Postoperative pain after low-pressure versus standard-pressure laparoscopic surgery in children. A randomized clinical trial.

Structured Abstract Background Children still suffer from substantial pain after laparoscopic surgery. It has been hypothesized that low-pressure pneumoperitoneum reduces postoperative pain after laparoscopic surgery. However, this has not yet been studied in school-aged children. Our objective was to determine whether low-pressure pneumoperitoneum (LPP) reduces postoperative abdominal pain compared to standard-pressure pneumoperitoneum (SPP) in children undergoing laparoscopic appendectomy for acute appendicitis. Methods Single-center, parallel-group, superiority randomized controlled trial including children aged 5–17 years undergoing laparoscopic appendectomy. Patients with four-quadrant peritonitis, intraabdominal abscess on ultrasound, or insufficient local language skills to assess postoperative pain were excluded. Patients were randomized to laparoscopic appendectomy with LPP (8 mmHg; intervention arm) or SPP (12 mmHg; control arm). The primary outcome was postoperative abdominal pain intensity, measured using the revised Faces Pain Score on the first postoperative day. Secondary outcomes were shoulder pain intensity, operative time, length of stay, surgeon-rated intraoperative view, analgesic use, intra- and postoperative complications. Results Of 250 randomized patients, 191 completed the study per protocol (LPP n=81, SPP n=110). Median age was 11.55 years and median weight 40 kg. Contrary to our hypothesis, LPP was associated with higher postoperative abdominal (odds ratio [OR] 1.74, 95% CI 1.01 - 3.00) and shoulder pain scores (OR 2.11, 95% CI 0.84 - 5.31) compared to SPP. Shoulder pain was more intense on the right side in both groups (OR 7.81, 95% CI 3.92 – 15.55). Intraoperative view was rated as superior by surgeons during SPP. There were no significant differences between groups regarding all other secondary outcomes. Conclusions In children undergoing laparoscopic appendectomy, LPP does not reduce postoperative pain compared to SPP.