Deep Neuromuscular Blockade in Laparoscopic One-Anastomosis Gastric Bypass (OAGB): A Randomized Controlled Trial

INTRODUCTION: Optimal visibility during Laparoscopic One-Anastomosis Gastric Bypass (OAGB) is challenging. This study compares moderate and deep neuromuscular blockade (NMB) for surgical field quality, respiratory and hemodynamic outcomes, atelectasis rates, pain, and bowel recovery. METHODS: This randomized controlled trial involved adults with severe obesity (ASA II/III) undergoing OAGB with general anesthesia. Patients were assigned to deep or moderate NMB, monitored by acceleromyography. Surgical workspace quality was measured using the Leiden Surgical Rating Scale. Collected intraoperative data included workspace, operative time, pulmonary mechanics, hemodynamics, and oxygenation; postoperative outcomes covered pain scores, analgesic use, time to first flatus, complications, hospital stay, and atelectasis via chest CT. RESULTS: Fifty-five patients were included (moderate: n = 28; deep: n = 27), with comparable baseline characteristics. NMB depth did not affect pulmonary mechanics. Deep NMB significantly improved intraoperative surgical field conditions (p < 0.001) and reduced operative time by approximately 10 min, with regression analysis confirming an 11.5 - minute reduction (p = 0.044). Hemodynamics and oxygenation were similar between groups. Patients in the deep NMB group reported lower postoperative pain scores, but comparable analgesic consumption. Length of hospital stay (p = 0.879), and incidence of atelectasis (p = 0.831) did not differ between groups. No association was found between BMI, NMB depth, and postoperative atelectasis. CONCLUSIONS: Deep NMB improves surgical conditions and shortens operative time for laparoscopic OAGB at standard pneumoperitoneum pressure. While it reduced postoperative pain, fixed intra-abdominal pressure and opioid-based anesthesia may have limited assessment of other outcomes. Further studies using multimodal strategies are needed to assess its impact on recovery.