Comparison of deep vs. moderate neuromuscular blockade on low-pressure pneumoperitoneum for laparoscopic cholecystectomy
Author(s): Barrio J, Molina I, Chiralt A, San Miguel G, Errando CL, Gallego J
Background and Goal of Study: Clinical and experimental studies have reported outcome advantages of low-pressure (< 9mmHg) vs. standard-pressure (12-14 mmHg) pneumoperitoneum for laparoscopic surgery. However, working with low-pressure pneumoperitoneum can limit working space and surgical conditions could be worse. The aim of this study was to assess the influence of neuromuscular blockade(NMB) depth on performing low-pressure pneumoperitoneum laparoscopic cholecystectomy(LC)
Materials and methods: Randomized, double blinded clinical trial. Ninety patients scheduled for elective LC were randomly allocated into three groups: 
Group 1: low-pressure LC (8mmHg) with deep NMB (TOF 0, PTC < 5); 
Group 2: low-pressure LC (8mmHg) with moderate NMB (TOF 1-3) and
Group 3: standard-pressure LC (12 mmHg) with no NMB depth pre-determined (control group). 
Three experienced surgeons (blinded to intraabdominal pressure (IAP) setting) performed all the surgeries and judged surgical conditions according to a 4-step scale (from 1-optimal to 4-not acceptable, the surgery cannot be performed in these conditions). Operating time and intraoperative complications were investigated. Rocuronium was used for NMB and sugammadex was used for reversal of NMB. Acceleromiography was used for NMB monitoring (TOF-WATCH-S).
Results and discussion: Group 3 showed statistically better surgical conditions (p=0.021 Chi2) and a higher proportion of optimal conditions (p=0.007 Chi2) than groups 1 and 2. No differences on surgical conditions (p=0.236 Chi2) or operating time (p=0.737 t test) were observed between groups 1 and 2. Four patients in group 1 and one patient in group 2 had bad surgical conditions (scoring 4) and IAP needed to be increased to 12 mmHg in order to perform the surgery (p=0.353 Fisher). No cases scoring 4 were observed in group 3. No complications of bleeding or bile duct injury were observed, however the rate of gallbladder perforation was higher at low-pressure LC (groups 1 and 2) when compared to standard-pressure LC (group 3) (p=0.018 Chi2).
Conclusion(s): We did not observe better surgical conditions when performing low-pressure LC with deep NMB compared with moderate NMB. The rate of bad surgical-conditions and complications, patients that needed to increase the IAP for performing the surgery and operating time were not different at both NMB levels. Surgical conditions were judged better when performing LC at 12 mmHg pneumoperitoneum than at 8 mmHg, unrelated to NMB level.