Improved Neuromuscular Blockade Using a Novel Neuromuscular Blockade Advisory System: A Randomized, Controlled, Clinical Trial

Terence J. Gilhuly, Bernard A. MacLeod, Guy A. Dumont, Alex M. Bouzane, Stephan K. W. Schwarz
2008 Anesthesia and Analgesia  
BACKGROUND: Conventional incremental bolus administration of neuromuscular blocking (NMB) drugs is associated with limitations in intraoperative control, potential delays in recovery, and residual blockade in the postanesthetic period. To overcome such limitations, we developed a novel adaptive control computer program, the Neuromuscular Blockade Advisory System (NMBAS). The NMBAS advises the anesthesiologist on the timing and dose of NMB drugs based on a sixth-order Laguerre model and the
more » ... model and the history of the patient's electromyographic responses. Here, we tested the hypothesis that the use of the NMBAS improves NMB compared to standard care. METHODS: We conducted a prospective, randomized, controlled, blinded, parallelgroup, clinical trial with n ϭ 73 patients (ASA physical status I-III) undergoing abdominal surgery under general anesthesia Ն1.5 h with NMB using rocuronium. Patients were allocated to standard care or NMBAS-guided rocuronium administration. The primary outcome variable was the incidence of intraoperative events reflecting inadequate NMB. Secondary outcome variables included train-of-four (TOF) ratios at the end of surgery before reversal, the total doses of rocuronium, reversal agents, anesthetics and other drugs, the incidence of postoperative adverse events, and the incidence of anesthesiologist noncompliance with NMBAS recommendations. RESULTS: Of 73 enrolled patients, n ϭ 30 per group were eligible for analysis. Patient demographics were comparable between the groups. The incidence in total intraoperative events associated with inadequate NMB was significantly lower in the NMBAS group compared to standard care (8/30 vs 19/30; P ϭ 0.004). Mean TOF ratios at the end of surgery before reversal were higher in the NMBAS group (0.59 [95% CI, 0.48 -0.69] vs 0.14 [95% CI, 0.04 -0.24]; P Ͻ 0.0001). Total administered doses of rocuronium, reversal drugs, and other drugs, and the incidence of postoperative adverse events were not different. CONCLUSIONS: Compared to standard practice, NMBAS-guided care was associated with improved NMB quality and higher TOF ratios at the end of surgery, potentially reducing the risk of residual NMB and improving perioperative patient safety. Convent ional incremental bolus administration of neuromuscular blocking (NMB) drugs, such as rocuronium, is associated with well-known shortcomings. These include limitations in intraoperative control and rapid adaptation to changing surgical conditions (including unanticipated termination of the procedure), fluctuations in plasma concentrations and the quality of blockade, possible inability to reverse intense blockade, potential delays in recovery, and a sizeable risk of residual blockade in the postanesthetic period. 1, 2 Automated drug delivery in the form of computerguided administration and/or infusion represents an attractive strategy to overcome such limitations and From the
doi:10.1213/ane.0b013e318185cfb6 pmid:18931219 fatcat:yqn7qncswzcc7cdamxsbwj5tf4