Effect of Different Levels of Positive End-Expiratory Pressure on Pulmonary Shunt During Laparoscopic Cholecystectomy

Background: Laparoscopic cholecystectomy is associated with altered respiratory mechanics due to carbon dioxide insufflation and pneumoperitoneum. Positive end-expiratory pressure (PEEP) may mitigate these effects, but the optimal level remains uncertain. Objective: This study aimed to evaluate the impact of different PEEP levels on pulmonary shunt indicators and respiratory mechanics during laparoscopic cholecystectomy. Patients and Methods: A randomized controlled trial was conducted on 48 adult patients undergoing elective laparoscopic cholecystectomy. Participants were equally assigned to three groups based on applied PEEP: 0 cmH₂O (Group A), 5 cmH₂O (Group B), and 10 cmH₂O (Group C). Plateau pressure, peak inspiratory pressure (PIP), heart rate, oxygen saturation, and mean arterial pressure were recorded at baseline, after insufflation, and at 15, 30, and 45 minutes intraoperatively. Intergroup comparisons were made using ANOVA and post hoc tests. Results: Demographic and operative characteristics were comparable among the groups. Following pneumoperitoneum, plateau and PIP values increased significantly within all groups (p < 0.05). However, Group C demonstrated significantly lower plateau and PIP values at 15, 30, and 45 minutes compared to Groups A and B (p < 0.001). Heart rate, oxygen saturation, and mean arterial pressure remained stable and did not differ significantly across groups throughout the study period (p > 0.05). Conclusion: Application of 10 cmH₂O PEEP during laparoscopic cholecystectomy effectively attenuates the rise in airway pressures following pneumoperitoneum without compromising hemodynamic stability or oxygenation. These findings support the use of moderate PEEP to optimize respiratory mechanics in laparoscopic procedures.