Ketamine Sub-Dissociative Dose Vs. Morphine Sulfate for Acute Pain Control in Patients with Isolated Limb Injuries in the Emergency Department: A Randomized, Double-blind, Clinical Trial.

Objective: To compare the ketamine efficacy at a sub-dissociative morphine dose to reduce pain in isolated limb traumatic injuries.

Methods: A double-blind randomized clinical trial study was carried out on patients referred to emergency departments (EDs) due to isolated limb traumatic injuries. Eligible patients were divided into two groups which one group received 0.1 mg/kg ketamine and the other group received 0.05 mg/kg morphine, intravenously. An observed side effect includes pain scores and vital signs were recorded at baseline of every 5 minutes for 30 minutes.

Results: Totally, 73 patients with the mean age of 32.9±10.4 were enrolled of whom 59 (80.8%) individuals were men. The baseline characteristics difference of the two study groups was not statistically significant. The results showed that the change of mean pain score was -6.2 (95% CI: -5.72 to -6.69) points in the group receiving ketamine compared to -5.8 (95%CI: -5.15 to - 6.48) in the group who were administered morphine. At all assessed checkpoints, the pain mean score was lower in the ketamine group than in the morphine group (p<0.05); the mean of total pain reduction was greater in the ketamine group during the observation period compared with patients who received morphine (p=0.002).

Conclusion: The study findings suggest that the sub-dissociative ketamine efficacy in controlling of the acute pain is not lower than morphine sulfate in patients with isolated limb trauma in ED's. Thus, it can be considered as a safe and effective alternative approach.