Sevoflurane Versus Isoflurane for Postoperative Cognitive Dysfunction of Patients Undergoing Major Cardiac Surgeries: A Prospective Cohort Study

Background: Postoperative cognitive dysfunction is a complication associated with low quality of life in patients receiving major cardiac surgeries. Postoperative cognitive dysfunction due to inhaled anesthesia is not well established. The objective of the present study was to compare the incidence of postoperative cognitive dysfunction in patients undergoing major cardiac surgeries anesthetized with isoflurane or sevoflurane. Materials and Methods: The observational study conducted in a teaching hospital to compare the incidence of postoperative cognitive dysfunction as assessed by Mini-Mental State Examination (MMSE) in patients undergoing major cardiac surgery who received isoflurane or sevoflurane. MMSE was administered preoperatively (D0), postoperative day 1 (D1), postoperative day 3 (D3) and postoperative day 5 (D5) to assess cognitive performance. An MMSE score of < 24 or a difference greater than 3 as compared to preoperative score was considered as postoperative cognitive dysfunction. Results: A total of 254 patients (126 patients on isoflurane and 128 patients on sevoflurane) were included in the analysis. At D0, MMSE scores were not significantly different between patients who received sevoflurane and who received isoflurane (p=0.191). The incidence of postoperative cognitive dysfunction was higher in the isoflurane group at all postoperative assessments compared to sevoflurane group (p<0.05 for all). Conclusion: Sevoflurane has fewer chances of incidences of postoperative cognitive dysfunction than isoflurane.