During active labor, 10 ml of bupivacaine 0.5% with epinephrine 1:200,000 is administered epidurally. Fifteen minutes later, maternal blood pressure is 70/50 mmHg and heart rate is 70 bpm; fetal heart rate is 90 bpm for 45 seconds, with loss of beat-to-beat variability. The most likely explanation for the fetal vital signs is
A 14-year-old girl with status asthmaticus is receiving oxygen 3 L/min through nasal prongs. Heart rate is 110 bpm. Arterial blood gas values are PaO2 90 mmHg, PaCO2 32 mmHg, and pH 7.46. If ventilation appears unchanged, which of the following is the most reliable sign of impending respiratory failure?
A 26-year-old patient with multiple trauma is admitted to the intensive care unit postoperatively. The early development of polyuria, hypotension, low urine sodium excretion, high serum osmolality, and normal serum creatinine concentration is best explained by
A 4-year-old child has just undergone a one-hour tonsillectomy with a volatile anesthetic, nitrous oxide, and oxygen. Which of the following will result in the most rapid emergence?
A middle-aged, 70-kg man with a brain tumor is scheduled for an elective craniotomy. Preoperatively, he is alert but papilledema is present. Anesthesia is induced with thiopental 300 mg and succinylcholine 100 mg, followed by tracheal intubation. Immediately following intubation vigorous bucking occurs. The best immediate management would be to
(A) administer succinylcholine 100 mg intravenously
(B) administer fentanyl 500 jug intravenously
(C) hyperventilate with isoflurane 2%
(D) administer thiopental 400 mg intravenously
(E) hyperventilate and administer lidocaine 1 mg/kg intravenously
A 30-year-old man who is breathing spontaneously has a ventilatory pattern of sustained deep inspiration and occasional expiratory gasps during emergence from general anesthesia after posterior fossa craniotomy. Which of the following is the most likely cause?