Convincing the skeptic. How to fix emergency department headache management

In their analysis of a research database from an academic emergency department (ED) in California (1), Drs McCarthy and Cowan identify three features of emergency headache care that have been reported by multiple clinical investigators from a multitude of North American EDs (2–7): (i) emergency physicians often fail to assign specific primary headache diagnoses to their headache patients; (ii) emergency physicians frequently treat migraine in particular and headaches in general with opioids; (iii) emergency physicians use triptans infrequently and dihydroergotamine rarely. These practices seem difficult to understand. In the outpatient setting, an accurate headache diagnosis will lead to appropriate treatment. Parenteral opioid use has been associated with undesirable headache outcomes, such as headache recurrence and ED recidivism (3). Long-term problems associated with recurrent use of opioids include refractoriness to standard headache medications (8) and chronification of migraine (9). Triptans and dihydroergotamine on the other hand are evidence-based therapies. The number needed to treat for subcutaneous sumatriptan, for example, is a very impressive ‘2’ (10). Unfortunately, there are no data available to help us comprehend and contextualize emergency practice—why do emergency physicians practice as they do? It is clear that time has not changed long-held practice patterns—opioid use for management of migraine in the ED is as prevalent today as it was 15 years ago (4). As demonstrated by Drs McCarthy and Cowan and elsewhere (1,4), this practice is highly prevalent in academic settings, the setting in which one might most expect to see appropriate practice. Use of opioids in the ED for migraine may be an education issue—it could be that emergency physicians simply do not appreciate the long-term sequelae of repeated opioid use. Alternatively, it may be an informed choice. Consider how a skeptic might respond to the American Headache Society’s Choosing Wisely guidelines (11): ‘Parenteral opioids are a guideline-supported, evidence-based therapy (12). There are no high quality clinical data demonstrating detrimental effects of parenteral opioids when compared to alternative therapy. Much of the data come from non-randomized studies, which failed to account for important baseline factors’. For example, Drs McCarthy and Cowan did indeed find an association between parenteral opioid use and length of stay. However, is this because of opioid administration, or are there plausible unmeasured confounders, such as the severity of the underlying headache disorder or duration of the acute attack? Could it be that the patients treated with parenteral non-steroidal anti-inflammatory drugs (NSAIDs) in Drs McCarthy and Cowan’s database were some of the many patients who present to the ED having not taken any medication at all, while the ones given opioids were the patients with chronic migraine and medication overuse headache who had already exceeded recommended doses of triptans and NSAIDs? Failure to account for these baseline differences is a limitation encountered in many retrospective ED analyses. There are compelling data demonstrating an association between outpatient oral opioids and progression of episodic to chronic migraine (9). However, it is not clear if these data are relevant to patients who receive a single dose of parenteral hydromorphone in the ED.