10 Random Questions
An 87-kg 64-year-old woman in good general health is undergoing a right knee arthroplasty while in the supine position with general anesthesia consisting of enflurane 2% and nitrous oxide 50% in oxygen. She is breathing spontaneously through a 7-mm endotracheal tube. During the first 30 minutes of the procedure, the arterial oxygen saturation measured by pulse oximetry decreases from 98% to 92%. The most likely cause of the desaturation is
- (A) decreased functional residual capacity
- (B) diffusion hypoxia
- (C) hypercarbia
- (D) increased airway resistance produced by the endotracheal tube
- (E) inhibition of hypoxic pulmonary vasoconstriction
To detect the delivery of hypoxic gas mixture, the optimal location for an oxygen analyzer in this circle is
- (A) 1
- (B) 2
- (C) 3
- (D) 4
- (E) 5
During cardiopulmonary bypass at a nasopharyngeal temperature of 28°C and a hematocrit of 20%, temperature-corrected PaCO2 is 50 mmHg and uncorrected PaCO2 is 60 mmHg. The most appropriate management is to
- (A) administer additional opioid
- (B) administer packed red blood cells to increase hematocrit to 25%
- (C) further decrease the patient's temperature
- (D) increase fresh gas flow to the oxygenator
- (E) institute mechanical ventilation
The acute onset of hypotension without a decrease in mixed venous oxygen saturation is most likely associated with the onset of
- (A) hemorrhage
- (B) myocardial infarction
- (C) pulmonary edema
- (D) pulmonary embolus
- (E) sepsis
Intraocular pressure is
- (A) decreased by glycopyrrolate
- (B) increased by hyperventilation
- (C) decreased by halothane
- (D) increased by nondepolarizing muscle relaxants
- (E) increased by phenylephrine eye drops
A 24-year-old man is undergoing induction of general anesthesia prior to appendectomy. During laryngoscopy, he regurgitates a large amount of bilious material. An endotracheal tube is inserted; aspiration shows bile-stained fluid. Which of the following is the most appropriate next step in management?
- (A) Infusion of a loading dose of aminophylline
- (B) Intravenous administration of broad-spectrum antibiotics
- (C) Lavage of the tracheobronchial tree with saline solution
- (D) Radiograph of the chest
- (E) Proceeding with the operation
The second gas effect refers to
- (A) acceleration of rise in alveolar concentration of a gas caused by concomitantly administered nitrous oxide
- (B) change in volatile anesthetic vaporizer output with the addition of nitrous oxide to the carrier gas mixture
- (C) decrease in MAC of a volatile anesthetic by addition of nitrous oxide
- (D) expansion of gas-containing spaces by addition of nitrous oxide
- (E) rapid diffusion of nitrous oxide from pulmonary capillary blood into alveolar gas at the termination of anesthesia
During active labor, 10 ml of bupivacaine 0.5% with epinephrine 1:200,000 is administered epidurally. Fifteen minutes later, maternal blood pressure is 70/50 mmHg and heart rate is 70 bpm; fetal heart rate is 90 bpm for 45 seconds, with loss of beat-to-beat variability. The most likely explanation for the fetal vital signs is
- (A) fetal bupivacaine cardiotoxicity
- (B) maternal bupivacaine cardiotoxicity
- (C) maternal hypotension
- (D) uterine artery vasoconstriction
- (E) umbilical cord compression
Which of the following is more likely to occur with use of trimethaphan to induce hypotension than with use of nitroprusside?
- (A) A predictable decrease in mean arterial pressure
- (B) Increased mixed venous P02
- (C) Increased serum lactate concentration
- (D) Mydriasis
- (E) Reflex tachycardia
A 2500-g, 12-hour-old infant is tracheally intubated and mechanically ventilated at a rate of 20/min with an FiO2 of 0.4 and peak inspiratory pressure of 25 cmH2O. At birth, amniotic fluid was meconium stained and Apgar scores were 2 and 7. The most recent arterial blood gas levels are PaO2, 50 mmHg, PaCO2, 55 mmHg, and pH 7.20. The most appropriate management is to
- (A) administer sodium bicarbonate
- (B) begin intravenous infusion of prostaglandin E,
- (C) increase FiO2
- (D) increase ventilation
- (E) perform bronchial lavage