Influência do propofol e do etomidato no bloqueio neuromuscular produzido pelo rocur？nio: avalia？？o pela aceleromiografia

background and objectives: some hypnotics may interact with neuromuscular blockers and potentiate their effects. this study aimed at evaluating the influence of propofol and etomidate on rocuronium-induced neuromuscular block. methods: participated in this study 60 patients, physical status asa i and ii, scheduled for elective surgeries under general anesthesia, who were randomly distributed in two groups according to the hypnotic drug: group i (propofol) and group ii (etomidate). all patients were premedicated with intramuscular midazolam (0.1 mg.kg-1), 30 minutes before surgery. anesthesia was induced with propofol (2.5 mg.kg-1) or etomidate (0.3 mg.kg-1) preceded by alfentanil (50 μg.kg-1) and followed by rocuronium (0.6 mg.kg-1). patients were ventilated under mask with 100% oxygen until achieving a decrease of 75% or more in the adductor pollicis muscle response amplitude. neuromuscular function was monitored by accelerometry. the following parameters were evaluated: rocuronium onset (t1 ￡ 25%); time for complete neuromuscular block; neuromuscular block degree at tracheal intubation; tracheal intubation conditions and hemodynamic effects. results: complete rocuronium-induced neuromuscular block onset times (in seconds) were: group i (48.20 ± 10.85 s and 58.87 ± 10.73 s) and group ii (51.20 ± 13.80 s and 64.27 ± 18.55 s). neuromuscular block degree at tracheal intubation was: group i (77.50%) and group ii (76.96%). tracheal intubation conditions were satisfactory in 100% of group i patients and in 83.33% of group ii patients. there has been a significant decrease in mean blood pressure, followed by an increase after hypnotic injection, in both groups. conclusions: propofol and etomidate had a similar behavior regarding time for rocuronium-induced neuromuscular block and tracheal intubation conditions.