Patients and surgery-related factors that affect time to recovery of consciousness in adult patients undergoing elective cardiac surgery

Background: Central nervous system dysfunction is a serious complication following cardiac surgery. The prompt and predictable recovery of consciousness (ROC) from anesthesia is essential for neurological evaluations. This retrospective study aimed to determine the factors that were related to ROC time after elective cardiac surgery. Methods: Patients receiving elective cardiac surgery under general anesthesia were included in the analysis. Patient and surgery-related factors were collected through chart review. Cox regression model was used to evaluate the associations between collected variables and ROC time. Backward model selection strategy was further applied to selecting independent factors from significant ones that affected ROC time in the univariate analysis. Results: A total of 253 patients were recruited in our study. Among significant patient characteristics, higher body mass index (hazard ratio, HR = 1.06) and female gender (HR = 1.72) tended to shorten ROC time, but older age was inclined to prolong it (HR = 0.98). Higher preoperative blood urea nitrogen level also significantly delayed ROC after cardiac surgery (HR = 0.99). Among surgery-related factors, only longer duration of cardiopulmonary bypass significantly increased ROC time after the model selection processes (HR = 0.96). Other factors were not significant after adjustment for these five factors. Conclusion: This study demonstrated that older age, male gender, lower body mass index, higher preoperative blood urea nitrogen level, and longer bypass duration were independent risk factors of delayed emergence after elective cardiac surgery. These findings provide insights into patient care and anesthetic management for clinicians in related fields. Copyright (C) 2011 Elsevier Taiwan LLC and the Chinese Medical Association. All rights reserved.