• The primary outcome of this study was the between-group difference in change of NRS pain scores from baseline to 30 minutes after medications were infused.
  

• Secondary outcomes included pain score comparisons at 5 minutes and 120 minutes, additional pain medications administered after initial medication, and comparison of adverse events
  

There is widespread agreement that pain is under-treated in the ED (18). The current recommended treatment of acute pain in the ED setting is administration of an initial bolus of morphine followed by titration until adequate analgesia is achieved (19,20). Several studies have shown that even 0.1 mg/kg IV morphine (7-10 mg administered to the average 70-100 kg patient) inadequately treats many patients’ acute pain (21,22). In spite of this, we have observed that many emergency physicians and nurses are hesitant to give 7-10 mg of morphine as an initial IV dose. In contrast, we observed that these same healthcare providers were not similarly reluctant to administer a roughly equianalgesic dose of hydromorphone (1-1.5 mg), perhaps because the more potent hydromorphone is given in much smaller milligram quantities than morphine, thus providing the illusion of substantially less opioid administered to the patient. Having repeatedly observed this phenomenon, we reasoned that if a smaller milligram dose of hydromorphone were shown to provide an efficacy, safety, and side-effect profile comparable or superior to a larger milligram dose of morphine, it would provide evidence supporting use of hydromorphone as an alternative first line opioid in the treatment of acute pain presenting to the ED. As a practical corollary to this, we reasoned further that the increased willingness of healthcare providers to use hydromorphone might contribute to reducing one component of the multifaceted problem of oligoanalgesia in the ED (18).