Comparison of the Analgesic Effect of Intravenous Acetaminophen and Morphine Sulfate in Rib Fracture; a Randomized Double-Blind Clinical Trial

Introduction: Rib fracture is one of the common causes of trauma disabilities in many events and the outcome of these patients are very extensive from temporary pain management to long-term significant disability. Control and management of the pain in such patients is one of the most important challenges in emergency departments. Thus, the aim of the present study was assessing the efficacy of IV acetaminophen in pain control of patients with rib fracture. Methods: In this double-blind clinical trial, 54 patients over 18 years of age, referred to two educational hospitals with rib fracture, were entered. Patients were randomly categorized in two groups of morphine sulfate (0.1 milligram per kilogram of body weight) and IV acetaminophen (1gram), as single-dose infused in 100 cc normal saline. The pain severity was measured by numeric rating scale (NRS) on arrival and 30 minutes after drug administration. At least three scores reduction was reported as therapeutic success. Results: The mean and standard deviation of patients' age was 41.2 +/- 14.1 years. There is no difference in gender (p=0.24) and age frequency (p=0.77) between groups. 30 minutes after drug administration the mean of pain severity were 5.5 +/- 2.3 and 4.9 +/- 1.7 in morphine and acetaminophen groups, respectively (p= 0.23). Success rate in morphine and acetaminophen groups were 58.6% (95% Cl: 39.6-77.7) and 80% (95% Cl: 63.2-96.7), respectively, (p=0.09). Only 3 (5.6%) patients had dizziness (p=0.44) and other effects were not seen in any of patients. Conclusion: The findings of the present study shows that intravenous acetaminophen and morphine have the same therapeutic value in relieving the pain of rib fracture. The success rate after 30 minutes drug administration were 80% and 58.6% in acetaminophen and morphine groups, respectively. Presentation of side effects was similar in both groups.