# Effect of tidal volume on gastric insufflation during laparoscopic cholecystectomy: a strictly retrospective observational study

## TL;DR

This study shows that using a tidal volume of 8 mL/kg during anesthesia for laparoscopic cholecystectomy reduces gastric insufflation compared to higher volumes.

## Contribution

The study provides evidence that 8 mL/kg tidal volume minimizes gastric insufflation during facemask ventilation for laparoscopic cholecystectomy.

## Key findings

- Gastric insufflation incidence was 60% in the 10 mL/kg group versus 15% in the 6 mL/kg group.
- Antral area expansion was significantly greater in the 10 mL/kg group compared to the 6 mL/kg group.
- PetCO2 and ETO2 levels varied significantly across the three tidal volume groups.

## Abstract

Laparoscopic cholecystectomy (LC) is the gold-standard minimally invasive gallbladder removal procedure. Optimal ventilation during LC requires positive end-expiratory pressure (PEEP) and low tidal volumes (TV) to prevent gastric insufflation (GI), which may cause regurgitation and cardiopulmonary complications.

This strictly retrospective observational study analyzed routine collected data from 60 patients undergoing laparoscopic cholecystectomy between January 2022 and December 2023. Patients were categorized into three groups based on anesthesia records of delivered tidal volumes (6, 8, or 10 mL/kg) during facemask ventilation. While group assignment was performed retrospectively, ventilation parameters were standardized per institutional protocol, ensuring consistent clinical delivery. Patients were divided into Group 1 (6 mL/kg), Group 2 (8 mL/kg), and Group 3 (10 mL/kg). Gastric insufflation was assessed via ultrasonography, and respiratory parameters end-tidal carbon dioxide (PetCO2), end-tidal oxygen (ETO2), and peak inspiratory pressure (PIP) were recorded.

GI incidence was significantly higher in Group 3 (60%) vs. Group 1 (15%, p = 0.0079) and Group 2 (20%, p = 0.0225). Group 3 showed greater antral area expansion post-ventilation (504.1 ± 109.8 mm2 vs. 420.1 ± 47.1 mm2, p = 0.001). PetCO2 and ETO2 levels differed significantly across groups (p < 0.001).

The study reveals that Group 2’s facemask ventilation may improve preoxygenation and minimize gastric insufflation during laparoscopic cholecystectomy anesthesia induction. Further research is needed due to the small sample size, ultrasonography accuracy issues, and a single-center scenario.