Low-pressure pneumoperitoneum with deep neuromuscular blockade in metabolic surgery to reduce postoperative pain: a randomized pilot trial

Background: For metabolic laparoscopic surgery, higher pressures up to 20 mmHg are often used to create a surgical field of sufficient quality. This randomized pilot study aimed to determine the feasibility, safety and tolerability of low intraabdominal pressure (IAP) and deep neuromuscular blockade (NMB) to reduce postoperative pain. Methods: In a teaching hospital in the Netherlands, 62 patients eligible for a laparoscopic Roux-en-Y gastric bypass (LRYGB) were randomized into one of four groups in a 2 × 2 factorial design: deep/moderate NMB and standard (20 mmHg)/low IAP (12 mmHg). Patient and surgical team were blinded. Primary outcome measure was the surgical field quality, scored on the Leiden-Surgical Rating Scale (L-SRS). Secondary outcome measures were (serious) adverse events, duration of surgery and postoperative pain. Results: 62 patients were included. L-SRS was good or perfect in all patients that were operated under standard IAP with deep or moderate NMB. In 40% of patients with low IAP and deep NMB, an increase in IAP was needed to improve surgical overview. In patients with low IAP and moderate NMB, IAP was increased to improve surgical overview in 40%, and in 75% of these cases a deep NMB was requested to further improve the surgical overview. Median duration of surgery was 38 min (IQR34-40 min) in the group with standard IAP and moderate NMB and 52 min (IQR46-55 min) in the group with low IAP and deep NMB. Conclusions: The combination of moderate NMB and low IAP can create insufficient surgical overview. Larger trials are needed to corroborate the findings of this study.