 119

Answer: B Rationale: MAC is inversely related to the oil-gas partition coefficient, which is a measure of lipid solubility. Higher lipid solubility corresponds to greater anesthetic potency and lower MAC.

Question 120

If 0.5 MAC of isoflurane is combined with 0.5 MAC of nitrous oxide, what is the resulting MAC? A) 0.5 MAC B) 1.0 MAC C) 1.5 MAC D) 2.0 MAC

Answer 120

Answer: B Rationale: MAC values are additive. Combining 0.5 MAC of one agent with 0.5 MAC of another results in a total of 1.0 MAC.

Question 121

Which MAC level is required to prevent awareness in 95% of patients? A) 0.8 MAC B) 1.0 MAC C) 1.2 MAC D) 2.0 MAC

Answer 121

Answer: C Rationale: At 1.2 MAC, approximately 95% of patients will not respond to surgical incision. This is based on the ED95 calculation, which accounts for individual variability in anesthetic requirements.

Question 122

Which of the following agents has the lowest MAC, indicating the highest potency? A) Desflurane B) Halothane C) Isoflurane D) Nitrous oxide

Answer 122

Answer: B Rationale: Halothane has the lowest MAC (0.75%) among the listed agents, indicating it is the most potent inhalational anesthetic.

Question 123

Which agent has the highest MAC, indicating the lowest potency? A) Nitrous oxide B) Isoflurane C) Desflurane D) Sevoflurane

Answer 123

Answer: A Rationale: Nitrous oxide has the highest MAC (104%), indicating it is the least potent inhalational agent.

Question 124

The potency of an inhalational agent can be estimated by its solubility in which medium? A) Olive oil B) Deionized water C) Ethylene glycol D) Coconut water

Answer 124

Answer: A Rationale: Potency correlates with solubility in olive oil, as described by the Meyer-Overton hypothesis. Lipid solubility is directly proportional to anesthetic potency.

Question 125

Which of the following statements about partition coefficients is true? (Select 2) A) Anesthetics with greater blood-gas partition coefficients have higher solubility in blood. B) Blood-gas partition coefficient is a key determinant of the speed of anesthetic induction and recovery. C) Oil-gas partition coefficient correlates directly with anesthetic elimination. D) Tissue partition coefficients are crucial in describing redistribution of chemicals in the body.

Answer 125

Answers: B, D Rationale: B: Blood-gas partition coefficient determines how quickly anesthetics equilibrate between alveoli and blood. Lower coefficients result in faster induction and recovery. D: Tissue partition coefficients help explain the redistribution of anesthetic agents and their movement within the body. A is false because higher blood-gas coefficients indicate slower induction and recovery due to greater solubility in blood. C is false because oil-gas partition coefficient correlates with potency, not elimination.

Question 126

Effect of Age on MAC At what age is MAC highest, and how does it change over time? A) MAC is highest at birth and declines after age 20. B) MAC is highest at 6 months and declines by approximately 6% per decade after age 40. C) MAC is highest at 6 months and remains stable throughout life. D) MAC is highest at birth and declines by 10% per decade after age 30.

Answer 126

Answer: B Rationale: MAC peaks at around 6 months of age, reflecting increased anesthetic requirements. After age 40, MAC decreases by roughly 6% per decade due to changes in physiology, including reduced metabolic demands and brain sensitivity to anesthetics.

Question 127

Which of the following medications decreases MAC? A) Ketamine B) Methamphetamine C) Barbiturates D) Tricyclic antidepressants

Answer 127

Answer: C Rationale: Barbiturates decrease MAC because they have sedative and hypnotic properties, reducing the need for inhaled anesthetic to achieve the desired depth of anesthesia. Ketamine and methamphetamine increase MAC, while tricyclic antidepressants do not directly affect MAC.

Question 128

Which physiologic condition increases MAC? A) Hypothermia B) Hypernatremia C) Pregnancy D) Hypoxia

Answer 128

Answer: B Rationale: Hypernatremia increases MAC because it enhances neuronal excitability. Conversely, hypothermia, pregnancy, and hypoxia reduce MAC by decreasing metabolic and neurologic demands.

Question 129

What is the approximate MAC value needed to prevent response to verbal or tactile stimulation (MACawake)? A) 1.0 MAC B) 0.4 MAC C) 1.6 MAC D) 0.6 MAC

Answer 129

Answer: B Rationale: MACawake is typically around 0.4 MAC, representing the concentration required to prevent response to non-painful stimuli such as verbal commands and tactile stimulation.

Question 130

Which condition is LEAST likely to increase the risk of intraoperative awareness? A) Emergency damage-control laparotomy B) Cesarean delivery under general anesthesia C) History of opioid abuse D) Red hair

Answer 130

Answer: D Rationale: While red hair is associated with a higher MAC requirement due to mutations in the melanocortin-1 receptor, it is not a recognized risk factor for intraoperative awareness. The other conditions are linked to insufficient anesthetic delivery.

Question 131

What is the most common sensation associated with intraoperative awareness? A) Pain B) Hearing voices C) Dreaming D) Seeing light

Answer 131

Answer: B Rationale: Hearing voices is the most common sensation reported during intraoperative awareness, as the auditory system remains functional even with light anesthesia.

Question 132

Which MAC level is required to blunt autonomic responses to noxious stimuli (MACBAR)? A) 1.0 MAC B) 1.3 MAC C) 1.6 MAC D) 0.4 MAC

Answer 132

Answer: C Rationale: MACBAR (1.6 MAC) represents the anesthetic concentration required to suppress autonomic responses, such as increases in heart rate and blood pressure, to painful stimuli.

Question 133

Which of the following factors increases MAC? A) Chronic alcohol use B) Pregnancy C) Anemia D) Propofol administration

Answer 133

Answer: A Rationale: Chronic alcohol use increases MAC due to the induction of metabolic tolerance and upregulation of central nervous system excitability.

Question 134

Which of the following causes the LEAST reduction in MAC? A) Morphine B) Nalbuphine C) Fentanyl D) Remifentanil

Answer 134

Answer: B Rationale: Nalbuphine, an opioid with partial agonist properties, has a minimal effect on MAC reduction compared to potent full agonists like fentanyl and remifentanil.

Question 135

Which sign is indicative of light anesthesia? A) Hypotension B) Bradycardia C) Tearing and coughing D) Decreased respiratory rate

Answer 135

Answer: C Rationale: Tearing and coughing are signs of light anesthesia due to inadequate suppression of reflexes and sympathetic activation.

Question 136

At what age is MAC highest? A) At birth B) 6 months of age C) 20 years of age D) After 40 years of age

Answer 136

Answer: B Rationale: MAC is highest at around 6 months of age due to peak metabolic and neurophysiological demands. It decreases with age after 40 years.

Question 137

Which of the following conditions decreases MAC? A) Hyperthermia B) Chronic opioid use C) Severe hypoxia D) Hypernatremia

Answer 137

Answer: C Rationale: Severe hypoxia decreases MAC as the brain's metabolic activity slows under oxygen deprivation. Chronic opioid use can increase tolerance but not reduce MAC.

Question 138

Why is trauma surgery associated with an increased risk of intraoperative awareness? A) Trauma patients often receive insufficient anesthetic doses due to their unstable condition. B) Trauma surgeries require high doses of opioids, which decrease awareness. C) Trauma patients typically have higher MAC requirements than non-trauma patients. D) Trauma surgeries are often performed without neuromuscular blockade.

Answer 138

Answer: A Rationale: Trauma patients often have unstable hemodynamics, limiting the use of anesthetics to avoid compromising cardiovascular function. As a result, insufficient anesthetic dosing may increase the risk of intraoperative awareness.

Question 139

Which of the following strategies can help reduce the risk of intraoperative awareness? A) Decreasing anesthetic concentration to maintain blood pressure B) Using at least 0.5-0.7 MAC of a potent inhalational agent C) Relying solely on muscle relaxants for anesthesia D) Avoiding the use of BIS or SedLine monitoring during TIVA

Answer 139

Answer: B Rationale: Using at least 0.5-0.7 MAC of a potent inhalational agent helps ensure adequate depth of anesthesia. Decreasing anesthetic concentration (A) can increase awareness risk, while muscle relaxants (C) alone do not prevent awareness. BIS or SedLine monitoring (D) can help assess depth during TIVA.

Question 140

Why is redosing intravenous anesthetic critical during long intubation or rigid bronchoscopy? A) To prevent cardiovascular instability B) To maintain adequate anesthesia depth when inhalational delivery is challenging C) To avoid respiratory depression D) To reduce the risk of hypotension

Answer 140

Answer: B Rationale: Redosing IV anesthetics ensures adequate depth of anesthesia when delivery of inhalational agents is limited due to procedural constraints.

Question 141

What is the ideal BIS range for adequate anesthesia depth? A) 10-20 B) 25-30 C) 40-60 D) 70-90

Answer 141

Answer: C Rationale: A BIS range of 40-60 indicates adequate anesthesia depth, minimizing the risk of awareness while avoiding excessive sedation.

Question 142

Why might BIS and SedLine monitoring have limited accuracy in certain cases? A) They cannot detect changes in EEG patterns. B) They have a 2-minute time lag in processing data. C) They are affected by medications such as ketamine and ephedrine. D) Both B and C.

Answer 142

Answer: D Rationale: Both monitoring systems have a time lag and can be influenced by medications like ketamine and ephedrine, which alter EEG patterns.

Question 143

Which of the following procedures is most associated with awareness under anesthesia? A) Cardiac surgery B) Laparoscopic appendectomy C) Hip replacement surgery D) Elective breast augmentation

Answer 143

Answer: A Rationale: Cardiac surgery is a high-risk procedure for awareness due to the need for lighter anesthesia to maintain hemodynamic stability in critically ill patients.

Question 144

What increases the likelihood of awareness during procedures involving neuromuscular blockade? A) The use of high-dose volatile anesthetics B) The inability of the patient to move despite inadequate anesthesia depth C) Continuous brain activity monitoring D) A low risk of intraoperative complications

Answer 144

Answer: B Rationale: Neuromuscular blockade prevents patients from moving in response to inadequate anesthesia, masking signs of light anesthesia or awareness.

Question 145

Why does the MAC of 0.8 with mostly nitrous oxide increase awareness risk compared to a MAC of 0.7 of a volatile agent? A) Nitrous oxide has a higher potency than volatile agents. B) Nitrous oxide lacks sufficient depth of anesthesia for surgical conditions. C) Nitrous oxide suppresses awareness more effectively than volatile agents. D) Volatile agents have slower onset than nitrous oxide.

Answer 145

Answer: B Rationale: Nitrous oxide is less effective at preventing awareness due to its inability to provide the same depth of anesthesia as potent volatile agents.

Question 146

What is the first step if you suspect your patient is aware during surgery? A) Administer benzodiazepines for amnesia. B) Immediately deepen anesthesia with a fast-acting agent like propofol. C) Reassure the patient after the case is completed. D) Document the event in the medical record.

Answer 146

Answer: B Rationale: The immediate response to suspected awareness is to deepen anesthesia with a fast-acting agent like propofol to prevent further distress or memory of the event.

Question 147

What should you do after a case if you suspect a patient experienced intraoperative awareness? A) Refer the patient for a neurological evaluation. B) Contact patient services and risk management for follow-up. C) Administer high-dose opioids to suppress memory. D) Document the event without informing the patient.

Answer 147

Answer: B Rationale: Addressing the issue with patient services and risk management ensures proper follow-up and care, including offering counseling if needed.

Question 148

Which neurotransmitter is primarily targeted by most IV anesthetic agents? A) Dopamine B) Serotonin C) GABA D) Glutamate

Answer 148

Answer: C Rationale: GABA is the primary inhibitory neurotransmitter in the CNS and the most common target for IV anesthetics like propofol and benzodiazepines, which enhance its inhibitory effects.

Question 149

What is the effect of propofol and barbiturates on GABA receptors? A) They block GABA binding sites. B) They decrease the rate of dissociation of GABA from its receptor. C) They increase chloride ion channel closure. D) They act as NMDA receptor antagonists.

Answer 149

Answer: B Rationale: Propofol and barbiturates enhance GABAergic activity by decreasing the rate of dissociation of GABA from its receptor, promoting prolonged inhibitory effects.

Question 150

How does dexmedetomidine produce analgesia? A) By inhibiting substance P release at the dorsal horn of the spinal cord B) By enhancing GABA receptor activation C) By antagonizing NMDA receptors D) By increasing norepinephrine release

Answer 150

Answer: A Rationale: Dexmedetomidine is an alpha-2 agonist that inhibits norepinephrine release and reduces substance P release at the dorsal horn, contributing to its analgesic properties.

Question 151

Which IV anesthetic is most associated with excitatory activity during induction? A) Propofol B) Methohexital C) Ketamine D) Midazolam

Answer 151

Answer: B Rationale: Methohexital, a barbiturate, is known to cause excitatory activity such as myoclonus during induction. (etomidate as well.. heard this drug is least fav)

Question 152

Which IV anesthetic has the shortest distribution half-life? A) Ketamine B) Propofol C) Thiopental D) Midazolam

Answer 152

Answer: C Rationale: Thiopental has a rapid distribution half-life of 2-4 minutes, contributing to its quick onset of action.

Question 153

Which drug has the highest protein binding percentage? A) Propofol B) Ketamine C) Lorazepam D) Methohexital

Answer 153

Answer: A Rationale: Propofol has 98% protein binding, which affects its pharmacokinetics and limits its free drug concentration.

Question 154

What is the elimination half-life of lorazepam? A) 2-4 hours B) 5-7 hours C) 10-20 hours D) 18-25 hours

Answer 154

Answer: C Rationale: Lorazepam has an elimination half-life of 10-20 hours, making it longer-acting compared to midazolam.

Question 155

Which IV anesthetic has the largest volume of distribution (steady state)? A) Ketamine B) Diazepam C) Propofol D) Methohexital

Answer 155

Answer: C Rationale: Propofol has a large steady-state volume of distribution (2-10 L/kg), indicating extensive tissue distribution due to its high lipid solubility.

Question 156

Which IV anesthetic does NOT cause dose-dependent respiratory depression? A) Etomidate B) Ketamine C) Propofol D) Midazolam

Answer 156

Answer: B Rationale: Ketamine does not cause dose-dependent respiratory depression, unlike most other IV anesthetics, making it safer in patients with respiratory concerns.

Question 157

Why do hypovolemic patients often require lower doses of IV anesthetics? A) They metabolize drugs more quickly. B) They have increased central compartment drug concentrations. C) They are resistant to the effects of anesthetics. D) They have increased clearance rates.

Answer 157

Answer: B Rationale: Hypovolemic patients have less circulating volume, leading to higher drug concentrations in the central compartment, thereby requiring lower doses of anesthetics.

Question 158

What is the primary reason elderly patients require reduced doses of IV anesthetics? A) Larger volume of distribution B) Reduced clearance and metabolism C) Increased cardiac output D) Enhanced protein binding

Answer 158

Answer: B Rationale: Elderly patients often have reduced hepatic and renal clearance, along with decreased metabolic activity, necessitating lower doses of IV anesthetics. They also have a lower volume of distribution.

Question 159

What is a significant risk associated with prolonged high-dose propofol infusions? A) Respiratory alkalosis B) Metabolic acidosis and rhabdomyolysis C) Hepatotoxicity D) Hyperkalemia

Answer 159

Answer: B Rationale: Prolonged infusions (>4 mg/kg/hr) of propofol can lead to Propofol Infusion Syndrome (PRIS), characterized by metabolic acidosis, rhabdomyolysis, renal failure, and cardiac dysfunction.

Question 160

How does propofol affect cerebral metabolic rate of oxygen (CMRO₂) and cerebral blood flow (CBF)? A) Increases both CMRO₂ and CBF B) Decreases CMRO₂ but increases CBF C) Decreases both CMRO₂ and CBF D) Increases CMRO₂ but decreases CBF

Answer 160

Answer: C Rationale: Propofol decreases CMRO₂ and CBF, which helps lower intracranial pressure (ICP), making it useful in neuroanesthesia.

Question 161

What is the typical infusion dose of propofol for sedation? A) 10-25 mcg/kg/min B) 25-75 mcg/kg/min C) 100-200 mcg/kg/min D) 200-300 mcg/kg/min

Answer 161

Answer: B Rationale: Propofol is commonly administered at 25-75 mcg/kg/min for sedation, depending on the desired level of sedation and the patient’s response.

Question 162

Why does propofol reduce systemic vascular resistance (SVR)? A) It enhances sympathetic activity. B) It acts as a direct myocardial depressant. C) It causes arterial and venous vasodilation. D) It increases central venous pressure.

Answer 162

Answer: C Rationale: Propofol decreases SVR by causing arterial and venous vasodilation, leading to hypotension. * Counterintuitively a cerebral vasoconstrictor!

Question 163

Which patient population is most at risk for Propofol Infusion Syndrome (PRIS)? A) Pediatric patients B) Elderly patients C) Patients with hepatic dysfunction D) Patients with renal insufficiency

Answer 163

Answer: A Rationale: Pediatric patients and critically ill patients are at higher risk for PRIS when receiving prolonged or high-dose propofol infusions.

Question 164

What is the primary mechanism by which propofol produces its central effects? A) Inhibition of acetylcholine release B) Enhancement of NMDA receptor activity C) Potentiation of GABA-mediated chloride ion influx D) Inhibition of sodium channel function

Answer 164

Answer: C Rationale: Propofol enhances GABAergic transmission, leading to hyperpolarization and central nervous system depression. GABA a

Question 165

Which property of propofol contributes to its ability to produce bronchodilation in patients with COPD? A) Inhibition of histamine release B) Activation of adrenergic receptors C) Inhibition of vagal tone D) Reduction in systemic vascular resistance

Answer 165

Answer: C) Propofol is considered beneficial for patients with COPD because it has a "vagolytic" effect, meaning it reduces the activity of the vagus nerve, which can lead to bronchoconstriction.

Question 166

Why does etomidate have minimal cardiovascular effects compared to propofol? A) It increases systemic vascular resistance. B) It does not induce histamine release. C) It promotes sympathetic stimulation. D) It reduces myocardial contractility.

Answer 166

Answer: B Rationale: Etomidate’s lack of histamine release and minimal myocardial depressant effects contribute to its hemodynamic stability.

Question 167

Which of the following effects is unique to etomidate compared to other IV anesthetics? A) High incidence of PONV B) Dose-dependent respiratory depression C) Increased systemic vascular resistance D) Significant bronchodilation

Answer 167

Answer: A Rationale: Etomidate is associated with a higher incidence of post-operative nausea and vomiting (PONV) compared to other anesthetics.

Question 168

Which adverse effect is associated with both propofol and etomidate? A) Pain on injection B) Bronchoconstriction C) Severe adrenal suppression D) Increased intracranial pressure

Answer 168

Answer: A Rationale: Both propofol and etomidate are associated with pain on injection, although this is more common with etomidate.

Question 169

T or F Propofol can produce bronchodilation in patients with COPD

Answer 169

Answer: True Rationale: Propofol is noted to cause bronchodilation, making it beneficial in patients with reactive airway diseases like COPD.

Question 170

T or F Propofol inhibits pulmonary vasoconstriction

Answer 170

Answer: False Rationale: There is no evidence from the material provided that propofol inhibits pulmonary vasoconstriction.

Question 171

T or F Premedication does not affect the speed to apnea after administration of propofol.

Answer 171

Answer: False Rationale: Premedication does affect the speed to apnea following propofol administration, as indicated in the material.

Question 172

T or F Propofol produces depression of central respiratory drive that is dose-independent.

Answer 172

Answer: True Rationale: The material explicitly states that propofol produces dose-independent depression of central respiratory drive.

Question 173

Which of the following statements about etomidate is TRUE (select 2)? A) Etomidate requires dose adjustment in renal insufficiency. B) Etomidate reduces cerebral perfusion pressure. C) Etomidate is a GABA(A) agonist. D) Etomidate inhibits 11-beta-hydroxylase.

Answer 173

Answer: D & C Rationale: Etomidate inhibits 11-beta-hydroxylase, leading to adrenocortical suppression. The material clarifies that it does not require renal dosing, cerebral perfusion pressure is preserved, and it acts on GABA(A) receptors (not GABA(B)).

Question 174

Which metabolic pathway is responsible for the metabolism of etomidate? A) Hepatic oxidation B) Hepatic ester hydrolysis C) Renal excretion of the active drug D) Cytochrome P450 pathway

Answer 174

Answer: B Rationale: The material specifies that etomidate is metabolized by hepatic ester hydrolysis to an inactive metabolite that is then renally excreted.

Question 175

What is a key risk associated with intra-arterial injection of thiopental? A) Increased systemic vascular resistance B) Intense vasoconstriction and tissue necrosis C) Severe allergic reaction D) Hyperkalemia and rhabdomyolysis

Answer 175

Answer: B Rationale: The material specifies that intra-arterial injection of thiopental can cause intense vasoconstriction, thrombosis, and tissue necrosis, requiring specific treatment.

Question 176

What is the induction dose of thiopental in adults? A) 2-3 mg/kg B) 3-5 mg/kg C) 5-6 mg/kg D) 6-8 mg/kg

Answer 176

Answer: B Rationale: The recommended induction dose for thiopental in adults is 3-5 mg/kg, with higher doses required in children and infants.

Question 177

What is a pharmacodynamic effect of thiopental? A) Increases cerebral blood flow and ICP B) Decreases CMRO₂, CBF, and ICP C) Decreases CMRO₂ but increases ICP D) No effect on cerebral blood flow or ICP

Answer 177

Answer: B Rationale: Thiopental decreases CMRO₂, CBF, and ICP, making it useful in neurosurgical procedures.

Question 178

Which clinical scenario might require larger doses of thiopental due to pharmacokinetics? A) Patients with hepatic dysfunction B) Patients with high peripheral compartment capacity C) Patients with reduced cardiac output D) Patients with hyperthyroidism

Answer 178

Answer: B Rationale: Larger doses of thiopental may be required when the peripheral compartments are larger, as this can prolong the duration of action. redistributes to skeletal muscles Rapid redistribution from brain to other tissues ‣after 5 min 1/2 dose available in brain ‣ at 30 minute, 10% of original dose available in brain ‣Initial redistribution to skeletal muscles ‣ Takes 15 minutes to reach equilibrium b/w skeletal muscles and plasma

Question 179

What is the primary reason for a reduced induction dose of thiopental in elderly patients? A) Decreased initial volume of distribution B) Enhanced brain sensitivity C) Increased protein binding D) Decreased hepatic metabolism

Answer 179

Answer: A Rationale: In elderly patients, a decrease in total body water leads to a reduced volume of the central compartment, resulting in higher plasma concentrations after IV administration.

Question 180

Which of the following statements about thiopental pharmacokinetics is TRUE? A) Thiopental requires renal dosing adjustments. B) Larger doses can saturate peripheral compartments, prolonging its duration of action. C) It increases CMRO₂, CBF, and ICP. D) Thiopental is commonly used in the U.S. for induction of anesthesia.

Answer 180

Answer: B Rationale: Thiopental saturates peripheral compartments at higher doses, leading to prolonged action. It decreases CMRO₂, CBF, and ICP and is rarely used in the U.S. today.

Question 181

Which of the following effects of ketamine makes it contraindicated in neurosurgical procedures? A) Increases cerebral metabolic rate of oxygen (CMRO₂) B) Preserves airway reflexes C) Causes psychomimetic reactions D) Causes bronchodilation

Answer 181

Answer: A \ Rationale: Ketamine increases CMRO₂, CBF, and ICP, making it unsuitable for use in neurosurgical cases requiring controlled ICP. (not sure this is legit)

Question 182

What is a notable cardiovascular effect of ketamine? A) Decreases systemic vascular resistance B) Indirect sympathetic stimulation leading to increased myocardial oxygen demand C) Causes significant bradycardia and hypotension D) Has no effect on pulmonary vascular resistance

Answer 182

Answer: B Rationale: Ketamine’s cardiovascular effects are primarily due to indirect sympathetic stimulation, which increases myocardial oxygen demand. (can cause myocardial depression in underlying conditions).

Question 183

What unique property of ketamine differentiates it from other IV anesthetics? A) Causes dose-dependent respiratory depression B) Increases airway secretions and preserves airway reflexes C) Does not provide analgesia D) Reduces myocardial oxygen demand

Answer 183

Answer: B Rationale: Ketamine preserves airway reflexes and increases airway secretions, a property unique among IV anesthetics.

Question 184

Which of the following is TRUE about ketamine’s mechanism of action? A) It is a competitive antagonist at NMDA receptors. B) It acts on GABA-A receptors to enhance chloride conductance. C) It is an uncompetitive NMDA receptor antagonist. D) It blocks sodium channels to reduce neuronal excitability

Answer 184

Answer: C Rationale: Ketamine is an uncompetitive NMDA receptor antagonist, which contributes to its analgesic and dissociative effects. (whatever the fuck that means) Ketamine primarily works by acting as a non-competitive antagonist at the NMDA receptor, meaning it binds to the open channel of the receptor, effectively blocking its function.

Question 185

Which patient population might experience unmasked myocardial depression when administered ketamine? A) Patients with normal sympathetic reserves B) Severely ill patients with catecholamine depletion C) Patients with hyperthyroidism D) Patients receiving beta-blockers

Answer 185

Answer: B Rationale: In patients with depleted catecholamine reserves, ketamine’s intrinsic myocardial depressant effects may be unmasked, leading to significant cardiovascular compromise.

Question 186

Which is a recommended co-administration with ketamine to manage its side effects? A) Atropine to reduce secretions B) Midazolam to reduce psychomimetic effects C) Glycopyrrolate to manage PVR D) Lidocaine to reduce pain on injection

Answer 186

Answer: B Rationale: Midazolam is commonly co-administered with ketamine to reduce its psychomimetic effects, such as hallucinations. Glyco for salivation 0.2mg

Question 187

In which patient population might ketamine’s bronchodilatory effects be particularly beneficial? A) Patients with severe pulmonary hypertension B) Patients with bronchospasm or reactive airway disease C) Patients undergoing neurosurgery D) Patients with catecholamine depletion

Answer 187

Answer: B Rationale: Ketamine causes bronchodilation, making it ideal for patients with bronchospasm or reactive airway diseases like asthma.

Question 188

Which of the following statements about ketamine is TRUE? A) Ketamine is a racemic mixture, and R(-) is more potent than S(+). B) Ketamine is secreted in the urine with a half-life of 2-3 hours. C) Ketamine is highly protein bound. D) Norketamine is the metabolite of ketamine and has no clinical effect.

Answer 188

Answer: B Rationale: Ketamine has a urinary half-life of 2-3 hours. S(+) ketamine is more potent, it is highly lipid-soluble (not protein-bound), and norketamine has approximately one-third the potency of ketamine.

Question 189

What is the potency of the S(+) isomer of ketamine compared to the R(-) isomer? A) Equally potent B) S(+) is less potent than R(-) C) S(+) is more potent than R(-) D) Neither is clinically relevant

Answer 189

Answer: C Rationale: The S(+) isomer of ketamine is more potent than the R(-) isomer due to better receptor affinity and reduced side effects.

Question 190

Which of the following is NOT a property of midazolam? A) Anxiolytic B) Anticonvulsant C) Analgesic D) Sedative

Answer 190

Answer: C Rationale: Midazolam lacks analgesic properties but has anxiolytic, sedative, hypnotic, and anticonvulsant effects

Question 191

What is the induction dose of midazolam? A) 0.04-0.08 mg/kg B) 0.1-0.2 mg/kg C) 1-2 mg/kg D) 5-10 mg/kg

Answer 191

Answer: B Rationale: The induction dose of midazolam is 0.1-0.2 mg/kg IV, with a premedication dose of 0.04-0.08 mg/kg. (typically 1-2mg)

Question 192

What is the action of flumazenil? A) Inhibits benzodiazepine metabolism B) Is a non-specific GABA receptor antagonist C) Specifically antagonizes benzodiazepines at GABA-A receptors D) Prolongs the half-life of benzodiazepines

Answer 192

Answer: C Rationale: Flumazenil is a specific antagonist of benzodiazepines at GABA-A receptors, used to reverse their effects.

Question 193

Which of the following is TRUE about midazolam’s effect on respiratory function? A) It causes dose-dependent respiratory depression. B) It causes significant respiratory depression only when used alone. C) It has no effect on respiratory function. D) It enhances respiratory drive in patients with chronic lung disease.

Answer 193

Answer: A Rationale: Midazolam causes dose-dependent respiratory depression, which can be exaggerated when combined with opioids or in patients with pre-existing respiratory disease.

Question 194

Midazolam decreases all of the following EXCEPT: A) Cerebral metabolic rate of oxygen (CMRO₂) B) Cerebral blood flow (CBF) C) Systemic vascular resistance (SVR) D) EEG burst suppression

Answer 194

Answer: D Rationale: While midazolam decreases CMRO₂, CBF, and SVR (with higher doses), it does not produce EEG burst suppression like other agents such as thiopental.

Question 195

How long should a patient who has received 0.2 mg of flumazenil be observed? A) 1 hour B) 2-3 hours C) 4-6 hours D) 24 hours

Answer 195

Answer: B Rationale: Flumazenil has a short half-life of 45 minutes to 1 hour, and patients should be observed for 2-3 hours to monitor for recurrent sedation as the effects of benzodiazepines may outlast flumazenil.

Question 196

Which of the following is NOT a characteristic of dexmedetomidine? A) Selective alpha-2 adrenergic agonist B) Significant respiratory depression C) Bradycardia as a side effect D) Opioid-sparing effect

Answer 196

Answer: B Rationale: Dexmedetomidine does not significantly depress respiratory drive, making it unique among sedative agents.

Question 197

What is the recommended loading dose of dexmedetomidine for sedation? A) 0.1-0.3 mcg/kg over 10 minutes B) 0.5-1 mcg/kg over 10 minutes C) 1-2 mcg/kg over 10 minutes D) 0.3-0.5 mcg/kg over 10 minutes

Answer 197

Answer: B Rationale: The loading dose of dexmedetomidine is 0.5-1 mcg/kg administered over 10 minutes.

Question 198

Which of the following conditions requires a reduced dose of dexmedetomidine? A) Asthma B) Chronic kidney disease C) Hepatic impairment D) Both B and C

Answer 198

Answer: D Rationale: Patients with renal insufficiency or hepatic impairment require reduced dosages due to altered drug metabolism or clearance.

Question 199

What is a common cardiovascular side effect of dexmedetomidine? A) Tachycardia B) Bradycardia C) Hypertension D) Ventricular arrhythmias

Answer 199

Answer: B Rationale: Dexmedetomidine can cause bradycardia and hypotension due to its alpha-2 agonist effects, which reduce sympathetic outflow.

Question 200

For what specific scenario is dexmedetomidine particularly useful? A) Inducing general anesthesia B) Sedation during awake fiberoptic intubations C) Treating acute pain D) Rapid sequence induction

Answer 200

Answer: B Rationale: Dexmedetomidine is effective for sedation during awake fiberoptic intubations due to its sedative and anxiolytic properties without significant respiratory depression.

Question 201

What is the alpha-2 receptor selectivity ratio of dexmedetomidine compared to clonidine? A) 100:1 B) 1600:1 C) 220:1 D) 10:1

Answer 201

Answer: B Rationale: Dexmedetomidine exhibits an alpha-2 receptor selectivity ratio of 1600:1, significantly higher than clonidine's ratio of 220:1, making it more specific for alpha-2 receptors.

Question 202

Dexmedetomidine undergoes complete biotransformation via which processes? A) Hepatic glucuronidation, hydroxylation, and N-methylation B) Renal filtration, glucuronidation, and methylation C) Hepatic hydroxylation, acetylation, and sulfation D) Renal hydroxylation, glucuronidation, and acetylation

Answer 202

Answer: A Rationale: Dexmedetomidine is metabolized in the liver via glucuronidation, hydroxylation, and N-methylation pathways.

Question 203

What is the elimination half-life of dexmedetomidine? A) 1-2 hours B) 2-3 hours C) 4-5 hours D) 5-6 hours

Answer 203

Answer: B Rationale: The elimination half-life of dexmedetomidine is 2-3 hours, and it exhibits a context-sensitive half-time of 4 minutes after a 10-minute infusion and 250 minutes after an 8-hour infusion.

Question 204

A 62yo male is undergoing a right ganglion cyst excision under local anesthesia with sedation. ABG is taken 30min after starting sedation and the PaCO2 is 38mmHg, unchanged from a preop baseline ABG. RR is 10, down from 12 bpm. _______(dexmedetomidine/midazolam/propofol/remifentanil) is most likely administered.

Answer 204

Rationale: Dexmedetomidine is most likely administered due to its characteristic reduction in respiratory rate without significant changes in PaCO₂ or blood gases. It does not cause significant respiratory depression like other agents.

Question 205

Which depth of sedation allows for normal response to verbal stimulation and unaffected airway reflexes? A) Minimal sedation (anxiolysis) B) Moderate sedation/analgesia C) Deep sedation/analgesia D) General anesthesia

Answer 205

Answer: A Rationale: Minimal sedation (anxiolysis) is characterized by normal verbal response and unaffected airway, ventilation, and cardiovascular functions.

Question 206

Which of the following best describes moderate sedation/analgesia ("conscious sedation")? A) The patient is unarousable even with painful stimulus, and airway intervention is required. B) The patient has a purposeful response to verbal or tactile stimulation, with adequate spontaneous ventilation and maintained cardiovascular function. C) The patient responds normally to verbal stimulation, and no airway intervention is required. D) The patient has a purposeful response only to repeated or painful stimulation, and spontaneous ventilation may be inadequate.

Answer 206

Answer: B Rationale: Moderate sedation/analgesia is characterized by purposeful response to verbal or tactile stimulation, with adequate spontaneous ventilation and maintained cardiovascular function. Unlike deep sedation, the patient does not require airway intervention.

Question 207

Which of the following is characteristic of deep sedation/analgesia? A) The patient maintains normal airway reflexes and responds normally to verbal commands. B) The patient responds purposefully following repeated or painful stimulation, and spontaneous ventilation may be inadequate. C) The patient is unarousable even with painful stimulus, and cardiovascular function is frequently impaired. D) The patient responds purposefully to verbal or tactile stimulation, and spontaneous ventilation is adequate.

Answer 207

Answer: B Rationale: Deep sedation/analgesia involves a purposeful response to repeated or painful stimulation, with potential inadequacy in spontaneous ventilation. Airway intervention may be required, but cardiovascular function is usually maintained.

Question 208

Where do opioids primarily act to produce analgesia? A) Cerebellum and hypothalamus B) Periaqueductal gray matter and substantia gelatinosa C) Hippocampus and motor cortex D) Reticular formation and spinal ganglia

Answer 208

Answer: B Rationale: Opioids produce analgesia by acting on the mu (µ) receptors in the brain (periaqueductal gray matter) and the spinal cord (substantia gelatinosa), reducing the perception of pain.

Question 209

Which of the following is a common side effect of opioid use? A) Tachycardia B) Miosis C) Hyperthermia D) Hyperventilation

Answer 209

Answer: B Rationale: Opioids commonly cause miosis (pupil constriction), which can be useful in assessing patients under general anesthesia. Other side effects include sedation, respiratory depression, and bradycardia.

Question 210

How do opioids affect the hemodynamic system when administered alone? A) Increase cardiac output (CO) and blood pressure (BP) B) Are hemodynamically stable C) Cause significant hypotension D) Reduce stroke volume (SV) and BP directly

Answer 210

Answer: B Rationale: Opioids are generally hemodynamically stable when given alone. However, in combination with other anesthetics, they can cause reductions in cardiac output, stroke volume, and blood pressure.

Question 211

What is a potential benefit of using opioids in conjunction with volatile anesthetics? A) Increase MAC of volatile anesthetics B) Reduce MAC of volatile anesthetics C) Enhance myocardial contractility D) Improve airway reflexes

Answer 211

Answer: B Rationale: Opioids reduce the minimum alveolar concentration (MAC) of volatile anesthetics, allowing for lower doses of the anesthetic to achieve the same effect, which can improve hemodynamic stability during surgery.

Question 212

Which of the following opioid receptor subtypes is most associated with marked constipation? A) Mu-1 B) Mu-2 C) Kappa D) Delta

Answer 212

Answer: B) Mu-2 Rationale: Mu-2 receptors are primarily responsible for effects such as constipation, depression of ventilation, and physical dependence.

Question 213

Which opioid receptor subtype is least likely to contribute to physical dependence (select 2)? A) Mu-1 B) Mu-2 C) Kappa D) Delta

Answer 213

Answer:A) Mu-1 & C) Kappa Rationale: Kappa receptors are associated with dysphoria and sedation but have a low abuse potential and are less involved in physical dependence compared to Mu-2 or Delta receptors.

Question 214

A patient on an opioid agonist develops urinary retention. This side effect is most likely mediated by which receptor subtype? A) Mu-1 B) Kappa C) Delta D) Sigma

Answer 214

Answer: A) Mu-1 & Delta Rationale: Mu-1 receptor activation leads to effects such as analgesia, euphoria, miosis, and urinary retention.

Question 215

Which receptor subtype is involved in diuresis as a clinical effect? A) Mu-2 B) Kappa C) Delta D) Sigma

Answer 215

Answer: B) Kappa Rationale: Kappa receptors uniquely contribute to diuresis as one of their clinical effects.

Question 216

Which receptor subtype is primarily targeted by endogenous enkephalins? A) Mu-1 B) Mu-2 C) Kappa D) Delta

Answer 216

Answer: D) Delta Rationale: Delta receptors are the primary target for enkephalins, which are endogenous opioid peptides involved in modulating pain and other effects.

Question 217

Naloxone acts as an antagonist at which of the following receptor subtypes? (Select all that apply.) A) Mu-1 B) Mu-2 C) Kappa D) Delta

Answer 217

Answer: A), B), C), and D) Rationale: Naloxone is a non-selective opioid receptor antagonist and works on Mu-1, Mu-2, Kappa, and Delta receptors.

Question 218

Which characteristic of fentanyl limits its use as a continuous infusion for prolonged surgeries? A) Rapid onset of action B) Very long context-sensitive half-life C) High potency compared to morphine D) Limited ability to blunt the sympathetic response

Answer 218

Answer: B) Very long context-sensitive half-life Rationale: Fentanyl has a very long context-sensitive half-life, which can lead to prolonged duration of action with repeated doses or continuous infusion, making it less ideal for prolonged surgeries.

Question 219

Why is hydromorphone often preferred for post-operative pain control over fentanyl? A) It is associated with a faster peak effect. B) It has a longer duration of action. C) It releases histamine, causing beneficial vasodilation. D) It has a shorter context-sensitive half-life.

Answer 219

Answer: B) It has a longer duration of action. 2-4 hrs compared to 1-1.5 hrs Rationale: Hydromorphone's longer duration of action makes it suitable for managing post-operative pain compared to fentanyl, which is shorter-acting.

Question 220

What is the significance of hydromorphone-3-glucuronide as a metabolite of hydromorphone? A) It has potent analgesic effects. B) It contributes to sedation. C) It may cause neuroexcitation. D) It prolongs the drug's duration of action.

Answer 220

Answer: C) It may cause neuroexcitation. Rationale: Hydromorphone-3-glucuronide has no analgesic properties but can lead to neuroexcitation in some cases.

Question 221

What is the peak onset time for hydromorphone after administration? A) 5 minutes B) 10 minutes C) 15 minutes D) 30 minutes

Answer 221

Answer: C) 15 minutes Rationale: Hydromorphone's peak effect typically takes around 15 minutes, requiring patience when titrating near the end of a case.

Question 222

Why does remifentanil have no context-sensitive half-life? A) It has a low volume of distribution. B) It is metabolized by plasma esterases. C) It has a high protein-binding affinity. D) It is rapidly cleared by the kidneys.

Answer 222

Answer: B) It is metabolized by plasma esterases. Rationale: Remifentanil undergoes rapid metabolism by plasma esterases, which ensures that its duration of action remains consistent (5–10 minutes) regardless of the infusion duration.

Question 223

What is a common side effect of remifentanil boluses, and how can it be managed? A) Hypotension, managed with norepinephrine. B) Bradycardia, managed with glycopyrrolate or atropine. C) Hyperalgesia, managed with long-acting opioids. D) Respiratory depression, managed with naloxone.

Answer 223

Answer: B) Bradycardia, managed with glycopyrrolate or atropine. Rationale: Bradycardia is a common side effect of remifentanil boluses and can be effectively managed with glycopyrrolate or atropine.

Question 224

Why is remifentanil not recommended for post-operative pain control? A) It has a long half-life. B) It causes severe sedation post-operatively. C) It lacks an analgesic tail after cessation. D) It leads to opioid-induced hyperalgesia in all patients.

Answer 224

Answer: C) It lacks an analgesic tail after cessation. Rationale: Most commonly used as infusion when significant intraoperative stimulation but minimal post-operative pain is expected (i.e. analgesic tail is NOT needed)

Question 225

What complication can occur with sudden cessation of remifentanil at the end of surgery? A) Acute opioid withdrawal B) Acute opioid tolerance C) Severe respiratory depression D) Profound sedation

Answer 225

Answer: B) Acute opioid tolerance Rationale: Sudden cessation of remifentanil can lead to acute opioid tolerance, requiring additional opioids for pain management post-operatively.

Question 226

What is a potential consequence of prolonged high-dose remifentanil infusions (>0.15 mcg/kg/min)? A) Opioid-induced hyperalgesia B) Respiratory alkalosis C) Prolonged sedation D) Increased intracranial pressure

Answer 226

Answer: A) Opioid-induced hyperalgesia Rationale: High-dose or prolonged infusions of remifentanil are associated with opioid-induced hyperalgesia, which can persist for days to weeks and is less responsive to additional opioids.

Question 227

What is the typical STARTING infusion dose range for remifentanil? A) 0.01–0.03 mcg/kg/min B) 0.05–0.1 mcg/kg/min C) 0.1–0.3 mcg/kg/min D) 0.5–1.0 mcg/kg/min

Answer 227

Answer: B) 0.05–0.1 mcg/kg/min Rationale: The typical starting infusion dose for remifentanil is 0.05–0.1 mcg/kg/min, titrated as needed for intraoperative analgesia. Doses rarely exceed 0.3 mcg/kg/min.

Question 228

Why should remifentanil not be confused with sufentanil in terms of dosing? A) Sufentanil is dosed in mcg/kg/HOUR, while remifentanil is dosed in mcg/kg/MINUTE. B) Remifentanil is more potent and requires lower doses than sufentanil. C) Sufentanil is metabolized by plasma esterases, unlike remifentanil. D) Remifentanil has a longer duration of action compared to sufentanil.

Answer 228

Answer: A) Sufentanil is dosed in mcg/kg/HOUR, while remifentanil is dosed in mcg/kg/MINUTE. Rationale: Remifentanil is dosed in mcg/kg/minute due to its rapid metabolism by plasma esterases, while sufentanil is dosed in mcg/kg/hour due to its longer duration of action and different pharmacokinetics.

Question 229

If a provider accidentally administers remifentanil at a rate meant for sufentanil (mcg/kg/hour), what is the most likely outcome? A) Underdosing, leading to inadequate analgesia. B) Overdosing, resulting in bradycardia and respiratory depression. C) No effect, as the two drugs are equivalent in potency. D) Excessive sedation due to remifentanil’s high lipid solubility.

Answer 229

Answer: B) Overdosing, resulting in bradycardia and respiratory depression. Rationale: Administering remifentanil at the higher infusion rates meant for sufentanil would lead to significant overdosing due to its rapid onset and potency.

Question 230

Which of the following medications is primarily metabolized by plasma esterases? A) Sufentanil B) Atracurium C) Esmolol D) Midazolam

Answer 230

Answer: B) Atracurium Rationale: Atracurium is primarily metabolized by plasma esterases, which contributes to its context-independent metabolism. Esmolol is metabolized by RBC esterases, and sufentanil and midazolam rely on hepatic metabolism.

Question 231

What is the typical infusion dosing protocol for sufentanil during a surgical case? A) 0.05–0.1 mcg/kg/min B) 0.3–0.2–0.1 mcg/kg/hour in thirds of the case duration C) 0.1–0.3 mcg/kg/min, titrated as needed D) 0.3–0.5 mcg/kg/hour, continuous until surgery completion

Answer 231

Answer: B) 0.3–0.2–0.1 mcg/kg/hour in thirds of the case duration Rationale: Sufentanil is commonly divided into thirds of the expected case duration, starting at 0.3 mcg/kg/hour and tapering to 0.2 mcg/kg/hour and then 0.1 mcg/kg/hour. This protocol helps manage intraoperative and postoperative pain effectively. Turn off 15 – 30 minutes prior to end of surgery

Question 232

Why is sufentanil considered more forgiving than fentanyl as an infusion? A) It has a shorter context-sensitive half-life. B) It does not require titration during surgery. C) Its context-sensitive half-life allows for controlled accumulation. D) It is metabolized entirely by plasma esterases.

Answer 232

Answer: C) Its context-sensitive half-life allows for controlled accumulation. Rationale: Sufentanil has a longer context-sensitive half-life compared to remifentanil, allowing for some controlled accumulation during the case, which makes it more predictable and forgiving than fentanyl for infusions.

Question 233

What is the primary use of alfentanil during a MAC case? A) Postoperative pain control B) Treating brief periods of intense stimulation C) Maintenance of general anesthesia D) Managing chronic pain

Answer 233

Answer: B) Treating brief periods of intense stimulation Rationale: Alfentanil, due to its rapid onset (90 seconds) and brief duration, is most commonly used as a bolus to manage intense but short-lived surgical stimulation, such as local injections during a MAC case.

Question 234

Why does alfentanil have the fastest onset among opioids? A) It is highly lipophilic with a low pKa of 6.5. B) It is not protein-bound and rapidly metabolized. C) It has a short elimination half-life and minimal redistribution. D) It crosses the blood-brain barrier due to low molecular weight.

Answer 234

Answer: A) It is highly lipophilic with a low pKa of 6.5. Rationale: Alfentanil’s pKa of 6.5 allows for a large fraction of the drug to be non-ionized at physiological pH, facilitating rapid crossing of the blood-brain barrier, despite high protein binding.

Question 235

What property of morphine’s active metabolite, morphine-6-glucuronide, makes it clinically significant? A) It is hepatically excreted and causes euphoria. B) It is renally excreted and has analgesic properties. C) It is lipid-soluble and rapidly crosses the blood-brain barrier. D) It is metabolized in the lungs and causes sedation.

Answer 235

Answer: B) It is renally excreted and has analgesic properties. Rationale: Morphine-6-glucuronide is an active metabolite with potent analgesic effects. It is renally excreted, making it clinically relevant in patients with renal failure where accumulation may occur.

Question 236

What is a common side effect of morphine that may limit its use during surgery? A) Hypertension B) Histamine release C) Tachycardia D) Hypokalemia

Answer 236

Answer: B) Histamine release Rationale: Morphine can cause significant histamine release, leading to side effects like hypotension and pruritus, which may make it less desirable in some surgical settings. Also slow peak time

Question 237

What is a significant safety concern associated with the use of meperidine? A) It inhibits cytochrome P450 enzymes. B) Its metabolite, normeperidine, lowers the seizure threshold. C) It causes prolonged sedation in renal failure. D) It has an unpredictable duration of action.

Answer 237

Answer: B) Its metabolite, normeperidine, lowers the seizure threshold. Rationale: Normeperidine, a toxic metabolite of meperidine, can accumulate in patients, especially those with renal impairment, leading to seizures.

Question 238

Question 3: Methadone is underutilized in anesthesia practice primarily due to: A) Its short terminal half-life. B) Its NMDA antagonism properties. C) The need for postoperative monitoring for at least 24 hours. D) Its inability to provide effective pain relief.

Answer 238

Answer: C) The need for postoperative monitoring for at least 24 hours. Rationale: Methadone has a long terminal half-life (~1 day), leading to potential accumulation and respiratory depression, requiring prolonged monitoring, which limits its routine use in outpatient settings.

Question 239

What differentiates the two enantiomers of methadone in their mechanisms of action? A) L-methadone is an NMDA antagonist, while D-methadone is an opioid agonist. B) L-methadone is an opioid agonist, while D-methadone is an NMDA antagonist. C) Both enantiomers act as opioid agonists. D) Both enantiomers act as NMDA antagonists.

Answer 239

Answer: B) L-methadone is an opioid agonist, while D-methadone is an NMDA antagonist. Rationale: Methadone is a racemic mixture where L-methadone provides opioid receptor agonism for pain relief, and D-methadone contributes NMDA antagonism, which may help in chronic pain management.

Question 240

Why should meperidine not be used in patients taking MAOIs? A) It causes severe hypotension. B) It can lead to serotonin syndrome. C) It reduces the effectiveness of MAOIs. D) It inhibits normeperidine metabolism.

Answer 240

Answer: B) It can lead to serotonin syndrome. Rationale: Meperidine, when combined with MAOIs, can cause serotonin syndrome, characterized by agitation, hyperthermia, rigidity, and potentially fatal outcomes.

Question 241

Which opioid's active metabolite has 100x greater affinity for μ-receptors than the parent compound and is highly problematic in renal failure? A) Morphine-3-glucuronide B) Morphine-6-glucuronide C) Normeperidine D) Oxymorphone

Answer 241

Answer: B) Morphine-6-glucuronide Rationale: Morphine-6-glucuronide is a potent active metabolite of morphine with significant μ-receptor activity, leading to enhanced effects in renal failure due to delayed excretion.

Question 242

Which opioid has an active metabolite that lowers the seizure threshold and is excreted renally? A) Meperidine B) Hydromorphone C) Morphine D) Fentanyl

Answer 242

Answer: A) Meperidine Rationale: Normeperidine, the active metabolite of meperidine, reduces the seizure threshold and accumulates in renal dysfunction, leading to neuroexcitatory effects.

Question 243

Why is hydromorphone generally safer than morphine in patients with compromised renal function? A) It is not metabolized to active compounds. B) Its metabolite is inactive but can still cause neuroexcitation in renal failure. C) It does not produce any metabolites. D) It is metabolized entirely by the liver.

Answer 243

Answer: B) Its metabolite is inactive but can still cause neuroexcitation in renal failure. Rationale: Hydromorphone-3-glucuronide is inactive but can accumulate in renal failure, causing neuroexcitatory symptoms.

Question 244

Which of the following opioids is considered safest for use in patients with renal impairment? A) Morphine B) Codeine C) Fentanyl D) Meperidine

Answer 244

Answer: C) Fentanyl Rationale: Fentanyl is primarily metabolized by the liver into inactive metabolites and is minimally affected by renal function, making it a safer choice for patients with renal impairment.

Question 245

What is the recommended opioid for blunting hemodynamic effects during standard GETA induction? A) Morphine B) Fentanyl C) Hydromorphone D) Meperidine

Answer 245

Answer: B) Fentanyl Rationale: Fentanyl is used during GETA induction to blunt hemodynamic responses to direct laryngoscopy and intubation due to its rapid onset and predictable effects. * Fyi: esmolol is a reasonable alternative

Question 246

Which opioid is most suitable for brief, intense stimulation, such as during rigid bronchoscopy or Mayfield head pin placement? A) Methadone B) Alfentanil C) Hydromorphone D) Meperidine

Answer 246

Answer: B) Alfentanil - (15mcg/kg before direct layngoscoopy and Retrobulbar blocks) Rationale: Alfentanil is ideal for short, intense stimulation due to its fast onset and short duration of action. Can also do Ultiva (0.5- 1mcg/kg - give over 1 min) as well. Consider giving 0.2mg glycopyrolate .. use Common sense when dosing.. use IBW.. if old consider 150-250mcg bolus.. if not phased then you can repeat with a half dose. Alfenta is LESS potent than Remifentinil so it causes LESS apnea.

Question 247

For ENT surgeries requiring stable analgesia and smooth emergence, which opioid infusion is commonly considered? A) Morphine B) Sufentanil C) Meperidine D) Hydromorphone

Answer 247

Answer: B) Sufentanil Rationale: Sufentanil provides stable analgesia, controlled hypotension, and a smooth transition to post-op analgesia, making it ideal for ENT cases. – “Narcotic wakeup” reduces bucking on ETT

Question 248

In patients with chronic opioid use, what is the recommended intraoperative opioid strategy? A) Reduce the patient's regular opioid dose and use adjuncts exclusively. B) Discontinue the chronic opioid dose preoperatively. C) Continue their chronic opioid dose intraoperatively and anticipate higher acute pain needs. D) Avoid all opioids and use regional anesthesia.

Answer 248

Answer: C) Continue their chronic opioid dose intraoperatively and anticipate higher acute pain needs. (e.g. methadone, MS Contin, OxyContin, etc.) Rationale: Chronic opioid users require continuation of their baseline dose intraoperatively and often require additional opioids for acute pain control. Adjuncts may be helpful (tylenol, lidocaine, ketamine, gabapentin, etc)

Question 249

Why should morphine and meperidine be used cautiously in renal patients? A) They are metabolized into active metabolites that can accumulate in renal impairment. B) They cause significant hypotension. C) They have prolonged half-lives regardless of renal function. D) They are contraindicated in elderly patients.

Answer 249

Answer: A) They are metabolized into active metabolites that can accumulate in renal impairment. Rationale: Both morphine and meperidine produce active metabolites that can lead to neurotoxicity and other adverse effects in renal failure.

Question 250

Why are both fentanyl and hydromorphone recommended for post-op pain control in the PACU? A) Both are titratable, with fentanyl offering rapid onset and hydromorphone providing prolonged effects. B) Both lack significant active metabolites, making them safe for renal patients. C) Both are equally effective in ambulatory and inpatient settings. D) Both are equally fast-acting, with similar onset times.

Answer 250

Answer: A) Both are titratable, with fentanyl offering rapid onset and hydromorphone providing prolonged effects. Rationale (Slide-Based): The slide explicitly mentions fentanyl’s rapid onset, easy titration, and familiarity among nurses, while hydromorphone is highlighted for its prolonged effect, making it a good transition to PCA.

Question 251

When should hydromorphone be considered over fentanyl in post-op settings? A) When a shorter duration of analgesia is desired. B) When the patient is transitioning to PCA. C) When immediate pain relief is required. D) When respiratory depression is a concern.

Answer 251

Answer: B) When the patient is transitioning to PCA. Rationale (Slide-Based): The slide specifies hydromorphone’s role in providing prolonged analgesia and its suitability for transitioning to PCA due to its predictable pharmacokinetics and longer duration.

Question 252

Which opioid is most appropriate for a bolus dose of 500 µg during induction for brief but intense stimulation, and what is its recommended hourly maintenance dose? A) Alfentanil; 250 µg hourly B) Meperidine; 50 µg hourly C) Methadone; 2.5 mg hourly D) Fentanyl; 150 µg hourly

Answer 252

Answer: A) Alfentanil; 250 µg hourly Rationale: The slide lists alfentanil as a common intraoperative bolus option with an induction dose of 500 µg and an hourly maintenance dose of 250 µg- first repeat dose at 30min. Fentanyl first repeat dose is usually 30 min as well then hourly.

Question 253

What is the recommended hourly dose for intraoperative boluses of meperidine during opioid shortages? A) 10 mg B) 25 mg C) 50 mg D) 100 mg

Answer 253

Answer: B) 25 mg Rationale: The slide clearly indicates that the hourly dose for intraoperative meperidine boluses is 25 mg, with an induction dose of 100 mg.

Question 254

tramadol in preoperative opioid-sparing strategies, and what is its recommended dose? A) 50 mg PO for mild pain relief B) 100 mg PO C) 150 mg IV for immediate analgesia D) 200 mg PO for breakthrough pain

Answer 254

Answer: B) 100 mg PO Rationale: The slide includes tramadol 100 mg PO in preoperative multimodal analgesic strategies, EXCEPT for patients with poor CYP2D6 metabolism who may not benefit from codeine.

Question 255

What is the initial infusion rate for sufentanil in mcg/kg/h for intraoperative opioid management? A) 0.1 mcg/kg/h B) 0.2 mcg/kg/h C) 0.5 mcg/kg/h D) 8 mcg/kg/h

Answer 255

Answer: B) 0.2 mcg/kg/h Rationale: The slide indicates that sufentanil should start at 0.2 mcg/kg/h, gradually titrated down to 0.1 mcg/kg/h at 30 minutes and 0.075 mcg/kg/h at 120 minutes. (Tex Wes suggests 0.5-1 mcg/kg/hr) (Vargo says range is between 0.2-0.5mcg/kg/hr) PRN bolus for pain 5-10mcg or 0.1mcg/kg Comes in 50mcg/mL, dilute 4mLs in 16mL syringe yields 10mcg/mL

Question 256

Which opioid infusion has the fastest (highest) starting infusion rate for intraoperative analgesia? A) Fentanyl B) Remifentanil C) Sufentanil D) Alfentanil

Answer 256

Answer: D) Alfentanil Rationale: When comparing infusion rates, remifentanil starts at 0.1 mcg/kg/min, which translates to 6 mcg/kg/hr. This rate is slower than alfentanil (8 mcg/kg/hr).... fentanyl is (2.5 mcg/kg/hr), and sufentanil (0.2 mcg/kg/hr).

Question 257

What is the recommended sufentanil maintenance infusion rate at 120 minutes for continuous opioid analgesia? A) 0.075 mcg/kg/hr B) 0.1 mcg/kg/min C) 0.2 mcg/kg/hr D) 2.5 mcg/kg/min

Answer 257

Answer: A) 0.075mcg/kg/hr Rationale: Sufentanil's maintenance dose decreases over time, with 0.2-0.5 mcg/kg/hr as the starting rate and 0.075 mcg/kg/hr as the adjusted infusion rate at 120 minutes. 0.1mcg/kg/hr at 30 min bolus of 0.1mcg/kg or 5-10 mcg

Question 258

A 65-year-old patient undergoing a long intraoperative procedure requires an opioid infusion. To minimize context-sensitive half-life and accumulation, which opioid is preferred? A) Fentanyl B) Remifentanil C) Alfentanil D) Sufentanil

Answer 258

Answer: B) Remifentanil Rationale: Remifentanil's metabolism via plasma esterases ensures no context-sensitive half-life, making it ideal for prolonged infusions without risk of accumulation. All the other infusions should be decreased over the course of the surgery due to accumulation. Typically you would decrease the dose of infusion at 30min and 120min.. Fentanyl start at 2.5mcg/kg/hr then 1, then 0.5 Afentanil start at 8mcg/kg/hr then 3, then 2 Sufentanil start at 0.2mcg/kg/hr then 0.1, then 0.075

Question 259

Which opioid is both a mu opioid receptor agonist and an NMDA receptor antagonist? A) Buprenorphine B) Methadone C) Nalbuphine D) Butorphanol

Answer 259

Answer: B) Methadone Rationale: Methadone's unique mechanism of action includes mu opioid receptor agonism and NMDA receptor antagonism, making it effective for chronic pain and opioid tolerance.

Question 260

Which mixed opioid agonist-antagonist acts as a partial mu receptor antagonist and a kappa receptor agonist? A) Meperidine B) Nalbuphine C) Buprenorphine D) Methadone

Answer 260

Answer: B) Nalbuphine Rationale: Nalbuphine is known for its dual action as a partial mu antagonist and kappa agonist, often used to mitigate opioid-induced respiratory depression.

Question 261

At what time point should the infusion rate for fentanyl be reduced to 0.5 mcg/kg/h in a prolonged intraoperative setting? A) 30 minutes B) 60 minutes C) 120 minutes D) 240 minutes

Answer 261

Answer: C) 120 minutes Rationale: The slide specifies that fentanyl's infusion rate decreases over time, reaching 0.5 mcg/kg/h at 120 minutes to align with reduced analgesic needs.

Question 262

Which of the following opioid-receptor agonists has anticholinergic properties? a. Morphine b. Hydromorphone c. Sufentanil d. Meperidine

Answer 262

Answer: d, Meperidine Rationale: Mu opioid agonist and Ach receptor antagonist

Question 263

Why does cardiac output (CO) depend primarily on heart rate (HR) in infants, while stroke volume (SV) plays a greater role in adults? A) Infants have a smaller ventricular capacity, making stroke volume changes insignificant. B) Parasympathetic dominance in infants limits stroke volume adaptability. C) Preload in infants is highly variable, making HR the primary determinant. D) Infants’ stroke volume is relatively fixed due to less compliant ventricles.

Answer 263

Answer: D) Infants’ stroke volume is relatively fixed due to less compliant ventricles. Rationale: In infants, ventricular compliance is limited, restricting the ability to adjust stroke volume. As a result, heart rate becomes the dominant factor in determining cardiac output. In adults, stroke volume adaptability increases due to better ventricular compliance and interaction of preload, afterload, and contractility.

Question 264

Which of the following represents the normal range for Systemic Vascular Resistance (SVR) in dynes·sec·cm⁻⁵? A) 500–1,000 B) 700–1,500 C) 1,200–2,000 D) 400–800

Answer 264

Answer: B) 700–1,500 Rationale: The normal range for systemic vascular resistance (SVR) is 700–1,500 dynes·sec·cm⁻⁵. This range reflects the typical resistance encountered by blood flow in the systemic circulation. Variations outside this range can indicate pathophysiological conditions such as shock, vasodilation, or increased vascular tone. Accurate measurement and interpretation of SVR are crucial in managing critically ill patients.

Question 265

Which of the following pulse pressure (PP) values is most likely associated with normal resting conditions in a healthy individual? A) 20 mm Hg B) 40 mm Hg C) 70 mm Hg D) 100 mm Hg

Answer 265

Answer: B) 40 mm Hg Rationale: Pulse pressure (PP) is the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP). In a healthy individual at rest, the normal PP is approximately 40 mm Hg. Narrow PP (< 25 mm Hg) may indicate conditions such as aortic stenosis or shock, while wide PP (> 40 mm Hg) can be seen in cases of aortic regurgitation, high-output states, or vascular pathologies.

Question 266

Which PP value indicates a narrow pulse pressure? A) < 25 mm Hg B) 40 mm Hg C) > 60 mm Hg D) > 100 mm Hg

Answer 266

Answer: A) < 25 mm Hg

Question 267

A wide pulse pressure (> 40 mm Hg) may be caused by: A) Aortic regurgitation B) Aortic stenosis C) Tension pneumothorax D) Shock

Answer 267

Answer: A) Aortic regurgitation

Question 268

Match the following PP values with their associated conditions: 20 mm Hg 40 mm Hg 90 mm Hg

Answer 268

A) Normal resting state B) Aortic regurgitation C) Myocardial failure Answer: 1 - C) Myocardial failure 2 - A) Normal resting state 3 - B) Aortic regurgitation

Question 269

Which antihypertensive agent has the shortest onset time? A) Clevidipine B) Nitroglycerin C) Nitroprusside D) Labetalol

Answer 269

Answer: C) Nitroprusside (Onset time is < 1 minute)

Question 270

What is the infusion rate range for Clevidipine? A) 0.1 – 1 mcg/kg/min B) 50 – 300 mcg/kg/min C) 0.5 – 32 mg/hr D) N/A

Answer 270

Answer: C) 0.5 – 32 mg/hr

Question 271

Which agent is a calcium-channel blocker and presented in a lipid emulsion? A) Hydralazine B) Esmolol C) Clevidipine D) Nitroprusside

Answer 271

Answer: C) Clevidipine (short acting)

Question 272

Match the duration of action to the drug: 1. 3 – 5 minutes 2. 5 – 15 minutes 3. 45 minutes – 6 hours A) Nitroglycerin B) Clevidipine C) Labetalol

Answer 272

Answer: 1 - A) Nitroglycerin- 3-5 min 2 - B) Clevidipine- 5-15min 3 - C) Labetalol. 45min - 6 hours

Question 273

Which drug should be avoided in the setting of intracerebral hemorrhage due to cerebral vasodilation? A) Hydralazine B) Nitroprusside C) Esmolol D) Labetalol

Answer 273

Answer: B) Nitroprusside (also nitro)

Question 274

Which agent affects heart rate (HR) >> blood pressure (BP)- select 2? A) Hydralazine B) Labetalol C) Esmolol D) Clevidipine

Answer 274

Answer: C) Esmolol & B) Labetalol - beta blockers

Question 275

What is the typical bolus dose for Nitroglycerin? A) 50 – 100 mcg B) 5 – 10 mg C) 10 – 50 mcg D) 10 – 20 mg

Answer 275

Answer: C) 10 – 50 mcg same for Nitroprusside, both with infusion rates of 0.1-1mcg/kg/min

Question 276

Which agent is primarily an arterial vasodilator and carries a risk for cyanide toxicity? A) Hydralazine B) Nitroprusside C) Nitroglycerin D) Clevidipine

Answer 276

Answer: B) Nitroprusside

Question 277

Match the antihypertensive drug to its pharmacologic category: 1. Beta-blocker 2. Calcium-channel blocker 3. Venous > arterial dilator A) Labetalol B) Clevidipine C) Nitroglycerin

Answer 277

Answer: 1 - A) Labetalol 2 - B) Clevidipine 3 - C) Nitroglycerin

Question 278

Which long-acting vasodilator has less predictable pharmacokinetics and pharmacodynamics? A) Hydralazine B) Labetalol C) Clevidipine D) Esmolol

Answer 278

Answer: A) Hydralazine duration = 2-6 hrs

Question 279

What is the infusion rate range for Nitroprusside? A) 0.5 – 32 mg/hr B) 50 – 300 mcg/kg/min C) 0.1 – 1 mcg/kg/min D) 0.5 – 1 mg/hr

Answer 279

Answer: C) 0.1 – 1 mcg/kg/min all the dosing is identical to Nitroglycerin.. only difference is that Nitroprusside has a faster onset and longer duration of action.. 1-10 min as opposed to 3-5 min.

Question 280

Which drug has a peak effect time of 10 – 15 minutes and a duration of action of 45 minutes – 6 hours? A) Labetalol B) Clevidipine C) Nitroglycerin D) Nitroprusside

Answer 280

Answer: A) Labetalol dosed at 5-10mg

Question 281

Which drug should be avoided in cases of severe cerebral vasodilation, such as intracranial hemorrhage? A) Clevidipine B) Nitroprusside C) Esmolol D) Hydralazine

Answer 281

Answer: B) Nitroprusside

Question 282

Which antihypertensive agent has the fastest onset of action and is commonly used for rapid arterial and venous vasodilation? A) Clevidipine B) Esmolol C) Nitroprusside D) Hydralazine

Answer 282

Answer: C) Nitroprusside Rationale: Nitroprusside has an onset of action of less than 1 minute, making it the fastest-acting agent. It is used for rapid control of blood pressure via balanced arterial and venous vasodilation.

Question 283

What is the initial bolus dose and infusion rate range for Clevidipine? A) 50 – 100 mcg bolus; 0.5 – 32 mg/hr infusion B) 10 – 50 mcg bolus; 0.1 – 1 mcg/kg/min infusion C) 5 – 10 mg bolus; no infusion rate D) 5 mg bolus; 50 – 300 mcg/kg/min infusion

Answer 283

Answer: A) 50 – 100 mcg bolus; 0.5 – 32 mg/hr infusion Rationale: Clevidipine is a calcium-channel blocker delivered as an emulsion, with a typical bolus dose of 50 – 100 mcg and an infusion rate range of 0.5 – 32 mg/hr.

Question 284

Which drug has a duration of action of 2–6 hours but an unpredictable pharmacodynamic profile? A) Labetalol B) Esmolol C) Hydralazine D) Nitroglycerin

Answer 284

Answer: C) Hydralazine Rationale: Hydralazine is a long-acting vasodilator with a duration of action lasting 2–6 hours, but its unpredictable effects make it less ideal for intraoperative emergencies.

Question 285

Match the infusion rate range with the correct drug arrangement: 0.1 – 1 mcg/kg/min, 50 – 300 mcg/kg/min, 0.5 – 32 mg/hr A) Clevidipine, Esmolol, Nitroprusside B) Nitroprusside, Esmolol, Clevidipine C) Clevidipine, Nitroprusside, Esmolol D) Nitroprusside, Clevidipine, Esmolol

Answer 285

Answer: B) Nitroprusside, Esmolol, Clevidipine Rationale: Nitroprusside: 0.1 – 1 mcg/kg/min Esmolol: 50 – 300 mcg/kg/min Clevidipine: 0.5 – 32 mg/hr

Question 286

What is the typical onset of Labetalol compared to Esmolol? A) Labetalol is faster B) Esmolol is faster C) Both have the same onset D) Labetalol has no bolus onset

Answer 286

Answer: B) Esmolol is faster - dosed at 10-20mg. Rationale: Esmolol has an onset of 1 minute, while Labetalol typically takes 2–5 minutes to begin effect - dosed at 5- 10mg.

Question 287

Why might most vasoactive drugs fail to work effectively in a patient with hypocalcemia? A. Hypocalcemia reduces adrenergic receptor sensitivity. B. Hypocalcemia decreases intracellular calcium necessary for vascular smooth muscle contraction. C. Hypocalcemia increases vascular smooth muscle tone, making drugs ineffective. D. Hypocalcemia impairs neurotransmitter release at the neuromuscular junction.

Answer 287

Correct Answer: B. Hypocalcemia decreases intracellular calcium necessary for vascular smooth muscle contraction. Rationale: Hypocalcemia limits the availability of intracellular calcium, which is essential for vascular smooth muscle contraction and cardiac myocyte function. Vasoactive drugs rely on calcium-mediated pathways to exert their effects. Without adequate calcium, these processes are impaired.

Question 288

Which of the following vasoactive agents might remain effective in a hypocalcemic patient due to its mechanism of action? A. Epinephrine B. Norepinephrine C. Phenylephrine D. Vasopressin

Answer 288

Correct Answer: D. Vasopressin Rationale: Vasopressin acts through V1 receptors to induce vasoconstriction, which is independent of calcium-mediated signaling pathways. In contrast, drugs like epinephrine, norepinephrine, and phenylephrine rely on calcium-dependent mechanisms for their vasoconstrictive effects, making them less effective in hypocalcemia.

Question 289

What is the most appropriate initial step in managing refractory hypotension in a hypocalcemic patient? A. Increase the dose of norepinephrine. B. Administer calcium gluconate or calcium chloride. C. Switch to a high-dose dopamine infusion. D. Administer magnesium sulfate to enhance calcium reuptake.

Answer 289

Correct Answer: B. Administer calcium gluconate or calcium chloride. Rationale: The underlying problem in hypocalcemia is a deficiency of available calcium for essential physiological processes. Administering calcium gluconate or calcium chloride corrects the hypocalcemia, thereby restoring intracellular calcium levels and improving the effectiveness of vasoactive drugs. Increasing drug doses or using other agents will not resolve the underlying calcium deficit.

Question 290

What is a critical management step for hypotension caused by high spinal anesthesia during pregnancy? A) Administer protamine B) Increase vasodilator infusion rate C) Ensure left uterine displacement D) Perform immediate surgery

Answer 290

Answer: C) Ensure left uterine displacement Also, volume loading

Question 291

Why can anticholinesterase medications cause hypotension during anesthesia? A) They block nicotinic acetylcholine receptors, leading to muscle relaxation and decreased cardiac output. B) They increase acetylcholine levels, leading to bradycardia and peripheral vasodilation. C) They inhibit parasympathetic activity, causing a sudden drop in systemic vascular resistance. D) They decrease acetylcholine levels, leading to impaired sympathetic nervous system function.

Answer 291

Answer: B) They increase acetylcholine levels, leading to bradycardia and peripheral vasodilation. Rationale: Anticholinesterases, such as neostigmine, inhibit acetylcholinesterase, increasing acetylcholine levels at parasympathetic synapses. This overstimulates muscarinic receptors, leading to bradycardia (reduced heart rate) and peripheral vasodilation, both of which can contribute to hypotension.

Question 292

What is the primary goal of temporizing measures in intraoperative hypotension? A) Cure the underlying cause B) Maintain blood pressure using short-acting drugs C) Treat hypovolemia with crystalloids D) Reduce acidosis with bicarbonate

Answer 292

Answer: B) Maintain blood pressure using short-acting drugs Turn down (sometimes turn off) the anesthetic—give versed if indicated

Question 293

What is the role of glycopyrrolate in treating hypotension? A) Vasoconstriction B) Positive inotropy C) Heart rate control D) Correcting metabolic acidosis

Answer 293

Answer: C) Heart rate control, also atropine

Question 294

If hypovolemia is suspected as the cause of hypotension, what is the recommended action? A) Increase PEEP to improve venous return B) Replace volume with crystalloids, colloids, or blood C) Administer vasoconstrictors like phenylephrine D) Use atropine to control heart rate

Answer 294

Answer: B) Replace volume with crystalloids, colloids, or blood

Question 295

Q5: Reducing PEEP during hypotension improves which of the following? A) Cardiac output by enhancing venous return B) Systemic vascular resistance (SVR) C) Metabolic acidosis D) Inspiratory-to-expiratory ratio

Answer 295

Answer: A) Cardiac output by enhancing venous return

Question 296

Why is it important to address acidosis or hypocalcemia in patients with hypotension? A) Acidosis increases the risk of vasodilation B) Hypocalcemia directly lowers systemic vascular resistance C) Most vasoactive drugs are less effective in acidotic or hypocalcemic states D) Both conditions increase fluid retention

Answer 296

Answer: C) Most vasoactive drugs are less effective in acidotic or hypocalcemic states

Question 297

Besides reducing PEEP, which of the following changes in ventilatory parameters can help manage intraoperative hypotension? A) Increase inspiratory time B) Increase expiratory time C) Increase tidal volume (Vt) D) Decrease respiratory rate E) Decrease FiO₂

Answer 297

Answer: B) Increase expiratory time Rationale: Increasing expiratory time (or decreasing inspiratory time) reduces intrathoracic pressure during exhalation, promoting improved venous return and cardiac output, which can help manage hypotension. Other changes, such as increasing tidal volume or decreasing respiratory rate, may not directly address hypotension and could potentially worsen the situation. Adjusting FiO₂ has no significant effect on hypotension.

Question 298

Which pressor/inotrope has the longest duration of action? A) Phenylephrine B) Vasopressin C) Ephedrine D) Norepinephrine E) Epinephrine

Answer 298

Answer: C) Ephedrine Rationale: Ephedrine has a duration of action of approximately 60 minutes, making it the longest-acting option among the listed agents. Phenylephrine lasts 10–15 minutes, vasopressin lasts 30–60 minutes, norepinephrine lasts 1–2 minutes, and epinephrine lasts less than 5 minutes. This extended duration makes ephedrine particularly useful in settings where a prolonged effect is desired without continuous infusion.

Question 299

Which pressor has the shortest duration of action? A) Ephedrine B) Phenylephrine C) Epinephrine D) Vasopressin

Answer 299

Answer: C) Epinephrine also norepinephrine is really short.. like 1-2 min, usually use both as a drip. both have the same infusion rates at 0.02-0.3 mcg/kg/min These rates can be higher with max around 2 if refractory shock.

Question 300

What is the infusion rate range for norepinephrine? A) 0.2–2 mcg/kg/min B) 0.02–0.3 mcg/kg/min C) 0.01–0.04 units/min D) 50–300 mcg/kg/min

Answer 300

Answer: B) 0.02–0.3 mcg/kg/min

Question 301

Which drug has an onset time of 1–2 minutes? A) Ephedrine B) Phenylephrine C) Norepinephrine D) Epinephrine

Answer 301

Answer: A) Ephedrine all the other drugs are less than 1 min.. Key takeaway is that all our vasoactive meds work really fast, including vasopressin.

Question 302

What is the bolus dose range for phenylephrine? A) 5–10 mcg B) 0.5–1 unit C) 50–100 mcg D) 10–50 mcg

Answer 302

Answer: C) 50–100 mcg

Question 303

Which pressor peaks in 1 minute but has a duration of 30–60 minutes? A) Vasopressin B) Norepinephrine C) Phenylephrine D) Ephedrine

Answer 303

Answer: A) Vasopressin Ephedrine is more around 60min. Norepi- 1-2 min Phenylephrine: 10 -15 min

Question 304

What is the time to peak for norepinephrine? A) <1 minute B) 1 minute C) 2 minutes D) 5 minutes

Answer 304

Answer: B) 1 minute onset is less than 1 min. Ephedrine peaks at 2-5 min.. everything else is less time.. so Ephedrine is the slowest and last the longest.

Question 305

Which drug's infusion rate is measured in units/min? A) Phenylephrine B) Vasopressin C) Norepinephrine D) Epinephrine

Answer 305

Answer: B) Vasopressin 0.01 – 0.04 units/min (at my hospital just ran it at 0.03, no titration).

Question 306

What is the duration of action for phenylephrine? A) 10–15 minutes B) <5 minutes C) 1–2 minutes D) 30–60 minutes

Answer 306

Answer: A) 10–15 minutes

Question 307

Which pressor is administered at an infusion rate of 0.2–2 mcg/kg/min? A) Norepinephrine B) Phenylephrine C) Vasopressin D) Epinephrine

Answer 307

Answer: B) Phenylephrine epi and norepi are both around 0.02- 0.3 mcg/kg/min

Question 308

What is the bolus dose range for vasopressin? A) 5–10 mcg B) 0.5–1 unit C) 50–100 mcg D) 10–20 mg

Answer 308

Answer: B) 0.5–1 unit

Question 309

Which 3 pressors have a bolus dose of 5-10mcg? A) Norepinephrine B) Vasopressin C) Phenylephrine D) Epinephrine

Answer 309

Answer: A) Norepinephrine & D) Epinephrine

Question 310

Which pressor has a duration of action of 1–2 minutes? A) Norepinephrine B) Vasopressin C) Phenylephrine D) Epinephrine

Answer 310

Answer: A) Norepinephrine norepi @ 1-2 min.. phelyephrine is 10 -15 min and vasopressin: 30 -60 min

Question 311

What is the bolus dose range for ephedrine? A) 5–10 mcg B) 50–100 mcg C) 5–10 mg D) 0.5–1 unit

Answer 311

Answer: C) 5–10 mg Max dose of 50mg total - may repeat dose q 5-10 min

Question 312

Which pressors has an infusion range of 0.02–0.3 mcg/kg/min? A) Epinephrine B) Phenylephrine C) Norepinephrine D) Vasopressin

Answer 312

Answer: A) Epinephrine & C) Norepinephrine

Question 313

Which vasopressor primarily increases systemic vascular resistance (SVR) with minimal effect on cardiac output (CO)? A) Norepinephrine B) Dobutamine C) Phenylephrine D) Dopamine (1–3 mcg/kg/min)

Answer 313

Answer: C) Phenylephrine - alpha 1

Question 314

What is the predominant receptor effect of norepinephrine? A) Alpha-1 agonist B) Beta-1 agonist C) Beta-2 agonist D) Dopamine receptor agonist

Answer 314

Answer: A) Alpha-1 agonist .. more alpha 1 than beta 1 agonism.. variable CO changes.

Question 315

Which vasopressor has a dose-dependent receptor effect, switching from dopamine receptors to alpha-1 receptors at higher doses? A) Dopamine B) Epinephrine C) Norepinephrine D) Phenylephrine

Answer 315

Answer: A) Dopamine

Question 316

Which inotrope increases cardiac output (CO) while decreasing SVR? A) Norepinephrine B) Dobutamine C) Phenylephrine D) Epinephrine

Answer 316

Answer: B) Dobutamine

Question 317

What is the effect of low-dose epinephrine (1–2 mcg/min) on SVR and CO? A) ↑ SVR, ↓ CO B) ↓ SVR, ↑ CO C) ↑ SVR, ↑ CO D) ↓ SVR, ↓ CO

Answer 317

Answer: B) ↓ SVR, ↑ CO

Question 318

Which vasopressor exhibits only alpha-1 receptor agonism? A) Epinephrine B) Phenylephrine C) Norepinephrine D) Dopamine

Answer 318

Answer: B) Phenylephrine

Question 319

What receptor activity does dopamine primarily exhibit at 1–3 mcg/kg/min? A) Alpha-1 agonism B) Beta-1 agonism C) Dopamine receptor agonism D) Beta-2 agonism

Answer 319

Answer: C) Dopamine receptor agonism. (renal dose)

Question 320

Which drug has a balanced effect on both alpha-1 and beta-1 receptors, increasing both SVR and CO? A) Norepinephrine B) Phenylephrine C) Dopamine D) Epinephrine

Answer 320

Answer: D) Epinephrine - as long as it is not low dose.

Question 321

Which inotrope has negligible alpha-1 receptor activity but significant beta-1 activity? A) Epinephrine B) Dobutamine C) Phenylephrine D) Norepinephrine

Answer 321

Answer: B) Dobutamine Decreases SVR by Beta-2 stimulation which dilates blood vessels.

Question 322

A 56-year-old patient with a history of liver disease and osteomyelitis is anesthetized for tibial debridement. After induction and intubation, the wound is inspected and debrided with a total blood loss of 300 mL. The patient is transported intubated to the recovery room, at which time the systolic blood pressure falls to 50 mm Hg. HR is 120 bpm, ABG reads 7.3/45/103, with SpO2 97% on 100% FiO2. VBG reads 7.25/50/60. Which of the following diagnoses is MOST consistent with this clinical picture? a. Hypovolemia b. CHF c. Cardiac tamponade d. SepsiswithARDS

Answer 322

Answer: d. The patient has an abnormally high mixed venous PO2 (50, versus a normal value of 40). This is consistent with a high cardiac output state, such as sepsis.

Question 323

What is the primary mechanism of action for succinylcholine? A) Inhibition of acetylcholinesterase B) Prolonged muscle depolarization via nAChR agonism C) Competitive inhibition of nicotinic acetylcholine receptors D) Release of acetylcholine into the synaptic cleft

Answer 323

Answer: B) Prolonged muscle depolarization via nAChR agonism

Question 324

What is the typical onset time for succinylcholine after administration? A) 10–15 seconds B) 30–60 seconds C) 1–2 minutes D) 5 minutes

Answer 324

Answer: B) 30–60 seconds

Question 325

Which enzyme metabolizes succinylcholine in the plasma? A) Acetylcholinesterase B) Pseudocholinesterase C) Butyrylcholinesterase D) Both B and C

Answer 325

Answer: D) Both B and C

Question 326

What is the normal dibucaine number in a patient without pseudocholinesterase deficiency? A) 10 B) 20 C) 80 D) 50

Answer 326

Answer: C) 80

Question 327

What is the expected duration of paralysis in a homozygous patient with pseudocholinesterase deficiency after receiving succinylcholine? A) 1–3 minutes B) 5–10 minutes C) 4–8 hours D) 24 hours

Answer 327

Answer: C) 4–8 hours

Question 328

What percentage of normal pseudocholinesterase activity is inhibited by dibucaine in a heterozygous patient? A) 10% B) 20% C) 50–60% D) 80%

Answer 328

Answer: C) 50–60%

Question 329

Which of the following is a contraindication for succinylcholine use? A) Malignant hyperthermia susceptibility B) Hyperkalemia C) Prolonged immobility D) All of the above

Answer 329

Answer: D) All of the above

Question 330

What is the primary ion movement when acetylcholine binds to nicotinic receptors during neuromuscular transmission? A) Na+ efflux and K+ influx B) Na+ and Ca++ influx, K+ efflux C) K+ and Cl– influx D) Only Na+ influx

Answer 330

Answer: B) Na+ and Ca++ influx, K+ efflux

Question 331

What is the most common cause of intraoperative anaphylaxis? A) Antibiotics B) Neuromuscular blocking agents (NMBAs) C) Latex D) Local anesthetics

Answer 331

Answer: B) Neuromuscular blocking agents (NMBAs) Rationale: NMBAs are implicated in >50% of intraoperative anaphylaxis cases due to their high potential for cross-reactivity.

Question 332

What is the initial epinephrine dose for mild to moderate hypotension during anaphylaxis in adults? A) 10-50 mcg IV B) 0.5-1 mg IV C) 1-16 mcg/min infusion D) 10 mcg/kg IV

Answer 332

Answer: A) 10-50 mcg IV dilute 1mg in 100mL NS

Question 333

For cardiovascular collapse during anaphylaxis, what is the recommended epinephrine IV bolus dose? A) 1-10 mcg B) 10-50 mcg C) 0.5-1 mg D) 10 mcg/kg

Answer 333

Answer: C) 0.5-1 mg

Question 334

What is the infusion rate range for epinephrine during anaphylaxis? A) 0.1-1 mcg/kg/min B) 1-16 mcg/min C) 50-300 mcg/min D) 0.2-2 mcg/kg/min

Answer 334

Answer: B) 1-16 mcg/min Just hang the bag of 1mg in 100mL NS and let it drip, titrate to effect (BP)

Question 335

blood pressure in anaphylaxis? A) Norepinephrine B) Vasopressin C) Methylene Blue D) All of the above

Answer 335

Answer: D) All of the above

Question 336

What is the recommended initial dose of vasopressin for anaphylaxis? A) 0.5-1 unit B) 1-2 units C) 10-40 units D) 1-16 units

Answer 336

Answer: B) 1-2 units If refractory to Epi than give 10-40 units.

Question 337

What is the role of glucagon in the treatment of anaphylaxis? A) Reverse bronchospasm B) Treat beta-blocker-induced poor response to epinephrine C) Manage refractory hypotension D) Stabilize mast cells

Answer 337

Answer: B) Treat beta-blocker-induced poor response to epinephrine Give 1-5mg IV

Question 338

Which corticosteroid dose is appropriate for anaphylaxis treatment in adults? A) Dexamethasone 20 mg IV B) Hydrocortisone 100-200 mg IV C) Methylprednisolone 100 mg IV D) All of the above

Answer 338

Answer: D) All of the above

Question 339

What is the pediatric epinephrine IM dose for anaphylaxis? A) 10 mcg/kg IM B) 0.01 mg/kg IM C) 1-10 mcg IM D) 0.1 mg/kg IM

Answer 339

Answer: B) 0.01 mg/kg or 10mcg/kg IM (Lateral thigh) Repeat every 5-15 min if refractory

Question 340

How should albuterol be administered during bronchospasm caused by anaphylaxis? A) 2.5 mg via aerosol device B) 4-10 puffs MDI C) Either A or B D) None of the above

Answer 340

Answer: C) Either A or B

Question 341

Which histamine antagonists are used during anaphylaxis? A) Diphenhydramine 50 mg IV B) Famotidine 20 mg IV C) Both A and B D) Neither

Answer 341

Answer: C) Both A and B

Question 342

What is the dose of methylene blue for refractory anaphylaxis? A) 1-2 mg IV B) 10-50 mg IV C) 0.01 mg/kg IV D) 5-10 mg IV

Answer 342

Answer: B) 10-50 mg IV

Question 343

Which of the following fluids is typically given to expand circulating volume during anaphylaxis? A) Colloids B) Crystalloids C) Albumin D) Blood products

Answer 343

Answer: B) Crystalloids

Question 344

What mast cell tryptase level indicates mast cell activation during anaphylaxis? A) ≥5 ng/ml B) ≥7.5 ng/ml C) ≥11.5 ng/ml D) ≥20 ng/ml

Answer 344

Answer: C) ≥11.5 ng/ml repeat Q4 after anaphylaxis as severe reactions can happen again.. monitor for 24 hours.

Question 345

What is the appropriate dose of hydrocortisone for pediatric anaphylaxis? A) 1-2 mg/kg B) 5 mg/kg C) 10 mg/kg D) 20 mg/kg

Answer 345

Answer: A) 1-2 mg/kg

Question 346

Which of the following conditions is a contraindication for the use of succinylcholine due to the risk of hyperkalemia? A. Hypertension B. Guillain-Barré Syndrome (GBS) C. Hypovolemia D. Chronic kidney disease with normal potassium levels

Answer 346

Answer: B. Guillain-Barré Syndrome (GBS)

Question 347

Why is Guillain-Barré Syndrome (GBS) a contraindication for the use of succinylcholine? A. It increases intracranial pressure. B. It causes malignant hyperthermia. C. It leads to upregulation of acetylcholine receptors, increasing the risk of hyperkalemia. D. It has a prolonged metabolism by pseudocholinesterase.

Answer 347

Answer: C. It leads to upregulation of acetylcholine receptors, increasing the risk of hyperkalemia.

Question 348

Which of the following is a contraindication for succinylcholine administration? A. Hyperkalemia B. Normokalemic end-stage renal disease (ESRD) C. History of malignant hyperthermia D. Both A and C

Answer 348

Answer: D. Both A and C

Question 349

What dose of rocuronium is recommended for a defasciculating dose before succinylcholine administration? A. 0.03 mg/kg B. 0.3 mg/kg C. 0.05 mg/kg D. 0.3 mg

Answer 349

Answer: A. 0.03 mg/kg give propofol first.. then this shit and wait 2-3 min.. the dose of succs would now be 1.5-2mg/kg bc you gave this.

Question 350

Which of the following is NOT a common side effect of succinylcholine? A. Increased intraocular pressure (IOP) B. Decreased intracranial pressure (ICP) C. Fasciculations D. Myalgia

Answer 350

Answer: B. Decreased intracranial pressure (ICP)

Question 351

Which structural class of nondepolarizing NMBAs is most likely to cause histamine release? A. Aminosteroids (e.g., Rocuronium) B. Benzylisoquinolinium (e.g., Atracurium) C. Both A and B D. None of the above

Answer 351

Answer: B. Benzylisoquinolinium (e.g., Atracurium) - not cisatricurium tho

Question 352

What is the mechanism of action for nondepolarizing neuromuscular blocking agents? A. Inhibition of acetylcholinesterase B. Competitive inhibition of nAChR C. Direct binding to acetylcholine D. Irreversible inhibition of presynaptic nAChR

Answer 352

Answer: B. Competitive inhibition of nAChR

Question 353

Which NMBA has the highest vagolytic effects? A. Pancuronium B. Vecuronium C. Rocuronium D. Cisatracurium

Answer 353

Answer: A. Pancuronium Vagolytic effects (Pancuronium > Rocuronium > Vecuronium)

Question 354

Which nondepolarizing NMBA is most commonly used for intermediate duration? A. Rocuronium B. Pancuronium C. Atracurium D. d-Tubocurarine

Answer 354

Answer: A. Rocuronium

Question 355

Which condition can increase the risk of hyperkalemia with succinylcholine administration? A. Burn injury greater than 24 hours old B. Recent spinal cord injury C. Multiple sclerosis (MS) D. All of the above

Answer 355

Answer: D. All of the above

Question 356

Why is succinylcholine contraindicated in patients with open globe injuries? A. It increases intraocular pressure (IOP). B. It reduces intraocular pressure (IOP). C. It causes bradycardia. D. It increases intracranial pressure (ICP).

Answer 356

Answer: A. It increases intraocular pressure (IOP).

Question 357

What is the typical intra-operative maintenance dose for vecuronium? Options: A. 0.1-0.2 mg/kg PRN B. 0.01-0.02 mg/kg PRN C. 0.3 mg/kg q20min D. 1.2 mg/kg

Answer 357

Correct Answer: B. 0.01-0.02 mg/kg PRN Rationale: Vecuronium is maintained intra-operatively with doses of 0.01-0.02 mg/kg as needed.

Question 358

Which muscle relaxant is primarily metabolized by Hoffman elimination? Options: A. Succinylcholine B. Rocuronium C. Vecuronium D. Cisatracurium

Answer 358

Correct Answer: D. Cisatracurium Rationale: Cisatracurium undergoes Hoffman elimination, making it independent of liver or kidney function for metabolism.

Question 359

What is the recommended intra-operative maintenance dose for cisatracurium? Options: A. 0.1-0.2 mg/kg PRN B. 0.3 mg/kg q20min PRN C. 1 mg/kg PRN D. 0.01-0.02 mg/kg PRN

Answer 359

Correct Answer: B. 0.3 mg/kg q20min PRN Rationale: Cisatracurium is maintained intra-operatively with a dose of 0.3 mg/kg every 20 minutes as needed. Or infusion

Question 360

What is the onset time for vecuronium when used for intubation? Options: A. 1-1.5 minutes B. 1.5-2 minutes C. 3-4 minutes D. 5-7 minutes

Answer 360

Correct Answer: C. 3-4 minutes Rationale: The onset time for vecuronium is 3-4 minutes, making it slower than rocuronium or succinylcholine.

Question 361

Which statement is correct regarding the priming dose for nondepolarizing NMBAs? Options: A. It is 10% of the intubating dose given 3-5 minutes prior to induction. B. It is 20% of the intubating dose given immediately before induction. C. It is 50% of the intubating dose given during induction. D. It is not used due to high variability in efficacy.

Answer 361

Correct Answer: A. It is 10% of the intubating dose given 3-5 minutes prior to induction. Rationale: The priming dose is 10% of the intubating dose given 3-5 minutes prior to speed up the onset of nondepolarizing NMBAs.

Question 362

What percentage of rocuronium is metabolized in the liver? Options: A. >70% B. 50% C. None; it is eliminated by Hoffman elimination. D. Variable based on patient renal function.

Answer 362

Correct Answer: A. >70% Rationale: Rocuronium is predominantly metabolized by the liver (>70%), with the remainder excreted in bile and urine.

Question 363

Which nondepolarizing NMBA has the longest duration to 25% recovery after intubation? Options: A. Rocuronium RSI dose B. Vecuronium C. Cisatracurium D. Succinylcholine

Answer 363

Correct Answer: A. Rocuronium RSI dose Rationale: Rocuronium RSI dose has a duration of >60 minutes to 25% recovery, making it longer than vecuronium or cisatracurium which are around 35-45 min. A normal dose of Roc would last 30-40 min to 25% recovery

Question 364

Which TOF ratio is considered a sign of full recovery from neuromuscular blockade? Options: A. 0.4 B. 0.6 C. 0.9 D. 1.0

Answer 364

Correct Answer: C. 0.9 Rationale: A TOF ratio of 0.9 indicates full recovery, typically assessed with an accelerometer, ensuring safe extubation. Or 5 seconds sustained tetany at 50-100 Hz without fade – TOF ratio = height of 4th compared to 1st

Question 365

What is a key feature of Phase I block with succinylcholine? Options: A. Presence of fade on TOF monitoring B. Antagonism by neostigmine C. Constant but diminished response on TOF D. Augmentation by administration of rocuronium

Answer 365

Correct Answer: C. Constant but diminished response on TOF Rationale: Phase I block produces a constant but diminished response on TOF, with no fade observed.

Question 366

Which factor differentiates Phase II block from Phase I block? Options: A. Sustained tetanic response B. Absence of post-tetanic fade C. Augmentation by neostigmine D. Presence of fade on TOF and tetany

Answer 366

Correct Answer: D. Presence of fade on TOF and tetany Rationale: Phase II block shows fade on both TOF and tetanic stimulation, similar to non-depolarizing blocks.

Question 367

What happens to the TOF ratio during a Phase II block with succinylcholine? Options: A. Increases to >0.7 B. Decreases to <0.3 C. Remains constant at 0.9 D. Becomes indistinguishable from a Phase I block

Answer 367

Correct Answer: B. Decreases to <0.3 Rationale: In a Phase II block, the TOF ratio falls below 0.3, indicating desensitization of acetylcholine receptors. The height of the 4th twitch is less than 30% of the 1st. apparently.. Can’t distinguish TOF ratio >0.4

Question 368

What is the appropriate response to tetanus in a Phase I block caused by succinylcholine? Options: A. Sustained response B. Unsustained response C. Absent response D. Post-tetanic potentiation

Answer 368

Correct Answer: A. Sustained response Rationale: Phase I block is characterized by a sustained response to tetanus, distinguishing it from Phase II block.

Question 369

How does neostigmine affect a Phase II block from succinylcholine? Options: A. Augments the block B. Antagonizes the block C. Has no effect on the block D. Converts it to a Phase I block

Answer 369

Correct Answer: B. Antagonizes the block Rationale: Neostigmine antagonizes a Phase II block if there is a low concentration of succinylcholine left.

Question 370

What is the TOF count indicative of 80-85% acetylcholine receptor blockade? Options: A. 0 twitches B. 1-2 twitches C. 3 twitches D. 4 twitches

Answer 370

Correct Answer: B. 1-2 twitches Rationale: A TOF count of 2 twitches corresponds to 80-85% receptor blockade, with partial paralysis. 1 twitch is 85-90 and 0 twitches is 90-98%

Question 371

Which drug antagonizes succinylcholine-induced Phase II block? Options: A. Rocuronium B. Succinylcholine C. Neostigmine D. Cisatracurium

Answer 371

Correct Answer: C. Neostigmine Rationale: Neostigmine can reverse Phase II blocks by restoring acetylcholine levels to compete with succinylcholine.

Question 372

What is the effect of administering rocuronium during a Phase I block caused by succinylcholine? Options: A. Augments the block B. Antagonizes the block C. Converts it to a Phase II block D. Has no effect on the block

Answer 372

Correct Answer: B. Antagonizes the block Rationale: Rocuronium, a non-depolarizing NMBA, competes with acetylcholine for the same receptor sites. In a Phase I block, succinylcholine is already depolarizing the receptors. Adding rocuronium can antagonize the Phase I block by competitively inhibiting succinylcholine’s binding, as it reduces depolarization at the receptor level.

Question 373

What is the primary muscle to monitor for deep blockade during intraoperative neuromuscular blockade monitoring? A) Adductor pollicis B) Corrugator supercilii C) Diaphragm D) Orbicularis oculi

Answer 373

Answer: B) Corrugator supercilii Rationale: The corrugator supercilii is monitored to assess deep blockade (e.g., diaphragmatic movement intraoperatively), as it closely correlates with diaphragm function.

Question 374

Which muscle is recommended for monitoring the return of function during neuromuscular blockade recovery? A) Adductor pollicis B) Corrugator supercilii C) Diaphragm D) Geniohyoid

Answer 374

Answer: A) Adductor pollicis Rationale: The adductor pollicis is used to assess readiness for extubation because it reflects pharyngeal muscle function.

Question 375

What is the recommended dose of neostigmine for neuromuscular blockade reversal when sufficient spontaneous recovery has occurred? A) 10-20 mcg/kg B) 15-20 mcg/kg C) 40-50 mcg/kg D) >70 mcg/kg

Answer 375

Answer: C) 40-50 mcg/kg Rationale: A dose of 40-50 mcg/kg of neostigmine is commonly appropriate for reversal (2 twitches). Lower doses (15-20 mcg/kg) may be sufficient if full recovery is evident with four equal twitches. If give too early, before 2 twitches can paradoxically prolong the block.

Question 376

Why must anticholinesterase inhibitors like neostigmine not be given until spontaneous recovery has started? A) They cause prolonged bradycardia. B) They slow recovery paradoxically if given too early. C) They do not work if no recovery is present. D) They only reverse competitive inhibition at acetylcholinesterase.

Answer 376

Answer: B) They slow recovery paradoxically if given too early. Rationale: Administering neostigmine too early can paradoxically slow recovery due to insufficient spontaneous recovery of the neuromuscular junction.

Question 377

When using glycopyrrolate alongside neostigmine, what is the recommended ratio of glycopyrrolate to neostigmine? A) 1:1 B) 1:2 C) 1:3 D) 1:5

Answer 377

Answer: D) 1:5 Rationale: The dose of glycopyrrolate is typically 1/5th of the neostigmine dose (e.g., 3 mg neostigmine with 0.6 mg glycopyrrolate) to prevent muscarinic side effects like bradycardia. or 0.2mg of Glycopyrrrolate per mg of Neostigmine for easier math (1/5th).

Question 378

Which nondepolarizing NMBA has an active metabolite almost as potent as the parent drug, potentially prolonging blockade in renal failure? A) Atracurium B) Cisatracurium C) Vecuronium D) Pancuronium

Answer 378

Answer: C) Vecuronium Rationale: Vecuronium has an active metabolite that can accumulate in renal failure, causing prolonged blockade.

Question 379

Which NMBA undergoes no clinically significant metabolism and is cleared primarily by the liver via bile excretion? A) Rocuronium B) Cisatracurium C) Atracurium D) Vecuronium

Answer 379

Answer: A) Rocuronium Rationale: Rocuronium is cleared through bile excretion with no significant metabolism.

Question 380

Which NMBA is metabolized by Hofmann elimination and non-specific ester hydrolysis? A) Atracurium B) Vecuronium C) Pancuronium D) Rocuronium

Answer 380

Answer: A) Atracurium Rationale: Atracurium and cisatracurium are both metabolized via Hofmann elimination and non-specific ester hydrolysis.

Question 381

Which NMBA has a metabolite, laudanosine, that can cause neuroexcitation and seizures? A) Rocuronium B) Cisatracurium C) Atracurium D) Pancuronium

Answer 381

Answer: C) Atracurium Rationale: Atracurium’s metabolite, laudanosine, may cause neuroexcitation and seizures, especially in high doses.

Question 382

Which NMBA causes a sympathomimetic response by blocking acetylcholine (ACh) receptors? A) Vecuronium B) Pancuronium C) Cisatracurium D) Atracurium

Answer 382

Answer: B) Pancuronium Rationale: Pancuronium’s sympathomimetic effects are due to its action on acetylcholine receptors.

Question 383

Which acetylcholinesterase inhibitor can cross the blood-brain barrier (BBB) and treat central anticholinergic syndrome? A) Neostigmine B) Pyridostigmine C) Physostigmine D) Edrophonium

Answer 383

Answer: C) Physostigmine Rationale: Physostigmine crosses the BBB and can treat central anticholinergic syndrome and atropine toxicity.

Question 384

What is paired with edrophonium to block muscarinic side effects due to its rapid onset? A) Atropine B) Glycopyrrolate C) Physostigmine D) Pyridostigmine

Answer 384

Answer: A) Atropine Rationale: Edrophonium, with its rapid onset, is paired with atropine to block muscarinic effects.

Question 385

What is the time to full reversal of a TOF 0.5 with 40 mcg/kg of neostigmine? A) <1 minute B) ~2 minutes C) ~5 minutes D) ~10 minutes

Answer 385

Answer: C) ~5 minutes Rationale: Full reversal at a TOF 0.5 with 40 mcg/kg of neostigmine typically takes about 5 minutes.

Question 386

Which reversal agent is specifically designed for rocuronium but also works for vecuronium? A) Sugammadex B) Neostigmine C) Edrophonium D) Pyridostigmine

Answer 386

Answer: A) Sugammadex Rationale: Sugammadex is a γ-cyclodextrin that traps rocuronium and also has an affinity for vecuronium.

Question 387

What is a possible benefit of sugammadex over neostigmine during pregnancy? A) Faster onset B) Reduced placental transfer C) Lower cost D) Increased effectiveness for atracurium

Answer 387

Answer: B) Reduced placental transfer Rationale: Unlike neostigmine, sugammadex does not cross the placenta, making it a safer option during pregnancy.

Question 388

What is the recommended dose of sugammadex for "cannot intubate, cannot ventilate" situations after 1.2 mg/kg of rocuronium? A) 2 mg/kg B) 4 mg/kg C) 8 mg/kg D) 16 mg/kg

Answer 388

Answer: D) 16 mg/kg Rationale: Sugammadex at 16 mg/kg is used in emergency situations to rapidly reverse rocuronium. decreases time to full recovery, 122 min→<2 min

Question 389

Does reversal increase the risk of postoperative nausea and vomiting (PONV)? A) Yes B) No C) Only with high doses D) Only with low doses

Answer 389

Answer: B) No Rationale: A metanalysis says no (Cheng CR, 2005).

Question 390

What is the main advantage of sugammadex over neostigmine in routine reversal? A) Crosses the BBB B) Faster onset and fewer side effects C) Effective for succinylcholine reversal D) Cheaper than neostigmine

Answer 390

Answer: B) Faster onset and fewer side effects Rationale: Sugammadex has a faster onset and fewer side effects, making it increasingly popular for routine use.

Question 391

How does sugammadex work to reverse neuromuscular blockade? A) By competitive inhibition of acetylcholine receptors B) By increasing acetylcholine in the NMJ C) By directly trapping NMBAs D) By metabolizing NMBAs in the liver

Answer 391

Answer: C) By directly trapping NMBAs Rationale: Sugammadex is a γ-cyclodextrin that directly traps NMBA molecules to reverse their action.

Question 392

What is the recommended dose of sugammadex for deep reversal when there is 1 twitch OR at least a post-tetanic count of 2? A) 2 mg/kg B) 4 mg/kg C) 8 mg/kg D) 16 mg/kg

Answer 392

Answer: B) 4 mg/kg Rationale: Sugammadex is given at 4 mg/kg for deep reversal under these conditions.

Question 393

Which condition is associated with upregulation of nAChR, making patients sensitive to succinylcholine but resistant to nondepolarizing NMBA? A) Myasthenia gravis B) Spinal cord injury C) Lambert-Eaton syndrome D) Anticholinesterase poisoning

Answer 393

Answer: B) Spinal cord injury Rationale: Conditions like spinal cord injury and prolonged immobility lead to nAChR upregulation.

Question 394

Patients with myasthenia gravis show what sensitivity pattern to muscle relaxants? A) Sensitive to succinylcholine; resistant to NMBA B) Resistant to succinylcholine; sensitive to NMBA C) Resistant to both succinylcholine and NMBA D) Sensitive to both succinylcholine and NMBA

Answer 394

Answer: B) Resistant to succinylcholine; sensitive to NMBA Rationale: Myasthenia gravis causes downregulation of nAChR, leading to resistance to succinylcholine and sensitivity to nondepolarizing NMBA. Same is true for Lambert-Eaton

Question 395

Which factor enhances the block by NMBA? A) Alkalosis B) Hyperthermia C) Volatile anesthetics D) Hypocalcemia

Answer 395

Answer: C) Volatile anesthetics Rationale: Volatile anesthetics potentiate the block by NMBA, along with other factors like hypokalemia and acidosis.

Question 396

In patients using hormonal contraceptives, what is the recommendation after receiving sugammadex? A) No additional action is needed. B) Use an additional non-hormonal contraceptive for 7 days. C) Stop using hormonal contraceptives immediately. D) Hormonal contraceptives remain fully effective.

Answer 396

Answer: B) Use an additional non-hormonal contraceptive for 7 days. Rationale: Sugammadex can interfere with the effectiveness of hormonal contraceptives, requiring additional non-hormonal methods for 7 days.

Question 397

Which clinical condition is a contraindication or caution for sugammadex administration? A) Severe liver dysfunction B) Severe renal insufficiency or dialysis C) Myasthenia gravis D) Spinal cord injury

Answer 397

Answer: B) Severe renal insufficiency or dialysis Rationale: Sugammadex is not recommended for patients with severe renal insufficiency due to potential risks.

Question 398

What coagulation effects are associated with sugammadex administration? A) Decreased PTT and PT B) Increased PTT and PT (~25%) C) Increased risk of coagulopathy D) No changes in PTT or PT

Answer 398

Answer: B) Increased PTT and PT (~25%) Rationale: Sugammadex can prolong PTT and PT by ~25% for up to 60 minutes but does not cause clinical coagulation issues.

Question 399

Which medication may precipitate when administered with sugammadex? A) Ondansetron B) Propofol C) Lidocaine D) Fentanyl

Answer 399

Answer: A) Ondansetron Rationale: Sugammadex can precipitate when combined with ondansetron, verapamil, or ranitidine.

Question 400

For which type of surgeries should NMBA be avoided due to the need for nerve monitoring? A) Abdominal surgeries B) Axillary node dissection C) Cardiac surgeries D) Orthopedic surgeries

Answer 400

Answer: B) Axillary node dissection Rationale: NMBA should be avoided in surgeries like axillary node dissection & ENT cases where nerve monitoring (e.g., NIMS tube) is required. Also when neuro monitoring is anticipated.

Question 401

Which factor does NOT enhance NMBA blockade? A) Acidosis B) Tetracycline C) Lithium D) Hyperkalemia

Answer 401

Answer: D) Hyperkalemia Rationale: Hypokalemia enhances NMBA blockade, while hyperkalemia does not.

Question 402

In patients with a stroke, succinylcholine should not be used after how many hours? A) 8 hours B) 24 hours C) 48 hours D) 72 hours

Answer 402

Answer: B) 24 hours Rationale: Succinylcholine should be avoided after 24 hours due to the risk of hyperkalemia, which can persist for months following a stroke.

Question 403

Why should succinylcholine be avoided in patients with Duchenne or Becker muscular dystrophy? A) It causes downregulation of acetylcholine receptors. B) It leads to hyperkalemic arrest due to upregulated acetylcholine receptors. C) It is ineffective due to receptor desensitization. D) It increases muscle contractility, worsening the condition.

Answer 403

Answer: B) It leads to hyperkalemic arrest due to upregulated acetylcholine receptors. Rationale: Patients with Duchenne or Becker muscular dystrophy have upregulation of acetylcholine receptors, making them highly sensitive to succinylcholine-induced hyperkalemia.

Question 404

What is a key consideration for nondepolarizing muscle relaxants (NDMR) in patients with multiple sclerosis? A) They are contraindicated in all cases. B) Use high doses to overcome resistance. C) Use small doses and monitor neuromuscular function carefully. D) NDMR are ineffective due to receptor upregulation.

Answer 404

Answer: C) Use small doses and monitor neuromuscular function carefully. Rationale: Patients with multiple sclerosis may show resistance or sensitivity to NDMRs, so careful titration and monitoring are necessary. Up-regulation of AchR's.. don't use succs.

Question 405

Which condition results in downregulation of acetylcholine receptors, making patients resistant to succinylcholine but sensitive to nondepolarizing muscle relaxants? A) Prolonged immobility B) Myasthenia gravis C) Guillain-Barré syndrome D) Burns

Answer 405

Answer: B) Myasthenia gravis Rationale: Myasthenia gravis causes downregulation of acetylcholine receptors, leading to resistance to succinylcholine and sensitivity to NDMRs.

Question 406

What is the recommended approach for using muscle relaxants in patients with prolonged immobility? A) Avoid succinylcholine after 24-48 hours due to hyperkalemia risk. B) Use standard dose of nondepolarizing relaxants. C) Succinylcholine and NDMR are equally safe in this population. D) Avoid all muscle relaxants due to receptor desensitization.

Answer 406

Answer: B) Use standard dose of nondepolarizing relaxants. Rationale: Prolonged immobility leads to receptor upregulation, significantly increasing the risk of hyperkalemia especially when immobile for > 16 days with succinylcholine.

Question 407

In which condition is succinylcholine contraindicated due to a high risk of prolonged paralysis? A) Myasthenia gravis B) Organophosphate poisoning C) Lambert-Eaton D) Multiple sclerosis

Answer 407

Answer: B) Organophosphate poisoning Rationale: Succinylcholine is degraded by plasma cholinesterase, which is inhibited in organophosphate poisoning, leading to prolonged paralysis. ( the other's can be resistant or sensitive but not necessarily contraindicated- but I wouldn't)

Question 408

What is the recommended management for Lambert-Eaton syndrome in relation to muscle relaxants? A) Succinylcholine is safe to use. B) Avoid nondepolarizing muscle relaxants. C) Use reduced doses of nondepolarizing muscle relaxants. D) Both depolarizing and nondepolarizing muscle relaxants are contraindicated.

Answer 408

Answer: C) Use reduced doses of nondepolarizing muscle relaxants. Rationale: Lambert-Eaton syndrome involves a disorder of prejunctional calcium channels, leading to sensitivity to NDMRs, requiring dose adjustments. Neo is ineffective for reversal

Question 409

How do you induce a patient with a full stomach and open globe? A) Rapid Sequence Induction (RSI) with succinylcholine and cricoid pressure B) RSI with rocuronium 1.2 mg/kg and cricoid pressure C) Maintain spontaneous ventilation with inhalational induction D) Avoid muscle relaxants altogether and use opioids for induction

Answer 409

B) RSI with rocuronium 1.2 mg/kg and cricoid pressure

Question 410

Can rocuronium be used for a renal transplant? A) No, due to its liver metabolism B) Yes, as it is primarily excreted via bile C) No, due to its active metabolite accumulation D) Yes, but at lower doses to prevent prolonged paralysis

Answer 410

Answer: B) Yes, as it is primarily excreted via bile Rationale: Rocuronium is primarily excreted via bile, making it suitable for patients with renal failure, such as those undergoing a renal transplant.

Question 411

You just gave reversal, and there is a surgical complication requiring paralysis. How do you manage this? A) Administer succinylcholine immediately B) Wait until reversal agents have worn off before re-paralyzing C) Use a higher dose of rocuronium to overcome reversal D) Switch to a depolarizing agent like succinylcholine

Answer 411

Answer: C) Use a higher dose of rocuronium to overcome reversal Rationale: Re-paralysis may require a higher dose of rocuronium or other nondepolarizing agents to overcome residual reversal agents.

Question 412

Why are repeated doses of succinylcholine associated with bradycardia? A) Due to parasympathetic stimulation from muscarinic receptor activation B) Accumulation of succinylcholine metabolites C) Increased vagal tone with cumulative doses D) It only occurs in pediatric populations

Answer 412

Answer: A) Due to parasympathetic stimulation from muscarinic receptor activation Rationale: Repeated doses of succinylcholine can stimulate muscarinic receptors, leading to bradycardia. MORE COMMON IN PEDS.

Question 413

Does a defasciculating dose of rocuronium reduce myalgia associated with succinylcholine? A) Yes, it significantly reduces myalgia B) No, it does not affect myalgia C) Yes, but it depends on the dose of succinylcholine D) No, it worsens myalgia in some patients

Answer 413

Answer: A) Yes, it significantly reduces myalgia Rationale: A defasciculating dose of rocuronium reduces the muscle fasciculations caused by succinylcholine, thus decreasing postoperative myalgia.

Question 414

When should neostigmine be used instead of Sugammadex to reverse neuromuscular blockade? A) For rapid reversal of rocuronium-induced blockade B) For deeper blocks requiring reversal C) For cost-effective reversal of moderate blockade D) For immediate reversal after a “cannot ventilate” situation

Answer 414

Answer: C) For cost-effective reversal of moderate blockade Rationale: Neostigmine is effective and more cost-efficient than Sugammadex for reversing moderate blocks.

Question 415

How do you decide what dose of reversal agent to administer? A) Always use a fixed dose regardless of block depth B) Dose based on patient weight and depth of neuromuscular blockade C) Administer Sugammadex in a 2 mg/kg dose for all cases D) Use double the dose for deeper blocks

Answer 415

Answer: B) Dose based on patient weight and depth of neuromuscular blockade Rationale: Reversal agent dosing depends on the depth of blockade (e.g., number of twitches in TOF) and patient weight.

Question 416

According to the ASA, what is the most important consideration during difficult airway management? A) Avoiding multiple intubation attempts B) Ensuring oxygenation of the patient C) Establishing a surgical airway immediately D) Administering muscle relaxants

Answer 416

Answer: B) Ensuring oxygenation of the patient Rationale: The ASA emphasizes that patients do not die from an inability to intubate; they die from a lack of oxygenation. Maintaining oxygenation is the primary goal in difficult airway management.

Question 417

What is the first decision to make when managing a difficult airway? A) Whether to perform tracheostomy B) Whether to call for help C) Whether the intubation will be awake or after induction D) Whether to attempt supraglottic airway placement

Answer 417

Answer: C) Whether the intubation will be awake or after induction Rationale: Deciding between awake intubation and intubation after induction is the critical first step in managing a difficult airway.

Question 418

Which of the following is NOT a factor that the ASA identifies as impacting the likelihood of difficult airway management? A) Difficulty with mask ventilation B) Patient obesity C) Difficulty with supraglottic airway placement D) Difficulty with surgical airway access

Answer 418

Answer: "D) Difficulty with surgical airway access". Explanation: The ASA primarily identifies factors like difficulty with mask ventilation, patient obesity, and difficulty with supraglottic airway placement as indicators of potential difficult airway management, while difficulty with surgical airway access is considered a management strategy used when other methods fail, not a predictive factor for a difficult airway

Question 419

When face mask ventilation is unsuccessful, what is the next recommended step? A) Proceed directly to surgical airway access B) Place a supraglottic airway (SGA) C) Attempt non-invasive oxygenation techniques D) Try another round of intubation attempts

Answer 419

Answer: B) Place a supraglottic airway (SGA) Rationale: The ASA algorithm recommends trying a supraglottic airway device as the next step if face mask ventilation is unsuccessful.

Question 420

What should be avoided during the initial approach to difficult airway management? A) Calling for help B) Multiple intubation attempts C) Using video-assisted laryngoscopy D) Preserving spontaneous ventilation

Answer 420

Answer: B) Multiple intubation attempts Rationale: Multiple intubation attempts increase the risk of airway trauma and hypoxia. The ASA guidelines stress minimizing attempts and proceeding to alternative strategies.

Question 421

What role does video-assisted laryngoscopy play in the management of a difficult airway? A) It is only used after other approaches fail B) It is the preferred initial approach to intubation C) It is not recommended due to lack of evidence D) It should be avoided in awake intubations

Answer 421

Answer: B) It is the preferred initial approach to intubation Rationale: Video-assisted laryngoscopy is often the preferred initial method for intubation as it improves visualization of the airway.

Question 422

What is the recommended approach if both intubation and supraglottic airway placement fail? A) Administer high-dose muscle relaxants B) Initiate emergency invasive airway access C) Attempt blind nasotracheal intubation D) Use bag-mask ventilation until help arrives

Answer 422

Answer: B) Initiate emergency invasive airway access Rationale: Emergency invasive airway access (e.g., cricothyrotomy) is recommended as a life-saving measure when other strategies fail. DO NOT POSTPONE

Question 423

When should you call for help during a difficult airway scenario? A) Only if face mask ventilation fails B) After multiple unsuccessful intubation attempts C) Immediately after initial unsuccessful intubation, recognizing a difficult airway D) If surgical airway access becomes necessary

Answer 423

Answer: C) Immediately after initial unsuccessful intubation, recognizing a difficult airway Rationale: Early mobilization of additional resources is critical in managing a difficult airway effectively.

Question 424

What is the importance of preserving spontaneous ventilation during difficult airway management? A) It avoids the need for oxygen supplementation B) It reduces the risk of hypoxia during failed intubation C) It ensures better visualization during intubation D) It prevents gastric insufflation

Answer 424

Answer: B) It reduces the risk of hypoxia during failed intubation Rationale: Preserving spontaneous ventilation can help maintain oxygenation, especially in cases of failed intubation or ventilation

Question 425

Why is emergency invasive airway access listed last in the difficult airway algorithm? A) It is rarely needed in clinical practice B) It should only be performed by experienced surgeons C) Other non-invasive options are generally safer and effective D) It requires general anesthesia

Answer 425

Answer: C) Other non-invasive options are generally safer and effective Rationale: Emergency invasive airway access is considered a last resort due to its invasive nature, with other non-invasive strategies prioritized. Don't forget to try and wake the patient up. 16mg/kg of suggamedex.

Question 426

What is the most important consideration when managing an airway? A. Proper positioning B. Availability of surgical airway access C. Oxygenation D. Ensuring patient cooperation

Answer 426

Answer: C. Oxygenation Rationale: The material emphasizes that oxygenation is paramount in airway management. (duh being able to oxygenate your patient)

Question 427

What makes difficult mask ventilation more dangerous than difficult intubation? A. It is harder to achieve proper positioning. B. Mask ventilation is often overlooked. C. Oxygenation cannot be achieved without it. D. It leads to increased patient cooperation issues.

Answer 427

Answer: C. Oxygenation cannot be achieved without it. Rationale: The material highlights that as long as mask ventilation is possible, oxygenation can be maintained through almost any anesthetic.

Question 428

What is the proper positioning for optimizing airway management? A. Aligning the nose to the chin, perpendicular to the floor B. Aligning the tragus to the sternum, parallel to the floor C. Aligning the eyes to the ear, parallel to the bed D. Aligning the head to the shoulders, perpendicular to the neck

Answer 428

Answer: B. Aligning the tragus to the sternum, parallel to the floor Rationale: Proper positioning is described as aligning the tragus to the sternum, which can improve the Cormack-Lehane view during intubation

Question 429

What is the first step in managing a difficult airway? A. Performing a thorough airway exam B. Assessing the likelihood of airway management problems C. Ensuring airway equipment is readily available D. Properly positioning the patient

Answer 429

Answer: B. Assessing the likelihood of airway management problems Rationale: The first step in the difficult airway algorithm is to assess the likelihood of airway management problems.

Question 430

Which of the following is NOT a factor contributing to difficult mask ventilation? A. Obesity (BMI >30 kg/m²) B. Mallampati III or IV C. History of prior difficulty D. Short neck

Answer 430

Answer: D. Short neck Rationale: While a short neck is a factor for difficult intubation, it is not listed under predictors of difficult mask ventilation.

Question 431

. What mnemonic can be used to remember predictors of difficult mask ventilation? A. MaMaBOATS B. MaMaBORa C. LEMONS D. CHAMPS

Answer 431

Answer: A. MaMaBOATS Rationale: The mnemonic MaMaBOATS is used for difficult mask ventilation, including factors such as Mallampati III or IV * Mandibular protrusion decreased * Beard * Obesity (BMI >30 kg/m2) * Age >57-58 * Teeth (lack of) * Snoring

Question 432

What additional factor distinguishes impossible mask ventilation from difficult mask ventilation? A. Mandibular protrusion decreased B. Radiation changes (neck) C. Snoring D. Obesity

Answer 432

Answer: B. Radiation changes (neck) Rationale: Radiation changes are specific to impossible mask ventilation as listed under MaMaBORa.

Question 433

Which predictor of difficult intubation involves the inability to fully open the mouth? A. Prominent “overbite” B. Long incisors, inter-incisor distance <3 cm C. Thyromental distance <3 cm D. Poor submandibular compliance

Answer 433

Answer: B. Long incisors, inter-incisor distance <3 cm Rationale: This directly relates to limited mouth opening, which is a predictor of difficult intubation.

Question 434

What physical feature increases the likelihood of a difficult laryngoscopy? A. Wide nasal bridge B. Highly arched or narrow palate C. Strong jawline D. Prominent cheekbones

Answer 434

Answer: B. Highly arched or narrow palate Rationale: A highly arched or narrow palate can make direct laryngoscopy more challenging by limiting the view.

Question 435

Why is a thorough airway exam critical before managing the airway? A. It allows time to prepare all emergency medications. B. It identifies predictors of difficult airway management. C. It helps decide on the anesthetic technique. D. It ensures patient comfort.

Answer 435

Answer: B. It identifies predictors of difficult airway management. Rationale: A thorough airway exam is critical to identify potential difficulties in mask ventilation, intubation, and other airway management aspects.

Question 436

Which of the following is a predictor of supraglottic airway failure? A. Mallampati class I B. Restricted mouth opening C. Short neck D. Highly arched palate

Answer 436

Answer: B. Restricted mouth opening Rationale: Predictors of supraglottic airway failure include restricted mouth opening, obstructed anatomy below the larynx, distorted anatomy, and stiff lungs. These factors limit the effectiveness of supraglottic devices, which rely on an open pathway for oxygen delivery.

Question 437

What Mallampati class is characterized by visualization of the soft palate, uvula, and pillars? A. Class I B. Class II C. Class III D. Class IV

Answer 437

Answer: A. Class I Rationale: The Mallampati score assesses airway visibility. Class I involves full visualization of the soft palate, uvula, and pillars, while Class IV represents the most restricted view, with no visible structures other than the hard palate. This scoring system helps predict the difficulty of intubation and supraglottic airway placement.

Question 438

What is the purpose of obtaining the sniffing position during airway management? A. To align the tragus and sternal notch parallel to the floor B. To reduce patient discomfort during intubation C. To minimize airway resistance D. To ensure neck flexion at C7-T1

Answer 438

Answer: A. To align the tragus and sternal notch parallel to the floor Rationale: The sniffing position optimizes airway alignment by flexing the cervical spine (C7-T1) and extending the atlanto-occipital joint. This alignment maximizes the visualization of the airway structures and facilitates intubation.

Question 439

When using a fiberoptic bronchoscope, which device allows positive pressure ventilation while using the bronchoscope? A. Atomizer B. Endoscopic mask C. Jet ventilation system D. Nasal cannula

Answer 439

Answer: B. Endoscopic mask Rationale: The endoscopic mask (e.g., Patil-Syracuse mask) allows positive pressure ventilation (PPV) while using a bronchoscope. This is critical for maintaining oxygenation during fiberoptic intubation. Additional tools, such as a swivel adapter, can be used with an endotracheal tube for oxygen delivery during fiberoptic procedures.

Question 440

Which method is NOT mentioned as a way to topicalize the airway? A. Atomizer B. Lidocaine nebulizer C. Lidocaine paste D. "Lollipop" method

Answer 440

Answer: C. Lidocaine paste Rationale: The material describes methods for airway topicalization, including an atomizer, lidocaine nebulizer, swish/spit techniques, and the "lollipop" method. These methods ensure adequate anesthetization of the airway to facilitate awake intubation, while lidocaine paste is not mentioned.

Question 441

What is a key consideration when deciding between awake and post-induction intubation? A. The patient's age B. The presence of spontaneous ventilation C. The patient's body position D. The presence of nasal intubation

Answer 441

Answer: B. The presence of spontaneous ventilation Rationale: Awake intubation preserves spontaneous ventilation, which is critical when there is a risk of airway collapse after sedation or induction. Post-induction intubation, on the other hand, often abolishes spontaneous ventilation, necessitating careful planning to maintain oxygenation.

Question 442

What is the correct step after a failed awake intubation attempt, according to the material? A. Cancel the procedure B. Consider other invasive airway access options C. Attempt video laryngoscopy D. Perform immediate tracheostomy

Answer 442

Answer: B. Consider other invasive airway access options Rationale: If awake intubation fails, the next steps include evaluating other invasive airway access options, such as cricothyroidotomy or retrograde intubation. The decision-making process prioritizes oxygenation and the patient's safety while considering all available techniques. (Cancel the case is always an option depending on the necessity of the case).

Question 443

Which option is NOT listed under oxygenation methods in Step 2 of the algorithm? A. Nasal cannula with high-flow oxygen B. Bag-mask ventilation C. Rigid bronchoscope D. Continuous positive airway pressure (CPAP)

Answer 443

Answer: D. Continuous positive airway pressure (CPAP) Rationale: Oxygenation options in Step 2 include mask ventilation, oral or nasal airways, supraglottic airway (SGA) devices, high-flow nasal cannula (e.g., THRIVE), jet ventilation, and using bronchoscopes with specialized attachments. CPAP is not mentioned as an oxygenation method in this context.

Question 444

What is the recommended approach if the patient is not in the sniffing position? A. Elevate the head B. Lower the head of the bed C. Increase neck extension D. Adjust shoulder height

Answer 444

Answer: A. Elevate the head Rationale: The material recommends elevating the head if the patient is not in the sniffing position. Proper positioning aligns the oral, pharyngeal, and laryngeal axes, facilitating airway management and improving intubation success.

Question 445

In awake intubation, what is the purpose of airway topicalization? A. To sedate the patient B. To ensure the airway is adequately anesthetized C. To reduce the need for invasive techniques D. To increase airflow through the nasal passages

Answer 445

Answer: B. To ensure the airway is adequately anesthetized Rationale: Airway topicalization ensures the patient’s airway is anesthetized, allowing tolerance of intubation procedures while awake. Methods such as the atomizer, lidocaine nebulizer, and "lollipop" method are used to deliver local anesthetic effectively.

Question 446

In post-induction intubation, what should you do if the initial intubation attempt is unsuccessful? A. Call for help and attempt to mask ventilate B. Immediately perform a surgical airway C. Try a blind nasal intubation D. Move directly to the emergency pathway

Answer 446

Answer: A. Call for help and attempt to mask ventilate Rationale: The material emphasizes calling for help immediately and attempting mask ventilation. If mask ventilation is possible, continue with the non-emergency pathway. If not, proceed to placing an SGA (supraglottic airway).

Question 447

Which of the following is an alternative approach in the non-emergency pathway for post-induction intubation? A. Trans-tracheal jet ventilation B. Light wand C. Cricothyroidotomy D. Scalpel-bougie technique

Answer 447

Answer: B. Light wand Rationale: Alternative approaches listed include SGA, video laryngoscopy, fiberoptic intubation, light wand, and blind nasal intubation. Emergency techniques like jet ventilation and surgical airway access are not part of the non-emergency pathway.

Question 448

What should you avoid during direct laryngoscopy to prevent a “Cannot Intubate, Cannot Oxygenate” situation? A. Overuse of sedation B. Multiple attempts without change C. Placement of an SGA D. Using a fiberoptic scope

Answer 448

Answer: B. Multiple attempts without change Rationale: The material advises against repeating direct laryngoscopy without altering technique (e.g., changing blade, position, or provider). Trauma to the oropharynx and larynx can cause swelling and bleeding, converting a manageable airway into an emergency.

Question 449

In the emergency pathway, which method is considered a non-invasive airway ventilation technique? A. Cricothyroidotomy B. Combitude C. Scalpel-bougie technique D. Trans-tracheal jet ventilation

Answer 449

Answer: B. Combitude Rationale: Non-invasive techniques in the emergency pathway include different SGAs, Combitude, and apneic oxygenation using tools like Optiflow. Surgical airway access involves invasive methods.

Question 450

What is the purpose of the Vortex Approach in airway management? A. To optimize pharmacologic choices for induction B. To limit the number of direct laryngoscopy attempts C. To guide a multidisciplinary approach to difficult airway management D. To standardize surgical airway techniques

Answer 450

Answer: C. To guide a multidisciplinary approach to difficult airway management Rationale: The Vortex Approach incorporates multidisciplinary efforts, limits each technique (e.g., facemask, LMA, ETT) to three attempts, and emphasizes optimizing each attempt. It stresses being proactive and prepared for surgical airway access.

Question 451

According to the ENT chief resident, which action should always be done first in a surgical airway emergency? A. Identify someone to assist B. Perform a cricothyroidotomy C. Palpate the cricothyroid membrane D. Place a shoulder roll to expose the trachea

Answer 451

Answer: A. Identify someone to assist Rationale: The ENT chief recommends identifying an assistant, placing a shoulder roll to expose the trachea, and directing a light source at the neck to ensure a clear view for surgical airway procedures.

Question 452

Which technique is associated with a higher failure rate in emergencies compared to surgical-based techniques? A. cannula based technique B. Cricothyroidotomy C. Surgical tracheostomy D. Trans-tracheal jet ventilation

Answer 452

A. cannula based technique Rationale: Cannula-based (percutaneous) techniques have a higher failure rate than surgical approaches like tracheostomy in emergency situations, according to the material.

Question 453

What is a critical step in the scalpel-bougie surgical airway technique after the initial midline incision and palpating the cricothyroid membrane? A. Perform a horizontal stab incision B. Place a shoulder roll under the neck C. Insert a rigid bronchoscope D. Pre-oxygenate the patient

Answer 453

Answer: A. Perform a horizontal stab incision Rationale: The scalpel-bougie technique involves making a horizontal stab incision at the cricothyroid membrane, followed by inserting the bougie, and railroading an endotracheal tube into place.

Question 454

What clinical pearl is emphasized for preventing airway emergencies? A. Never attempt more than two laryngoscopies B. Pre-oxygenate to buy yourself safe apnea time C. Always use an atomizer to topicalize the airway D. Avoid SGAs in non-emergent cases

Answer 454

Answer: B. Pre-oxygenate to buy yourself safe apnea time Rationale: Pre-oxygenation is critical in airway management to maintain oxygenation during apnea. The material highlights it as a key step in preparation for intubation.

Question 455

Why is it important to know and practice surgical airway techniques? A. They are required for all elective intubations B. They reduce the need for fiberoptic intubation C. They can save a life in a “Cannot Intubate, Cannot Oxygenate” situation D. They are preferred over non-invasive approaches

Answer 455

Answer: C. They can save a life in a “Cannot Intubate, Can use a bougie and a 6.0 ETT tube with scapel #10 blade. Cannot Oxygenate” situation Rationale: Surgical airway techniques, such as cricothyroidotomy, are vital for emergencies where ventilation and oxygenation are not possible by other means. Practicing these techniques on models is emphasized in the material.

Question 456

Stopped on 46.

Question 457

What laboratory finding is most associated with hypervolemia? A) Rising hematocrit B) Serum osmolality >450 C) Hyponatremia D) Urine specific gravity >1.010

Answer 457

Answer: C) Hyponatremia Rationale: Hyponatremia is a common finding in hypervolemia due to dilutional effects.

Question 458

What is the normal percentage of total body water located in the intracellular compartment in a 70-kg male? A) 5% B) 15% C) 40% D) 60%

Answer 458

Answer: C) 40% Rationale: In males, 40% of total body water is intracellular, with 15% in the interstitial space and 5% intravascular. males are 60% water on mass so a 70kg male has 42L of water.

Question 459

Which modality provides the most accurate assessment of volume status in patients undergoing major cardiac surgery? A) Central venous catheter B) Pulmonary artery catheter C) Transesophageal echocardiogram (TEE) D) Foley catheter

Answer 459

Answer: C) Transesophageal echocardiogram (TEE) Rationale: TEE is commonly used in cardiac surgery and provides accurate volume status assessment, particularly via transgastric views.

Question 460

Which hormone is responsible for enhancing water reabsorption in the renal tubules? A) Aldosterone B) Vasopressin C) Atrial Natriuretic Peptide D) Renin

Answer 460

Answer: B) Antidiuretic hormone (Vasopressin) Rationale: Vasopressin enhances water reabsorption by increasing permeability in the renal collecting ducts. Renin, produced in the kidney's juxtaglomerular cells, does not directly act within the renal tubule itself; instead, it initiates a cascade of reactions in the bloodstream that ultimately leads to the reabsorption of sodium and water in the distal convoluted tubule by stimulating the production of angiotensin II, which then triggers the release of aldosterone from the adrenal glands, thereby indirectly influencing the function of the renal tubule to regulate blood pressure and fluid balance Aldosterone * Enhances sodium reabsorption * Increases intravascular volume

Question 461

What physiological change is most likely in a hypovolemic patient? A) Pitting edema B) Tachycardia C) Elevated Jugular Venous Pressure (JVP) D) Wheezing

Answer 461

Answer: B) Tachycardia Rationale: Tachycardia is a compensatory response to hypovolemia to maintain cardiac output.

Question 462

Which of the following is a common indicator of hypovolemia in bedside ultrasound assessment? A) IVC diameter >1.7 cm B) IVC collapsibility >50% C) Increased pulmonary vascular markings on CXR D) Wheezing

Answer 462

Answer: B) IVC collapsibility >50% Rationale: High IVC collapsibility (>50%) indicates low right atrial pressures, often associated with hypovolemia.

Question 463

Which patient population would most benefit from intraoperative Pulmonary Artery Catheter (PAC) placement? A) Healthy adult undergoing elective surgery B) Patient with mitral regurgitation undergoing valve replacement C) Pediatric patient undergoing appendectomy D) Geriatric patient with stable coronary artery disease undergoing knee replacement

Answer 463

Answer: B) Patient with mitral regurgitation undergoing valve replacement Rationale: PACs are most useful in cases involving pulmonary hypertension, valvular pathology, or right ventricular dysfunction.

Question 464

What is the "5 – 15 – 40 Rule" in fluid compartment estimation? A) 5% extracellular, 15% intracellular, 40% interstitial B) 5% intravascular, 15% interstitial, 40% intracellular C) 5% interstitial, 15% intravascular, 40% extracellular D) 5% intracellular, 15% interstitial, 40% extracellular

Answer 464

Answer: B) 5% intravascular, 15% interstitial, 40% intracellular Rationale: The rule approximates the breakdown of body fluid compartments: 5% intravascular, 15% interstitial, and 40% intracellular. Extracellular is the rest or 20% of the water.. so about 14L.. which is subdivided into the interstitial and intravascular. Total Body Water (TBW): Approximately 60% of body weight. For a 70 kg individual: 70 kg × 0.60 = 42 liters. Intracellular Fluid (ICF): About two-thirds of TBW. ICF: 42 liters × 2/3 ≈ 28 liters. Extracellular Fluid (ECF): About one-third of TBW. ECF: 42 liters × 1/3 ≈ 14 liters. The ECF is further divided into: Interstitial Fluid: Approximately 75% of ECF. Interstitial Fluid: 14 liters × 0.75 ≈ 10.5 liters. Plasma (Intravascular Fluid): Approximately 25% of ECF. Plasma: 14 liters × 0.25 ≈ 3.5 liters.

Question 465

Which of the following would most likely show fluid responsiveness during surgery? A) Increased ADH secretion B) Increased PPV >12% C) High systemic vascular resistance D) Low heart rate

Answer 465

Answer: B) Increased PPV >12% Rationale: PPV >12% is a dynamic indicator that the patient may respond to fluid boluses, improving cardiac output.

Question 466

Which crystalloid solution is considered physiologic due to its balanced electrolyte composition? A. Normal Saline B. Lactated Ringer's C. D5W D. 0.45% Saline

Answer 466

Answer: B. Lactated Ringer's Rationale: Lactated Ringer's is often referred to as a "balanced crystalloid" because it contains electrolytes similar to plasma, including lactate, which is metabolized to bicarbonate in the liver.

Question 467

What is a disadvantage of using Normal Saline (NS) in large volumes? A. Hyperkalemia B. Hyperchloremic metabolic acidosis C. Hypoglycemia D. Hypochloremia

Answer 467

Answer: B. Hyperchloremic metabolic acidosis Rationale: Large volumes of NS can lead to hyperchloremic metabolic acidosis due to its high chloride content. The acidosis could exacerbate hyperkalemia as well.

Question 468

Which of the following colloid solutions is derived from pooled donor blood and is heat-treated to reduce infection risk? A. Hetastarch B. Albumin C. Gelatin D. D5W

Answer 468

Answer: B. Albumin Rationale: Albumin is derived from pooled donor blood and is heat-treated to inactivate viruses, making it a safer option for volume expansion in specific cases.

Question 469

What is the primary advantage of colloids over crystalloids in volume resuscitation? A. Lower cost B. Longer half-life C. Maintains plasma oncotic pressure D. No risk of coagulopathy

Answer 469

Answer: C. Maintains plasma oncotic pressure Rationale: Colloids such as albumin maintain oncotic pressure, resulting in preferential plasma volume expansion compared to crystalloids. Also, much longer half-life 3-6 hrs vs 20-30 min

Question 470

Which crystalloid is preferred for diluting packed red blood cells (PRBCs)? A. D5W B. Lactated Ringer's C. Normal Saline D. Normosol

Answer 470

Answer: C. Normal Saline Rationale: Normal Saline is preferred for diluting PRBCs to avoid calcium-related clotting issues associated with Lactated Ringer's.

Question 471

Which colloid solution can interfere with platelet function and increase bleeding risk? A. Albumin B. Hetastarch C. Lactated Ringer's D. Normal Saline

Answer 471

Answer: B. Hetastarch Rationale: Hetastarch can cause coagulopathy by interfering with platelet aggregation and clotting factors. increase PTT via factor VIII/vWF inhibition.

Question 472

What is a key concern when using colloids in patients with kidney injury? A. Hyperglycemia B. Increased risk of infection C. Renal dysfunction D. Hypokalemia

Answer 472

Answer: C. Renal dysfunction Rationale: Colloids, particularly synthetic ones like hetastarch, can worsen renal dysfunction in vulnerable patients.

Question 473

Which of the following is true about Lactated Ringer's solution? A. It contains glucose for caloric supplementation. B. It is hyperosmolar compared to plasma. C. It can cause hyperchloremic acidosis. D. Its lactate is metabolized into bicarbonate by the liver.

Answer 473

Answer: D. Its lactate is metabolized into bicarbonate by the liver. Rationale: The lactate in Lactated Ringer's is converted to bicarbonate in the liver, making it suitable for acid-base balance correction in certain cases.

Question 474

What percentage of a preexisting fluid deficit is given in the first hour of surgery? A. 25% B. 50% C. 75% D. 100%

Answer 474

Answer: B. 50% Rationale: For preexisting fluid deficits, half (50%) of the calculated maintenance requirement is given in the first hour.

Question 475

Which type of trauma is associated with evaporative losses of 4-8 mL/kg/hr? A. Minimal trauma (hernia repair) B. Moderate trauma (cholecystectomy) C. Severe trauma (bowel resection) D. No trauma

Answer 475

Answer: C. Severe trauma (bowel resection) Rationale: Severe tissue trauma leads to higher evaporative and interstitial fluid losses, estimated at 4-8 mL/kg/hr.

Question 476

Which crystalloid solution is generally preferred for neuro cases? A. Lactated Ringer's B. Normal Saline C. Normosol D. D5W

Answer 476

Answer: B. Normal Saline Rationale: Normal Saline is often chosen for neuro cases due to its hyperosmolar nature (308) - 154 Na & 154 Cl- compared to the mOsm of the vasculature 275-295.. LR is 273 with pretty normal parts of Na+ Cl- K+ and Ca2+.. but is slightly hypo-osmolar.. so not good for neuro cases. nature and lack of potassium, which minimizes risks of hyperkalemia and cerebral edema.

Question 477

What is the estimated blood loss (EBL) from 2 "laps" and 8 4×4 sponges? A. 200-300 mL B. 400-500 mL C. 600-700 mL D. 800-900 mL

Answer 477

Answer: B. 400-500 mL Rationale: Laps: 100-150 mL each × 2 = 200-300 mL 4×4 sponges: 10 mL each × 8 = 80 mL Total = 280-380 mL (rounded to 400-500 mL for clinical estimates).

Question 478

What is a potential disadvantage of using Normal Saline in large volumes for resuscitation? A. Hypoglycemia B. Metabolic alkalosis C. Hyperchloremic metabolic acidosis D. Hypercalcemia

Answer 478

Answer: C. Hyperchloremic metabolic acidosis Rationale: Normal Saline contains a high chloride concentration, which can lead to hyperchloremic acidosis when administered in large quantities.

Question 479

When administering over 2 units of packed red blood cells (pRBCs), what should be considered to prevent dilutional coagulopathy? A. Administer additional Normal Saline B. Use Lactated Ringer's instead of Normosol C. Add fresh frozen plasma (FFP) D. Decrease infusion rate

Answer 479

Answer: C. Add fresh frozen plasma (FFP) Rationale: Adding FFP can help prevent coagulopathy when rapid volume resuscitation requires multiple units of pRBCs.

Question 480

Which patients should avoid Lactated Ringer's due to potential complications? A. Patients with liver failure B. Patients with renal failure C. Patients with hypernatremia D. Patients with metabolic alkalosis

Answer 480

Answer: B. Patients with renal failure Rationale: The calcium in Lactated Ringer's can exacerbate complications in renal failure patients due to impaired excretion. Also, LR has a K+ of 4 which should be watched in Renal patients.

Question 481

What is the primary benefit of a balanced crystalloid like Normosol over Normal Saline? A. Lower cost B. Better maintenance of acid-base balance C. Longer half-life D. Higher chloride content

Answer 481

Answer: B. Better maintenance of acid-base balance Rationale: Balanced crystalloids like Normosol and Lactated Ringer's help maintain acid-base balance compared to Normal Saline, which can cause hyperchloremic acidosis.

Question 482

Which of the following is a potential consequence of volume overload? A. Increased pulmonary edema B. Decreased ICU length of stay C. Increased hematocrit levels D. Improved wound healing

Answer 482

Answer: A. Increased pulmonary edema Rationale: Volume overload can lead to pulmonary edema, periorbital edema, and gut edema, among other complications.

Question 483

What is the preferred strategy for rational fluid management in surgical patients? A. Avoid any use of colloid fluids B. Use a fixed maintenance rate for all surgeries C. Tailor fluid management to patient, surgery, and clinical picture D. Maximize interstitial volume replacement in all patients

Answer 483

Answer: C. Tailor fluid management to patient, surgery, and clinical picture Rationale: A balanced approach to fluid therapy considers the individual patient's needs, type of surgery, and clinical condition.

Question 484

What is the formula to calculate fluid resuscitation volume in burn patients? A. 4 mL/kg × TBSA% × weight (kg) B. 2 mL/kg × TBSA% × weight (kg) C. 4 mL × weight (kg) × TBSA% D. 2 mL × weight (kg) × TBSA%

Answer 484

Answer: A. 4 mL/kg × TBSA% × weight (kg) Rationale: The Parkland Formula calculates fluid volume required for burn resuscitation using 4 mL/kg × TBSA%. It seems stupid so here is an example Formula: 4 milliliters x body weight in kilograms x percentage of body surface area burned Example: For an adult weighing 80 kg with a 16% TBSA burn, the calculation would be 4 × 80 × 16 = 5120 mL

Question 485

How is the fluid volume from the Parkland Formula administered? A. 75% in the first 8 hours, 25% in the next 16 hours B. 50% in the first 8 hours, 50% in the next 16 hours C. 25% in the first 8 hours, 75% in the next 16 hours D. 100% in the first 8 hours

Answer 485

Answer: B. 50% in the first 8 hours, 50% in the next 16 hours Rationale: The fluid volume is split evenly over the first 24 hours, with half given in the first 8 hours and the remainder over the next 16 hours. Use LR

Question 486

What is a common cause of intraoperative oliguria? A. Hypervolemia B. Baroreceptor reflex suppression C. Foley catheter obstruction D. Increased ADH secretion

Answer 486

Answer: C. Foley catheter obstruction Rationale: Foley catheter kinking, displacement, or obstruction is a common mechanical cause of oliguria. D is possible, usually w/ advanced age

Question 487

What treatment is recommended for pre-renal causes of intraoperative oliguria? A. Replace fluids and consider vasopressors B. Use high-dose diuretics C. Discontinue vasopressors D. Restrict fluids

Answer 487

Answer: A. Replace fluids and consider vasopressors Rationale: For pre-renal causes, optimizing fluid status and vasopressor use to improve perfusion are appropriate treatments

Question 488

Which intravenous fluid is most likely to cause hypernatremia? A. Lactated Ringer's B. 3% NaCl C. 0.45% NaCl D. 5% Dextrose in water

Answer 488

Answer: B. 3% NaCl Rationale: 3% NaCl is a hypertonic solution and can lead to hypernatremia if not carefully monitored. Used in neuro cases at 5mL/kg, sometimes preferred over mannitol

Question 489

What is the primary disadvantage of using Hetastarch (HES) as a colloid? A. Short half-life B. Coagulopathy and renal failure C. High cost D. Increased risk of viral infection

Answer 489

Answer: B. Coagulopathy and renal failure Rationale: Hetastarch can interfere with coagulation and lead to renal complications, limiting its use in clinical practice.

Question 490

Which fluid is most associated with the BEST survival rates in major abdominal surgery? A. 5% Albumin B. Hydroxyethyl starch C. Crystalloids D. Dextran 70

Answer 490

Answer: C. Crystalloids Rationale: While controversy exists, crystalloids are generally favored for resuscitation in trauma and major surgeries due to their safety profile and cost-effectiveness.

Question 491

Stopped on 49

Question 492

What is a unique property of thiopental compared to other IV anesthetics? A) High solubility at physiological pH B) Causes EEG burst suppression at high doses C) Maintains hemodynamic stability D) Used frequently in the US for anesthesia induction

Answer 492

Answer: B Rationale: Thiopental causes EEG burst suppression at large doses, which has historically been useful in neurosurgical and anticonvulsant applications.

Question 493

Which IV anesthetic acts as an uncompetitive NMDA receptor antagonist? A) Propofol B) Ketamine C) Etomidate D) Dexmedetomidine

Answer 493

Answer: B Rationale: Ketamine inhibits NMDA receptors by acting as an uncompetitive antagonist, blocking glutamate-mediated excitatory transmission.