Deep Neuromuscular Blockade Improves Laparoscopic Surgical Conditions: A Randomized, Controlled Study

Introduction: Sustained deep neuromuscular blockade (NMB) during laparoscopic surgery may facilitate optimal surgical conditions. This exploratory study assessed whether deep NMB improves surgical conditions and, in doing so, allows use of lower insufflation pressures during laparoscopic cholecystectomy. We further assessed whether use of low insufflation pressure improves patient pain scores after surgery.

Methods: This randomized, controlled, blinded study (NCT01728584) compared use of deep (1-2 post-tetanic-counts) or moderate (train-of-four ratio 10%) NMB, and lower (8 mmHg) or higher (12 mmHg; 'standard') insufflation pressure in a 2 × 2 factorial design. Primary endpoint was surgeon's overall satisfaction with surgical conditions, rated at end of surgery using an 11-point numerical scale. Post-operative pain scores were also evaluated. Data were analyzed using analysis of covariance.

Results: Of 127 randomized patients, 120 had evaluable data for the primary endpoint. Surgeon's score of overall satisfaction with surgical conditions was significantly higher with deep versus moderate NMB indicated by a least-square mean difference of 1.1 points (95% confidence interval 0.1-2.0; P = 0.026). Furthermore, strong evidence of an effect was observed for standard versus low pressure: least-square mean difference of 3.0 points (95% confidence interval 2.1-4.0; P < 0.001). No significant difference was observed in average pain scores within 24 h post-surgery for low versus standard pressure [0.17 (95% confidence interval -0.67 to +0.33); P = 0.494].

Conclusions: Although associated with significantly improved surgical conditions, deep NMB alone was insufficient to promote use of low insufflation pressure during laparoscopic cholecystectomy. Furthermore, low insufflation pressure did not result in reduced pain, compared with standard pressure.

Clinical trial registration: ClinicalTrials.gov identifier, NCT01728584.

Funding: Merck Sharp and Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA.