Effect of controlled hyperventilation on post-laparoscopic cholecystectomy shoulder pain: a prospective randomized controlled trial

Objective This study investigated whether intraoperative controlled hyperventilation could reduce the incidence and severity of post-laparoscopic shoulder pain. Methods In this prospective, randomized, double-blind controlled trial, 150 patients undergoing elective laparoscopic cholecystectomy were randomly assigned to either controlled hyperventilation (n = 75) or conventional ventilation (n = 75) groups. The hyperventilation group received mechanical ventilation with a tidal volume of 10 mL/kg and respiratory rate adjusted to maintain end-tidal CO2 between 30 and 35 mmHg, while the control group received conventional ventilation (tidal volume 8 mL/kg, end-tidal CO2 35-45 mmHg). The primary outcome was the incidence and severity of shoulder pain during the first 48 postoperative hours. Secondary outcomes included intraoperative parameters, gas exchange values, surgical site pain, and patient satisfaction. Results The hyperventilation group demonstrated significantly lower shoulder pain incidence (36.0% vs. 60.0%, P = 0.003), shorter pain duration (4.13 +/- 6.25 vs. 9.24 +/- 7.82 h, P < 0.001), and consistently lower pain intensity scores at all time points up to 48 h postoperatively. The intervention group also showed shorter operation time (50.01 +/- 12.04 vs. 80.32 +/- 34.23 min, P < 0.001), lower pneumoperitoneum pressure requirements (11.73 +/- 1.19 vs. 33.72 +/- 19.47 mmHg, P < 0.001), and improved patient satisfaction (73.33% vs. 42.67%, P < 0.001). No significant differences were observed in postoperative complications, time to first flatus, or length of hospital stay. Conclusion Intraoperative controlled hyperventilation effectively reduces the incidence and severity of shoulder pain following laparoscopic cholecystectomy, while improving surgical conditions and patient satisfaction. This simple intervention provides a safe and cost-effective approach to enhancing postoperative outcomes in laparoscopic surgery.