The use of cerebral oximetry as a monitor of the adequacy of cerebral perfusion in a patient undergoing shoulder surgery in the beach chair position

Four cases of ischemic injury have been reported in patients undergoing orthopedic surgery in the upright position. We describe the use of cerebral oximetry as a monitor of the adequacy of cerebral perfusion in a 63-year-old woman who underwent arthroscopic rotator cuff surgery in a beach chair under general anesthesia. During positioning, a decrease in blood pressure was accompanied by a decrease in cerebral oxygen saturation (S_ctO₂) and was treated with phenylephrine. When spontaneous ventilation resumed, an increase in end-tidal carbon dioxide was accompanied by an increase in S_ct O₂. Cerebral oximetry may prove useful as a guide monitor and manage nonsupine patients.