Onset time and duration of rocuronium, atracurium and mivacurium in pediatric patients.

BACKGROUND AND OBJECTIVES Neuromuscular blockers (NMB) are widely used in pediatric anesthesia, but there is no ideal NMB. This study aimed at evaluating onset and recovery time, hemodynamic changes and tracheal intubation conditions of rocuronium, atracurium and mivacurium in pediatric patients. METHODS Participated in this study 67 children aged 30 months to 12 years, physical status ASA I and II, who were allocated into three groups: G1 = 0.9 mg kg(-1) rocuronium (n = 22); G2 = 0.5 mg kg(-1) atracurium (n = 22); G3 = 0.15 mg kg(-1) mivacurium (n = 23). Anesthesia was induced with 50 microg kg(-1) alfentanil, 3 mg kg(-1) propofol, sevoflurane and N2O/O2. Neuromuscular block was monitored by acceleromyography on the ulnar nerve pathway. The following parameters were evaluated: onset time (OT), clinical duration (T25) relaxation time (T75) and recovery time (T(25-75)). Heart rate (HR) and mean blood pressure (MBP) were recorded in 6 moments, as well as tracheal intubation conditions. RESULTS Median OT was: G1 = 0.6 min, G2 = 1.3 min, G3 = 1.9 min. Median T25 was: G1 = 38 min, G2 = 41.5, G3 = 8.8 min. Median T75 was: G1 = 57.7 min; G2 = 54.6 min, G3 = 13.6 min. Median T(25-75) was: G1 = 19.7 min, G2 = 13.1 min and G3 = 4.8 min. Tracheal intubation conditions were excellent for most children in all groups. There were no significant MBP and HR clinical changes. CONCLUSIONS Rocuronium (0.9 mg kg(-1)) had the fastest onset time and mivacurium (0.15 mg kg(-1)) the shortest recovery time in pediatric patients anesthetized with sevoflurane. Rocuronium, mivacurium and atracurium had also not determined significant hemodynamic changes and allowed for excellent tracheal intubation conditions.