(A) metabolites contribute more significantly to the sedative effect
(B) elimination is less dependent on hepatic metabolism
(C) has more predictable action after intramuscular administration
(D) produces less respiratory depression
(E) produces less hypotension during induction of anesthesia with opioids
C
A 70-kg 58-year-old man with unstable angina is scheduled to undergo coronary artery bypass grafting. Intravenous heparin and nitroglycerin are administered for four days before surgery. Before initiating cardiopulmonary bypass, 21,000 units of heparin are administered through the central venous catheter; five minutes later, activated clotting time is 280 seconds. Which of the following is the most appropriate next step in management?
During induction of anesthesia in a 70-year-old man with aortic stenosis, the blood pressure decreases from 140/ 80 to 70/45 mmHg as the cardiac rhythm changes from normal sinus at 70 bpm to junctional at 120 bpm. The most appropriate initial therapy would be
Which of the following increases the cephalad spread of hyperbaric intrathecal local anesthetics?
(A) Cephalad-directed needle bevel
(B) Coughing
(C) Lithotomy position
(D) Obesity
(E) Rapid injection
D
Oxygen 100 ml/min is bubbled through a vaporizer containing an anesthetic with a vapor pressure of 150 mmHg, and this mixture is added to a fresh gas flow of 5 L/min. The delivered anesthetic concentration is
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
In a patient receiving an epidural analgesic infusion postoperatively, clear fluid is noted to drip back freely from the epidural catheter. Each of the following findings correctly identifies the associated fluid EXCEPT
(A) precipitation when mixed with an equal volume of thiopental — local anesthetic