Prevalence of cerebrovascular events during shoulder surgery and association with patient position.

The beach chair position is commonly used in both arthroscopic and open shoulder procedures. There has been recent concern that beach chair positioning may be an independent risk factor for intraoperative cerebrovascular insult, especially in concert with hypotensive anesthesia. We attempted to quantify the prevalence of intraoperative cerebrovascular events during shoulder surgery in the beach chair position. Two hundred and eighty-seven members of the American Shoulder and Elbow Surgeons (ASES) Society were e-mailed surveys, and 93 (32%) responded. The majority of these surgeons average >300 shoulder cases annually. Most of these cases are arthroscopic, and patient position is primarily beach chair. The total number of beach chair-position surgeries was estimated between 173,370 and 209,628, and lateral decubitus-position surgeries were estimated between 64,597 and 100,855. The overall rate of intraoperative cerebrovascular event was 0.00291% (8/274,225). All cerebrovascular events were associated with surgeries in the beach chair position. The rate in the beach chair position ranged from 0.00382% (8/209,628) to 0.00461% (8/173,370). If reported primary patient position was used > or = 75% of the time, no significant difference in observed cerebrovascular event rates was found between positions (P=.051-.0233). In relation to orthopedic procedures performed in the supine position, beach chair positioning does not appear to increase the risk of intraoperative cerebrovascular event.