Acute Pain Management in Emergency Department, Low Dose Ketamine Versus Morphine, A Randomized Clinical Trial

[Background]Ketamine, as an opium alternative, has been proposed for pain relief in the emergency department (ED).[Objectives]This study was carried out to compare low dose ketamine (LDK) with morphine for pain relief in trauma patients.[Methods]In this randomized double-blinded clinical trial, 300 trauma patients from the ED of 2 teaching hospitals in Tehran, Iran were enrolled and randomly divided into 2 equal groups. The 1st group received 0.2 mg/kg of ketamine while the 2nd group received 0.1 mg/kg of intravenous morphine. The pain intensity and complications were measured and compared every 15 minutes to 1 hour.[Results]Fifteen minutes after drug injection in both groups, a significant reduction was found in average pain intensity compared to the initial pain (P = 0.01). At 15 minutes, no significant difference was found in both groups in regards to average pain intensity (P = 0.23). The average pain intensity at 30, 45, and 60 minutes in the group receiving morphine was lower than the ketamine group (P = 0.01, P < 0.001, P < 0.001 respectively). Two complications (drop in O₂ saturation below 90% and flushing) were significantly greater in the morphine group.[Conclusions]The results of this study suggest that LDK, at a dose of 0.2 mg/kg, in the earlier minutes leads to significant reduction of pain when compared to that of intravenous morphine. It also created fewer complications than morphine.