This study was designed to assess the possible superiority of intravenous lidocaine to morphine for pain management.

This was a randomized double blind controlled superiority trial, carried on in the emergency department (ED). Traumatic patients older than 18-year-old with the complaint of acute pain greater than 4 on a numeric rating scale (NRS) from 0 to 10 on their extremities were eligible. One group received IV lidocaine (1.5 mg/kg), and the other received IV morphine (0.1mg/kg). Pain scores and adverse effects were assessed at 15, 30, 45 and 60 minutes and patients' satisfaction was evaluated two hours later. A minimum pain score reduction of 1.3 from baseline was considered clinically significant.

Fifty patients with the mean age of 31.28±8.7 were enrolled (78% male). The demographic characteristics and pain scores of the two groups was similar. The on-arrival mean pain scores in two groups were, lidocaine: 7.9±1.4 and morphine: 8.0±1.4 (p=0.57) and after 1 hour were, lidocaine: 2.28±1.2 and morphine: 3.2±1.7. Although the pain score decreased significantly in both group (p=0.027), there were not any clinically and statistically significant difference between the two groups (p=0.77). Patients' satisfaction with pain management in both groups were almost similar (p=0.49).

The reduction in pain score using IV lidocaine is not superior to IV morphine in adult ED patients with traumatic limb pain.