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 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?
A patient has severe hypotension, bronchospasm, and edema of the upper airway after injection of radiocontrast medium during cerebral angiography. The most appropriate immediate treatment is administration of
A patient receiving propranolol and nifedipine is scheduled for elective coronary artery bypass surgery. During induction with fentanyl and oxygen, heart rate decreases from 52 to 36 bpm and blood pressure decreases from 130/85 to 80/50 mmHg. Administration of atropine 2 mg intravenously has no effect. The most appropriate treatment at this time is administration of
Which of the following findings necessitates the preoperative insertion of a ventricular pacemaker in a 48-year-old man scheduled to undergo cholecystectomy?
(A) Atrial flutter with 3:1 atrioventricular block
(B) Bifascicular (right bundle branch block and left anterior hemiblock) block
(C) Left bundle branch block with first-degree atrioventricular block