Esmolol pretreatment reduces the frequency and severity of pain on injection of rocuronium

ObjectiveTo determine the effect of esmolol on the frequency and severity of pain and withdrawal reactions after injection of rocuronium and to compare it with lidocaine and placebo.DesignProspective, randomized, double-blind, placebo-controlled study.SettingSingle university hospital.Patients120 ASA physical status I and II patients undergoing general anesthesia for elective surgery.InterventionsPatients were randomized to receive esmolol (0.5 mg/kg), lidocaine (0.5 mg/kg), or placebo, followed by a subparalyzing dose of rocuronium. After induction of anesthesia with propofol and fentanyl, an intubating dose of rocuronium 0.6 mg/kg was given.MeasurementsPatients were observed after injection of rocuronium 0.05 mg/kg, then immediately asked if they had pain in the arm. The response was assessed; discomfort, pain, and withdrawal of the hand were recorded and graded using a 4-point scale (none, mild, moderate, or severe). After the intubating dose of rocuronium, withdrawal reactions were scored as follows: (a) no pain response, (b) pain limited to the wrist, (c) pain limited to the elbow/shoulder, or (d) generalized pain response.Results31 patients (77.5%) in the esmolol group, 32 (80%) in the lidocaine group, and 15 (37.5%) in the placebo group reported no pain (both groups vs placebo, P < 0.001). Moderate pain was seen in only one patient receiving lidocaine, in 6 placebo patients, but in none in the esmolol group (esmolol vs placebo, P < 0.05). Severe pain was felt by 8 patients receiving placebo, but by none receiving esmolol or lidocaine (P < 0.01). Frequency of withdrawal response after rocuronium was 2.5%, 17.5%, and 40% in the esmolol, lidocaine, and placebo groups, respectively (esmolol group vs placebo, P < 0.001; lidocaine group vs placebo, P < 0.05).ConclusionEsmolol, like lidocaine, reduces the frequency of pain and withdrawal reaction associated with rocuronium injection.