A 58-year-old man with a history of angina is undergoing resection of an abdominal aortic aneurysm under morphine, nitrous oxide, d-tubocurarine anesthesia. Just before removal of the aortic cross-clamp, heart rate is 74 bpm, blood pressure is 115/70 mmHg, and pulmonary artery occlusion pressure is 7 mmHg. Immediately after removal of the cross-clamp, heart rate increases to 120 bpm, blood pressure decreases to 80/55 mmHg, and pulmonary artery occlusion pressure decreases to 3 mmHg. The V5 lead on the EKG demonstrates sudden ST-segment depression and T-wave inversion. Initial therapy should be
(A) reapplication of the aortic cross-clamp
(B) intravenous administration of sodium bicarbonate
(C) initiation of a phenylephrine infusion
(D) rapid expansion of blood volume by transfusion
A 70-year-old man with stable angina is scheduled for cataract removal with a retrobulbar block. After injection of 5 ml of 0.75% bupivacaine, heart rate decreases from 90 to 55 bpm, and frequent premature ventricular contractions are noted on the EKG. These changes are most likely caused by
A 60-kg 25-year-old woman is undergoing laparoscopy in the Trendelenburg position during general anesthesia. Five minutes after peritoneal inflation, the peak airway pressure required to deliver a tidal volume of 800 ml increases from 25 cmH2O to 60 cmH2O. SpO2 decreases from 100% to 80% and systolic blood pressure increases from 110 mmHg to 140 mmHg. Which of the following is the most likely cause?