Neer Award 2012: Cerebral oxygenation in the beach chair position: a prospective study on the effect of general anesthesia compared with regional anesthesia and sedation

Background: Devastating neurologic ischemic episodes, such as stroke and deafness, have occurred in patients undergoing shoulder surgery in the beach chair position. We hypothesized that awake patients would be able to avoid significant cerebral deoxygenation events (CDEs) compared with anesthetized patients when procedures were performed in the beach chair position. Materials and methods: Sixty patients underwent elective shoulder surgery in the beach chair position. Thirty patients underwent an interscalene block and monitored sedation (awake group); 30 patients underwent general anesthesia (asleep group). Cerebral oxygenation saturation (SctO(2)) was measured during the procedure. SctO(2) values below critical thresholds were defined as CDEs and treated. Results: Baseline mean arterial pressure and SctO(2) values were lower in the asleep group during the operation (P < .0001). A higher incidence of CDEs was seen in the asleep group (56.7% vs 0% awake group), and more CDEs were seen per patient (2.97 in asleep vs 0 awake, P <. 0001). SctO(2) below a threshold value of 55% was seen in 23.3% in the asleep group vs 3.3% in the awake group. A total of 89 combined desaturation events were documented in the asleep vs 1 in the awake group (P < .0001). Conclusions: Patients in the beach chair position treated with regional anesthesia and sedation had almost no cerebral desaturation events, unlike patients who had general anesthesia. Avoidance of general anesthesia in the beach chair position may reduce the risk of ischemic neurologic injury. Level of evidence: Level II, Prospective Cohort Design, Treatment Study. (C) 2013 Journal of Shoulder and Elbow Surgery Board of Trustees.