Intranasal ketamine reduces pain of digital nerve block; a double blind randomized clinical trial.

BACKGROUND: Low dose ketamine can be used as analgesic in acute pain management in the emergency department (ED). OBJECTIVE: Efficacy of IN ketamine in acute pain management in the ED. METHOD: This is a double blind randomized clinical trial on patients older than 15 years who needed digital nerve block (DNB). Participants randomly received IN Ketamine (1 ml = 50 mg) or placebo (normal saline, 1 ml) 5 min before DNB. In both groups, patients' pain score was recorded by visual analogue score (VAS) at baseline, after DNB and 45 min after completion of DNB. Adverse effects of ketamine and changes in vital signs were also recorded and compared with placebo group. RESULTS: A total number of 100 patients were enrolled in the study with the median (IQR) age of 36.5 (26) years, including 65 men and 35 women. IN ketamine resulted in less pain compared to placebo after performing DNB and 45 min after the procedure. Median (IQR) basic VAS score was 50 (15) in ketamine group, and 49 (27) in control group. Median (IQR) block pain VAS score was 28.5 (19) in ketamine group and 47.5 (31) in control group. Median (IQR) procedural pain VAS score was 21.5 (16) in ketamine group and 43.5 (29) in control group. Only 7 patients had adverse effects in either group. CONCLUSION: The findings of this study suggest that IN ketamine can be effective in reducing pain in patients with acute pain, without adding significant side effects.