Effects of depth of neuromuscular block on surgical conditions during laparoscopic colorectal surgery: a randomised controlled trial

There have been few objective evaluations of the effects of deep neuromuscular blockade on intra-operative conditions. In this prospective randomised controlled study, we evaluated the effects of deep neuromuscular block on surgical conditions during laparoscopic colorectal surgery. Patients were randomly allocated using a computer-generated randomisation code to either moderate (train-of-four count 1-2 maintained and antagonised with neostigmine) or deep (post-tetanic count 1-2 maintained and reversed with sugammadex) levels of neuromuscular blockade. The primary outcome measure was the number of abrupt increases in intra-abdominal pressure intra-operatively. Secondary outcome variables were intra-operative restoration of spontaneous breathing, number of surgical requests for additional neuromuscular blockade, surgical rating of operating conditions and patient satisfaction. The surgeon who rated the surgical conditions score and investigator who checked the postoperative variables were blinded to patient allocation. In total, we recruited 70 patients of whom 64 (32 in each group) were analysed. Increases in intra-abdominal pressure (14/32 vs. 6/32; p = 0.031), intra-operative restoration of spontaneous breathing (16/32 vs. 2/32; p < 0.001) and request for additional neuromuscular blockade (21/32 vs. 8/32; p = 0.001) were more frequent in the moderate compared with the deep group. In patients undergoing elective laparoscopic colorectal surgery, deep neuromuscular blockade provided better surgical conditions than moderate neuromuscular blockade, as measured by a reduction in the incidence of intra-abdominal pressure alarms.