Effects of deep neuromuscular block on surgical workspace conditions in laparoscopic bariatric surgery: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION: It has been hypothesized that routine use of deep neuromuscular block (dNMB) is advisable in laparoscopic bariatric surgery in order to optimize workspace conditions. dNMB seems to have advantages in laparoscopic procedures on non-obese patients as it improves surgical space conditions and reduces postoperative pain scores. This systematic review and meta-analysis aimed at comparing the impact of deep vs moderate NMB (mNMB) on surgical conditions and outcomes, including duration of surgery and postoperative pain in patients undergoing laparoscopic bariatric surgery. EVIDENCE ACQUISITION: Studies were identified from Medline, Embase and Cochrane library (update: Sep 1 2019). Randomized controlled trials (RCTs) comparing dNMB with mNMB were identified if they reported surgeon satisfaction for workspace conditions (primary outcome). The effects of dNMB on surgery duration and postoperative pain (secondary outcomes) were also investigated. EVIDENCE SYNTHESIS: Of the 45 retrieved records, 4 were finally included. dNMB improved the surgeon's satisfaction score about workspace (on a scale ranging from 1 to 5), with a mean difference (MD) of 0.52 (95% CI: 0.36-0.68). Surgical duration was not affected by block level (MD: -3.29 minutes; 95% CI: from -14.35 to 7.76). Only one study showed that dNMB also decreased postoperative pain. CONCLUSIONS: It was found that dNMB helps improve surgical space conditions in patients undergoing laparoscopic bariatric surgery whereas it fails to shorten procedure duration. More high-quality large-sampled RCTs are needed to confirm these results. The relationship between dNMB use and other clinical outcomes, such as complications occurrence, needs to be further investigated.