Basic Exam

Question 1

the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limits for anesthetic gases of 2 ppm when only halogenated anesthetic gases are used, 25 ppm when only nitrous oxide is used and 0.5 ppm for halogenated anesthetics in combination with nitrous oxide

Answer 1

Calcium, sodium, and potassium are all responsible for generating an action potential in the sinoatrial node. An influx of calcium is responsible for the actual depolarization of the cell, while an efflux of potassium repolarizes the cell after depolarization. After repolarization, funny sodium channels cause spontaneous depolarization, augmented by the opening of calcium channels that speed the spontaneous depolarization during phase 4 of the action potential.

Question 2

Diffusion hypoxia is a well-known phenomenon that can occur following administration of nitrous oxide as part of general anesthesia. The low blood solubility of nitrous oxide, coupled by relatively low potency leads to large amounts of nitrous oxide being eliminated into the alveoli over a short period of time following cessation of anesthesia. This leads to displacement of oxygen and carbon dioxide in the alveoli. Supplemental oxygen should be provided to mitigate this effect.

Answer 2

When the α1 receptor is activated, it increases IP3,leading to vasoconstriction.

When the β1 receptor is activated, it increases cAMP, leading to an increase in heart rate.

Activation of the β2-adrenergic receptor results in the activation of adenylyl cyclase, increasing cAMP leading to bronchodilation

Question 3

In normal-weight adult males and females, total body water makes up approximately 60% and 50% of total body weight, respectively. Approximately 2/3 of total body water is intracellular while 1/3 is extracellular. About 75% of extracellular fluid is interstitial fluid and 25% is plasma. Obese individuals have a proportionally smaller TBW compared to their weight.

Answer 3

Neonates and infants have a proportionately higher total body water than adults which causes them to require higher doses of water-soluble drugs (succinylcholine, midazolam) to achieve the same effect.

Question 4

The axillary block is an upper extremity nerve block with an axillary approach but does not involve the axillary nerve. The block provides anesthesia to the median, radial, and ulnar nerves at the level of the branches. To provide more anesthetic coverage of the lateral forearm, the clinician gives supplementation to the musculocutaneous nerve. To provide more coverage of the medial upper arm, the clinician gives supplementation to the intercostobrachial nerve.

Answer 4

Question 5

Answer 5

A supraclavicular block is performed at the level of the distal trunks and proximal divisions of the brachial plexus. Major structures involved at this level include the brachial plexus, subclavian artery, first rib, and pleura. The brachial plexus lies superficial and lateral to the subclavian artery, and the subclavian artery lies superficial to the first rib.

Question 6

Restrictive transfusion strategies are preferred and wait for lower hemoglobin levels to reduce the number of transfusions performed. Red blood cells should be administered unit-by-unit, when possible, with interval reevaluation.

Answer 6

It has been found that patients rarely require a transfusion when hemoglobin is > 10 g/dL, they will likely require a transfusion with acute blood loss lowering hemoglobin to less than 7 g/dL, and chronic anemia of 6-7 g/dL can usually be tolerated.

Question 7

The opening of voltage-dependent Ca2+ channels leads to induction of phosphorylation of synapsins and fusion of presynaptic acetylcholine vesicles to the presynaptic membrane. This causes a release of acetylcholine through exocytosis at the synaptic cleft.

Acetylcholine is then degraded by cholinesterase into acetate and choline, and the choline is taken back up into the neuron by the Na+/choline transporter.

Answer 7

Cryoprecipitate contains approximately 200 mg/unit of fibrinogen. Cryoprecipitate is indicated as factor replacement in hypofibrinogenemia, von Willebrand disease, and hemophilia A. Cryoprecipitate is high in factors 8 and 13 as well as fibrinogen and von Willebrand factor (vWF).

Question 8

Stages of Anesthesia

Stage 1- Conscious but decreased perception of pain
Slow, regular breathing

Stage 2- Unconscious with irregular breathing, breath-holding, hyperreflexia, and excitation
Hypertensive, tachycardic, and loss of eyelash reflex but laryngeal reflexes remain intact
Higher risk of laryngospasm

Answer 8

Stage 3- Surgical depth of anesthesia, diaphragm paralysis, loss of laryngeal reflexes

Stage 4- Anesthesia overdose, Cardiovascular and respiratory depression

Question 9

The TOF ratio is the ratio of the height of the fourth twitch to the height of the first twitch, and is used in evaluating reversal of neuromuscular blockade. The gold standard TOF ratio indicating appropriate reversal is 0.9

Answer 9

Double burst stimulation is a series of two short tetanic stimulations (two impulses at 50 Hz, separated by 750 ms) which correlates well to the TOF ratio up to a ratio of 0.6. Tetanus is a sustained stimulus of 50 to 100 Hz for five to ten seconds and can be useful in confirming adequate reversal of neuromuscular blockade

Question 10

The likelihood of infection or ischemia is low in brachial artery catheterization. In the cardiac surgery population, brachial artery catheterization is more reliable than radial artery catheterization, especially after cardiopulmonary bypass. Brachial artery lacks collateral blood flow.

Answer 10

Cisatracurium undergoes nonenzymatic Hofmann elimination in plasma. The reaction speed is increased with higher pH and higher temperature. As the drug undergoes minimal renal or hepatic metabolism, it is safe to use in patients with significant kidney or liver disease.

Question 11

Infusion of a 20% intravenous lipid emulsion (ILE) is the treatment for systemic toxicity from local anesthetics, and particularly for cardiac arrest that is refractory to standard therapy. ASRA guidelines recommend consideration of lipid emulsion therapy at the earliest signs of systemic toxicity from local anesthetics.

Answer 11

The lipid infusion extracts the lipid-soluble molecules of the local anesthetic from the plasma. An initial bolus of 1.5 mL/kg is administered over several minutes followed by an infusion at a rate of 0.25 mL/kg/min for 30-60 minutes or until hemodynamic stability is achieved.

Question 12

Plavix inhibits the P2Y12 receptor. It is a prodrug. 40% people don’t have a response. Irreversible. Is associated with thrombotic thrombocytopenic purpura.

Answer 12

Cangrelor is an IV version of the active form of Plavix. Return of platelet function in 60-90min

Question 13

Five important risk factors for difficult bag mask ventilation are the presence of a beard, BMI > 26, edentulous, age > 55 years, and a history of snoring. Other risk factors include Mallampati class III or IV, severely limited mandibular protrusion, and mouth opening < 3 cm. Finally, a thyromental distance < 6 cm has been shown to be an independent risk factor for difficult bag mask ventilation.

Answer 13

A bobbin flowmeter is structured with a weighted bobbin within a tapered cylindrical tube. As the flow and pressure beneath the bobbin increases, it will rise until reaching equilibrium. Due to the shape of the cylinder, as the bobbin rises the cross-sectional area around it will increase as well.

Question 14

treatment for hyperkalemia includes calcium & insulin to stabilize the myocardium in the setting of ECG changes, shifting potassium intracellularly, and elimination of potassium from the body

Answer 14

Atelectasis develops in about 90% of patients in the postoperative period. Atelectasis is caused by a combination of changing the patient from an upright to a supine position, loss of muscle tone during induction, a subsequent decrease in FRC, loss of surfactant, and compression of lung tissue.

Question 15

In patients with end-stage renal disease, baseline electrolytes should be obtained.

A CBC is indicated for patients with a history of increased bleeding, hematologic disorders, recent chemotherapy, steroid or anticoagulant therapy, poor nutritional status, and surgical procedures with a high predicted blood loss.

Answer 15

A grade II includes the visualization of only the posterior aspects of the glottic aperture.
Grade III is when the epiglottis is only visible.
Finally, a grade IV view is the visualization of only the soft palate

Question 16

Systolic blood pressure is the most overestimated and least accurate measurement comparing to direct invasive monitoring.

Answer 16

The alpha-2 agonist drugs clonidine and dexmedetomidine help to reduce the risk of postoperative shivering.

Ondansetron, ketamine, and tramadol may also prevent shivering.

Dexmedetomidine is extensively metabolized in the liver before being excreted in urine and feces.

Question 17

High-frequency oscillatory ventilation uses high mean airway pressures to stent the airways open while small and frequent tidal volumes actively drive air in and out of the lungs providing ventilation. This mode has been used to good effect in premature neonates with respiratory distress syndrome but not adults

Answer 17

Both high-frequency jet ventilation (HFJV) & high-frequency percussive ventilation (HFPV) allow for passive exhalation throughout the respiratory cycle, however, in HFOV exhalation is actively driven by the device.

Question 18

Glucagon, catecholamines, and cortisol are counter-regulatory hormones because they oppose the effects of insulin and synergistically act to increase hepatic glucose production. These hormones act to stimulate hepatic glycogenolysis and gluconeogenesis. Insulin opposes the action of gluconeogenesis.

Answer 18

Delayed hemolytic transfusion reaction is a result of recipient antibodies targeting donor minor red blood cell antigens to which the recipient has previously been exposed, leading to hemolysis of the donated red blood cells. Hemolysis occurs within days to weeks after the transfusion, and symptoms are generally mild or absent.

Question 19

Donor antibodies activating recipient neutrophils are the cause of transfusion-related acute lung injury (TRALI). These neutrophils result in damage to the pulmonary vascular capillary bed, leading to pulmonary edema.

Answer 19

TRALI is typically present during or within 6 hours of the blood transfusion with fever, hypotension, hypoxia, pink frothy airway secretions, and transient leukopenia. Chest radiographs will reveal bilateral infiltrates similar to transfusion-associated circulatory overload.

Question 20

Train-of-four fade and tetanic fade are due to blockade of α3β2 prejunctional receptors.

Answer 20

Aα fibers transmit motor and proprioception.

Aβ fibers transmit sensation of touch and pressure from stretch receptors.

Aγ(GAMMA) fibers transmit motor efferent signals to the muscle spindle.

Aδ (DELTA) fibers transmit pain impulses, temperature, and sensation of touch.

Question 21

The intervillous space has the lowest intravascular pressures within the uteroplacental and fetoplacental circulation. This low pressure allows for large volumes of blood to be moved through this space to allow adequate maternofetal nutrient and oxygen transfer. It also prevents the collapse of umbilical veins as they return to this space

Answer 21

Uteroplacental circulation is not fully established until the beginning of the second trimester

Question 22

adductor canal block, a variant of a saphenous block, is often used as an analgesic adjunct for knee surgery. pain relief provided by adductor canal block is noninferior to that of femoral nerve block. Adductor canal blocks were also found to have less risk for falls. Although the saphenous nerve is purely sensory, an adductor canal block often affects the nerve to the vastus medialis because of its location within the adductor canal. Motor weakness may occur, and patients should be closely monitored as they begin to ambulate.

Answer 22

The saphenous nerve is a terminal branch of the femoral nerve providing sensory innervation to the medial aspect of the leg and foot. It originates from the L2 through L4 nerve roots and descends through the femoral triangle, Then, it traverses the adductor canal with the femoral artery and courses superficially in the anteromedial leg alongside the saphenous vein.

Question 23

Metoclopramide’s GI promotility properties result in increased lower esophageal sphincter (LES) pressure, increased speed of gastric emptying, and decreased pyloric pressure.

Answer 23

Long-term use of metoclopramide (> 12 weeks) increases the risk for extrapyramidal side effects, including tardive dyskinesia, and it has the potential to prolong the QT interval

Question 24

Agents which decrease both cerebral metabolic rate and also have vasodilatory effects (e.g. propofol, dexmedetomidine, inhaled halogenated anesthetics <0.5 MAC) will tend to cause a decreased cerebral blood flow and volume

Answer 24

Any agent that causes cerebral vasodilation without also decreasing cerebral metabolic rate will result in an increase in cerebral blood flow and cerebral blood volume. This can be seen when direct-acting vasodilators (e.g. nicardipine, hydralazine, nitroglycerin) are administered.

Question 25

A rare side effect of sedation with intramuscular ketamine is laryngospasm. If the patient has no IV, you can administer IM succinylcholine to break the laryngospasm, 4 mg/kg intramuscular dose.

Answer 25

Calcium channel blockers have a minor potentiation effect on nondepolarizing and depolarizing neuromuscular blockers, but it is clinically insignificant in patients taking CCBs chronically.

Question 26

A shift in the Frank-Starling curve up or down is an indication of changes in contractility, with upward shifts providing evidence of positive inotropy and downward shifts providing evidence of negative inotropy.

Answer 26

Droperidol, a D2-antagonist, is contraindicated in patients with a suspected QT prolongation. Patients with electrolyte disturbances such as severe hypomagnesemia, are at risk for developing a prolonged QT interval

Question 27

A paired t-test compares means in a single group who serve as their own control, whereas an unpaired t-test compares a mean in two different groups.

Answer 27

Analysis of variance (ANOVA) is used to test the means when 3 or more groups exist.

Question 28

The right main bronchus should give rise to a very close right take off which is the right upper lobe that will have three take-offs which are the anterior, posterior, and superior lung segments of the right upper lobe. The left main bronchus has two take-offs which are the upper and lower lobes of the left lung.

Answer 28

The intercostobrachial nerve typically arises from the dorsal rami of T1-T3 and, thus, is spared in brachial plexus blocks. The intercostobrachial nerve innervates the medial upper arm. It is anesthetized by a subcutaneous field block injection starting at the deltoid prominence

Question 29

ERAS protocols include allowing clear liquids until 2 hours before the start of surgery. Nutritional strategies also include intraoperative fluid optimization and early postoperative enteral nutrition with high-calorie supplements.

Answer 29

The administration of lactated Ringer solution is safe in patients with kidney disease and does not produce hyperkalemia.

Question 30

Botulism is characterized by flaccid paralysis, blurred vision, ptosis, nausea, and respiratory difficulty. Botulinum toxin binds to pre-synaptic cholinergic nerve terminals and inhibits the release of acetylcholine by preventing vesicle fusion.

Answer 30

Guillain-Barre syndrome (GBS) is characterized by sudden onset of ascending motor paralysis, areflexia, and variable paresthesias. GBS is associated with antibodies against gangliosides and myelin sheath of peripheral nerves.

Question 31

In simple terms shunt is defined as a portion of the lungs that is perfused but not ventilated while dead space is the opposite (portion of the lungs that is ventilated but not perfused).

Answer 31

High concentrations of oxygen decrease FRC through development of microatelectasis. This occurs because of alveolar collapse – when higher concentrations of oxygen are used, less nitrogen is part of the alveolar gas. Nitrogen helps keep alveoli ‘stented’ open, helping to decrease the amount of micro collapse.

Question 32

The Bohr effect refers to the shift in the oxygen dissociation curve caused by changes in the concentration of carbon dioxide or the pH of the environment.

Answer 32

The chloride shift refers to the reaction in which bicarbonate is exchanged for a chloride ion across the red blood cell membrane.

Question 33

Airway obstruction after total thyroidectomy may be caused by a postoperative hematoma, compression of the trachea, tracheomalacia, bilateral recurrent laryngeal nerve damage, or hypocalcemia resulting from inadvertent removal of the parathyroid glands. Although the airway symptoms of hypocalcemia can develop as early as 1 to 3 hours after surgery, they typically do not develop until 24 to 72 hours postoperatively.

Answer 33

Areas of mechanical dead space in a typical anesthesia machine circle system setup are: 1) The portion of the endotracheal tube (ETT) which extends out of the trachea 2) The breathing circuit elbow connector 3) Any connector used between the ETT and the breathing circuit 4) The Y-piece at the end of the circuit

Question 34

The cricoid cartilage (C6) has a complete cartilaginous ring. Carina is at T5. The trachea contains 16 to 20 C-shaped rings of hyaline cartilage. The bronchi have complete circular cartilage rings. The lower airway loses cartilage support at the level of the bronchioles. The trachea is lined by ciliated pseudostratified columnar cells.

Answer 34

Compared to the central arterial waveform, the peripheral waveform will exhibit a higher systolic peak and lower diastolic nadir with a lower mean arterial pressure

Question 35

Prosthetic cardiac valves, previous infective endocarditis, special cases of congenital heart disease, and valvular heart disease after cardiac transplantation are cardiac conditions that have the highest risk of adverse outcomes from Infective Endocarditis.

Answer 35

These patients should receive antibiotic prophylaxis if they undergo dental procedures with gingival manipulation or perforation of oral mucosa and respiratory tract procedures that involve incision or biopsy of mucosal tissue. Prophylaxis for genitourinary or gastrointestinal procedures is not recommended unless there is an active infection.

Question 36

An odds ratio of > 1 indicates a positive effect, an odds ratio of 1 indicates no effect , and an odds ratio of < 1 indicates a negative effect.

Answer 36

Laboratory Findings Suggestive of Acute Hemolytic transfusion reactions *In the setting of DIC; **Both direct and indirect elevated, indirect > direct; ***Indicative of renal damage.

Question 37

Oxygen regulators are present in anesthesia machines to help ensure proper oxygen delivery and backup. The first-stage regulator will shut off the lower pressure oxygen cylinder tanks when the higher-pressure oxygen pipeline is sensed.

Answer 37

The pipeline system delivers pressures of 50-55 psig Pressure through the oxygen tank is regulated to enter at 40 to 45 psig.

Question 38

Pulse oximetry measures functional hemoglobin saturation. Fractional hemoglobin saturation is measured by co-oximetry (which uses multiple wavelengths) is needed when you suspect the presence of carboxyhemoglobin or methemoglobin.

Answer 38

Oxyhemoglobin absorbs less red light than does deoxyhemoglobin. Pulse oximetry is a poor monitor of ventilation, especially when patients are breathing 100% oxygen.

Question 39

The osmolality gap is the measure of the unmeasured solutes in the plasma which is the difference between the measured serum osmolality and the calculated osmolality. 2 x [Na+] + [Glucose]/18 + [BUN]/2.8. The 3 main contributors to plasma osmolality are Na+, glucose, and urea.

Answer 39

alcohols (ethanol, methanol, and ethylene glycol), sugars (mannitol and sorbitol), ketones, and lactate are unmeasured solutes. Common causes of osmolality gap include ethanol ingestion and the causes of an elevated anion gap.

Question 40

Bayes theorem is used to help develop preoperative testing algorithms by helping clinicians interpret testing results in light of the patient presentation and surgical procedure.

Answer 40

Bayes theorem describes the probability of an event, based on conditions that might be related to the event (conditional probability).

Question 41

**2,3-DPG** is an intermediate step in the glycolytic pathway and this product of cellular metabolism is a factor in the shifting of the oxyhemoglobin dissociation curve. Given that it is **indicative of cellular metabolism** occurring, increases in its production shifts the curve to the right, favoring oxygen unloading at the level of the tissues.

Answer 41

**Storage of red blood cells** shifts the oxyhemoglobin dissociation curve to the **left**, as does hypothermia.

Question 42

If the **inspiratory valve** is incompetent, exhaled gas will be allowed to enter a part of the inspiratory limb close to the patient

Answer 42

if the **expiratory valve** is incompetent, carbon dioxide will enter the patient (as backflow) throughout the inspiratory phase

Question 43

**Metformin** can be **continued** throughout the perioperative period for **minor surgeries **but may be held starting the day before surgery for major surgeries. The primary risk of continuing metformin is metformin-associated lactic acidosis (MALA).

Answer 43

Metformin is an oral antidiabetic belonging to the biguanide group. Its mechanism of action is to **decrease hepatic gluconeogenesis** and increase insulin sensitivity. Metformin is contraindicated in conditions that increase the risk of **renal hypoperfusion, lactate accumulation, and tissue hypoxia.**

Question 44

Two types of postoperative liver injuries have been reported to be associated with halogenated anesthetic administration. The first type is a mild injury characterized by nausea, lethargy, and fever. The second type, mediated by the patient’s immune system, is severe acute hepatitis with histological findings of widespread hepatic necrosis. This is rare. **Isoflurane & halothane** have highest incident rate. **Desflurane**, as a consequence of **trifluoroacetic acid (TFA) reactive intermediates,** has been implicated in the formation of dangerous immunogenic compounds.

Answer 44

**Sevoflurane** metabolism has not resulted in the formation of TFA intermediates and the potential for hepatic toxicity is low. Instead, sevoflurane metabolism yields a compound **hexafluoroisopropanol** (HFIP), which does not accumulate and rapidly undergoes phase II biotransformation.

Question 45

C7 is the most superior process that is visible, the **spinous process of T1** may be the most prominent in some people. This is a useful landmark for finding the correct level to place a **thoracic epidural.**

Answer 45

Adult **oxygen consumption** = **3-4 mL/kg/min**, **FRC** of any healthy patient = **30 mL/kg.** [FRC (mL) ÷ O2 consumption (ml/min)] * %O2 in FRC = minutes until hypoxemia

Question 46

Approximately 25-30% of **rocuronium** is renally excreted. It is cleared primarily by hepatic uptake and** hepatobiliary excretion**. 80% of **pancuronium** is renally excreted

Answer 46

Redistribution of heat from the core to the periphery is the largest contributor to the initial reduction in core temperature during general anesthesia. Prevention or reduction of this can be accomplished by pre-warming the patient’s extremities prior to the induction of general anesthesia.

Question 47

The parts of the “Scotty dog”

Answer 47

Transverse process: nose Pedicle: eye Pars interarticularis: neck Superior articular facet: ear Inferior articular facet: front leg

Question 48

In liver disease, the blood urea nitrogen (BUN) will be decreased due to decreased production of urea in the liver. If urea production is decreased, toxic ammonia will build up leading which can lead to cerebral edema, encephalopathy, nausea and vomiting, and asterixis.

Answer 48

Ammonia is converted to urea in liver hepatocytes

Question 49

Labetalol has a half-life of six hours when it is administered intravenously and has an effect on blood pressure for ~16 to 18 hours. Onset 5min

Answer 49

Labetalol overall impact is antagonism of α1, β1 resulting in arteriolar vasodilation (α1) and reductions in the heart rate and myocardial contractility (β1). Labetalol is also a partial β2 partial agonist contributing to arteriolar vasodilation.

Question 50

Signs of hypokalemia on ECG include prolonged PR interval, pseudo-prolonged QT interval (actually the QU interval with hidden T wave), QRS prolongation, ST segment depression, decreased wave amplitude, inverted T waves, and U waves.

Answer 50

Question 51

# opiod receptors The µ1 receptor produces the analgesic and physical dependence properties of most opioids the µ2 receptor results in respiratory depression, miosis, euphoria, decreased gastrointestinal motility, and physical dependence.

Answer 51

The κ receptor mediates analgesia, dysphoria, sedation, miosis, but inhibits antidiuretic hormone release. The δ receptor is responsible for analgesia, physical dependence, and perhaps antidepressant effects.

Question 52

Meperidine’s beneficial effects are multimodal and center around the kappa opioid receptor. treats post op shivering. Meperidine metabolite can cause seizures

Answer 52

Meperidine has structural similarities to atropine. Which is why its associated with increases in heart rate

Question 53

Certain spirometry features are characteristic of poor patient effort. The most common of these is a blunting of the initial expiratory burst. If a patient is engaging appropriately, all air within the large airways should be expelled rapidly until the small airways begin to collapse as pleural pressure increases, and then flow should rapidly begin to decline. This results in a sharp point at the top of the expiratory limb and is very apparent in patients with more significant small airway closure (obstructive lung disease). In patients providing a poor expiratory effort, this point will be blunted

Answer 53

A=Normal B= Poor patient effort C= asthma D=COPD

Question 54

Here are some useful anesthetic considerations regarding **Parkinson disease**: - If on carbidopa-levodopa, avoid antidopaminergic medications - Due to levodopa therapy, caution with sympathomimetics (e.g. ephedrine, ketamine) as they may precipitate severe hypertension - Aim to minimize interruptions to levodopa therapy in the perioperative period - Anticipate possible increased dyskinesias with propofol and possible rigidity with opioids

Answer 54

If recently taken an anticholinesterase inhibitor (e.g. rivastigmine, donepezil, or galantamine) anticipate prolonged action from succinylcholine and resistance to non-depolarizing relaxants. - If on selegiline, avoid meperidine due to risk for serotonin syndrome

Question 55

The basal ganglia is responsible for voluntary motor control. It is also involved in procedural learning, habit learning, eye movements, cognition, and emotion.

Answer 55

Norepinephrine is significantly metabolized by the lungs as is serotonin, bradykinin, and angiotensin-1.

Question 56

Angiotensinogen is secreted by the liver and cleaved by renin, which is made in the kidney. Renin converts angiotensinogen to angiotensin-1. Angiotensin-1 is converted to angiotensin-2 by angiotensin converting enzyme (ACE), which is found extensively in the lungs.

Answer 56

Stimulation chassaignac tuberbacle of carotid sinus baroreceptors results in increased parasympathetic discharge This leads to hypotension and bradycardia, which can potentially be prevented by local anesthetic infiltration.

Question 57

For patients with an INR > 5 with no signs of bleeding, warfarin can be held for 1 or 2 doses. If the INR is > 8, oral vitamin K should be administered.

Answer 57

If the INR is elevated and nonmajor bleeding is present, intravenous vitamin K should be administered and will correct INR within 6 to 8 hours.

Question 58

For patients with major bleeding or requiring immediate surgery with INR >3, four-factor PCC should be given

Answer 58

The addition of bicarbonate to a local anesthetic increases the pH of the solution and increases the amount of the non-ionized free base. This, in turn, increases the rate of diffusion and hastens the onset of blockade of the local anesthetic.

Question 59

The following strong ion changes result in the following SID changes: ↓ [Na+] → ↓ SID = acidosis ↑ [Na+] → ↑ SID = alkalosis ↑ [Cl−] → ↓ SID = acidosis ↑ organic acids → ↓ SID and acidosis

Answer 59

Afterload changes demonstrate an inverse relationship with the velocity of fiber shortening. Thus, a decreased afterload will result in increased fiber shortening, as the heart can easily pump more blood through the aorta.

Question 60

Cerebral blood flow remains unchanged within the autoregulatory range of MAPs (50-150 mm Hg) and with PaO2 >50 mm Hg.

Answer 60

For every 1 mm Hg change in PaCO2, CBF changes by approximately 3%. for every one °C decrease in temperature, CMRO2 decreases by approximately 6% with a proportional decrease in CBF

Question 61

Mixing propofol with lidocaine has been shown to decrease the stability of propofol emulsion and may cause pulmonary embolism. The US FDA recommends against mixing propofol with any other therapeutic medications before administration.

Answer 61

For anesthesia providers risk factors for relapse from substance use disorder (SUD) are family history of substance abuse, abuse of a major opioid, and the presence of coexisting psychiatric disorder

Question 62

Local anesthetics have the largest amount of systemic absorption when injected in the intercostal space, followed by caudal, epidural, brachial plexus, and lastly femoral/sciatic. BICEPS: Blood, Intercostal, Caudal, Epidural, Plexus (brachial), Sciatic, Subcutaneous.

Answer 62

Etomidate’s actions on pulmonary vascular tone is by reducing bronchoconstrictive responses to acetylcholine and bradykinin. Etomidate & ketamine are perfect for RSI

Question 63

Higher blood:gas partition coefficients (or blood solubilities) correspond with greater degrees of volatile agent uptake to the pulmonary blood and, thus, a slower onset of action.

Answer 63

inhaled agents with a high FA/FI ratio are associated with a low solubility, while higher blood solubility values are associated with a lower FA/FI ratio.

Question 64

Transtracheal injection of local anesthetic through the cricothyroid membrane results in anesthesia of the recurrent laryngeal nerve. The patient will cough, but ultimately this reflex will be inhibited by the local anesthetic.

Answer 64

Epidural 2-chloroprocaine has an onset time of approximately 6-12 minutes, as a result of the high concentration of local anesthetic that is used. Concentrations are 2-3%

Question 65

Risk factors of transient neurologic symptoms after spinal anesthesia include the use of lidocaine, ambulatory anesthesia, and the lithotomy position.

Answer 65

dabigatran is best corrected with idarucizumab, a drug developed for targeted reversal of dabigatran's effects. PCC cant also reverse dabigatran Andexanet alfa is an agent capable of specifically reversing the effects of apixaban and rivaroxaban.

Question 66

Difference between minimal, moderate, and deep sedation

Answer 66

Question 67

The Parkland formula was designed to approximate how much crystalloid fluid should be administered over the first 24 hours after burn injury. albumin is not recommended in the first 12 hours after a burn injury because it can leak into the interstitial space

Answer 67

4 mL × weight (kg) × TBSA First half given for the first 8 hours, and the second half given for the next 16 hours

Question 68

Barbiturates undergo slow terminal elimination via hepatic metabolism, biliary conjugation, and renal excretion Methohexital has an average elimination half life of 4 hours

Answer 68

The anesthetic action of barbiturates, like most IV anesthetics, are primarily terminated by redistribution. The drug redistributes from the central lipophilic tissues of the brain to the peripheral lean muscle compartments, and lastly to the fat and less well-perfused tissue compartments.

Question 69

The great radicular artery (aka arteria radicularis magna or artery of Adamkiewicz) originates from the aorta between the T9 and T12. The anterior spinal cord is perfused by a single Anterior spinal artery (ASA) with collateralization from the radicular arteries. Interruption of the great radicular artery may result in ASA syndrome, which includes bilateral lower extremity paraplegia as well as bowel and bladder dysfunction.

Answer 69

Sensation and proprioception are classically spared as the posterior portion of the spinal cord is supplied by two Posterior spinal arteries. Spinalcord perfusion pressure = MAP - CSF pressure. CSF pressure is measured via a lumbar spinal drain. Arterial pressure augmentation and CSF pressure reduction are therefore the best methods by which SCPP may be optimized.

Question 70

The respiratory centers in the brain are located in the cerebral medulla, including both dorsal (inspiration) and ventral (expiration) respiratory groups.

Answer 70

The dorsal group is further controlled by two specific pontine areas; the lower pontine center (apneustic) is excitatory, while the upper pontine center (pneumotaxic) is inhibitory.

Question 71

Answer 71

The epidural's improved postoperative pain control improves cardiovascular outcomes, allows a more rapid return of gastrointestinal function, reduces pulmonary complications, reduces the incidence of thrombotic events, and improves participation in postsurgical rehabilitation.

Question 72

Concentration-calibrated variable bypass vaporizers adjust the ratio of fresh gas flow between the bypass flow path and the vaporizing chamber flow path to achieve the desired percentage of volatile anesthetic delivered to a patient. The ratio of flows between the two paths is called the splitting ratio.

Answer 72

Question 73

Infants are more likely than adults to have bradycardia during laryngoscopy and intubation due to a predominance of the parasympathetic nervous system.

Answer 73

The onset of action after an intubation dose of rocuronium (0.6 mg/kg) is approximately one to two minutes.

Question 74

Dexamethasone’s antiemetic activity is likely mediated via central inhibition of the nucleus tractus solitarii. 8-10mg can help reduce pain, sore throat post op. Can cause perianal burning if given while awake

Answer 74

MRI is the best imaging modality for patients with possible neuraxial pathology. Neuraxial anesthesia for a suspected epidural hematoma are acute motor weakness, progressive sensory loss, fever, incontinence. Rarely happens

Question 75

The gag reflex arc (pharyngeal reflex) is controlled by the glossopharyngeal nerve (afferent limb) and the vagus nerve (efferent limb).

Answer 75

An esophageal balloon is useful in determining the transpulmonary pressure. Transpulmonary pressure can guide PEEP titration to improve the patient's respiratory mechanics.

Question 76

A bronchopleural fistula is a connection between the bronchi and the pleural space. This communication between the airways and the pleural space increases the risk of airway infections and makes mechanical ventilation difficult. Will have an airleak if chest tube is present

Answer 76

Question 77

Vasopressin is associated with increased platelet aggregation, which results in a pseudothrombocytopenia

Answer 77

Low-dose vasopressin infusions have been shown to increase nitric oxide levels at the endothelial level; this may be the cause of cerebral, renal, and pulmonary vasodilation while mesenteric and peripheral vascular beds become constricted.

Question 78

According to the Haldane effect, deoxygenated hemoglobin has a higher affinity for CO2. After the deoxygenated hemoglobin reaches the lungs, the high O2 concentration decreases this affinity, and the CO2 is released.

Answer 78

An emergency exists when life or limb is threatened if the patient is not in the operating room within six hours An urgent procedure is required when life or limb is threatened if the patient is not in the operating room within 24 hours A time sensitive procedure can be delayed one to six weeks for evaluation if it will change management An elective procedure can be delayed up until one year

Question 79

Norepinephrine has an affinity for the following: α1 > α2 > β1. Because of its affinities, administration of norepinephrine results in intense vasoconstriction (with reflex bradycardia) and increased myocardial contractility. As a result, norepinephrine elevates arterial blood pressure without significantly affecting cardiac output.

Answer 79

Isoproterenol is a nonselective β-agonist; its use leads to an increase in heart rate and cardiac output via β1 and a decrease in blood pressure via β2.

Question 80

The oxygen analyzer will be the first device to detect a hypoxic mixture in the event of a pipeline crossover or mix-up where oxygen is replaced. A key step in the management of a pipeline supply issue is disconnecting the pipeline supply gases.

Answer 80

The hypoxic guard, or proportioning system, is the system that links oxygen flow to nitrous oxide flow to prevent a hypoxic mixture. These systems are pressure and flow based, thus a crossover will still cause a hypoxic mixture.

Question 81

The nasopharynx provides an accurate measure of cerebral temperature, particularly during hypothermic cardiopulmonary bypass.

Answer 81

Pulmonary artery temperature is considered the gold standard for determining core body temperature. It is not used during cardiopulmonary bypass.

Question 82

Postop ulnar nerve injury occurs more commonly in males and very thin or obese patients. Nerve conduction studies are beneficial in evaluating both motor and sensory deficits. Electromyography can help determine the timing & location of the nerve injury.

Answer 82

E-sized cylinders

Question 83

In order to activate the nicotinic acetylcholine receptor (nAChR), either 2 acetylcholine (ACh) molecules or 1 succinylcholine molecule must bind. The postjunctional nicotinic acetylcholine receptor are composed of 5 subunits (2 alpha, 1 beta, 1 delta, and 1 epsilon).

Answer 83

Due to transection of the cardiac autonomic plexus during transplantation, the donor heart will not exhibit reflex responses such as reflex bradycardia with the administration of phenylephrine nor will it respond to hypovolemia or exercise. With the loss of parasympathetic tone, the resting heart rate is usually 90 to 110 bpm, and there is no heart rate response to anticholinergics.

Question 84

Answer 84

Leads II and V5 is the preferred lead combination because it allows for rhythm monitoring and is sensitive for detecting myocardial ischemia. When it is used alone, V5 has the highest sensitivity for myocardial ischemia.

Question 85

Caution should be taken with anticholinergics in the elderly because the elderly have a decrease in acetylcholine-induced transmission in the central nervous system and an increase in the permeability in the blood-brain barrier allowing for increased central effects.

Answer 85

Contraindications for scopolamine are acute angle-closure glaucoma and allergy to belladonna alkaloids. Anticholinergics, including scopolamine, should be avoided in patients with preeclampsia because they can promote seizures (eclampsia).

Question 86

Nitroglycerin is converted to nitric oxide, sildenafil inhibits its breakdown by phosphodiesterases, and inhaled nitric oxide convert GTP into cyclic guanosine monophosphate (GMP).

Answer 86

Increases in intracellular cyclic GMP will result in smooth muscle relaxation, but can also exert a potent anti-inflammatory effect and inhibit platelet aggregation.

Question 87

Answer 87

In newborns, the dural sac typically ends at S3 and the conus medullaris at L3. In adults, the dural sac typically ends at S2 and the conus medullaris at L1-L2

Question 88

With a complete unilateral injury to the recurrent laryngeal nerve, both the abductor and the adductor fibers would be involved causing the affected vocal cord to remain in a paramedian position.

Answer 88

A partial injury affecting abductor fibers primarily, however, would place the vocal cords in a midline position making a bilateral partial injury a potential airway emergency.

Question 89

Hagen–Poiseuille equation radius is most impactful

Answer 89

Equation can be rephrased as Resistance = 8ηl / πr^4

Question 90

The figure shows the time it takes for isoflurane, sevoflurane, and desflurane concentrations to decrease by 90%

Answer 90

Muscle weakness from high magnesium concentrations results from inhibition of calcium influx, leading to reduced acetylcholine release.

Question 91

A rapid bolus of Mannitol can transiently increase ICP. Prolonged infusions of mannitol have been shown to reverse the osmotic gradient and increase ICP.

Answer 91

CBF decreases 1 to 2 mL/100 g/min for each 1 mmHg decrease in PaCO2. High PaCO2 leads to low CSF pH, which in turn causes release of vasodilator prostaglandins and nitric oxide.

Question 92

Propofol infusion syndrome, or propofol toxicity, occurs in patients receiving prolonged infusions of propofol and manifests with profound bradycardia coupled with metabolic acidosis, lipemia, rhabdomyolysis, and hepatic dysfunction.

Answer 92

A serum lipemia will often occur prior to the onset of other symptoms, which leads to impairment of hepatic lipid regulation in early propofol toxicity. regularly serum triglyceride levels should be checked

Question 93

Immature extrajunctional acetylcholine receptors are unique because of the γ (gamma) subunit type they contain. Both mature and immature receptors contain α1 (alpha 1), β1 (beta 1), and δ (delta) subunit types.

Answer 93

Coronary perfusion pressure of the left ventricle = aortic diastolic pressure − left ventricular end-diastolic pressure (LVEDP)

Question 94

Clevidipine is an IV, dihydropyridine calcium channel blocker that is rapidly metabolized by plasma/red cell esterases providing its short duration of action.

Answer 94

Pulmonary edema can be seen with naloxone administration, especially in larger bolus doses.

Question 95

The muscles of forced exhalation Diaphragm, external/internal oblique muscles, rectus abdominis, transversus abdominis

Answer 95

Inhalational accessory muscles scalene External intercostal muscles sternocleidomastoid muscles, pectoralis major, pectoralis minor, serratus anterior, latissimus dorsi Levator labii superioris alaeque nasi muscle quadratus lumborum.

Question 96

Risk factors for post-dural puncture headache.

Answer 96

Female gender age < 40 vaginal delivery, use of cutting needles (Quinke) needle bevel in the short axis to the spine relative to the long axis

Question 97

The subglycocalyceal layer is a protein-poor fluid compartment within the intravascular space that explains why isotonic crystalloid solutions do not diffuse throughout the extracellular fluid compartments and remain mostly within the intravascular space itself. The volume of this protein-poor fluid compartment may be as much as 700 to 1000 mL in adults.

Answer 97

It has been shown to be primarily responsible for the oncotic gradient driving transcapillary flow between itself and the intravascular space in the traditional starling equation, instead of between the intravascular and interstitial spaces as was previously assumed.

Question 98

The intercostal muscles contain a large number of Golgi tendon organs, also known as tendon spindles, that respond to stretch and allow for chest wall proprioception. Stimulation of these muscles through an inspiratory effort will result in afferent signals to the brainstem respiratory centers to inhibit further inspiration.

Answer 98

The mainstay of treatment for delirium includes multi-component non-pharmacologic approaches such as re-orientation, early mobilization, therapeutic activities, hydration, nutrition, sleep strategies, and hearing and vision adaptations. Only give antipsychotics if the patient is severely agitated, posing harm to themselves or caregivers and threatens interruption of essential medical therapies.

Question 99

Nitric oxide (NO), also known as endothelium-derived relaxing factor (EDRF), is produced in endothelial cells and has vasodilatory effects and anti-aggregating effects on platelets.

Answer 99

NO stimulates insulin release in the pancreas. . Production in vascular endothelium is important in the regulation of blood flow. Anesthesia: NMDA antagonist Analgesia: induction of the release of endogenous opioids Anxiolytic: activation of GABA-A receptors

Question 100

patients with lower extremity bypass also benefit from antithrombotic therapy. Aspirin 325 to 650 mg should be started at least 48 hours before the procedure

Answer 100

All patients with cardiovascular disease should receive lifelong aspirin to prevent ischemic cardiovascular events.

Question 101

It is safe and likely beneficial to allow patients to drink clear liquids for up to 2 hours prior to surgery to optimize their intravascular volume status, decrease their risk of aspiration, and provide patient comfort by decreasing hunger and thirst.

Answer 101

When comparing the intake of fluids 2 hours prior to surgery to 4 hours prior to surgery, however, there is no difference in gastric pH or gastric volume.

Question 102

The interscalene block (ISB) is used to anesthetize the shoulder and proximal upper extremity. The ISB primarily anesthetizes the ventral rami of C5-C7. The C5-C6 nerve roots are identified in the interscalene groove between the middle and anterior scalene muscles. When it is performed properly, the ISB will almost always also block the ipsilateral phrenic nerve, causing hemidiaphragmatic paralysis. The ISB is not recommended for procedures of the forearm and hand because the ulnar nerve (C8-T1) is usually spared.

Answer 102

AS, anterior scalene muscle, MS, middle scalene muscle; SCM, sternocleidomastoid muscle.

Question 103

When opioids are used for neuraxial anesthesia, hydrophilic opioids spread more extensively and persist longer within the cerebrospinal fluid or epidural space.

Answer 103

Question 104

The first step in managing bronchospasm intraoperatively is to raise the FI02 to 100% and begin hand ventilation. If the bronchospasm is mild, it can be treated by deepening the anesthetic by either increasing the inhaled anesthetic or providing a bolus of intravenous propofol or ketamine.

Answer 104

If bronchospasm persists, then a short-acting β2 agonist such as albuterol should be administered via a nebulizer through the breathing circuit. If the bronchospasm is severe or refractory, intravenous epinephrine should be administered.

Question 105

CYP3A4

Answer 105

metabolism of most anesthetics, lidocaine, and dexamethasone

Question 106

MC1R

Answer 106

metabolizes morphine

Question 107

CYP2C9

Answer 107

metabolizes warfarin, phenytoin, and ibuprofen

Question 108

CYP2C19

Answer 108

metabolism of proton pump inhibitors, such as omeprazole, and antidepressants

Question 109

CYP2D6

Answer 109

metabolizes codeine, tramadol, beta-blockers, diltiazem

Question 110

uremia is decreases protein-binding of drugs. Because it is the free-fraction of a medication that exerts its physiologic effect, decreased protein binding of the drug would cause an exaggerated effect and the dosage should, therefore, be decreased.

Answer 110

Methemoglobinemia is potential complication of benzocaine and prilocaine use. Prilocaine’s effect is dose-dependent whereas methemoglobinemia with benzocaine is not dose-dependent.

Question 111

intravenous dyes such as methylene blue, indocyanine green, and indigo carmine can cause falsely low oxygen saturations to be displayed by standard two-wave pulse oximeters.

Answer 111

Fluorescein has not been shown to interfere with standard pulse oximetry measurements.

Question 112

At RED wavelengths 660 nm

Answer 112

deoxyhemoglobin absorbs more light than oxyhemoglobin Pulse ox will be low

Question 113

at INFRARED wavelengths 990nm

Answer 113

oxyhemoglobin absorbs more light than deoxyhemoglobin Pulse ox will be high

Question 114

Anesthesia decreases hepatic blood flow

Answer 114

Glucagon receptors, along with dopaminergic D1, and adrenergic beta2 receptors, cause hepatic artery vasodilation leading to increased hepatic blood flow.

Question 115

Typically, the tourniquet can be used safely for 2 hours. To increase the duration of the tourniquet use, a perfusion break can occur by deflating the tourniquet

Answer 115

Question 116

When the femoral block is performed at the inguinal crease, the structures encountered by the needle as it traverses are skin, subcutaneous tissue, fascia lata, and fascia iliaca. The femoral nerve is enclosed between the iliopsoas muscle and fascia iliaca.

Answer 116

1 ATM = 14 psi = 1013 cmH20 = 101Kpa = 760mmHG

Question 117

An increase in plateau pressure (Pplat) reflects decreased respiratory system compliance (CRS), which is composed of lung and chest wall compliance. Therefore, conditions that decrease CRS such as pulmonary edema, acute respiratory distress syndrome, transfusion-related acute lung injury,pleural effusion

Answer 117

Question 118

Critical temperature is the temperature above which a gas cannot be liquified no matter the pressure applied. If the critical temperature of a medical gas is above room temperature (eg, nitrous oxide, 36.5°C and carbon dioxide, 31.1°C), the gas can potentially exist in both gaseous and liquid forms at room temperature when it is compressed in a medical gas cylinder.

Answer 118

Triple point temperature at which a gas can exist in the solid, liquid, or gas phase

Question 119

Sugammadex does affect the efficacy of oral contraception. It is recommended to use alternative means of birth control for 1 week after sugammadex administration because sugammadex can bind to progesterone.

Answer 119

Cormack-Lehane system

Question 120

Defibrillation success can be improved by using a larger paddle size, biphasic waveform, and conductive materials.

Answer 120

Defibrillation results from a current being passed through the heart causing simultaneous depolarization of the myocardium. This allows the myocardium to repolarize, and then ideally to return to normal conduction

Question 121

Use the following equation to determine expected agent output for the vaporizer being used: Concentration = Agent Output Volume / (Fresh Gas Flow Volume + Agent Output Volume)

Answer 121

Agent output volume = (Saturated Vapor Pressure * Gas Flow) / (Atmospheric pressure - Saturated vapor pressure)

Question 122

Antibody screen: the recipient's serum is mixed with commercially supplied red blood cells (RBCs) (known as screen cells) containing selected antigens commonly implicated in hemolytic transfusion reactions (other than ABO-Rh). Antigens not represented in screen cells are unlikely to cause clinically significant hemolytic reactions.

Answer 122

Crossmatching: the recipient's serum is mixed with donor RBCs. It is possible for some patients, especially those with a history of multiple transfusions or pregnancies, to carry antibodies that would not be detected during an antibody screen. The chance of crossmatching detecting a potentially dangerous antibody that was missed by the antibody screen is .001%

Question 123

Laser procedures pose a substantial risk of airway fire so a METAL Norton ETT is the only nonflammable laser safe tube.

Answer 123

Succinylcholine can be given within 24hrs but should be avoided after 24-48 hours since the initial burn injury and avoided for at least 1-2 years after the burned skin has healed.

Question 124

Pulmonary vascular resistance (PVR) is affected by lung volumes. It is lowest at functional residual capacity (FRC), while increasing or decreasing lung volumes beyond FRC results in an increase in PVR.

Answer 124

Question 125

Magnesium & Dextromorthophan have NMDA antagonist properties

Answer 125

SSRI may inhibits the Cytochrome P450 system and may prolong the actions of different anesthetic drugs

Question 126

ketamine inhibits nitric oxide endothelial production. This results in vasoconstriction and a positive inotropic state. Additionally, ketamine acts as a vagal nerve inhibitor.

Answer 126

Citrate is metabolized into bicarbonate and may cause metabolic alkalosis & hypokalemia

Question 127

During forced exhalation, the lung apices are emptied first, and airway closure occurs first in the lung bases.

Answer 127

The pulmonary system of the newborn displays early alveolar closure when lung volumes are higher than the FRC. Therefore, closing volume approaches the tidal volume

Question 128

Cobra Perilaryngeal Airway and the Tulip Airway device are considered cuffed pharyngeal sealers without esophageal occlusion.

Answer 128

Devices that provide true esophageal occlusion with an esophageal cuff are the Esophageal Tracheal Combitube, EasyTube, and Laryngeal Tube (King LT)

Question 129

Scopolamine is an antimuscarinic drug that, when applied as a transdermal patch, can help prevent or treat PONV for up to 72 hours. The patch should be applied at least 4 hours prior to the need for its antiemetic action.

Answer 129

The patch should never be cut or otherwise damaged as this can alter drug delivery. Common side effects include blurred vision, dry mouth, and elevated intraocular pressure.

Question 130

Halogenated inhalational anesthetics and nitrous oxide are classified as greenhouse gasses. The global warming potential of a halogenated anesthetic is up to 2,000 times greater than CO2.

Answer 130

Naltrexone is a longer-acting opioid antagonist that is better suited for the longer acting opioids such as morphine or hydromorphone

Question 131

Naloxone, an opioid antagonist, has an onset of action of 1-2 minutes and duration of 30-60 minutes. Recurrence of respiratory depression can occur after naloxone administration if used to reverse morphine or hydromorphone

Answer 131

Naloxone can also reverse opioid-induced nausea, vomiting, pruritus, and urinary retention. Naloxone can increase sympathetic stimulation which can cause pulmonary edema and/or myocardial ischemia

Question 132

Scopolamine may also be administered in intravenous (IV) form for amnesia. Neostigmine is used in the treatment of colonic pseudoobstruction (Ogilvie syndrome).

Answer 132

Primary hyperparathyroidism is associated with a tendency for resistance to nondepolarizing neuromuscular blocking agents. This is due to hyperparathyroidism resulting in hypercalcemia which triggers the release of acetylcholine from the presynaptic neuron at the neuromuscular junction.

Question 133

Answer 133

The modified Mallampati score is inadequate as a stand-alone test to predict difficult tracheal intubation with a sensitivity of 35% in predicting difficult intubation or laryngoscopy

Question 134

The tight junctions between endothelial cells surrounding intracranial capillaries restrict the diffusion of small ionic solutes into the brain. Because of this, the cerebral capillary fluid shift becomes a function of both hydrostatic and total osmotic forces.

Answer 134

Of these osmotic forces, the osmolar gradient plays a much larger role than oncotic pressures in contrast to extracranial capillaries. As the osmolar gradient is primarily determined by sodium concentrations, rapid increases or decreases in serum sodium will result in either cerebral desiccation or edema respectively.

Question 135

Receptor Sites α2 (postsynaptic)

Answer 135

Coronary constriction Inhibition of insulin release Decreased bowel motility Analgesia

Question 136

α2 (presynaptic)

Answer 136

Inhibit norepinephrine release in vascular smooth muscle Inhibition of CNS activity

Question 137

ED95 (neuromuscular blockers)

Answer 137

effective dose of a neuromuscular blocking drug required to achieve 95% block of a single twitch in 50% of individuals who receive this drug and dose. For effective relaxation during intubation, one to two times the ED95 is typically administered

Question 138

Glasgow-Coma Scale (GCS)

Answer 138

Question 139

A rightward shift of hemoglobin P50 can occur within a day of smoking cessation. Patients may have improved oxygen delivery to their tissues if they do not smoke on the day of their operation

Answer 139

It is recommended that a patient stop smoking 8 weeks before surgery to help reduce postoperative pulmonary morbidity.

Question 140

CO2 response curve

Answer 140

Cushing Syndrome can cause Hypokalemic metabolic alkalosis as a result of excess cortisol mimicking the action of aldosterone.

Question 141

Reynolds number (R)= velocity * density * diameter / viscosity

Answer 141

When R < 2000, laminar flow is present. When R > 4000, turbulent flow is more likely.

Question 142

CBF increases linearly with PaCO2 between 20 to 80 mm Hg.

Answer 142

Dopamine, fenoldapam , or dobutamine do not help prevent acute kidney injury after cardio pulmonary bypass

Question 143

Atrial natriuretic peptide is released from the atria in response to high filling pressures. Atrial natriuretic peptide is a vasodilator of the afferent arterioles and a vasoconstrictor of the efferent arterioles and will, therefore, increase blood flow to the kidneys when it is released in response to stretching of the atria.

Answer 143

Epinephrine is a potent vasoconstrictor and would be expected to decrease renal blood flow without increasing the glomerular filtration rate

Question 144

Bronchial blockers may be preferred rather than a dual-lumen endotracheal tube (DLT) in the following situations:

Answer 144

presence of tracheostomy, anticipated difficult airway, requirement for nasal intubation, distortion of tracheobronchial anatomy, requirement for a selective lobar blockade, or expected prolonged intubation

Question 145

The halothane-caffeine contracture test is considered the gold standard for malignant hyperthermia diagnostic testing.

Answer 145

mixed venous oxygen tension/saturation

Question 146

Myotonic dystrophy is a disease of impaired muscle relaxation with an abnormal response to succinylcholine administration resulting in excessive fasciculations/contractures that may impair the ability to ventilate and intubate the patient.

Answer 146

Patient with Myotonic dystrophy can have cardiac, endocrine, impaired response to hypoxia and hypercarbia

Question 147

The dicrotic notch in the arterial line waveform tracing correlates with aortic valve closure

Answer 147

Administration of a sodium bicitrate in combination with a histamine 2-antagonist reduces the risk of aspiration injury in patients with a high risk for aspiration. sodium bicitrate has immediate onset time.

Question 148

Required dial setting = Normal dial setting (volume %) * 760 mmHg / (Ambient pressure mmHg)

Answer 148

Example 6% desflurane = ? sea level % * 760 mmHg / 380 mmHg. So 6% desflurane at 0.5 atm is equivalent to 3% desflurane at 1 atm, or about 0.5 MAC.

Question 149

Volume of Distribution (Vd) = Drug dose / Plasma concentration Drugs with high degree of plasma protein binding, low degree of tissue protein binding, and hydrophilic nature have a smaller Vd.

Answer 149

Lipophilic drugs with high degree of tissue proteins, tissue lipids binding have a large volume of distribution.

Question 150

The Valsalva maneuver causes increased intrathoracic pressure, increased central venous pressure, and decreased venous return. The result of this is an initial increase in aortic pressure with a reflexive heart rate decrease, followed by a decrease in venous return causing decreased cardiac output and reflexive increase in heart rate.

Answer 150

After the release of the intrathoracic pressure, there is a brief decrease in aortic pressure with a reflexive increase in heart rate, followed by an increase in cardiac output due to improved venous return with reflexive decreased heart rate

Question 151

Postoperative cerebral hyperperfusion syndrome is an abrupt increase in cerebral blood flow with the loss of autoregulation in the surgically reperfused brain. This syndrome is manifested as headache, seizure, neurological deficits, brain edema, and hypertension. Typically, this syndrome does not occur until several days after a CEA.

Answer 151

RCRI

Question 152

Typical intracardiac pressures are: RA 1-10 mmHg RV 15-30/0-8 mmHg LA 8-10 mmHg LV 90-140/4-12 mmHg

Answer 152

Hypokalemia, hypomagnesemia, and hypercalcemia can potentiate digoxin toxicity. The mechanism for potentiation with hypokalemia is competition between digoxin and K+ for the same binding site on the Na+-K+ATPase enzyme, and, with less potassium, digoxin is able to occupy more binding sites.

Question 153

Protective factors against developing succinylcholine-induced myalgias include

Answer 153

Being male Pregnancy extremes of age high level of muscular fitness.

Question 154

The modified Aldrete scoring system is used to determine when a postoperative patient may be discharged from phase I postanesthesia care unit (PACU) or whether a patient may bypass phase I PACU and go directly to phase II from the operating room.

Answer 154

Components of the modified Aldrete scoring system are activity, breathing, blood pressure, consciousness, and oxygen saturation.

Question 155

ASRA Guidelines for Neuraxial Procedures and Anticoagulation (Heparins)

Answer 155

Question 156

Extrapyramidal side effects include acute dystonias (abnormal movement or posturing due to involuntary/sustained muscle contractions), akathisia (restlessness and the need to be in constant motion), and tardive dyskinesia (involuntary repetitive or purposeless movements).

Answer 156

Anticholinergics are considered first-line therapy for EPS. Additional or second-line therapies include antihistamines, benzodiazepines, beta-blockers, and dopamine receptor agonists

Question 157

metoclopramide has weak antiemetic effect at 10 mg and therefore the recommended dosing for PONV is 25-50 mg IV. Extrapyramidal symptoms occur in 0.3% with 10 mg dosing, and 0.6% with both 25 mg and 50 mg dosing

Answer 157

Thiamine is necessary for pyruvate dehydrogenase and α-ketoglutarate dehydrogenase, two cofactors in the citric acid cycle (also called the tricarboxylic acid cycle or Krebs cycle). Glycolysis is the initial breakdown of glucose into pyruvate, which then enters the citric acid cycle

Question 158

Phases of Emergence From General Anesthesia

Answer 158

Question 159

The pulse pressure variation are effective at indicating fluid responsiveness when:

Answer 159

mechanically ventilated Tidal volumes must be ≥ 8 mL/kg PEEP < 15 cm H2O The patient must be in sinus rhythm

Question 160

NMDA receptor functions as both a ligand and voltage gated receptor. The two primary receptor agonists are glutamate and glycine.

Answer 160

The NMDA receptor’s effects are primarily mediated via increased intracellular calcium.

Question 161

Free water restriction is the primary treatment for hyponatremia unless the sodium drops below 120 mEq/L or there are symptoms, at which point hypertonic saline should be used.

Answer 161

The ventrolateral preoptic nucleus is a hypothalamic structure primarily associated with reduced consciousness when it is activated.

Question 162

DLCO, a measurement of gas exchange, correlates with the total functioning surface area of the alveolar-capillary interface. Arterial blood gas measurements of PaCO2 and PaO2 is an alternative to DLCO.

Answer 162

A DLCO of less than 40% is predictive of postoperative respiratory complications. Postoperative DLCO can be predicted by the formula: Postoperative DLCO = (1 - fraction of resected lung) * preoperative DLCO.

Question 163

Termination of succinylcholine’s effects is a function of its passive diffusion away from the motor endplate.

Answer 163

Pseudocholinesterase is primarily found in the plasma and is not present in significant concentrations at the neuromuscular junction.

Question 164

respiratory quotient (RQ) carbs=1 protein= 0.8 lipid=0.7

Answer 164

When a patient is receiving TPN, monitoring a patient's RQ can help to guide nutritional requirements. Excessive periods of lipogenesis can result in fatty liver injury and excessive CO2 production.

Question 165

Bainbridge reflex

Answer 165

Increased preload stretches the atrial fibers increasing heart rate

Question 166

standard error of the mean

Answer 166

describes the precision of the sample mean to the population mean. SEM = standard deviation / square root (n)

Question 167

Static compliance = VT/Plateaupressure-PEEP normal compliance in men= 40-50 cmH20

Answer 167

Dynamic compliance = VT/Peak Pressure-PEEP normal compliance in women= 35-45 cmH20

Question 168

Regular insulin 10 units IV should be administered with 25 grams of IV dextrose and the blood glucose level should be monitored. If the patient has a blood glucose > 250 mg/dL, then the administration of dextrose can be withheld. A dose of 10 units lowers serum potassium by approximately 1 mEq/L.

Answer 168

An opioid with a pKa less than physiologic pH (~7.4) will have a much greater nonionized fraction whereas an opioid with a pKa >7.4 will have a greater ionized fraction.

Question 169

Double-burst stimulation was developed to allow clinicians to have better tactile stimulation feedback

Answer 169

Redistribution of most anesthetic drugs primarily occurs by movement into the skeletal muscle to terminate drug action.

Question 170

The glycocalyx forms a protein-poor subglycocalyceal layer and is freely permeable to water and electrolytes, although it excludes large molecules such as proteins. When constant capillary pressures are assumed, the primary determinant of transcapillary flow is the plasma-to-subglycocalyceal layer colloid oncotic pressure gradient and not the plasma-to-interstitial fluid colloid osmotic pressure gradient, as has been traditionally taught. Damage to this layer results in increased vascular permeability, which causes interstitial edema and diminished vascular responses to shear stresses.

Answer 170

In periods of acutely decreased hydrostatic pressures (capillary hypotension), an autotransfusion of up to 500 mL may occur from the subglycocalyceal layer into the plasma circulation as the hydrostatic pressure gradient between the subglycocalyceal layer and plasma decreases. Colloid infusion in this situation increases plasma volume, while crystalloid increases total intravascular volume, both plasma and subglycocalyceal layer.

Question 171

Ketamine increases the amplitude of somatosensory evoked potentials. Auditory and visual evoked responses are decreased by ketamine.

Answer 171

The most important sites of action for spinal and epidural anesthesia are the spinal nerve roots and dorsal root ganglia.

Question 172

The action potential is generated by an influx of sodium and efflux of potassium allowed by the opening of voltage-gated ion channels in response to membrane depolarization.

Answer 172

The resting membrane potential is maintained by the sodium-potassium pump that is driven by adenosine triphosphate and extrudes sodium from the neuron while returning potassium to the intracellular fluid.

Question 173

Older physicians with mild cognitive decline likely have little insight about their deficiencies

Answer 173

While reasoning and cognitive flexibility ("fluid" intelligence) declines with increasing age, accumulated knowledge ("crystallized" intelligence) is thought to be maintained. Crystallized intelligence includes professional expertise and wisdom

Question 174

The proper approach for anatomic landmark-guided subclavian vein central line placement involves inserting the needle 1 cm below the inferior margin of the medial 1/3 of the clavicle, directed toward the sternal notch.

Answer 174

For internal jugular central line placement, insert the needle lateral to the carotid artery & angle towards the ipsilateral nipple

Question 175

Nalbuphine is a partial mu opioid receptor antagonist & kappa opioid receptor agonist Treats opioid induced pruritus

Answer 175

Buprenorphine is a partial mu opioid agonist & kappa opioid antagonist. Has mild withdrawal symptoms Has a protective ceiling effect preventing respiratory depression 25 times more potent than morphine

Question 176

It is important to note that atrioventricular (AV) nodal blockers (eg, adenosine, diltiazem, verapamil, beta-blockers) are contraindicated in Wolff-Parkinson-White (WPW) syndrome and must be ruled out before administration of any AV blocking drug.

Answer 176

In WPW, AV nodal blockers prevent normal physiologic conduction through the AV node, leading to preferential conduction down the accessory or preexcitation pathway that can lead to a fatal arrhythmia.

Question 177

The Doppler effect can be used to determine both the direction and the speed of flow. Misalignment of the ultrasound beam will underestimate the blood velocity.

Answer 177

When blood flows toward the ultrasound transducer, the reflected signal frequency is higher

Question 178

Nitroglycerin is a potent direct-acting venous vasodilator that results in preload reduction and coronary vasodilation.

Answer 178

Sodium nitroprusside is a direct-acting vasodilator via conversion to nitric oxide in vascular smooth muscle which leads to increased cGMP levels. It is a balanced arteriolar and venous vasodilator and decreases both afterload and preload.

Question 179

Wilson Score (Predicts the Difficulty of Endotracheal Intubation Before Anesthesia)*

Answer 179

While pulse oximetry does not reflect ventilation per se, it is the most consistent with airway obstruction

Question 180

Absolute contraindications to neuraxial anesthesia include

Answer 180

patient refusal, increased intracranial pressure (except in cases of idiopathic intracranial pressure), infection at the site of injection, uncorrected hypovolemia, allergy to any of the drugs

Question 181

Cefazolin should be redosed if there is > 1500ml of blood loss If a tourniquet is being used, the antibiotic dose should be completed at least 5 minutes prior to tourniquet inflation

Answer 181

Both sympathetic and parasympathetic preganglionic neurons are cholinergic

Question 182

Posterior Ischemic optic neuropathy risk factors are:

Answer 182

prone positioning, long surgical length >5hrs obesity, male gender, significant blood loss, Wilson frame use, external ocular compression.

Question 183

(ASA) physical status classification IV best describes a patient with severe systemic disease that is a constant threat to life.

Answer 183

ASA 4 are myocardial infarction, CVA, or TIA less than 3 months previously ASA 4 =ESRD without undergoing regular dialysis.

Question 184

Airway topicalization focuses on anesthetizing 3 main sensory nerves:

Answer 184

1) Glossopharyngeal nerve (cranial nerve IX) 2) Internal branch of the superior laryngeal nerve (cranial nerve X, vagus nerve) 3) Recurrent laryngeal nerve (cranial nerve X, vagus nerve)

Question 185

Vertebral artery can be punctured during an interscalene nerve block & may lead to seizures

Answer 185

Tramadol is a weak mu agonist that also works like a SNRI. The potential for abuse is high. Risk of serotonin syndrome is high

Question 186

Dopamine is synthesized in

Answer 186

Substania Nigra & Ventral Tegmental

Question 187

Acetylcholine is synthesized in

Answer 187

Laterodorsal Tegmentum

Question 188

Norepinephrine is synthesized in

Answer 188

Locus Coerulues

Question 189

The beneficial physiological effects of colloids result from their long intravascular half-lives (three to six hours) and ability to increase capillary oncotic pressure, which minimizes transcapillary filtration, accounting for their ability to expand intravascular volume. I

Answer 189

In addition, colloid solutions alter blood rheology and can improve blood flow through hemodilution, reduction in plasma viscosity, and reduced red cell aggregation effects.

Question 190

In cirrhosis, the cardiovascular system is hyperdynamic, characterized by increased cardiac output and decreased peripheral vascular resistance and arterial pressure.

Answer 190

In addition, patients with cirrhosis also have a decreased activity of the hepatic arterial buffer response, increased arteriovenous shunting, reduced blood viscosity, congestive heart failure, and cardiomyopathy.

Question 191

In Acute normovolemic hemodilution , the blood is returned to the patient with the units reinfused to the patient in the reverse order of their withdrawal. Theoretically preserving the patient's red blood cell mass and avoiding allogeneic transfusions.

Answer 191

Contraindications to this therapy: severe end-organ dysfunction, preoperative hemoglobin <12 g/dL, presence of bacteremia. 

Question 192

Answer 192

Hypoxic Pulmonary Vasocontriction

Question 193

The function of modern pacemakers is generally designated using a 3 letter code. The first letter indicates the heart chamber(s) paced, the second is the chamber(s) for which intrinsic electrical activity is sensed, and the third is response to sensing. The presence of an R as a fourth letter means the pacemaker is rate-responsive and will increase its rate, for example, when it senses exercise.

Answer 193

When a patient’s intrinsic heart rate is greater than the set pacemaker rate along with a pacemaker in an asynchronous mode, an R-on-T phenomenon may occur leading to ventricular tachycardia or ventricular fibrillation.

Question 194

Morphine duration of action is Morphine peak effect is Morphine onset time is

Answer 194

Duration of action 4hrs (240 min) Peak effect is 90min Onset time is 15 min

Question 195

Hydromorphone duration of action is Hydromorphone peak effect is Hydromorphone onset time is

Answer 195

Duration of action 2 hrs Peak effect is 15min Onset time is 10-15 min

Question 196

Amiodarone side effects also a CYP450 inhibitor

Answer 196

Bradycardia QT prolongation Pulmonary fibrosis/Pneumonitis Blue skin Hepatitis Hyperthyroidism/Hypothyroidism Corneal deposits Peripheral neuropathy

Question 197

The superficial cervical plexus block provides cutaneous analgesia for surgical procedures in the neck, anterior shoulder, and clavicle by blocking the cutaneous branches of the cervical plexus Cervical plexus block used for carotid endarterectomy, tracheostomy, thyroidectomy

Answer 197

The Needle is inserted in the Midpoint of the posterior border of the sternocleidomastoid. *Caution as may puncture vertebral artery

Question 198

To prevent rebreathing in a semiclosed circle system,

Answer 198

the fresh gas inlet cannot be placed between the patient and the expiratory valve APL valve cannot be placed between the patient and the inspiratory valve.

Question 199

Left sided central line placement can cause

Answer 199

Thoracic duct injury ipsilateral supraclavicular swelling or unilateral pleural effusions.  The pleural effusion will most likely manifest as gradually worsening dyspnea and pleuritic chest pain.

Question 200

Postoperative cognitive dysfunction risk factor

Answer 200

Low education level Elderly age Hx of CVA

Question 201

All cervical nerves except C8 emerge above their corresponding vertebrae, while the C8 nerve emerges below the C7 vertebrae.

Answer 201

C1, aka "atlas", has no spinous process or vertebral body

Question 202

Intravenous administration of etomidate is associated with

Answer 202

pain on injection, PONV, and superficial thrombophlebitis.  Ways to prevent thrombophlebitis are to use larger veins, increase the speed of injection, and pretreatment with lidocaine.  T reatment options are controversial but include the use of NSAIDs and elastic stockings.

Question 203

Functional residual capacity increases with age due to loss of elastic lung tissue which acts as an inward force pulling the lungs closed.  An increase will also be seen with increased height secondary to the larger lungs compared to short counterparts.

Answer 203

Transcutaneous nerve stimulation (TENS) provides pain relief by stimulating A-beta mechanoreceptors (which inhibit A-delta and C pain fiber signaling), increasing levels of B-endorphins, and facilitating descending inhibitory pathways.

Question 204

A double-cuff tourniquet can be used to limit the discomfort caused by a tourniquet during a Bier block. 

Answer 204

When tourniquet pain begins to occur, the distal cuff is inflated over the area that had been previously anesthetized, followed by deflation of the proximal cuff to decrease the pain over the proximal cuff.

Question 205

Obstructive Sleep Apnea Criteria

Answer 205

Question 206

Post-cardiac arrest care focuses on the following:

Answer 206

EKG Rapid coronary angiography and intervention For comatose patients, targeted temperature management (TTM) of 32 to 36 degrees Celsius Avoidance of hypotension After TTM, avoidance of fever 72 hours after TTM, prognostication of neurologic outcome

Question 207

Potential complications of Electrosurgery

Answer 207

Burns Small Bowel Perforation Arrhythmias

Question 208

In advanced COPD, hypercapnia with the administration of supplemental oxygen is mainly the result of worsened V/Q mismatch from impaired hypoxic pulmonary vasoconstriction.

Answer 208

Insulin increases the activity of the Na-K-ATPase pump in skeletal muscles, resulting in temporarily lower serum potassium by ~1 mEq/L.

Question 209

Hyperoncotic starches, such as hydroxyethyl starch, are associated with increased risks of coagulopathy, renal injury including the requirement for renal replacement therapy, anaphylactic/anaphylactoid reactions, and mortality compared to crystalloid solutions.

Answer 209

Water is transported across the blood-brain barrier via channel-mediated transport by aquaporin 4 channels.

Question 210

The common peroneal and tibial nerves are located superficial and lateral to the popliteal artery.

Answer 210

The popliteal artery is the most anterior structure on ultrasound from the popliteal fossa.

Question 211

The normal right ventricle is perfused throughout the cardiac cycle. Left ventricle is perfused during diastole

Answer 211

Sedatives and anxiolytics should be given in smaller, incremental doses in obese patients Obesity is no longer considered a risk factor for aspiration.

Question 212

Additives to peripheral nerve blocks such as dexamethasone, and alpha-2-adrenergic agonists (clonidine) may prolong analgesia when combined with local anesthetics.  

Answer 212

Epinephrine does not significantly prolong ropivacaine and bupivacaine epidural and peripheral nerve blockade.   Bicarbonate may lead to precipitation when combined with bupivacaine & wont hasten the onset time.

Question 213

Types of needles

Answer 213

Huber= non cutting epidural Quincke = cutting Whitacre=pencil cutting

Question 214

The administration of dexmedetomidine has minimal to no direct impact on evoked potential monitoring. Sedation caused by dexmedetomidine mimics that of non–rapid eye movement sleep.

Answer 214

The posterior one-third of the spinal cord is supplied by the two Posterior Spinal Arteries, along with collateral radicular vessels.

Question 215

Time constant (in minutes) = Circuit Volume (in liters) / Fresh gas flow (in liters/minute).  

Answer 215

1 time constant= 63% change 2 time constants= 86% change 3 time constants= 95% change

Question 216

Symptoms of Hypermagnesemia

Answer 216

Question 217

Hypertrophic cardiomyopathy is a midsystolic murmur best heard at the apex or left lower sternal border,

Answer 217

HOCM murmur increases with decreased preload HOCM murmur decreases with increased preload

Question 218

 Plasma proteins are relatively higher in

Answer 218

obesity, pregnancy, and burn patients

Question 219

Factors that how prolong neuromuscular blockade

Answer 219

- Desflurane - Phenytoin, Carbamazepine - Ketamine - Antibiotics( aminoglycosides, clindamycin) - Dantrolene - Lithium - Magnesium

Question 220

Nearly all anesthetic agents have a benzene ring in their structure

Answer 220

PRBCs, fresh, frozen plasma, can be transfused through a fluid warmer. Platelets can be transfused through a fluid warmer

Question 221

When to give steroids for chronic users of prednisone

Answer 221

The external iliac arteries become the common femoral artery after the groin crease. The common femoral artery branches off into the deep femoral artery (profunda femoris) and the superficial femoral artery. The deep femoral artery supplies the tissue and muscles in the thigh and proximal part of the femur. The superficial femoral artery continues down the leg and becomes the popliteal artery at the knee crease. The popliteal artery branches off into the anterior tibial artery and the tibiofibular (tibioperoneal) trunk. The tibioperoneal trunk bifurcates into the posterior tibial artery and the fibular (peroneal) artery.

Question 222

Extravasation of vasopressors can be managed with

Answer 222

limb elevation, warm compresses, irrigating with saline (Gault technique), injection of phentolamine, hyaluronidase stellate ganglion block (for upper limbs).

Question 223

Second gas effect is

Answer 223

describes the effect that the rapid diffusion of nitrous oxide has on an additional inhalational agent by increasing its concentration in the alveoli

Question 224

Answer 224

The most common causes of atlantoaxial instability include trauma, achondroplasia, Down syndrome, and rheumatoid arthritis.

Question 225

P50 is normally ~27 mm Hg and corresponds to the PO2 at which 50% of Hgb is saturated at normal physiologic pH and temperature. 

Answer 225

A left shift (due to hypothermia, alkalosis, decreased DPG) causes a decreased P50 and an increased Hgb affinity for oxygen.  A right shift (due to hyperthermia, acidosis, increased DPG) causes an increased P50 and a decreased Hgb affinity for oxygen, meaning more offloading of oxygen.

Question 226

Efficacy is the maximum effect of a drug.  It does not depend on dose.    The efficacy of a partial agonist cannot be higher than that of a full agonist.

Answer 226

Potency is the relative dose required to achieve a given effect and is related to receptor affinity.  The potency of a partial agonist may be higher than that of a full agonist.

Question 227

Barbiturates are to be avoided in patients with  acute intermittent porphyria

Answer 227

Most barbiturates are hepatically metabolized, except for phenobarbital, which is renally cleared

Question 228

Emergence delirium occurs more frequently in children between the ages of 2 to 4 years.  Emergence delirium lasts less than 30 minutes, and treatment is supportive.

Answer 228

The use of desflurane and sevoflurane are strongly associated with the development of emergence delirium.

Question 229

When the line isolation monitor alarm sounds, the first step is to unplug the most recent electronic device that was plugged in.

Answer 229

Velocity measurement as assessed by Doppler ultrasound is governed by the Doppler equation.  The accuracy of the measured value is significantly affected by the cosine of the angle between the blood flow and ultrasound probe.  Values less than 20 degrees have limited effect on actual measured values.

Question 230

ASA risk factors of a Difficult Airway 

Answer 230

Question 231

Alpha waves Beta waves Delta waves Theta waves

Answer 231

resting eyes closed, BIS 65-85 awake, BIS >85 deep anesthesia, BIS 40-65 sedated/sleep, BIS 65-85

Question 232

PaCO2 is normally higher than ETCO2 due to dead space ventilation.

Answer 232

In awake pts, nonmechanical ventilation PaCO2 is 2-5mmHG > than ETCO2 In sedated, mechanically ventilated pts PaCO2 is 5-10 mmHG > than ETCO2

Question 233

The work of breathing (WOB) is composed of the ventilatory rate (VR), airway resistance (AR), and lung compliance (LC).  WOB= VR x (AR/LC)

Answer 233

As lung compliance decreases or the ventilatory rate and airway resistance increase, the work of breathing increases.

Question 234

Disc Herniations

Answer 234

Meperidine is a weak serotonin reuptake inhibitor and can therefore lead to serotonin syndrome if given to patients taking MAO inhibitors.

Question 235

Epidural blood patch is performed by injecting 15 cc patient blood into the epidural space to plug off the leakage of CSF from the post dural puncture. Must be performed within 24 hours of onset of symptoms.

Answer 235

Maintenance of Certification in Anesthesiology, anesthesiologists

Question 236

High-frequency ultrasound waves have greater absorption by the tissues, resulting in a decreased depth of penetration and a higher resolution. (Linear probe)

Answer 236

Low-frequency ultrasound waves have a decreased absorption with increased depth of penetration, but a lower resolution. (Curvilinear probe)

Question 237

Methods to help prevent peripheral nerve injury include injection pressure monitoring. The presence of a high opening injection pressure (> 20 PSI [pounds per square inch]) is a sensitive sign of intrafascicular needle tip placement. Also, high-pressure injection is associated with neurologic deficits and severe axonal damage after the block

Answer 237

Extrafascicular needle tip placement is associated with low pressures (< 20 PSI). . Other methods of preventing peripheral nerve injury include electrical nerve stimulation and ultrasonography.

Question 238

Tetanic stimulation of a nerve will result in an accumulation of calcium within the presynaptic neuron and result in a greater than normal release of acetylcholine into the synaptic cleft.

Answer 238

Nitrous oxide percentages and increase in bowel distention

Question 239

The maximum recommended dose of lidocaine withOUT epinephrine is 5 mg/kg. The maximum recommended dose with epinephrine is 7 mg/kg

Answer 239

symptoms of neonatal myasthenia gravis persist for up to four weeks and diminish as the maternal antibodies against postsynaptic acetylcholine receptors are cleared

Question 240

A clinical examination is considered superior to all ancillary testing such as neurovascular imaging, transcranial doppler, and electrophysiology when one is diagnosing brain death because of the limitations and confounding factors in these ancillary studies.

Answer 240

To reduce the risk of anaphylactic reactions to IgA, patients with established IgA deficiency should receive washed red blood cells. Autologous blood products or those obtained from IgA-deficient donors are also suitable alternatives.

Question 241

infant dehydration

Answer 241

Delayed emergence can be due to residual medication effects, metabolic abnormalities, hyperglycemia, hypoxia or hypercarbia, temperature abnormalities, or neurologic events.

Question 242

the maximum doses for hetastarches is generally less than that of tetrastarches

Answer 242

hetastarches cause a decrease in platelet adhesion, factor 8, and protein C/von willibrand factor