A patient whose trachea is intubated develops partial airway obstruction two hours after induction of fentanyl, nitrous oxide, oxygen anesthesia. The anesthesiologist discontinues the nitrous oxide and controls ventilation, and there is gradual improvement during the next hour. No evidence of a respiratory disorder is found at the conclusion of the anesthetic. Which of the following is most likely?
(A) The endotracheal tube was in the right mainstem bronchus
(B) The patient had an unrecognized air embolism
(C) The patient had a nitrous oxide pneumothorax
(D) The endotracheal tube cuff narrowed the airway
Which of the following is most effective for maintaining core body temperature in an adult during general anesthesia for foot surgery?
(A) Heating inspired gas to 28°C
(B) Warming intravenous fluids to 30°C
(C) Increasing ambient temperature to 28°C
(D) Placing a warming blanket beneath the patient
(E) Placing four 200-watt warming bulbs within 76 cm of the wound
C
Each of the following conditions is a cause of agitation in a patient following transurethral resection of the prostate EXCEPT
(A) bladder distention
(B) glycine absorption
(C) inadequate analgesia
(D) serum sodium concentration of 127 mEq/L
(E) systolic pressure of 60 mmHg
D
Which of the following combinations of hemoglobin, blood gases, and cardiac output provides the greatest delivery of oxygen to tissue? (Hb, PaO2, SaO2, CO)
In an anesthetized patient being mechanically ventilated, end-expired carbon dioxide is 58 mmHg and peak inspiratory airway pressure is 15 cmH20. Ventilator settings indicate a delivered tidal volume of 800 ml, but the expiratory flowmeter shows a tidal volume of 360 ml. Which of the following is the most likely cause of this discrepancy?
(A) Fresh gas flow of 0.5 L/min
(B) Incompetence of the pressure-relief valve
(C) Low ventilatory rate
(D) Presence of a hole in the ventilator bellows
(E) Prolongation of the inspiratory phase
B
Which of the following is an effect of ketorolac administered after vaginal hysterectomy?
A patient who is paraplegic secondary to spinal cord transection at T3 develops bradycardia and facial flushing during a nephrectomy under general anesthesia with nitrous oxide, fentanyl, and atracurium. The most likely cause of this response is