Quiz 9 Flashcards
What is a consequence of venous air embolism (VAE), and how is it identified?
A. VAE will decrease dead space, causing an ABG to show alkalosis.
B. VAE will result in increased perfusion, causing increased EtCO2.
C. VAE increases dead space, causing EtCO2 to decrease.
D. VAE decreases dead space, causing EtCO2 to decrease.
Answer: C - VAE increases dead space and causes EtCO2 to decrease.
Rationale: VAE increases dead space and contains nitrogen. Therefore, capnography will show a drop in EtCO2 and the presence of end tidal nitrogen. The other answers are either partially correct or completely incorrect. A - VAE would cause respiratory acidosis since EtCO2 decreases. B - VAE results in decreased perfusion, not increased. D- VAE causes an increase in dead space, not a decrease.
Which of the following statements best describes how the lithotomy position can affect blood pressure during surgery?
A. It causes blood pooling in the lower extremities, falsely lowering the blood pressure.
B. Tilting the head down increases venous return, leading to consistently elevated blood pressure.
C. Leg elevation above the trunk increases central blood volume, potentially leading to falsely elevated blood pressure.
D. Blood pressure readings are not affected because the legs are at the same level as the heart.
Answer: C. Leg elevation above the trunk increases central blood volume, potentially leading to falsely elevated blood pressure.
Rationale: In the lithotomy position, the legs are elevated above the trunk of the body. Due to central redistribution of blood volume and autotransfusion, blood pressure can appear falsely normal or high.
Which of the following factors are associated with to nerve injuries in the operating room? (SATA)
A) Extremes of body habitus such as obesity or malnutrition.
B) Preexisting conditions like hypertension, diabetes mellitus, peripheral vascular disease and alcoholism.
C) Orthopedic surgical cases, specifically joint replacements
D) Prolonged surgical times.
E) Anesthetic techniques that include hypotension with poor perfusion, neuromuscular blockade with allows extremes in stretching that can cause harm, and positioning devices used incorrectly.
Correct Answers: A, B, D, E
Rationale: Prolonged surgical times, improper use of positioning devices, and anesthetic techniques like those listed above are factors that contribute to nerve injuries. Patient-related factors such as extremes in body habitus and preexisting health conditions like those listed above are aspects related to the specific patient that can contribute to nerve injuries. There is no information in the text that orthopedic cases have a higher risk for nerve injury.
What type of nerve injury occurs when the nerve is pulled across immovable structures?
A) Compression injury
B) Transection injury
C) Traction injury
D) Crush injury
Answer: C) Traction injury
Rational: Traction injuries can occur when a peripheral nerve is pulled over or under immovable structures. Compression can happen when a nerve is forced against a bony prominence or a hard surface. Stretch injuries occur where nerves such as the sciatic nerve or brachial plexus have a long course across many structures. Transection can occur as a result of surgical maneuvers or by trauma.
What surgical position carries the highest risk for compartment syndrome in lower extremities?
A) Prone
B) Supine
C) Lateral decubitus
D) Lithotomy
Correct Answer: D)
Rationale: Long surgical duration with the patient in lithotomy position is the distinguishing characteristic of surgeries where patients develop lower extremity compartment syndrome. Compartment pressures increase over time in the lithotomy position, and the legs should be periodically lowered to the level of the body if the procedure lasts beyond 2-3 hours.
Which nerve is most at risk from compression at the fibular head in the lithotomy position?
A. Sciatic nerve
B. Femoral nerve
C. Peroneal nerve
D. Obturator nerve
Correct Answer: C. Peroneal nerve
Rationale: The peroneal nerve runs close to the fibular head and is vulnerable to compression from stirrups in the lithotomy position, potentially leading to foot drop.
Which of the following statements regarding operating room safety standards is incorrect?
A. Healthcare providers must have radiation level monitoring if exposed to greater than 40 REM (Roentgen equivalent in man).
B. Air volume exchanges should occur every 15 minutes, as per the NFPA.
C. Operating room humidity should be maintained between 20% and 60%.
D. The ambient operating room temperature should be maintained between 68°F (20°C) and 75°F (24°C).
Correct Answer: B. Air volume exchanges should occur every 15 minutes per NFPA.
Rationale
The National Fire Protection Agency recommends exchanging air via circulation 20 times per hour within an operating room (Butterworth et al., 2023, p. 16). This equates to approximately an air volume exchange every 3 minutes. Inadequate air volume exchange can lead to air stagnation, thereby promoting bacterial growth and increasing the risk of surgical site contamination (Butterworth et al., 2023, p. 16). All other answer choices are correct guidelines and standards associated with operating room safety.
What is the most common metabolic disease associated with spontaneous isolated femoral neuropathy?
A) Hypertension
B) Diabetes
C) Peripheral vascular disease
D) History of smoking within 5 months
Correct Answer: B) Diabetes
Preexisting conditions appear to be associated with an increased risk of developing postoperative position-related injuries. Hypertension, diabetes mellitus, peripheral vascular disease, peripheral neuropathies, and alcoholism can exacerbate the physiologic effects of various positions. Nerve injury and preexisting neuropathies are more common in patients with diabetes, and diabetes is the most common metabolic cause of spontaneous isolated femoral neuropathy.
How much does the Mean Arterial Pressure (MAP) increase or decrease by per inch change in height between the heart and a body region?
A) 1mmHg
B) 2mmHg
C) 3mmHg
D) 4mmHg
Answer: B) 2mmHg
Rationale: Mean arterial pressure increases or decreases by approximately 2mmHg per inch for each change in height between the heart and a body region. Therefore regions elevated above the heart in the head-up, sitting, and lithotomy positions may be at risk for hypoperfusion and ischemia, particularly if hypotension occurs.
Which crew resource management principle is described as the most important for operating room safety?
A. Communication
B. Leadership
C. Assertiveness
D. Situational awareness
Answer: D. Situational awareness
Rationale: According to Butterworth et al. (2022), situational awareness is the most important principle, which is the ability to accurately understand what is happening in the operating room. Losing this awareness can delay vital decisions, especially when a sudden monitor change, like a drop in end-tidal CO₂ or arterial pressure, diverts attention to equipment rather than the patient. Clinicians must quickly decide whether the change reflects a real patient emergency or a monitor error, carefully evaluating both possibilities without delay. Focusing too narrowly, or falling into tunnel vision, can lead to devastating errors.
What is the maximum leakage current allowed in the Operating Room?
A. 10 milliamperes (mA)
B. 10 microamperes (μA)
C. 100 microamperes (μA)
D. 100 milliamperes (mA)
Answer: B. 10 microamperes (μA).
Rationale: As little as 100 microamperes (μA) is enough to stop the heart (if it bypasses the skin). The maximum leakage current allowed in the operating room is 10 microamperes (μA).
Which of the following is typically the responsibility of the anesthesia provider in the event of an intra-operative fire?
A. alcohol-based solutions, drapes, adhesive removers, and towels
B. electrocautery, drills, lasers, burrs, and light-sources
C. oxygen and nitrous oxide concentrations
D. None of the above
Answer: C
Rationale: The fire triad is composed of fuel, oxidizers, and ignition. Different members of the surgical team are typically responsible for a given part of the triad. Surgical techs control fuels, the surgical team controls ignition sources, and anesthesia controls the oxidizer (Butterworth, et al., 2022).
Which of the following nerves in the leg is most susceptible to injury from OR table straps that are placed too tightly?
A. Lateral femoral cutaneous nerve
B. Radial nerve
C. Saphenous nerve
D. Deep peroneal nerve
Answer: A: Lateral femoral cutaneous nerve
Rationale: Straps are commonly used in the operating room to secure patients to the operating room table, to ensure that they do not fall off during the operation. Straps that are too tight are a common reason for nerve injury related to equipment. The lateral femoral cutaneous nerve, which provides sensory information to the lateral thigh, is particularly susceptible to injury from table straps that are placed too tightly around the hip, or thigh region.
Which of the following statements best describes the cardiovascular response to Trendelenburg positioning in hypotensive patients?
A. It consistently increases mean arterial pressure (MAP) and cardiac index (CI)
B. It leads to predictable improvements in stroke volume and venous return
C. It may increase central venous pressure (CVP) but not necessarily improve cardiac output or MAP
D. It effectively treats hypovolemia by redistributing blood volume
Correct Answer:
C. It may increase central venous pressure (CVP) but not necessarily improve cardiac output or MAP
Rationale: Although Trendelenburg positioning can increase CVP, PAP, and pulmonary artery occlusion pressure, these changes do not reliably correlate with improved MAP or cardiac output in hypotensive individuals. In fact, some patients may experience no improvement or even a decrease in cardiac index, and hypovolemia may be masked while the patient is in this position. Therefore, it should not be relied upon as a definitive treatment for hypotension.
When a patient is placed in a steep Trendelenburg position, what happens to the endotracheal tube, which is a complication of the patient’s airway?
A. Inadvertently right mainstem movement of the endotracheal tube
B. inadvertently left mainstem movement of the endotracheal tube
C. No movement of the endotracheal tube happens
D. The endotracheal tube may become obstructed by gastric contents due to increased aspiration risk
Answer: A. Right mainstem movement of the endotracheal tube placement
Rationale: When neck flexion occurs, the endotracheal tube moves downward and may inadvertently enter the right mainstem bronchus. In the Trendelenburg position, pressure of the abdominal contents forces the diaphragm cephalad (move towards the head or anterior), and causes inadvertent right mainstem bronchial endotracheal tube movement.
What is the most sensitive noninvasive device to identify a venous air embolism (VAE)?
A. Transesophageal echocardiogram (TEE)
B. Precordial Doppler
C. End-Tidal CO2 (EtCO2)
D. Transcranial Doppler
Answer: B. Precordial Doppler
Rationale: According to the text, TEE is the gold standard to identify a VAE. However, this requires special training and takes time to perform, it is invasive, and has undesired risks to the patient. Instead, a noninvasive device such as the precordial doppler can be used and is most sensitive. Transcranial Doppler is an alternative, noninvasive device that has great diagnostic capabilities but is not the most sensitive noninvasive device to identify a VAE. EtCO2 will decrease from a VAE, but other pathologies can cause a decrease in EtCO2 as well and is not a specific diagnostic.
While the fibrillation threshold is 100 mA even small electrical shocks can cause ventricular fibrillation if the shock occurs at which point on an ecg?
A. On the P wave
B. On the R wave
C. Just after the S wave
D. On the T wave
Answer: D
Rationale: It is difficult to determine the exact minimum voltage at which an electrical shock would lead to v-fib. Timing, not just voltage, plays an important role in causing v-fib. It has been shown that leak currents measuring as low as 100 microamperes (μA) can cause v-fib if the shock bypasses the resistance of the skin during the T wave phase (ventricular repolarization).
Which of the following is the most likely clinical consequence of ulnar neuropathy resulting from improper surgical positioning?
A. Inability to extend the wrist and loss of sensation to the lateral forearm
B. Diminished grip strength and inability to flex the elbow
C. Inability to oppose the fifth finger and sensory loss in the fourth and fifth digits
D. Numbness over the posterior upper arm and medial forearm
Correct Answer: C. Inability to oppose the fifth finger and sensory loss in the fourth and fifth digits
Rationale: Damage to the ulnar nerve results in the inability to oppose the fifth finger and diminished sensation to the fourth and fifth finger and, if prolonged, can result in atrophy of the intrinsic muscles of the hand, creating a clawlike contracture. (Nagelhout, Elisha, & Heiner, 2023, p. 415)
