Which of the following statements concerning the choice of nitroprusside or nitroglycerin to induce deliberate hypotension is true?
(A) Nitroglycerin is more potent
(B) Nitroglycerin produces hypotension by acting on both arterial and venous capacitance vessels
(C) Nitroprusside produces less rebound hypertension on discontinuation
(D) The toxic effects of nitroprusside are independent of dose
(E) The therapeutic effects of nitroprusside may persist on discontinuation
B
A 60-kg, 45-year-old woman who takes digoxin for atrial fibrillation receives furosemide 40 mg and mannitol 60 g during resection of a supratentorial meningioma. After initiation of hyperventilation to decrease PaC02 from 35 to 20 mmHg, multifocal premature ventricular contractions are noted on the ECG. The most likely cause is
(A) acute hypokalemia
(B) cerebral ischemia
(C) impending herniation of the brain stem
(D) paradoxical air embolism
(E) surgical manipulation of the meningioma
A
When PaO2 is increased to 300 mmHg in a healthy parturient at term, the umbilical vein PCs will
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 70-kg patient experiences pain on incision of a thigh abscess. The area around the abscess had been infiltrated with 30 ml of 1% lidocaine in 1:200,000 epinephrine. The local anesthetic was most likely ineffective because of
(A) acidosis at the site of the injection
(B) epinephrine-induced limitation of drug diffusion