Rocuronium has a high incidence of vascular pain when injected intravenous by, and diverse methods have been examined to reduced this pain. The aim of this study was to evaluate the effect of ketamine pretreatment on vascular pain during the injection of rocuronium in pediatric patients.

Sixty ASA physical status 1 patients scheduled for elective surgery were randomly divided into three groups; a control group (placebo: normal saline, n = 20), group 1 (ketamine 0.5 mg/kg pretreatment, n = 20), and group 2 (ketamine 1 mg/kg pretreatment, n = 20). The ketamine pretreatment was injected in the preanesthetic room. After being moved into the operation room, general anesthesia was induced using thiopental sodium 5 mg/kg in control group. All groups were followed during and after injecting rocuronium 0.9 mg/kg IV. Vascular pain was graded using a 4-point scale.

The incidence of vascular pain diminished significantly in the ketamine pretreated group, as follows: 17 (85%) in control group, 4 (20%) in group 1 and 7 (35%) in group 2.

Intravenous ketamine pretreatment at 0.5-1 mg/kg may effectively reduce or prevent vascular pain on injecting rocuronium in pediatric patients.