Comparison of the Analgesic Effects of Low-Dose Ketamine Versus Fentanyl in Patients With Long Bone Fractures in the Emergency Department: A Prospective Observational Study

Aim and background In most emergency departments (ED), opioids are the primary analgesic agents for trauma patients. However, safe alternative drugs are required because of possible adverse effects. Ketamine, an anesthetic agent, provides satisfactory analgesia at low doses and is an alternative drug that has begun to be used in numerous areas with fewer side effects. This study aimed to compare low-dose ketamine and fentanyl infusions in terms of their pain-relieving effects and observed adverse effects in patients presenting to the ED with isolated long bone fractures. Materials and methods This single-center observational study was conducted in the ED of the Marmara University Pendik Training and Research Hospital between August 2018 and December 2019. Patients diagnosed with isolated long bone fractures who were administered low-dose ketamine or fentanyl rapid infusions for pain relief were included in the study. Patient pain scores were evaluated using the visual analog scale (VAS) with a standard horizontal 10-centimeter line. The primary outcome of the study was to compare the changes in pain at 30 and 60 min after medication administration for each group. Results A total of 100 patients were included in the study. Ketamine infusion was administered to 48% (n=48) of the patients as a pain reliever. After 60 min of observation, pain was significantly reduced in both study groups. However, the pain scores at baseline (p=0.319), 30 min (p=0.631), and 60 min (p=0.347) after treatment were similar in both groups. In terms of the observed adverse effects, dizziness was more common in the ketamine group (p=0.010). Conclusion The results of this study showed that low-dose ketamine infusion (0.3 mg/kg/h) had a similar effect to fentanyl infusion (1 mcg/kg/h) as a pain reliever in patients with isolated long bone fractures in the ED.