A 70-kg 61-year-old patient undergoes a four-hour resection of an abdominal aortic aneurysm during anesthesia with fentanyl and enflurane. Infrarenal clamping is required during the procedure. Twelve hours after the procedure, urine output is 15 ml/hr with a fractional sodium excretion of 6%. Which of the following is the most likely cause?
A 62-year-old man is in the intensive care unit after successful craniotomy for excision of a meningioma. Blood volume is normal; laboratory studies show serum sodium concentration of 120 mEq/L, serum osmolality of 260 mOsm/L, urine sodium concentration of 50 mEq/L, and urine osmolality of 820 mOsm/L. Which of the following is the most likely explanation?
(A) Fluid overload with 5% dextrose in water
(B) Inappropriate secretion of antidiuretic hormone
A patient receiving monoamine oxidase inhibitor therapy for depression undergoes an emergency cholecystectomy. Which of the following is the best means of providing postoperative analgesia in this patient?
(A) Epidural analgesia using 0.25% bupivacaine
(B) Intravenous meperidine
(C) Epidural analgesia using meperidine
(D) Epidural analgesia using 1% lidocaine with epinephrine
(E) Intercostal analgesia using 1% lidocaine with epinephrine
A 75-year-old man is confused, restless, and disoriented two days after an aortic aneurysm repair. Serum sodium concentration is 112 mEq/L, serum osmolality is low, and urine is hypertonic. The most appropriate treatment is
(A) restriction of fluid intake
(B) administration of isotonic saline solution
(C) administration of hypertonic (3%) saline solution
(D) administration of spironolactone
(E) infusion of mannitol 25 g
C
During insertion of a Harrington rod with deliberate hypotension for correction of spinal scoliosis, accurate interpretation of somatosensory evoked potentials requires
(A) core temperature greater than 35∞C
(B) hematocrit of at least 25%
(C) mean arterial pressure greater than 70 mmHg
(D) P02 of at least 80 mmHg
(E) reversal of neuromuscular block
A
During exploration of the posterior fossa with the patient in the sitting position, blood pressure decreases from 120/70 to 70/40 mmHg, central venous pressure increases from 6 to 16 mmHg, oxygen saturation decreases to 88%, nitrogen is detected by the mass spectrometer, and premature ventricular contractions appear on the ECG. The most appropriate management is to
A 2.8-kg 8-hour-old infant undergoes laparotomy for a ruptured omphalocele. Following primary closure of the abdominal wall, arterial blood gases are PaO2 40 mmHg (FiO2 0.6), PaCO2 55 mmHg, and pH 7.1. Blood pressure is 30/20 mmHg. After increasing the FiO2, the most appropriate action would be to
(A) obtain a radiograph of the chest immediately
(B) withdraw the endotracheal tube 1 cm
(C) assess the patient for coexisting congenital heart disease
(D) administer lactated Ringer's solution 15 ml/kg