Evaluation of the effect of fluid management on intracranial pressure in patients undergoing laparoscopic gynaecological surgery based on the ratio of the optic nerve sheath diameter to the eyeball transverse diameter as measured by ultrasound: a randomised controlled trial

Abstract Background During gynecological laparoscopic surgery, pneumoperitoneum and the Trendelenburg position (TP) can lead to increased intracranial pressure (ICP). However, it remains unclear whether perioperative fluid therapy impacts ICP. The purpose of this research was to evaluate the impact of restrictive fluid (RF) therapy versus conventional fluid (CF) therapy on ICP in gynecological laparoscopic surgery patients by measuring the ratio of the optic nerve sheath diameter (ONSD) to the eyeball transverse diameter (ETD) using ultrasound. Methods Sixty-four patients who were scheduled for laparoscopic gynecological surgery were randomly assigned to the CF group or the RF group. The main outcomes were differences in the ONSD/ETD ratios between the groups at predetermined time points. The secondary outcomes were intraoperative circulatory parameters (including mean arterial pressure, heart rate, and urine volume changes) and postoperative recovery indicators (including extubation time, length of post-anaesthesia care unit stay, postoperative complications, and length of hospital stay). Results There were no statistically significant differences in the ONSD/ETD ratio and the ONSD over time between the two groups (all p > 0.05). From T2 to T4, the ONSD/ETD ratio and the ONSD in both groups were higher than T1 (all p