Two days after myocardial infarction involving the left anterior descending coronary artery, a patient's blood pressure decreases acutely from 125/80 to 70/40 mmHg, heart rate increases from 75 to 90 bpm, pulmonary artery pressure increases to 50/30 mmHg, and urine output decreases from 60 to 10 ml/hr. Thermodilution cardiac output has increased from 4 to 7 L/min. The most appropriate action is to
(A) compare mixed venous oxygen saturation in the right atrium and pulmonary artery
(B) draw blood for culture and start antibiotic therapy
(C) start dopamine infusion in low dose
(D) administer a fluid challenge
(E) monitor peripheral capillary oxygenation by transcutaneous oximetry
Two months ago a 68-year-old man with insulin-dependent diabetes mellitus had a transurethral resection of the prostate under spinal anesthesia with tetracaine plus epinephrine. He now has numbness and tingling in both feet and disturbance of gait. Physical examination demonstrates stocking-type hypesthesia of both feet and ankles. The most likely diagnosis is
(A) anterior spinal artery syndrome
(B) diabetic neuropathy
(C) adhesive arachnoiditis
(D) cauda equina syndrome
(E) peripheral nerve injury from the lithotomy position