Effects of Pretreatment with Lidocaine or Ketamine on Injection Pain and Withdrawal Movements of Rocuronium

Aims: The incidence and severity of pain on injection of rocuronium and its pretreatment with saline, lidocaine or ketamine were evaluated.Materials and Methods: One hundred and twenty patients were randomized into three groups to receive intravenous (i.v.) lidocaine 30 mg (Group Lidocaine, n=40), ketamine 0.5 mg/kg (Group Ketamine, n=40) orsaline 2 ml (Group Saline, n=40). Thirty seconds after the pretreatment drug, intubation dose of rocuronium(0.6 mg/kg) was injected by i.v. route in 5 seconds. The pain and the withdrawal movements were assessed by a five-point and a four-point scale, respectively. Six hours after anesthesia, patients were asked whether they recalled pain in the arm during induction of anesthesia.Results: The incidence of pain response after rocuronium injection (grade 2 or more) was 82.5%, 12.5% and62.5% in saline, lidocaine and ketamine groups, respectively. The median pain score in Group Lidocaine was significantly lower than those of groups Ketamine and Saline (P 0.001). The incidence of withdrawal movements was 32.5%, 2.5% and 15% in the saline, lidocaine and ketamine groups, respectively. The median withdrawal movement score was significantly lower only in Group Lidocaine compared to Group Saline(P=0.011). There was no difference in reported pain or withdrawal movements between men and women.Conclusions: For decreasing the severity of pain and withdrawal movements induced by rocuronium injection,lidocaine is more effective when compared with ketamine.