Efficacy and Safety of Morphine and Low Dose Ketamine for Pain Control of Patients with Long Bone Fractures: A Randomized, Double-Blind, Clinical Trial

Objective: To compare the effects of intravenous morphine and a low dose of ketamine on pain intensity of patients with traumatic fractures of the long bones. Methods: This randomized, controlled, double-blinded, clinical trial was conducted in the adult emergency department (ED) of Emam Khomeini hospital, a tertiary general hospital affiliated with Mazandaran University of Medical Sciences, in Northern Iran, during a 6-month period. Patients were randomly assigned to receive intravenous morphine (0.1 mg/kg) or low dose ketamine (0.5 mg/kg) for control of the pain in the emergency room. The pain intensity was checked by a nurse using the visual analogue scale (VAS) at 30, 60, 90, 120, 180 and 240, minutes after the intervention. Results: Overall we included a total number of 156 patients with mean age of 35.87±3.38 years. There were 111 (71.2%) men and 4 (28.8%) women among the patients. Patients were randomly assigned to receive intravenous morphine (n=78) or low dose ketamine (n=78). The pain intensity decreased significantly in both study groups after 240 minutes of intervention. However, there was no significant difference between the two study groups regarding the pain intensity at 30 ( p =0.378), 60 ( p =0.927), 90 ( p =0.434), 120 ( p =0.557), 180 ( p =0.991) and 240 ( p =0.829) minutes. The side effects were comparable while low dose ketamine was associated with higher need for rescue analgesic ( p =0.036). Conclusion: The results of the current study demonstrates that the intravenous low dose ketamine leads to successful pain control in patients with long bone fractures and the effects are comparable with intravenous morphine. The study is registered with the Iranian Registry for Clinical trials ( www.irct.ir ; IRCT2017041221480N6)