# Bispectral Index and Surgical Space Conditions in Day Surgery Benign Gynecological Laparoscopies: A Double-Blinded Randomized Clinical Trial

## TL;DR

This study tested if using BIS monitoring during anesthesia improves surgical visibility in gynecological laparoscopies but found no significant difference.

## Contribution

This is the first study to investigate BIS-guided anesthesia's impact on surgical field overview in gynecological laparoscopies.

## Key findings

- No significant difference in excellent surgical overview between BIS and control groups.
- Control group used less remifentanil compared to the BIS group.

## Abstract

Background: Ambulatory surgery is increased in numbers, healthcare costs are reduced, and patient safety is high when patient characteristics and type of surgery are properly evaluated. To maintain efficiency and patient safety, anesthesia and surgery must be optimized. The bispectral index (BIS) is a widely used and simplified measure of the depth of anesthesia and may provide a more stable anesthesia and avoid insufficient levels of anesthesia. We investigated whether BIS–guided anesthesia could increase the frequency of excellent overview of the surgical field.

Methods: This is a single-center double-blinded randomized clinical trial. We enrolled patients undergoing gynecologic laparoscopies on a benign indication from April 2019 to March 2021. Using closed envelopes, patients were randomized to receive either a BIS–assisted anesthesia, or to receive anesthesia without BIS monitoring (i.e., control group). Surgeons graded their surgical field overview using a four-grade numerical scale at three predefined time points. The primary outcome was the proportion of patients graded with an excellent surgical overview.

Results: We included 160 women: 80 patients were randomized to the BIS group and 80 to the control group. There was no statistically significant difference between groups in excellent surgical overview at any time point. Among secondary outcomes, a lower remifentanil consumption in the control group was found in comparison with the BIS group.

Conclusions: This trial found no clinically relevant differences regarding surgical overview quality during gynecological laparoscopic surgery when using BIS to titrate anesthesia. To our knowledge, this is the first study investigating this aspect.

Trial Registration: ClinicalTrials.gov identifier: NCT03911544