piperidines and Rotator-Cuff-Injuries

During shoulder arthroscopy in the beach-chair position, cerebral ischemia may be a serious complication because prolonged hypotension may affect regional cerebral oxygen supply. We present the cases of 2 patients in whom a reduction in mean arterial pressure after anesthesia provoked a decrease in frontal lobe oxygenation to below the level that causes presyncopal symptoms in the awake subject. In the healthy middle-aged patient, cerebral oxygenation decreased by approximately 40%, indicating that cerebral blood flow was markedly reduced, and intravenous administration of ephedrine rapidly restored cerebral oxygenation. During surgery in the beach-chair position, hypotension must be avoided, and in all patients regional, cerebral oxygenation should be monitored and optimized.

Topics: Anesthesia, General; Arthroscopy; Blood Gas Monitoring, Transcutaneous; Brain Ischemia; Cerebrovascular Circulation; Ephedrine; Frontal Lobe; Humans; Hypotension; Hypoxia, Brain; Intraoperative Complications; Male; Middle Aged; Monitoring, Intraoperative; Piperidines; Posture; Propofol; Remifentanil; Rotator Cuff; Rotator Cuff Injuries