A 62-year-old woman with obesity and type II diabetes mellitus is scheduled to undergo vitrectomy of the right eye. Five minutes after retrobulbar injection with 0.75% bupivacaine 4 ml and intravenous administration of fentanyl 50 ju-g and midazolam 1 mg, she is apneic and unresponsive. Which of the following is the most likely cause?
(A) Fentanyl-midazolam interaction
(B) Hypoglycemia
(C) Intravenous bupivacaine
(D) Retrobulbar hematoma
(E) Subarachnoid bupivacaine
C
Which of the following factors causes a decrease in mixed venous oxygen saturation?
Following a vaginal hysterectomy in the lithotomy position under general anesthesia, a patient has numbness of the lateral aspect of the left calf and medial half of the dorsum of the left foot. On physical examination she has footdrop and the toes cannot be extended. Which nerve is most likely to be involved?
A 25-year-old woman undergoes a difficult open cholecystectomy during anesthesia with isoflurane, nitrous oxide, fentanyl, and vecuronium. Five units of blood are administered intraoperatively. Two days later, the patient has mildly increased serum transaminase concentrations and markedly increased alkaline phosphatase and direct bilirubin concentrations. Which of the following is the most likely cause?