Effect of deep neuromuscular blockade on serum cytokines and postoperative delirium in elderly patients undergoing total hip replacement: A prospective single-blind randomised controlled trial

BACKGROUND – Deep neuromuscular blockade (NMB) may reduce muscle injury and related inflammation. The inflammation is one of the pathophysiological processes of peri-operative complications. OBJECTIVE – To compare the degree of inflammation and related postoperative complications including postoperative delirium (POD) and peri-operative bleeding according to the degree of NMB during general anaesthesia for total hip replacement. DESIGN – A prospective, single-blind, randomised controlled trial. SETTING – Tertiary, university hospital, single centre. PATIENTS – Eighty-two patients undergoing total hip replacement surgery were included in the final analysis. INTERVENTIONS – Moderate (Mod) and deep (Deep) NMB groups. MAIN OUTCOME MEASURES – The changes in inflammatory cytokines were measured. The incidence of POD was evaluated by using confusion assessment method (CAM). The differences of postoperative bleeding and peri-operative oxygenation in both groups were also measured. RESULTS – The NMB reversal duration was significantly longer in the Mod NMB group than in the Deep NMB group. Changes in interleukin-6 were significantly smaller in the Deep NMB group than in the Mod NMB group (P < 0.001). The incidence of POD was not significantly different between groups (34 versus 17% in Mod and Deep NMB groups, respectively; P = 0.129). The amount of postoperative bleeding until postoperative day 2 was significantly greater in the Mod NMB group than in the Deep NMB group (P = 0.027). CONCLUSION – Our findings suggest that inflammation related to peri-operative complications could be associated with the depth of NMB during total hip replacement. However, the incidence of POD might not be associated to the depth of NMB. TRIAL REGISTRATION – National Library of Medicine (NLM) at the National Institutes of Health (NIH) of United States. (Identifier: NCT02507609). Online address: http://clinicaltrials.gov