Variations among emergency departments in the treatment of benign headache☆

Article Outline

• Abstract
• Introduction
• Methods
• Results
• Discussion
• Acknowledgements
• Appendix
• References
• Copyright

Abstract 

Study objective: The practice patterns of US emergency departments in the treatment of patients with isolated benign headache have been recently described. How treatment varies among EDs has not been reported. To assess institutional variability in the pharmacotherapy of patients with benign headache, we describe and analyze the practice patterns of 3 US EDs. Methods: This health records survey included a cohort sample of consecutive adult patients aged 16 to 65 years treated with parenteral medication for isolated benign headache at 3 nonaffiliated US EDs: a large, group-model health maintenance organization, a tertiary-care academic center, and a rural community hospital. Patients who underwent a diagnostic search for intracranial pathology, who had any nonheadache secondary diagnosis, or who had coexistent trauma, fever (temperature of ≥38.0°C [100.4°F]), or known pregnancy were excluded from study analysis. Demographic, clinical, and pharmacotherapeutic variables were collected for each ED visit. Descriptive analyses were performed; comparisons were made with t tests. Results: Of the 490 eligible patients treated during the 4-month study period, the mean age was 36.4 years, and 374 (76%) were women. During their 629 visits, 364 (58%) received a migraine diagnosis, and 258 (41%) received a nonspecific headache diagnosis. Polypharmacy was common: 515 (82%) received 2 or more medications, and 154 (25%) received 3 or more medications. Pharmacotherapy varied greatly among the EDs. Use of opioid agonists showed the widest variation (16% to 72%), although use of dihydroergotamine (5% to 16%), prochlorperazine (32% to 59%), and adjunct diphenhydramine with prochlorperazine (42% versus 88%) also varied. Conclusion: Great institutional variability exists among US EDs in the parenteral treatment of patients with isolated benign headache. [Ann Emerg Med. 2003;41:90-97.]

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Introduction 

Headache is a common condition and a frequent reason for seeking emergency medical attention.¹, ² Approximately 5% of US emergency department patients list headache or migraine headache among the top 3 reasons for their visit.³ The majority of these headaches are benign, primary headaches.² For their treatment, the clinician uses a diverse pharmacopoeia, comprising more than 30 medications.³ Parenteral agents used for moderate-to-severe migraine headache include nonsteroidal anti-inflammatory drugs, dopamine-antagonist antiemetics, ergotamines, 5- hydroxytryptamine₁ (5-HT₁) receptor agonists, mixed opioid agonist-antagonists, and opioid agonists. The efficacy, hazards, and costs of these migraine drugs have been carefully reviewed.⁴, ⁵, ⁶, ⁷ Canadian⁸ and US⁹ guidelines have been published as well to assist in the management of migraine headache.

The practice patterns of US emergency physicians in the treatment of patients with isolated benign headache were recently described.³ Most migraineurs (85%) were treated with parenteral medication. Dopamine-antagonist antiemetics (eg, prochlorperazine) and 5-HT_1B/1D receptor agonists (triptans) were less commonly used than opioids, the favorite of which was meperidine.³ Nearly 90% of patients with headache who received opioids received an adjunct antiemetic. Less effective antiemetics (eg, promethazine, hydroxyzine), which also lack antiheadache effects, were used far more frequently than superior antiemetics with established antiheadache effects (eg, prochlorperazine, droperidol, metoclopramide).³ Because the data were presented en masse, practice patterns of individual EDs were not reported. As such, it is unknown whether uniformity or variation characterizes the contemporary ED treatment of isolated benign headache. To analyze the degree of variation among US EDs, we describe and compare the practice patterns of 3 nonaffiliated EDs in the parenteral treatment of patients with isolated benign headache.

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Methods 

This health records survey included a cohort sample of consecutive adult patients aged 16 to 65 years treated with parenteral medication for isolated benign headache between January 1 and April 30, 2000, at 3 nonaffiliated US EDs staffed by board-certified emergency physicians. One (A) is located in the West, has an annual ED census of 85,000 patient visits, and is part of a large, group-model health maintenance organization. Another (B) is an academic, tertiary-care military hospital in the Northwest with an on-site emergency medicine residency training program and an annual ED census of 68,000 patient visits. The other (C) is a rural community hospital in the Midwest with an annual ED census of 25,000 patient visits. The institutional review boards of each participating medical center approved the study.

All ED patients aged 16 to 65 years with benign headache were identified retrospectively by using the following ED diagnoses: migraine headache (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM ] 346), nonspecific headache (ICD-9-CM 784.0), or tension-type headache (ICD-9-CM 307.81). Pediatric patients aged 15 years and younger were excluded from consideration because the management of headache in the pediatric population might differ from that of adults. Also, elderly patients older than 65 years were not evaluated in this study because they are less likely to have primary benign headache, and their treatment is more likely to be complicated by comorbidities and drug effects. Patients with a primary diagnosis of nonspecific headache and a secondary diagnosis of migraine were considered to have a migraine headache. The diagnosis ascribed to the patient was at the treating physician's discretion and might not comply with the formal diagnostic criteria established by the International Headache Society.¹⁰ Those who received parenteral pharmacotherapy in the treatment of benign headache were eligible for the study.

The retrievable medical records of all patients aged 16 to 65 years with an ED diagnosis of benign headache were reviewed. Patients were excluded from the study for the following reasons: failure to receive parenteral therapy; diagnostic search for intracranial pathology (computed tomography or lumbar puncture); any nonheadache secondary diagnosis; trauma; fever (temperature of ≥38.0°C [100.4°F]); known pregnancy; history of cancer (other than localized skin malignancies); or receipt of medical treatment elsewhere before transferal to the study facility.

Each chart was explicitly reviewed in a systematic fashion by the investigator or investigators at each respective facility. The following variables were collected for each visit from the patient's medical record and transcribed onto a standardized data collection sheet: demographic data (ie, age, sex, date of visit, method of payment, assignment to a primary care provider); clinical information (ie, type of headache diagnosis; comorbidities, including hypertension, diabetes, coronary artery disease, congestive heart failure, asthma, chronic obstructive pulmonary disease, seizure disorder, and renal insufficiency; exclusion criteria; discharge disposition); and pharmacotherapeutics (name of drugs and sequence of administration). If assignment to a primary care provider was not ascertainable, it was recorded as undocumented. Comorbidities not listed in the patient's medical record or the facility's comprehensive computerized databases were assumed absent. Medications given within 5 minutes of each other were considered coadministered. The sequence of drug administration was determined from the timed nurse's notes. When the timing of administration was not discernible from the nurse's notes, the physician's orders were used. Each site entered their data onto a uniform database spreadsheet. These databases were reviewed by the principle investigator (DRV) for completeness and consistency. Discrepancies were adjudicated through the principal investigator.

Opioids were classified into initial, second line, or third line depending on when in the sequence of polypharmacy they were administered (ie, first, second, or third). Repeat ED visits were noted only when they met all other study entry criteria (ie, when they occurred within the 4-month study period for patients who returned to the index ED with a diagnosis of an isolated benign headache that was treated with a parenteral medication).

The analytic method is descriptive. Continuous variables are presented as means with SDs. Categoric data are presented as the percentage of frequency of occurrence. Descriptive statistics were performed with standard software. Exact confidence intervals (CIs) were calculated with binomial distributions.

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Results 

Over the 4-month study period, 993 patients between the ages 16 and 65 years received a diagnosis of benign headache in 1 of the EDs. The distribution of excluded patients was as follows (only one criterion was noted per patient): failure to receive parenteral therapy, 175 (17.6%); diagnostic search for intracranial pathology, 122 (12.2%); any nonheadache secondary diagnosis, 96 (9.7%); trauma, 39 (3.9%); irretrievable or incomplete records, 36 (3.6%); fever, 19 (1.9%); known pregnancy, 11 (1.1%); history of cancer, 4 (<1%); or receipt of medical treatment elsewhere before transferal to study facility, 1 (<1%). Of the 993 patients with headache, 490 (49.3%) were enrolled in the study. Patients were young and predominantly female (Table 1).

Table 1. Characteristics of ED patients receiving parenteral pharmacotherapy for benign headache.

Nearly the entire cohort was medically insured (95.5%), and most were established with a primary care provider (84.1%) and were generally healthy (only 20.8% had ≥1 of the defined comorbidities documented in their records).

During the study period, these 490 patients made 629 ED visits, during which they received parenteral pharmacotherapy for benign headache. The diagnoses are listed in Table 2. Sixty (12.2%) patients made 2 or more visits to the ED. Only 3 (0.6%) patients catalogued greater than 10 visits with parenteral medication in 4 months.

Table 2. Diagnosis given at ED visits during which patients received parenteral pharmacotherapy for benign headache.

During the 629 visits, 1,349 doses of medications were given (excluding multiple administrations of the same medication during the same visit). On average, each patient received 2.1±0.8 different parenteral medications per visit, a figure that did not vary among departments. Most patients (515; 81.9%) were treated with 2 or more parenteral medications, 154 (24.5%) were treated with 3 or more drugs, and 42 (6.7%) received 4 or more different agents.

The armamentarium of parenteral pharmacotherapy consisted of 20 medications (Table 3).

Table 3. Parenteral medications administered during ED visits for patients with benign headache.*

Opioids were used in nearly half of the visits (47.5%), and the pure agonists were used far more frequently than the mixed agonist-antagonists (279 [44.3%] versus 20 [3.2%]). Meperidine was the most frequently used opioid agonist (224/279 [80.3%]). Prochlorperazine and ketorolac also were commonly used (45.5% and 25.9%, respectively). Dihydroergotamine (DHE) and sumatriptan were uncommonly administered. Intravenous caffeine was rarely given, as were steroids and benzodiazepines. Prochlorperazine was the most commonly used nonopioid parenteral agent in the ED treatment of benign headache. In 65.3% of the patients, adjunct diphenhydramine was coadministered to prevent akathisia.

Initial medication use according to headache diagnosis is shown in Table 4. Patients with a migraine diagnosis more commonly received meperidine (37.9% versus 19.4%) and less commonly received prochlorperazine (39.0% versus 50.0%), yet patients with both migraine headache and tension-type headache were administered first-line DHE (6.0% versus 6.2%) and sumatriptan (3.0% versus 2.3%) in equal measure. Of note, initial treatment of migraine headache in these EDs was as likely to include an opioid agonist as it was a headache-specific antiemetic, such as prochlorperazine, or a migraine-specific agent, such as DHE or sumatriptan.

Table 4. Initial parenteral medications administered during ED visits for patients with benign headache.*

When opioids were used in the treatment of benign headache, they usually were the first medication given (78.9%; Table 5).

Table 5. Sequence of parenteral opioids and their adjuncts in the ED treatment of benign headache.

Adjunctive medications were nearly always coadministered (93.6%). Promethazine and hydroxyzine served as the predominant opioid adjuncts (when combined, they were used in 165 [67.3%] of 245 visits). Forty-one (21.2%) of 193 patients who received parenteral opioids during their first visit returned for parenteral headache therapy compared with only 19 (6.4%) of 297 patients who received nonopioid pharmacotherapy (difference between groups of 14.8%; 95% CI 8.7% to 22.4%). Sixty patients had 2 or more ED visits with parenteral medications given for headache. Of the 41 who received an opioid during the first visit, 36 (87.8%) also received an opioid during the second visit. Of the 19 who received nonopioid agents alone during the first visit, only 2 (10.5%) received opioids during the second visit (difference between groups of 77.3%; 95% CI 68.6% to 84.8%).

Headache management varied widely among the 3 EDs (Table 3). Opioid agonists showed the widest variation (16.4% versus 72.4%; difference of 56.0%; 95% CI 45.7% to 65.9%), although DHE (4.5% versus 15.6%; difference of 10.1%; 95% CI 4.9% to 17.6%) and prochlorperazine (32.1% versus 58.7%; difference of 26.6%; 95% CI 18.6% to 35.7%) also were quite variable. The use of adjunct diphenhydramine with prochlorperazine showed similar variation (42.0% versus 88.1%; difference of 46.1%; 95% CI 36.9% to 56.2%).

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Discussion 

We describe the parenteral pharmacotherapy used in the emergency treatment of isolated benign headache in 3 US EDs during a 4-month period in the year 2000. Several of our results concur with those reported among US EDs in general.³ More than 70% of ED patients with benign headache are women. Polypharmacy is common: most patients treated parenterally receive 2 or more different medications. The pharmacopoeia is broad: 20 parenteral agents were used, including headache-specific drugs, general analgesics, and a number of adjuncts.

Our study demonstrates great institutional variability in the parenteral treatment of ED patients with benign headache. That one ED would use opioids more than 4 times as frequently as another is remarkable. The reasons for this departmental variation have not been studied but likely include differences in patient population and patient expectations, as well as microcultural factors that influence physicians to adopt established local peer-practice patterns.

Guidelines for the management of acute migraine headache have been developed and disseminated in North America by both the Canadian Headache Society⁸ and the American Academy of Neurology US Headache Consortium,⁹ the latter of which is endorsedby the American College of Emergency Physicians. These expert groups strongly advocate the use of nonopioids, particularly the 5-HT_1B/1D receptor agonists (triptans), DHE, and antiheadache antiemetics (eg, prochlorperazine). The consensus of the US Headache Consortium is that DHE plus an antiemetic remains the “therapy of choice” in the ED for moderate-to-severe migraine headache.⁹ The Canadian Headache Society's algorithm for the treatment of severe migraine headache moves in the same direction: dopamine-antagonist antiemetics are their agents of choice, followed by DHE or a 5-HT_1B/1D agonist if needed.⁸ Kelly⁴ reaches a similar conclusion in her literature review: “the most effective agents seem to be prochlorperazine, chlorpromazine, and sumatriptan, each of which in a number of studies, have achieved greater than 70% efficacy.” A comparable sequence of parenteral medications had been advocated previously for the ED treatment of benign headache.⁷ Although droperidol was not discussed in the US or Canadian recommendations because the supporting evidence postdates the guidelines, it might in fact be more effective than prochlorperazine.¹¹ Recent concerns about the dysrhythmogenic potential of droperidol have dampened enthusiasm for its use.¹²

Despite their suggestions that nonopioids be used as the first choice in the treatment of acute moderate-to-severe migraine headache, both guidelines fail to mount convincing evidence to support this recommendation. In fact, they agree that there is evidence that opioids are effective and admit that studies comparing opioids with nonopioids have found neither group superior.⁸, ⁹ The paucity of management-shaping data is recognized by the US Headache Consortium. At the outset of their guidelines they emphasize this predicament: “Evidence to support pharmacological treatment strategies indicates which medications can be effective, but it does not provide sufficient evidence to establish how to select one therapy over another.”⁹ Given this shortcoming, one cannot expect inadequately supported guidelines to have standardized the ED management of migraine headache.¹³ Without an evidence-based argument for superiority of one therapy over another, “there is little moral standing to intervene by changing behavior.”¹³

Among the opioids used in the acute treatment of isolated benign headache, meperidine was most commonly used in these 3 EDs (Table 3). Although some consider meperidine an inferior opioid in comparison with other less toxic, equianalgesic alternatives (eg, morphine sulfate),¹⁴, ¹⁵ US emergency physicians at large use meperidine more than any other opioid in the treatment of primary headache.³

Consistent with US ED practice patterns,³ opioids were nearly always administered with adjunct antiemetics (Table 5). This might be unnecessary,¹⁴, ¹⁶ yet if the practice is to continue, 2 advantages exist to substituting droperidol, prochlorperazine, or metoclopramide for the more popular promethazine and hydroxyzine. The dopamine-antagonist antiemetics are superior antiemetics¹⁷ and possess antiheadache effects of their own.¹¹, ¹⁸, ¹⁹, ²⁰, ²¹

We observed that opioid recipients were more likely to return to the ED for parenteral therapy than those patients who received nonopioid agents. Also, of repeat visitors, those who received an opioid during the first visit were more likely to receive the same at the second visit. The reasons for recidivism in this subgroup of patients are unclear. More frequent ED use and opioid reception might indicate the severity of their disorder, the medication-refractory nature of their headaches, contraindications to nonopioid agents, an inadequate outpatient care plan, or drug-seeking behavior. Also, frequent use of symptomatic migraine drugs (nonopioids included) can transform migraine headache into chronic daily migraine.²² These drug-rebound or drug-withdrawal headaches are notably refractory to pharmacotherapy.²³ We do not know how many of our recurrent opioid recipients fell into this diagnostic category.

This study has several strengths. The strict entry criteria narrowed the cohort to patients with simple, uncomplicated benign headache. Those patients whose headache was considered secondary to another process (history of trauma, presence of fever, or any additional diagnoses) or whose clinical presentation raised the suspicion of another process (by virtue of having undergone computed tomography or lumbar puncture) were excluded. This obviated confounding the therapy for migraine headache with that of meningitis, subarachnoid hemorrhage, or postdural puncture headache, for example. Pediatric and elderly patients also were excluded to avoid the influence that age might have on both diagnosis and treatment.

For this study, we evaluated heterogeneous EDs, which each represented different geographic regions of the United States, varying annual patient volumes, and disparate institutional structures. This diversity was selected to minimize patterns of practice influenced by region, by population, or by facility affiliations. Unlike the study of US ED practice patterns,³ we were able to determine the timing of medication administration and thereby to distinguish between coadministered adjuncts and subsequently administered rescue medications.

This study has several weaknesses. We cannot ascertain the accuracy of the diagnoses given to the patients. Misclassification is to be expected. More than 40% of our patients were given a diagnosis of unspecified headache, a diagnosis by definition without criteria.¹⁰ Some patients given a diagnosis of unspecified headache in this study were believed by the physician to have a migraine headache because 1 in 10 received migraine-specific medications (ie, either sumatriptan or DHE). However, migraineurs have been shown to respond to migraine-specific medication (sumatriptan) regardless of the type of disabling headache they might have, including tension-type headache.²⁴ Fiesseler et al²⁵ found only half of ED patients given a diagnosis of acute migraine by the emergency physician met the formal International Headache Society criteria. By dropping the requirement of 5 prior episodes and the duration restriction of more than 4 but not more than 72 hours, more than 90% of their patients were able to meet the revised diagnostic criteria. Because many features of the formal International Headache Society criteria were selected arbitrarily without scientific validation,²⁶ simpler criteria for migraine have been proposed for use in clinical practice.²⁷

Another shortcoming of this retrospective study is the failure to report medical therapy tried before the ED visit. Lacking this information, we cannot assess the influence of failed outpatient therapy on the choice of ED treatment. Allergies and medication intolerance, other influential factors, also are absent. These data elements were too inconsistently reported in the medical records to be of any use in this study. Likewise, although we can report how patients were treated, we can make no comment regarding how well they were treated.

Our measure of ED revisit rates is limited by incomplete data. Patients enrolled at the end of the 4-month study period (eg, in mid-April) had less opportunity for a revisit within the study period than those who were treated in January. This might have led to temporal confounding if the kinds of patients who presented in January differ from those presenting in April. Also, we did not tabulate visits for headache treatment to non-ED sites, such as clinics or urgent-care facilities. Likewise, visits in which study patients returned to the index ED with a benign headache for which they received nonparenteral therapy were not included in this analysis.

In summary, great variation exists among EDs in the parenteral therapy of patients with isolated benign headache. Although migraine treatment guidelines suggest approaches to pharmacotherapy, insufficient evidence exists to guide selection of one drug over another. Lack of sufficient evidence might contribute to lack of standardization of care. Concordant with US migraine treatment practice patterns, we found that more than 20 parenteral medications are used and that polypharmacy is common.

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Acknowledgements 

We thank William Pryse-Phillips, MD, for his critical review of an earlier version of the manuscript. Cheryl Durstein-Decker, MD, also helped with data collection.

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Appendix 

Author contributions

. 

DRV conceived and designed the study, collected and analyzed the data, drafted and revised the manuscript, and takes responsibility for the paper as a whole. TRH, JTV, and LB undertook data collection and contributed substantially to the revision of the manuscript.

 

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• endorsed *Endorsement by the American College of Emergency Physicians means that the American College of Emergency Physicians agrees with the general concepts in the guidelines and believes that the developers have begun to define a process of care that considers the best interests of patients with migraine headache.