Dilution and slow injection reduces the incidence of rocuronium-induced withdrawal movements in children

The aim of this study was to evaluate whether slow injection of diluted rocuronium could reduce rocuronium-induced withdrawal movements effectively in children. After loss of consciousness, rocuronium 0.6 mg/kg was administered into 171 children according to the pre-assigned groups as follows: Group CF, injection of non-diluted rocuronium over 5 seconds; Group CS, injection of non-diluted rocuronium over 1 minute; Group DF, injection of diluted rocuronium (10 times) over 5 seconds; Group DS, injection of diluted rocuronium over 1 minute. An investigator who was blind to the injection techniques recorded patient movements followed by rocuronium injection. The incidence of withdrawal movement in Group CF was highest among the groups (all P < 0.0001). Moreover, withdrawal movement was less frequently observed in Group DS than in Groups CS and DF (P = 0.021 and P = 0.007, respectively). Slow injection of diluted rocuronium reduced the incidence of withdrawal movements in children.