Few studies have been conducted in the ED of China regarding the acute treatment of migraine. We retrospectively collected data of 300 ED visits of patients with migraine for a migraine attack for six years.
Most emergency department visits for migraines were female, which is consistent with previous studies (5, 6). The prevalence of migraines in women is higher than in men, which may also explain the higher number of female emergency department visits. According to the diagnostic criteria of ICHD-3 and ICHD-3β versions, most patients were diagnosed with migraine without aura and only 7% of patients were referred to neurology after discharge from ED, similar to the UK study (7). The referral rate was relatively low when compared to other countries(9, 10). Possible reasons for the low referral rate: due to financial problems patients tended to back home directly after pain relief; Although at ED, at least one neurologist is available 24 h a day, 7days a week. If prehospital assessment suggested any neurological problem, the neurologist would assess firstly. If a patient was diagnosed with a primary headache by an emergency physician, consulted with neurologist only when treatments were not effective. Our study also suggested that there was a lack of a referral system to a neurologist or headache specialist from ED. It is also necessary to develop a referral protocol for emergency patients with primary headache in the future.
As for medical treatment, we found that the most commonly used medicine was NSAIDs, among them, loxoprofen and celecoxib were most prescribed. However, these two drugs are not the first choice for acute migraine headache (11).A possible reason is that the emergency doctors were not familiar with migraine treatment guidelines. There were no patients used triptans because it was not currently available in ED. Our study also found that the second most used drugs were opioids (17.9%). In expert recommendations and guidelines, opioids are not the evidence-based treatment for the acute phase of migraine (12, 13) and with possible side effects, especially the risk of substance abuse and headache chronicity (14). Some researchers suggested that migraine patients who have previously used opioids in ED were associated with increased future health resource utilization (HRU)(15). The rate of opioids used in the emergency department of migraine patients had varied widely across the literature, from 6.9–69.9% (16). In addition, compared with previous studies, the proportion of opioid use in emergency patients was higher than that in outpatient patients (7.1%) (6). From our study, opioids should be restricted in emergency rooms in the future. Moreover, our study found that none of the enrolled patients was offered prophylactic therapy at discharge. Knowledge of the management of migraine medications should be trained to non-neurologists.
In terms of examination, our study found that about 36% of patients underwent head CT and 0.3% underwent head MRI. The proportion of head CT and MRI in our emergency department was lower than that reported by Alberto Doretti et al. (53%)(17), and the meta-analysis showed that vascular and intracranial abnormalities were rarely detected by imaging in headache patients with no abnormalities on physical examination (18). Overuse of head CT may increase patients' disease burden and radiation exposure. Experts recommend that head CT or MRI should be used for differential diagnosis only when a secondary headache is suspected (13, 19). A recent study found that a 9.6% decrease in the use of head CT scans for patients presenting to ED with a major headache complaint was not followed by an increase in deaths or missed diagnoses(20). However, in the condition of emergency department, the primary responsibility of an emergency doctors is to distinguish whether headache is primary or secondary, to avoid misdiagnosis. A timely head CT examination can also relieve patients' anxiety and fear (21). Our study also revealed some migraine patients received blood tests (25.3%), which could be unnecessary. Cynthia M. C. Lemmens et al suggested that age 50 years or older, presentation within 1 h after headache onset, clinical history of aphasia, and focal neurological deficit at the examination were significantly associated with abnormal cranial CT results(22). Most of them are red flag symptoms that ED doctors are very familiar with. In future research, a multi-factor prediction model based on clinical symptoms and physical examination should be established to facilitate emergency doctors to quickly identify patients with intracranial lesions. It may help to avoid excessive use of cranial CT and blood test.
In this study, the average cost of emergency room visits for migraine patients was $57.17. There have been no studies on ED visits for migraine patients in China. The mean annual cost per migraine outpatient was 46.5 USD (6)in China. This number may be related to patients with different health care conditions, hospital levels and different regions. Improving the evidence-based management of migraine among non-neurologists are expected to improve the disease burden of patients.
This study has some limitations:1. Although West China Hospital is currently the largest hospital in southwest China, our study was still a single-center study. It limits the representativeness of this study.2. Since the medical records of emergency department were difficult to obtain the patients’ detailed history, such as patients' previous headache history, medication history and family history and so on. This is what limits our further analysis.