10 Random Questions
In a patient with surgically significant aortic insufficiency, cardiac output measured by thermodilution will
- (A) be greater than right ventricular output
- (B) be less than left ventricular output
- (C) be less than cardiac output measured by the Fick method
- (D) be inaccurate because of decreased signal-to-noise ratio
- (E) underestimate net systemic arterial blood flow
The primary mechanism for pharmacologic reduction of intraoperative blood loss is
- (A) decreased blood viscosity
- (B) decreased cardiac output
- (C) decreased venous return
- (D) direct myocardial depression
- (E) hypotension
A patient spontaneously breathes nitrous oxide 60%, oxygen 40%, and enflurane for one hour. The nitrous oxide is then replaced with oxygen, and the inspired enflurane concentration is increased from 1% to 2%. Over 10 minutes, the end-tidal carbon dioxide tension increases from 30 to 40 mmHg. The most likely cause is
- (A) discontinuation of nitrous oxide
- (B) decreased alveolar-arterial carbon dioxide tension gradient
- (C) increased metabolic rate
- (D) increased physiologic dead space
- (E) decreased central ventilatory response to carbon dioxide
The ECG tracing shows
- (A) aberrant intraventricular conduction
- (B) acceleration of phase 4 depolarization of the sinus node
- (C) a compensatory pause
- (D) initiation of re-entrant supraventricular tachycardia
- (E) paroxysmal atrial fibrillation
Each of the following changes is expected with deliberate hypothermia EXCEPT
- (A) decreased unloading of oxygen from hemoglobin
- (B) a 5% decrease in MAC for each 1°C decrease in temperature
- (C) increased arterial oxygen and carbon dioxide contents
- (D) a 50% decrease in cerebral metabolic rate at 28°C
- (E) spike and dome EEG activity at temperatures below 30°C
A 1-month-old infant becomes hypoxemic faster during apnea than an adult. Which of the following is the primary cause of this difference?
- (A) Functional residual capacity in an infant is half that of an adult
- (B) Metabolic rate in an infant is twice that of an adult
- (C) Resting PaO2 in an infant is lower than that in an adult
- (D) The number of alveoli in an infant is 12% the number in an adult
- (E) The hemoglobin dissociation curve in an infant is shifted to the right
A patient is anesthetized using an inhaled anesthetic with a blood/gas partition coefficient of 13.0. Recovery time depends primarily on
- (A) oil/gas solubility of the drug
- (B) cardiac output
- (C) tidal volume
- (D) duration of administration
- (E) MAC of the drug
A 6-year-old child with severe cerebral palsy is scheduled for general anesthesia. He is at increased risk for each of the following EXCEPT
- (A) gastroesophageal reflux
- (B) hypersensitivity to central nervous system depressants
- (C) poor function of laryngeal reflexes
- (D) postoperative pulmonary complications
- (E) succinylcholine-induced hyperkalemia
A 90-kg, 59-year-old man with chronic obstructive pulmonary disease is undergoing laparotomy. Mechanical ventilation is being carried out with a fresh gas flow of 2 L/min at a rate of 16/min and tidal volume of 900 ml; I:E ratio is 1:2.5. PaCO2 remains greater than 50 mmHg. Preoperative PaCO2, was normal. Which of the following is the most appropriate next step?
- (A) Adding 10 cmH20 of positive end-expiratory pressure
- (B) Converting to spontaneous ventilation
- (C) Decreasing inspiratory flow rate
- (D) Increasing exhalation time
- (E) Increasing fresh gas flow
Compared with halothane, desflurane has which of the following characteristics?
- (A) Greater potency
- (B) A higher boiling point
- (C) Increased blood solubility
- (D) Less airway irritability
- (E) Less biodegradation