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
A 2.3-kg 1-day-old term infant requires repair of a gastroschisis. Which of the following combinations is most appropriate for intraoperative fluid management?
(A) Dextrose 5% in water for maintenance and lactated Ringer's solution for replacement of third space losses
(B) Dextrose 10% in water for maintenance and lactated Ringer's solution for replacement of third space losses
(C) Lactated Ringer's solution for maintenance and replacement of third space losses
(D) Lactated Ringer's solution for maintenance and albumin 5% for replacement of third space losses
(E) Normal saline solution for maintenance and lactated Ringer's solution for replacement of third space losses
A 120-kg 56-year-old man undergoing gastrectomy during anesthesia with fentanyl and isoflurane has a PetCO2 of 35 mmHg and a PaCO2 of 50 mmHg. His FEV,/FVC ratio is 80% of predicted. Heart rate is 120 bpm and arterial blood pressure is 80/40 mmHg. Which of the following is the most likely cause of the difference in PaCO2 and PetCO2?
A 45-year-old woman who sustained a subarachnoid hemorrhage 18 hours ago develops a severe headache and becomes unresponsive. Which of the following is the most likely cause of this patient's change in mental status?
An anesthetized, paralyzed patient is placed in the lateral position and mechanically ventilated. End-tidal PCO2 is 34 mmHg and PaCO2 is 43 mmHg. This gradient
(A) increases during spontaneous breathing
(B) indicates increased dead space ventilation
(C) is caused by increased intrapulmonary shunt
(D) reflects inhibition of hypoxic pulmonary vasoconstriction
During pulmonary artery catheterization, a 65-year-old man receives morphine 6 mg and scopolamine 0.4 mg intravenously. The pulse oximeter indicates desaturation, which quickly resolves with stimulation. When the drapes are removed, he has unilateral eye pain, decreased visual acuity, and dilated and irregular pupils. These eye symptoms are most likely caused by