An infant with congenital lobar emphysema is scheduled for thoracotomy. Which of the following should be included in the anesthetic management of this infant?
(A) Helium-oxygen inspired gas mixture
(B) Nitrous oxide administration
(C) Positive pressure ventilation
(D) Prophylactic placement of a chest tube
(E) Spontaneous ventilation until the chest is opened
A 4-month-old child undergoing a craniectomy for craniosynostosis is anesthetized with nitrous oxide and halothane. Suddenly the systolic blood pressure decreases from 75 to 30 mmHg, and the PetCO2 decreases from 35 to 6 mmHg. Which of the following maneuvers is LEAST likely to have a beneficial effect?
(A) Administration of a fluid bolus
(B) Administration of a vasopressor
(C) Application of positive end-expiratory pressure
(D) Discontinuation of nitrous oxide
(E) Flooding the surgical wound with saline solution
The shorter duration of action of alfentanil relative to fentanyl is due to its
(A) greater lipid solubility
(B) increased clearance
(C) increased rate of hepatic metabolism
(D) lesser protein binding
(E) smaller volume of distribution
E
A 60-year-old man undergoing resection of an abdominal aortic aneurysm has an increase in measured mixed venous oxygen saturation from 70% to 90%. Which of the following is the most likely cause?
(A) Decreased cardiac output
(B) Decreased hematocrit
(C) Intrapulmonary shunting
(D) Right to left shunting at the atrial level
(E) Wedging of the pulmonary artery catheter
E
Ten days after sustaining burns over 40% of his body surface area, a patient requires greater than expected doses of vecuronium for adequate relaxation of skeletal muscle. The primary cause is increased