Does deep neuromuscular blockade provide improved perioperative outcomes in adult patients? A systematic review and meta-analysis of randomized controlled trials

Deep neuromuscular blockade provides better surgical workspace conditions in laparoscopic surgery, but it is still not clear whether it improves perioperative outcomes, not to mention its role in other types of surgeries. We performed this systematic review and meta-analysis of randomized controlled trials to investigate whether deep neuromuscular blockade versus other more superficial levels of neuromuscular blockade provides improved perioperative outcomes in adult patients in all types of surgeries. Medline, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar were searched from inception to June 25, 2022. Forty studies (3271 participants) were included. Deep neuromuscular blockade was associated with an increased rate of acceptable surgical condition (relative risk [RR]: 1.19, 95% confidence interval [CI]: [1.11, 1.27]), increased surgical condition score (MD: 0.52, 95% CI: [0.37, 0.67]), decreased rate of intraoperative movement (RR: 0.19, 95% CI: [0.10, 0.33]), fewer additional measures to improve the surgical condition (RR: 0.63, 95% CI: [0.43, 0.94]), and decreased pain score at 24 h (MD: -0.42, 95% CI: [-0.74, -0.10]). There was no significant difference in the intraoperative blood loss (MD: -22.80, 95% CI: [-48.83, 3.24]), duration of surgery (MD: -0.05, 95% CI: [-2.05, 1.95]), pain score at 48 h (MD: -0.49, 95% CI: [-1.03, 0.05]), or length of stay (MD: -0.05, 95% CI: [-0.19, 0.08]). These indicate that deep neuromuscular blockade improves surgical conditions and prevents intraoperative movement, and there is no sufficient evidence that deep neuromuscular blockade is associated with intraoperative blood loss, duration of surgery, complications, postoperative pain, and length of stay. More high-quality randomized controlled trials are needed, and more attention should be given to complications and the physiological mechanism behind deep neuromuscular blockade and postoperative outcomes.