A 33-year-old primigravid woman with myasthenia gravis, well-controlled with pyridostigmine, is in labor with the cervix dilated 7 cm. She has a headache and feels very nervous. Blood pressure is 160/115 mmHg, she has 3+ pitting edema, and urinalysis shows 4+ protein. Appropriate management of her labor should include
(A) lumbar epidural block with bupivacaine 8 ml of 0.5% solution
(B) is caused by direct suppression of platelet production
(C) is immunologically mediated
(D) is diagnosed by peripheral blood smear
(E) occurs only with larger intravenous doses of heparin
C
During anesthesia with nitrous oxide, oxygen, and a relaxant, the patient's lungs are being mechanically ventilated and there is a heated humidifier in the circuit. The most likely cause of an apparent increase in inspired oxygen concentration is
(A) a hole in the ventilator bellows
(B) backflow of fresh gas because of resistance in the humidifier
A 35-kg child requires mechanical ventilation with 100% oxygen at a tidal volume of 350 mL and a rate of 20/min during a severe asthma attack. The most likely cause of severe hypotension after initiating mechanical ventilation is
A 36-year-old woman who undergoes peritoneal dialysis for chronic renal failure requires emergency surgical exploration for bowel obstruction. Serum creatinine concentration is 9.8 mg/dl and BUN concentration is 124 mg/dl. The most likely abnormality of coagulation is
(A) decreased euglobulin lysis time
(B) decreased platelet count
(C) prolonged activated partial thromboplastin time