Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies

Background The results of studies on changes in intracranial pressure in patients undergoing laparoscopic surgery are inconsistent. Meanwhile, previous neurosurgery studies have suggested that propofol and sevoflurane have inconsistent effects on cerebral blood flow and cerebrovascular self-regulation. The purpose of this study is to compare changes in the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery under anesthetic maintenance with propofol versus sevoflurane. Methods This study included 110 patients undergoing laparoscopic gynecological surgery with an estimated operative time of more than 2 hours under general anesthesia. The study was a randomized controlled study. The optic nerve sheath diameter（ONSD）at various time points was measured by ultrasound, including when the patients entered the operating room (Tawake), after successful anesthesia induction and endotracheal intubation (Tinduction), when the body position was adjusted to the Trendelenburg position and the CO 2 pneumoperitoneum pressure reached 14 mmHg, which was recorded as T 0 . Then, measurements were conducted every 15 minutes for the first 1 hour and then once every hour until the end of the surgery（T 15 ,T 30 ,T 45 ,T 1h ,T 2h …）, after the end of surgery and the tracheal tube was removed (T end ), and before the patients were transferred to the ward (T pacu ). Results A significant difference in optic nerve sheath diameter was found between two groups at T 15 , T 30 , T 45 (4.64±0.48mm and 4.50±0.29mm, respectively, p=0.031;4.77±0.45mm and 4.62±0.28mm, respectively, p=0.036;4.84±0.46mm and 4.65±0.30mm, respectively, p=0.012), while there was no significant difference at T awake and other time points. Conclusion During laparoscopic gynecological surgery lasting more than 2 hours, the optic nerve sheath diameter was slightly larger in the propofol group than that in the sevoflurane group in the first 45 minutes. No significant difference was observed between the two groups 1 hour after surgery. Trial registration clinicaltrials.gov，NCT03498235. Retrospectively registered 1 March2018,https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0007UMM&selectaction=Edit&uid=U00040C5&ts=39&cx=c7i8icThe manuscript adheres to CONSORT guidelines.