CEREBRAL EMBOLI AND SERUM S100-BETA DURING CARDIAC OPERATIONS

Background. The glial protein S100 beta has been used to estimate cere bral damage in a number of clinical settings. The purpose of this inve stigation was to determine the correlation between cerebral microembol i and S100 beta levels during cardiac operations. Methods. Transcrania l Doppler ultrasonography was used to measure emboli in the right midd le cerebral artery. Emboli counts (n = 111) were divided into five tim e periods: (1) incision to aortic cannulation; (2) aortic cannulation to cross-clamp onset; (3) cross-clamp onset to cross-damp release; (4) cross-clamp release to decannulation; and (5) decannulation to chest closure. The level of S100 beta (n = 156) was measured at baseline, at the end of cardiopulmonary bypass, then 150 and 270 minutes after cro ss-clamp release. Results. The level of S100 beta correlated with age, cardiopulmonary bypass time, cross-clamp time, and number of emboli a t time period 2. Although cardiopulmonary bypass time was univariately associated with S100 beta level, it became nonsignificant in a multiv ariable model that included age and cross-clamp time. Conclusions. The correlation of S100 beta level with emboli measured during cannulatio n (time period 2) supports the hypothesis that cannulation is a high-r isk time period for cerebral injury. (C) 1998 by The Society of Thorac ic Surgeons.