Low-pressure pneumoperitoneum with deep neuromuscular blockade versus standard pressure pneumoperitoneum in patients undergoing laparoscopic cholecystectomy for gallstone disease: a non-inferiority randomized control trial.

Background: Low-pressure pneumoperitoneum (LPP) is an attempt at improving laparoscopic surgery. However, it has the issue of poor working space for which deep neuromuscular blockade (NMB) may be a solution. There is a lack of literature comparing LPP with deep NMB to standard pressure pneumoperitoneum (SPP) with moderate NMB.

Methodology: This was a single institutional prospective non-inferiority RCT, with permuted block randomization of subjects into group A and B [Group A: LPP; 8-10 mmHg with deep NMB [ Train of Four count (TOF): 0, Post Tetanic Count (PTC): 1-2] and Group B: SPP; 12-14 mmHg with moderate NMB]. The level of NMB was monitored with neuromuscular monitor with TOF count and PTC. Cisatracurium infusion was used for continuous deep NMB in group A. Primary outcome measures were the surgeon satisfaction score and the time for completion of the procedure. Secondarily important clinical outcomes were also reported.

Results: Of the 222 patients screened, 181 participants were enrolled [F: 138 (76.2%); M: 43 (23.8%); Group A n = 90, Group B n = 91]. Statistically similar surgeon satisfaction scores (26.1 ± 3.7 vs 26.4 ± 3.4; p = 0.52) and time for completion (55.2 ± 23.4 vs 52.5 ± 24.9 min; p = 0.46) were noted respectively in groups A and B. On both intention-to-treat and per-protocol analysis it was found that group A was non-inferior to group B in terms of total surgeon satisfaction score, however, non-inferiority was not proven for time for completion of surgery. Mean pain scores and incidence of shoulder pain were statistically similar up-to 7 days of follow-up in both groups. 4 (4.4%) patients in group B and 2 (2.2%) in group A had bradycardia (p = 0.4). Four (4.4%) cases of group A were converted to group B. One case of group B converted to open surgery. Bile spills and gallbladder perforations were comparable.

Conclusion: LPP with deep NMB is non-inferior to SPP with moderate NMB in terms of surgeon satisfaction score but not in terms of time required to complete the procedure. Clinical outcomes and safety profile are similar in both groups. However, it could be marginally costlier to use LPP with deep NMB.