Deep neuromuscular blockade improves surgical conditions during laparoendoscopic single-site (LESS) surgery for total hysterectomy and reduces postoperative pain: a randomized controlled trial

PURPOSE: To evaluate the impact of neuromuscular blockade (NMB) depth on surgical conditions and postoperative outcomes in patients undergoing laparoendoscopic single-site (LESS) surgery for total hysterectomy. METHODS: A total of 243 female patients scheduled for LESS surgery for total hysterectomy under intravenous anesthesia were randomly allocated to two groups: the deep NMB group (1–2 post-tetanic count) and the moderate NMB group (1–2 train-of-four response) with continuous intravenous infusion of cisatracurium. The primary endpoint was the Surgical Rating Scale (SRS) score during the surgery. Secondary endpoints included additional NMB requirements during surgery, and postoperative outcomes including Visual Analog Scale (VAS) scores, incidence of shoulder pain, morphine consumption, and the incidence of nausea and vomiting. RESULTS: Mean (standard deviation) SRS was 4.31 (0.86) during moderate NMB and 4.75 (0.54) during deep NMB (P < 0.001). Moderate NMB resulted in 16.26% of scores at the lower end of the scale (scores 1–3), whereas deep NMB achieved 90.83% of scores at the higher end (scores 4–5). The deep NMB group demonstrated decreased postoperative shoulder pain (P < 0.001) with lower VAS scores at 6/24/48 hours (P < 0.001), and reduced morphine consumption 72 h post-hysterectomy (P < 0.001). However, the time from agent withdrawal to train-of-four (TOF) ratio 25%, to TOF ratio 90%, and to extubation was significantly prolonged in the deep NMB group (P < 0.001). No significant differences were observed between groups regarding recovery index, length of stay in the post-anesthesia care unit (PACU), blood gas analysis, or postoperative complications, including postoperative nausea and vomiting (PONV) and pulmonary infection (P > 0.05). CONCLUSION: Deep NMB significantly improves surgical conditions during LESS hysterectomy while reducing postoperative pain.