Effects of sevoflurane versus propofol on cerebrovascular reactivity to carbon dioxide during laparoscopic surgery

PURPOSE Cerebrovascular reactivity to carbon dioxide (CVR-CO2) reflects cerebrovascular reserve capacity, which is important in many brain disorders, including cerebrovascular and Alzheimer's diseases. Meanwhile, there is a relationship between CVR-CO2 and cognitive function. Therefore, the study is aimed at investigating the effects of sevoflurane versus propofol on CVR-CO2 during laparoscopic surgery, as well as the role of CVR-CO2 on cognitive function during perioperative period. PATIENTS AND METHODS Eighty-eight patients, aged 18-65 years undergoing elective laparoscopic cholecystectomy, were randomly assigned to group S and group P. The patients in group S were induced with propofol and maintained with sevoflurane. The patients in group P were induced and maintained with propofol (target-controlled infusion). Remifentanil was given to both groups. CVR-CO2 at baseline (before induction), before pneumoperitoneum and during pneumoperitoneum, as well as Mini-Mental State Examination scores at baseline and 24 hours after surgery were recorded. RESULTS In group S, CVR-CO2 before and during pneumoperitoneum increased significantly compared with baseline (P<0.05). In group P, CVR-CO2 before pneumoperitoneum increased significantly (P<0.05), but CVR-CO2 during pneumoperitoneum was not different compared with baseline. In either group, there was no significant correlation between mean blood pressure and CVR-CO2 during surgery, and there was no significant difference between Mini-Mental State Examination scores at baseline and 24 hours after surgery. CONCLUSION Sevoflurane could maintain CVR-CO2 at a higher level during pneumoperitoneum in surgery. Therefore, in patients with impaired cerebrovascular reserve capacity, inhaled anesthetic could be a priority strategy for anesthesia maintenance to improve the compensatory vasodilation ability of cerebral small vessels.