A healthy, spontaneously breathing, supine, anesthetized patient has an arterial to end-tidal carbon dioxide tension difference of 3 mmHg. Following institution of mechanical ventilation the value increases to 12 mmHg. The most likely cause of this change is
(A) cephalad displacement of the diaphragm
(B) decreased production of carbon dioxide
(C) increased cardiac output
(D) increased shunting of blood through dependent lung zones
(E) increased ventilation of nondependent lung zones
A 65-year-old patient with compensated congestive heart failure undergoes resection of a large tumor of the temporal lobe. During the procedure, the brain is noted to protrude through the surgical incision. After increasing minute ventila- tion, which of the following is the most appropriate next step in management?
(A) Administration of dexamethasone
(B) Administration of furosemide
(C) Administration of mannitol
(D) Induction of barbiturate coma
(E) Induction of deliberate hypotension
B
The increased resistance of severely burned patients to pancuronium is primarily due to
(A) enhanced urinary excretion of pancuronium
(B) decreased number of presynaptic cholinergic receptors
(C) increased number of postsynaptic cholinergic receptors
(D) increased rate of metabolism of pancuronium
(E) increased volume of distribution of pancuronium
C
A 14-month-old child has tetralogy of Fallot with dynamic obstruction to right ventricular outflow. Which of the following is most likely to decrease cyanosis in this child?
During anesthesia with nitrous oxide 65% in oxygen, fentanyl, and pancuronium, nitroprusside is administered to decrease arterial pressure to 85/50 mmHg. A decrease in PaO2 from 120 to 65 mmHg is most likely caused by
A 25-year-old man with Wolff-Parkinson-White syndrome has paroxysmal supraventricular tachycardia with a heart rate of 200 bpm during insertion of an intramedullary rod for a femoral fracture. Duration of the QRS complex is 0.12 sec. Each of the following antidysrhythmic agents would be appropriate for use in this patient EXCEPT
(A) lidocaine
(B) metoprolol
(C) procainamide
(D) propranolol
(E) verapamil
E
Block of each of the following nerves is required for inguinal herniorrhaphy EXCEPT the