In a patient who is receiving nitroglycerin intravenously after a coronary artery operation, peripheral oxygen saturation is 85% and PaO2 is 200 mmHg. The most appropriate management is administration of
A 37-year-old woman with pregnancy-induced hypertension develops oliguria two hours after cesarean delivery during epidural .anesthesia. Despite infusion of 2000 mL of crystalloid solution, urine output remains 10 mL/hr. Which of the following laboratory findings is most suggestive of acute tubular necrosis?
(A) Blood urea nitrogen level of 30 mg/dL
(B) Serum creatinine level of 1.2 mg/dL
(C) Urinary/plasma osmolality of 1:1
(D) Urinary sodium level of 10 mEq/L
(E) Urinary specific gravity of 1.024
C
Which of the following statements concerning metoclopramide is true?
(A) It is antagonized by concomitant administration of atropine
(B) It decreases gastrointestinal motility
(C) It decreases gastric secretion
(D) It lacks antiemetic properties
(E) It stimulates dopamine receptors
A
The Mapleson A system (Magill circuit) illustrated
(A) is functionally equivalent to the Bain circuit
(B) prevents rebreathing more effectively during controlled ventilation than during spontaneous ventilation
(C) provides better humidification than the Mapleson D system
(D) requires a fresh gas flow equal to minute ventilation to prevent rebreathing during spontaneous ventilation
(E) results in less rebreathing during controlled ventilation than the Mapleson C system
D
Having received excessive intraoperative blood replacement, a patient anesthetized with fentanyl, diazepam, and nitrous oxide develops acute pulmonary edema. The drug most likely to have an immediate beneficial effect is
(A) nitroglycerin
(B) nitroprusside
(C) digoxin
(D) isoflurane
(E) mannitol
A
During axillary brachial plexus anesthesia, motor block frequently precedes sensory block because of
(A) conduction velocity of motor fibers
(B) myelination of motor fibers
(C) size of motor fibers
(D) presence of septa between motor fibers
(E) peripheral location of motor fibers in the nerve bundle
A 70-year-old man who has just undergone an abdominal aortic aneurysm repair under halothane anesthesia develops hypertension, dyspnea, and cyanosis shortly after awakening in the recovery room. Administration of furosemide 20 mg intravenously improves the cyanosis within 10 minutes. This immediate effect of furosemide is best explained by