Dilution of Rocuronium with 0.9% NaCl Reduces Withdrawal Movement during Anesthetic Induction

ABSTRACT

BACKGROUND: After induction of anesthesia with propofol or thiopental, rocuronium causes hand or limb withdrawal or generalized movements, suggesting the presence of intense pain even under anaesthesia. We evaluated the effect of diluting rocuronium 10 mg/ml solution to 5 mg/ml or 3.3 mg/ml with 0.9% NaCl solution on the withdrawal movements associated with IV administration of rocuronium given at intubating doses after thiopental administration. METHODS: Sixty three patients undergoing surgical procedures that required general anesthesia were randomized into three groups. Group 1 received rocuronium 0.9 mg/kg in 10 mg/ml solution, while Group 2 and 3 received the same dose of rocuronium in 5 mg/ml and 3.3 mg/ml solutions with 0.9% NaCl solution after thiopental IV administration, respectively. RESULTS: We observed that the incidence of withdrawal movements was 71.4% in the Group 1, 47.6% in the Group 2 and 14.3% in the Group 3. Intense withdrawal movements involving elbow or shoulder and generalized movements were observed in 42.8% of patients in Group 1, but they were seen in 23.8% of patients in Group 2 and 4.8% of patients in Group 3. There were significant differences in incidence and degree of withdrawal movements between Group 1 and 3 (P < 0.05). The pH values and osmolalities of study solutions were not significantly different between the groups. CONCLUSIONS: Dilution of rocuronium with 0.9% NaCl solution given at intubating doses after thiopental administration is a simple and cost-effective strategy for preventing withdrawal movements during IV rocuronium injection.