The initial reduction in core temperature during general anesthesia is caused by
(A) ablation of thermoregulatory vasoconstriction
(B) conductive heat loss
(C) evaporative heat loss in the respiratory tract
(D) neuromuscular blockade
(E) redistribution of heat from the core to the periphery
E
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
A 19-year-old woman has severe nausea and vomiting following laparoscopy. After intramuscular administration of prochlorperazine 10 mg, she has muscle spasms in the face, neck, and tongue. Which of the following is the most appropriate management?
A patient has an anterior neck injury, hoarseness, labored respirations, subcutaneous emphysema, and laryngeal crepitus following a motor vehicle accident. Which of the following is the best method of securing the airway in this situation?
(A) Blind nasotracheal intubation
(B) Lightwand intubation
(C) Retrograde wire-guided intubation
(D) Tracheostomy
(E) Transtracheal jet ventilation
D
Which of the following is a characteristic of VVI pacemakers?
(A) They are inhibited by the R wave
(B) They are triggered by the P wave
(C) They are more likely to precipitate ventricular fibrillation than fixed-rate pacemakers
(D) They are unaffected by unipolar electrocautery
(E) They sense both atrial and ventricular depolarization
A
Which of the following is most indicative of reflex sympathetic dystrophy?
Which of the following is the most likely cause of a decrease in end-tidal carbon dioxide tension during general anesthesia with a constant minute ventilation?
(A) Administration of sodium bicarbonate
(B) Intravenous administration of hypertonic glucose solution
(C) Decrease in cardiac output
(D) Decrease in fresh gas flow in a Bain circuit
(E) Malfunction of the inspiratory valve in a circle system
After tracheal extubation, a healthy 21-year-old man has a 30-second episode of laryngospasm with marked intercostal and sternal retractions, which are corrected with continuous positive airway pressure administered by mask. He now has dyspnea and tachypnea, and a roentgenogram of the chest shows diffuse bilateral interstitial edema. The most likely cause is increased
During general anesthesia using a modern anesthesia machine, a patient's spontaneous ventilation is manually assisted with a fresh gas flow of 5 L/min. A sudden malfunction of the pressure-relief (pop-off) valve of the circle absorption system occurs, and the valve cannot be opened. The most appropriate next step is to