A 35-year-old man has acute onset of low back pain, lower extremity weakness, and bladder dysfunction. He had a lumbar laminectomy two years ago. A myelogram shows disk herniation at L4-5. The most appropriate management is
(A) bed rest
(B) administration of a nonsteroidal anti-inflammatory agent
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
An 8-kg, 1-year-old child has a measured blood loss of 50 ml during the first two hours of a rectal pull-through operation. Preoperative hematocrit was 31%. Balanced saline solution 150 ml has been administered for replacement. Urine output has been 2 ml for the last hour, heart rate is 160 bpm, and blood pressure is 40/15 mmHg. The most appropriate fluid therapy is,
A 72-year-old woman is somnolent one day after left carotid endarterectomy. She has smoked 2 packs of cigarettes daily for 50 years. Six weeks ago, she underwent right carotid endarterectomy. At this time, arterial blood gases while breathing room air are PO2, 45 mmHg, PCO2, 60 mmHg, and pH 7.30. Which of the following is the most likely cause of the increased PCO2?