10 Random Questions
The five curves shown represent the uptake of enflurane, desflurane, halothane, isoflurane, and nitrous oxide. Which uptake curve best depicts desflurane?
- (A) Curve A
- (B) Curve B
- (C) Curve C
- (D) Curve D
- (E) Curve E
A 65-kg 70-year-old man in the PACU is breathing spontaneously at 20/min through an endotracheal tube connected to a T-piece with a fresh gas flow of 5 L/min. He has a tidal volume of 350 mL and an FiO2 of 0.5. SpO2 decreases from 98% to 84% over one hour, then improves to 92% with an FiO2 of 1.0. Which of the following is the most likely cause of the hypoxemia?
- (A) Decreased functional residual capacity
- (B) Increased dead space ventilation
- (C) Inhibition of hypoxic pulmonary vasoconstriction
- (D) Room air admixture during inspiration
- (E) Shivering
Which of the following neurophysiologic monitoring modalities is LEAST affected by administration of volatile anesthetic agents?
- (A) Brain stem auditory evoked potentials
- (B) Electroencephalogram
- (C) Motor evoked potentials
- (D) Somatosensory evoked potentials
- (E) Visual evoked potentials
Evaluation of a postoperative neurologic deficit discloses inability to oppose the thumb and little finger, weakness of abduction of the thumb, and loss of flexion of the distal phalanx of the index finger. This problem is most likely related to
- (A) paresthesia occurring during an interscalene brachial plexus block
- (B) attempted radial artery cannulation at the wrist
- (C) inadequate padding under the elbow
- (D) attempted venipuncture in the antecubital fossa
- (E) abduction of the upper humerus against an "ether screen"
Which of the following statements concerning diabetes mellitus in pregnancy is true?
- (A) Beta-mimetic tocolytics cause maternal hypoglycemia
- (B) Epidural anesthesia produces hyperglycemia
- (C) Fetal insulin secretion is suppressed
- (D) Maternal insulin does not cross the placenta
- (E) Maternal insulin resistance develops abruptly after delivery
For 30 minutes, a patient has been receiving oxygen 2 L, nitrous oxide 2 L, and halothane from an agent-specific vaporizer set at 1%. A mass spectrometer sampling gas from the patient's airway shows an end-tidal halothane concentration of 0.7%. The most likely explanation for this difference is
- (A) hyperventilation
- (B) low cardiac output
- (C) the second-gas effect
- (D) tissue solubility of halothane
- (E) vaporizer temperature less than 19°C
Following antagonism of a nondepolarizing muscle relaxant with neostigmine, twitch height is normal. To achieve this effect, the percentage of the acetylcholine receptor pool that must be free of muscle relaxant is
- (A) 10
- (B) 25
- (C) 33
- (D) 50
- (E) 75
Compared with adult hemoglobin, which of the following is a characteristic of fetal hemoglobin?
- (A) It has a greater oxygen-carrying capacity
- (B) It has a lower P50
- (C) It is more likely to cause an artifactual increase in Sp02
- (D) It is more likely to sickle
- (E) It unloads oxygen more readily at the tissues
The mortality rate of patients given drug A is 12% (8 of 66) and the mortality rate of patients given drug B is 15% (10 of 66). Which of the following tests is most appropriate to compare these mortality rates?
- (A) t-Test for paired data
- (B) t-Test for unpaired data
- (C) Wilcoxon rank test
- (D) Chi-square test
- (E) Analysis of covariance
In patients with pregnancy-induced hypertension, magnesium sulfate is most likely to
- (A) decrease maternal heart rate
- (B) decrease sensitivity to relaxants
- (C) decrease succinylcholine-induced fasciculations
- (D) prevent hypokalemia
- (E) produce fetal bradycardia