RESUMEN
BACKGROUND: Intravenous (IV) Lidocaine can be used as analgesic in acute pain management in the emergency department (ED). OBJECTIVE: Efficacy of IV Lidocaine in comparison with IV morphine in acute pain management in the ED. METHOD: This is a double-blind randomized clinical trial on adult (18-64 year) patients with right upper abdominal pain suspected of biliary colic who needed pain management. Participants randomly received IV lidocaine (5 cc = 100 mg) or morphine sulfate (5 cc = 5 mg). In both groups, patients' pain scores were recorded and assessed by Numeric Rating Scale (NRS) at baseline, 10, 20, 30, 45, 60 and 120 min after drug administration. Adverse side effects of lidocaine and morphine sulfate and changes in vital signs were also recorded and compared. RESULTS: A total number of 104 patients were enrolled in the study, including 49 men and 55 women. IV lidocaine reduced pain in less time in comparison with morphine sulfate. Mean (±SD) basic pain score was 8.23 (±1.76) in the lidocaine group and 8.73 (±0.96) in the morphine group. Patients' mean (±SD) pain score in both groups had no significant difference during the study except that of NRS2 (10 min after drug administration), which was 5.05 (±2.69) in lidocaine group compared with 6.39 (±2.06) in the morphine group and NRS4 (30 min after drug administration), which was significantly lower (P-value = 0.01) in the morphine group [3.84(±1.73) vs 4.41(±2.82)]. Only 9 patients had adverse effects in either group. CONCLUSION: The findings of this study suggest that IV lidocaine can be a good choice in pain management in biliary colic and can reduce pain in less time than morphine sulfate (in 10 min) without adding significant side effects; however, our primary outcome was the comparison of these two drugs after 60 min of drug administration in pain reduction which showed no significant difference between two groups.