A 70-year-old man with intraoperative hypoxia and hypotension during total hip replacement.

A 70-year-old man underwent total hip replacement surgery under general anesthesia, endotracheal intubation, and controlled ventilation, with the patient in left lateral position. Intraoperatively, the patient was hemodynamically stable, with a normal range of pulse, ECG trace, oxygen saturation as measured by pulse oximetry (Spo2), and end-tidal CO2 (etco2). Five minutes after insertion of the hip prosthesis, his heart rate dropped to 30 beats/min, BP to 40/30 mm Hg, Spo2 to 70%, and etco2 to 10 mm Hg.