The effect of the sitting upright or 'beachchair' position on cerebral blood flow during anaesthesia for shoulder surgery

Abstract

The sitting upright or 'beachchair' position is commonly used for shoulder arthroscopic surgery. There is a theoretical concern that anaesthetised patients placed in this posture are at risk of reduced cerebral blood flow (CBF), especially if there is associated hypotension. This study investigated the effect of anaesthetic-induced hypotension on estimated cerebral blood flow in patients placed in the beachchair position for shoulder surgery. Forty patients were randomised to either sedation (propofol infusion 10 to 20 mg.hour -1, n=20) or general anaesthesia using sub minimum alveolar concentration of sevoflurane (n=20). All patients received an interscalene brachial plexus regional block. ..