Influence of Hypnotics on Cisatracurium-induced Neuromuscular Block. Use of Acceleromyograhpy

Background and objective: Different drugs, including hypnotics, may influence the pharmacodynamic effects of neuromuscular blockers (NMB). The aim of this study was to evaluate the influence of propofol and etomidate on cisatracurium-induced neuromuscular blockade. Method: We included 60 patients, ASAI and II, undergoing elective surgery under general anesthesia in the study and randomly allocated them into two groups, according to their hypnotic drug: GI (propofol) and GII (etomidate). Patients received intramuscular (IM) midazolam (0.1 mg.kg(-1)) as premedication and we performed induction with propofol (2.5 mg.kg(-1)) or etomidate (0.3 mg.kg(-1)), preceded by fentanyl (250 mg) and followed by cisatracurium (0.1 mg.kg(-1)). The patients were ventilated with 100% oxygen until obtaining a reduction of 95% or more in the adductor pollicis response amplitude, with subsequent laryngoscopy and tracheal intubation. Neuromuscular function was monitored by acceleromyograhpy. We evaluated the onset of action of cisatracurium, tracheal intubation conditions, and hemodynamic repercussions. Results: The mean time and standard deviations of cisatracurium onset were: GI (86.6 +/- 14.3 s) and GII (116.9 +/- 11.6 s), with a significant difference (p < 0, 0001). Intubation conditions were acceptable in 100% of GI and 53.3% of GII patients (p < 0.0001). Conclusion: Induction of neuromuscular blockade with cisatracurium was faster, with better intubation conditions in patients receiving propofol compared to those receiving etomidate, without hemodynamic repercussions. (C) 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.