Out-of-Hospital Intranasal Ketamine as an Adjunct to Fentanyl for the Treatment of Acute Traumatic Pain: A Randomized Clinical Trial

Abstract

Study objective: To evaluate if out-of-hospital administration of fentanyl and intranasal ketamine, compared to fentanyl alone, improves early pain control after injury.

Methods: We conducted an out-of-hospital randomized, placebo-controlled, blinded, parallel group clinical trial from October 2017 to December 2021. Participants were male, aged 18 to 65 years, receiving fentanyl to treat acute traumatic pain prior to hospital arrival, treated by an urban fire-based emergency medical services agency, and transported to the region's only adult Level I trauma center. Participants randomly received 50 mg intranasal ketamine or placebo. The primary outcome was the proportion with a minimum 2-point reduction in self-described pain on the verbal numerical rating scale 30 minutes after study drug administration assessed by 95% confidence interval overlap. Secondary outcomes were side effects, pain ratings, and additional pain medications through the first 3 hours of care.

Results: Among the 192 participants enrolled, 89 (46%) were White, (median age, 36 years; interquartile range, 27 to 53 years), with 103 receiving ketamine and 89 receiving placebo. There was no difference in the proportion experiencing improved pain 30 minutes after treatment (46/103 [44.7%] ketamine versus 32/89 [36.0%] placebo; difference in proportions, 8.7%; 95% confidence interval, -5.1% to 22.5%; P=.22) or at any time point through 3 hours. There was no difference in secondary outcomes or side effects.

Conclusion: In our sample, we did not detect an analgesic benefit of adding 50 mg intranasal ketamine to fentanyl in out-of-hospital trauma patients.