A 62-year-old woman with polycythemia vera is scheduled to undergo total knee arthroplasty using a tourniquet. Preoperative hematocrit is 60%. Which of the following is the most appropriate action?
(A) Perform total knee arthroplasty without use of a tourniquet
(B) Preoperative reduction of the hematocrit to 45% to 50%
(C) Prophylactic administration of aprotonin during surgery
(D) Prophylactic administration of epsilon-aminocaproic acid during surgery
(E) Prophylactic administration of low-dose heparin during surgery
B
A patient undergoes differential spinal block for evaluation of persistent foot pain. If the pain returns coincident with a decrease in skin temperature, which of the following is the most appropriate conclusion?
Five minutes after intrathecal administration of tetracaine 12 mg in hyperbaric solution, a 60-year-old man has a weak hand grasp. Respirations are normal, heart rate has decreased from 80 to 45 bpm, and blood pressure has decreased from 150/80 to 90/50 mmHg. The most appropriate management at this time is
(A) administration of atropine
(B) administration of ephedrine
(C) administration of phenylephrine
(D) placement of the patient in the head-down position
Immediately after a retrobulbar block for cataract surgery, the eye grossly protrudes and the patient has the sensation of pressure in the eye. The most appropriate initial intervention is
Following antagonism of a nondepolarizing muscle relaxant with neostigmine, twitch height is normal. To achieve this effect, the percentage of the acetylcholine receptor pool that must be free of muscle relaxant is