Intravenous opioid dosing and outcomes in emergency patients: a prospective cohort analysis.

Objectives: Pain management in emergency department (ED) patients is variable and often inadequate. This study sought to (1) describe the variability in intravenous opioid dosing and (2) compare the outcomes that result from the most commonly prescribed opioid doses.

Methods: This prospective cohort study enrolled emergency patients who were prescribed intravenous morphine or hydromorphone as their initial analgesic. Subjects were interviewed at the time of opioid administration and 1 to 2 hours after opioid administration. Outcomes included the numeric pain score change (using a 0-10 scale), the proportion achieving a 50% pain score reduction, and the proportion developing side effects. Logistic regression was used to assess the effects of demographic, clinical, and treatment variables on outcomes.

Results: Six hundred ninety-one patients were analyzed. Initial equianalgesic dosages varied by a factor of 27 (from 1 mg morphine to 4 mg hydromorphone). Opioid dose titration occurred in only 21% of patients. Outcomes were similar across the range of opioid dosages before and after adjusting for potentially confounding variables. Among patients not taking opioids at home who received a total of 4 mg of morphine or less. 48% achieved at least a 50% pain score reduction and 60% did not want additional analgesics.

Conclusions: We found marked opioid dosing variability and infrequent opioid dose titration. A substantial number of ED patients with severe pain responded well to relatively low opioid dosages. Improved ability to predict opioid dose requirements and strategies that increase the use of opioid dose titration in ED patients are needed.