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

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.

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.

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.

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.