The Effect of Low Dose Ketamine on the Need for Morphine in Patients with Multiple Trauma in Emergency Department

Abstract

Aim: There are a few analgesic drugs (morphine, ketamine, Paracetamol, etc.) used for pain control in injury patients. Previous studiesshowed that low-dose ketamine (doses less than 1 mg/kg) promptly and satisfactorily resolved pain. This study aimed to compare theanalgesic effects of morphine with placebo (MP group) to that of a combination of morphine with ketamine (MK group) for patients withmultiple trauma (MT) in the emergency department (ED).Materials and Methods: This randomized, controlled, double-blinded clinical trial was conducted in the ED of two university teachinghospitals. Seventy multiple trauma patients aged between 16 and 50 years with a severe acute pain defined as a visual analog scale (VAS)score of at least 70 (between 0 and 100) were enrolled. Patients were randomly assigned to receive intravenous morphine (0.1 mg/kg) withplacebo or morphine (0.05 mg/kg) with low-dose ketamine (0.3 mg/kg) for pain control. The pain intensity was evaluated before and 10th,20th, 30th, and 60th minutes after the intervention, and probable side effects were recorded. Efficient analgesia was defined as a VAS score notexceeding 30. If the VAS score was still above 30, additional morphine (3 mg) was administered for both groups. The primary outcome wasthe VAS score at 30 minutes.Results: Seventy patients were enrolled in this study. There was no difference between the groups in terms of demographic characteristicsor vital signs and baseline pain scores. The pain intensity decreased significantly in both groups 30 minutes after the intervention. However,there was no significant difference between the mean VAS scores of the two groups before and after the intervention. Morphine consumptionwas significantly lower in the MK group versus the MP group (9.3±2.2 vs 6.1±2.7, p=0.01). In addition, there was no significant differencebetween the two groups in terms of complications (p>0.05).Conclusion: Low-dose ketamine in combination with morphine significantly reduced the need for an additional dose of morphine withoutincreasing the complication rate related to morphine alone.