Rapid injection of rocuronium reduces withdrawal movement on injection.

STUDY OBJECTIVE To test whether rapid injection of rocuronium reduces withdrawal movement on injection. DESIGN Randomized, prospective trial. SETTING Operating room in a university hospital. PATIENTS 150 ASA physical status I and II patients aged 18 to 60 years, undergoing general anesthesia. INTERVENTIONS Patients were randomized to three groups. After undergoing anesthesia induction with thiopental sodium, then 5 seconds later receiving a rubber tourniquet applied to the mid-forearm to stop intravenous (IV) flow by gravity, the pretreatment drug was injected. The tourniquet was held for 15 seconds then released, and 1.0 mg/kg of 1% rocuronium was injected IV. Group C patients (n = 50) were pretreated with 0.1 mL/kg of 0.9% NaCl and then injected with rocuronium slowly within 10 seconds. Group L patients (n = 50) were pretreated with 0.1 mL/kg of preservative-free 1% lidocaine and then injected with rocuronium slowly within 10 seconds. Group R patients (n = 50) were pretreated with 0.1 mL/kg of 0.9% NaCl and then rapidly injected with rocuronium within approximately one second (as quickly as possible). MEASUREMENTS After injection of the patient with the study drug, a single anesthesiologist with no knowledge of the study protocol graded each patient's response as follows: 0 = no response; 1 = mild movement limited to the wrist only; 2 = moderate movement involving the elbow and shoulder; and 3 = severe movement involving more than one extremity. MAIN RESULTS Group C had the most intense and frequent withdrawal response. The frequency and intensity of withdrawal movement was significantly less in Groups L and R than Group C. No significant difference in withdrawal response between Groups L and R was noted. CONCLUSIONS Withdrawal response can be significantly reduced for rocuronium injection without lidocaine pretreatment, simply through rapid injection.