Low-dose ketamine combined with morphine in the hospital emergency department relieves pain and improves trauma patients satisfaction

Abbasi S, Yosefzadeh M, Hafezimoghadam P, Amin Zare M, Rezai M, Farsi D

Background and objective: Pain control is a critical aspect of trauma care in hospital emergency departments. Ketamine is an antagonist of the N-methyl-D-aspartate receptor and co-administration may enhance the effect of opioids. We aimed to compare the efficacy of a morphine-ketamine combination to a morphine-placebo combination in trauma patients.

Methods: Multicenter, randomized, double-blind trial. Block randomization was used to assign 220 patients with severe acute pain in 3 hospital emergency departments. One group received the standard dose of 0.1 mg/kg of morphine combined with 0.1 mg/kg of ketamine. The other group received 0.1 mg/kg of morphine with placebo. Effective analgesia was defined by a numerical pain score of 3 or less on a pain scale. Pain severity and patient satisfaction were assessed until 120 minutes after dosing. The data were analyzed on an intention-to-treat basis.

Results: Pain was better controlled in the morphine-ketamine group 10 and 30 minutes after administration of the combination (P<.05) and fewer patients required a second analgesic dose (21.8% vs 39.4% in the placebo group, P=.007). The mean (SD) total morphine consumption was 8.29 (3.2) mg in the ketamine group and 9.54 (3.41 mg) in the placebo group (P=.008); the analgesic effect in the ketamine group was superior at 30 minutes (P<.001).

Conclusion: The combination of morphine and ketamine provides effective analgesia for hospital emergency department trauma patients with severe acute pain.

Abbasi S, Amin Zare M, Farsi D, Hafezimoghadam P, Rezai M, Yosefzadeh M