An anesthesia machine is set to deliver oxygen 2 L/min, nitrous oxide 2 L/min, and sevoflurane. After 30 minutes of stable anesthesia, which of the following, is the most likely cause of a decrease in the oxygen analyzer reading from 50% to 30%?
(A) A leak in the ventilator bellows
(B) Accumulation of water on the oxygen sensor membrane
(C) Calibration at 100% oxygen using less than 100% oxygen
(D) Disconnection of the wall oxygen hose
(E) Presence of the oxygen analyzer in the expiratory limb
A 73-year-old woman with a preoperative serum creatinine concentration of 2.1 mg/dl develops oliguria during enflurane anesthesia. Urine sodium concentration is 10 mEq/L and urine osmolality is 450 mOsm/L. The most likely cause of these findings is
A multigravid woman is receiving oxytocin by infusion for augmentation of labor. Fetal heart rate is 190 bpm with beat-to-beat variability of 6 to 8 bpm. The most appropriate immediate action would be to
(A) continue observation
(B) sample fetal scalp blood
(C) discontinue oxytocics
(D) administer a beta-adrenergic blocker to the mother
A 60-year-old man undergoes transurethral resection of a bladder tumor in the lithotomy position with spinal anesthesia. During the procedure the surgeon reports that the patient's right leg is "jumping." This movement is most likely caused by stimulation of which of the following nerves?
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
The two E oxygen cylinders on an anesthesia machine have pressure readings of 1100 psi each. At an oxygen flow of 3 L/min, there will be sufficient oxygen for approximately