Tissue residue depletion of fenbendazole after oral administration in turkeys.

The objectives of this study were to determine tissue depletion of fenbendazole in turkeys and estimate a withdrawal interval (WDI). Forty-eight 9-week-old turkeys were fed fenbendazole at 30 mg/kg of feed for 7 consecutive days. Three hens and 3 toms were sacrificed every 2 days from 2 to 16 days post-treatment, and tissues were collected to determine fenbendazole sulfone (FBZ-SO2) concentrations using mass spectrometry. At all timepoints, FBZ-SO2 concentrations in liver and skin-adherent fat were above the limit of quantification (1 ppb), with higher concentrations than those in kidney and muscle. Two turkeys had detectable FBZ-SO2 concentrations in kidney at 16 days. No detectable FBZ-SO2 concentrations were found in muscle at 14 and 16 days. Fenbendazole residues depleted very slowly from the liver and a WDI of at least 39 days should be observed under the conditions of this study, in order to comply with Canadian regulatory agencies.

Déplétion du fenbendazole pour les résidus tissulaires après l'administration orale chez les dindons. Les objectifs de cette étude consistaient à déterminer la déplétion du fenbendazole dans les tissus chez les dindons et d'estimer un délai d'attente (DA). Du fenbendazole a été administré à quarante-huit dindons âgés de 9 semaines, à raison de 30 mg/kg d'aliments pendant 7 jours consécutifs. Trois dindes et 3 dindons ont été sacrifiés tous les deux jours pendant les jours 2 à 16 après le traitement et les tissus ont été prélevés pour déterminer les concentrations de fenbendazole sulfone (FBZ-SO2) en utilisant la spectrométrie de masse. À tous les moments de prélèvement, les concentrations de FBZ-SO2 dans le foie et le gras adhérent à la peau étaient supérieures à la limite de quantification (1 ppm), avec des concentrations supérieures à celles présentes dans les reins et les muscles. Deux dindes avaient des concentrations de FBZ-SO2 détectables dans les reins à 16 jours. Aucune concentration détectable de FBZ-SO2 n'a été trouvées dans les muscles à 14 et à 16 jours. Les résidus de fenbendazole se résorbaient très lentement du foie et un DA d'au moins 39 jours devrait être observé conformément aux conditions de cette étude afin de satisfaire aux exigences des agences réglementaires canadiennes.(Traduit par Isabelle Vallières).

Emergency Physician Patterns Related to Anticoagulation of Patients with Recent-Onset Atrial Fibrillation and Flutter.

Guidelines strongly recommend long-term anticoagulation with warfarin for patients with newly recognized AF who have high embolic risk by virtue of a CHADS2 (Congestive Heart Failure, Hypertension, Age >65, Diabetes, History of Stroke) score ≥ 2. The goal of this study was to determine patterns of emergency department-initiated anticoagulation among eligible patients discharged from Canadian centers with an episode of recent-onset atrial fibrillation and flutter (RAFF) and determine if decision-making is driven by the CHADS2 score or other factors. This was accomplished by examining health records using uniform case identification and data abstraction as well as centralized quality control; it was conducted in 8 Canadian university emergency departments over a 12-month period. Eligible patients for this analysis demonstrated RAFF requiring emergency management, were not already taking warfarin and were not admitted to hospital. Univariate analyses were conducted using T-test or Chi-square to select factors associated with anticoagulation initiation at a significance level of p < 0.15 and multiple logistic regression was employed to evaluate independent predictors after adjustment for confounders. Among 633 eligible patients, only 21 out of 120 patients (18%) with a CHADS2 score ≥ 2 received anticoagulation and among 70 patients who were given anticoagulation only 21 (30%) had a CHADS2 score ≥ 2. Independent predictors of anticoagulation included age by 10-year strata: (OR = 1.7; 95% CI 1.3 - 2.1), heparin use in the anticoagulation (OR = 9.6; 95% CI 4.9 - 18.9), a new prescription for metoprolol (OR = 9.6; 95% CI 4.9 - 18.9) and being referred to cardiology for follow-up (OR = 5.6; 95% CI 2.6 - 12.0). CHADS2 ≥ 2 doubled the likelihood of being prescribed anticoagulation (OR= 2.0; 95% CI 1.5 - 3.5) but was not an independent predictor. It was thus determined that patients discharged from the emergency department in this study were not prescribed anticoagulation in keeping with current recommendations. This practice gap merits further investigation and may benefit from educational efforts or enhanced support for anticoagulation use from the emergency department.

A consensus-based process to define standard national data elements for a Canadian emergency department information system.

Canadian hospitals gather few emergency department (ED) data, and most cannot track their case mix, care processes, utilization or outcomes. A standard national ED data set would enhance clinical care, quality improvement and research at a local, regional and national level. The Canadian Association of Emergency Physicians, the National Emergency Nurses Affiliation and l'Association des médecins d'urgence du Québec established a joint working group whose objective was to develop a standard national ED data set that meets the information needs of Canadian EDs. The working group reviewed data elements derived from Australia's Victorian Emergency Minimum Dataset, the US Data Elements for Emergency Department Systems document, the Ontario Hospital Emergency Department Working Group data set and the Canadian Institute for Health Information's National Ambulatory Care Reporting System data set. By consensus, the group defined each element as mandatory, preferred or optional, and modified data definitions to increase their relevance to the ED context. The working group identified 69 mandatory elements, 5 preferred elements and 29 optional elements representing demographic, process, clinical and utilization measures. The Canadian Emergency Department Information System data set is a feasible, relevant ED data set developed by emergency physicians and nurses and tailored to the needs of Canadian EDs. If widely adopted, it represents an important step toward a national ED information system that will enable regional, provincial and national comparisons and enhance clinical care, quality improvement and research applications in both rural and urban settings.

Emergency physicians' attitudes toward a clinical prediction rule for the identification and early discharge of low risk patients with chest discomfort.

OBJECTIVES: To determine Canadian emergency physicians' estimates regarding the safety and efficiency of chest discomfort management in their emergency department (ED), and their attitudes toward and perception of the need for a chest discomfort clinical prediction rule that identifies very low risk patients who are safe to discharge after a brief ED assessment. METHODS: 300 members of the Canadian Association of Emergency Physicians (CAEP) were randomly selected to receive a confidential mail survey, which invited them to provide information on current disposition of patients with chest discomfort and their opinions regarding the value of a clinical prediction rule to identify patients with chest discomfort who are safe to discharge after a brief (approximately 2 hour) assessment. RESULTS: Of the 300 physicians selected, 288 were eligible for the survey and 235 (82%) responded. Only 5% follow discharged patients to measure safe practice. Overall, 165 (70%) felt the proposed prediction rule would be very useful and 43 (18%) felt it would be useful. Almost all (94%) believed a prediction rule would be useful if it identified patients safe for discharge without increasing the current rate of missed acute myocardial infarction (estimated at 2%). Most respondents (59%) believed that a clinical prediction rule should suggest a course of action, while 30% felt it should convey a probability of disease. CONCLUSIONS: Canadian emergency physicians support the concept of a clinical prediction rule for the early discharge of patients with chest discomfort. Most believe that such a rule would be useful if it identified patients who are safe for discharge after a brief assessment, while maintaining current levels of safety. Future research should be aimed at deriving a clinical prediction rule to identify low risk patients who can be safely discharged after a limited emergency department evaluation.

A randomized trial of the effects of early cardiac serum marker availability on reperfusion therapy in patients with acute myocardial infarction: the serial markers, acute myocardial infarction and rapid treatment trial (SMARTT).

OBJECTIVES: The purpose of this study was to assess whether the immediate availability of serum markers would increase the appropriate use of thrombolytic therapy. BACKGROUND: Serum markers such as myoglobin and creatine kinase, MB fraction (CK-MB) are effective in detecting acute myocardial infarction (AMI) in the emergency setting. Appropriate candidates for thrombolytic therapy are not always identified in the emergency department (ED), as 20% to 30% of eligible patients go untreated, representing 10% to 15% of all patients with AMI. Patients presenting with chest pain consistent with acute coronary syndrome were evaluated in the EDs of 12 hospitals throughout North America. METHODS: In this randomized, controlled clinical trial, physicians received either the immediate myoglobin/CK-MB results at 0 and 1 h after enrollment (stat) or conventional reporting of myoglobin/CK-MB 3 h or more after hospital admission (control). The primary end point was the comparison of the proportion of patients within the stat group versus control group who received appropriate thrombolytic therapy. Secondary end points included the emergent use of any reperfusion treatment in both groups, initial hospital disposition of patients (coronary care unit, monitor or nonmonitor beds) and the proportion of patients appropriately discharged from the ED. RESULTS: Of 6,352 patients enrolled, 814 (12.8%) were diagnosed as having AMI. For patients having AMI, there were no statistically significant differences in the proportion of patients treated with thrombolytic therapy between the stat and control groups (15.1% vs. 17.1%, p = 0.45). When only patients with ST segment elevation on their initial electrocardiogram were compared, there were still no significant differences between the groups. Also, there was no difference in the hospital placement of patients in critical care and non- critical care beds. The availability of early markers was associated with more hospital admissions as compared to the control group, as the number of patients discharged from the ED was decreased in the stat versus control groups (28.4% vs. 31.5%, p = 0.023). CONCLUSIONS: The availability of 0- and 1-h myoglobin and CK-MB results after ED evaluation had no effect on the use of thrombolytic therapy for patients presenting with AMI, and it slightly increased the number of patients admitted to the hospital who had no evidence of acute myocardial necrosis.

Early discharge of patients with presumed opioid overdose: development of a clinical prediction rule.

OBJECTIVE: To develop a clinical prediction rule to identify patients who can be safely discharged one hour after the administration of naloxone for presumed opioid overdose. METHODS: Patients who received naloxone for known or presumed opioid overdose were formally evaluated one hour later for multiple potential predictor variables. Patients were classified into two groups: those with adverse events within 24 hours and those without. Using classification and regression tree methodology, a decision rule was developed to predict safe discharge. RESULTS: Clinical findings from 573 patients allowed us to develop a clinical prediction rule with a sensitivity of 99% (95% CI = 96% to 100%) and a specificity of 40% (95% CI = 36% to 45%). Patients with presumed opioid overdose can be safely discharged one hour after naloxone administration if they: 1) can mobilize as usual; 2) have oxygen saturation on room air of >92%; 3) have a respiratory rate >10 breaths/min and <20 breaths/min; 4) have a temperature of >35.0 degrees C and <37.5 degrees C; 5) have a heart rate >50 beats/min and <100 beats/min; and 6) have a Glasgow Coma Scale score of 15. CONCLUSIONS: This prediction rule for safe early discharge of patients with presumed opioid overdose performs well in this derivation set but requires validation followed by confirmation of safe implementation.

Acute thromboscintigraphy with (99m)Tc-apcitide: results of the phase 3 multicenter clinical trial comparing 99mTc-apcitide scintigraphy with contrast venography for imaging acute DVT. Multicenter Trial Investigators.

UNLABELLED: (99m)Tc-apcitide (formerly known as (99m)Tc-P280) is a radiolabeled peptide that binds with high affinity and specificity to the glycoprotein IIb/IIIa receptors expressed on the activated platelets that are involved in acute thrombosis. The purpose of the phase 3 multicenter clinical trials was to compare (99m)Tc-apcitide scintigraphy with contrast venography for imaging acute deep venous thrombosis (DVT). METHODS: A total of 280 patients were enrolled in 2 clinical trials conducted in North America and Europe. Patients were to be within 10 d of onset of signs and symptoms of acute DVT or within 10 d of surgery associated with a high risk of DVT. (99m)Tc-apcitide scintigraphy and contrast venography were to be performed within 36 h. Planar scintigraphic images were obtained at 10, 60, and 120-180 min after injection. (99m)Tc-apcitide scintigrams and contrast venograms were read with masking and also by the institutional investigators. RESULTS: Of a total of 243 patients who were evaluable, 61.7% were receiving heparin at the time of imaging. Masked reading of (99m)Tc-apcitide scintigraphy, compared with masked reading of contrast venography, had a sensitivity, specificity, and agreement of 73.4%, 67.5%, and 69.1%, respectively, which met the prospectively defined target efficacy endpoint in both trials. Institutional reading of (99m)Tc-apcitide scintigraphy, compared with institutional reading of contrast venography, had a sensitivity, specificity, and agreement of 75.5%, 72.8%, and 74.0%, respectively. However, the entire trial population included patients with a history of DVT who may have had old, nonacute venous thrombi that could confound the venography results. Therefore, data from patients having no history of DVT or pulmonary embolism and who presented within 3 d of onset of signs and symptoms (n = 63), i.e., patients for whom a venogram would be expected to be positive only if acute DVT were present, also were analyzed as a subset. In these patients, institutional reading of (99m)Tc-apcitide scintigraphy, compared with institutional reading of contrast venography, had a sensitivity, specificity, and agreement of 90.6%, 83.9%, and 87.3%, respectively. CONCLUSION: (99m)Tc-apcitide scintigraphy is a new diagnostic modality that is highly sensitive for imaging acute DVT.

Development, implementation and reliability assessment of an emergency physician performance evaluation tool.

UNLABELLED: Evaluation of physician practice is necessary, both to provide feedback for self-improvement and to guide department heads during yearly evaluations. OBJECTIVE: To develop and implement a peer-based performance evaluation tool and to measure reliability and physician satisfaction. METHODS: Each emergency physician in an urban emergency department evaluated their peers by completing a survey consisting of 21 questions on effectiveness in 4 categories: clinical practice, interaction with coworkers and the public, nonclinical departmental responsibilities, and academic activities. A sample of emergency nurses evaluated each emergency physician on a subset of 5 of the questions. Factor analysis was used to assess the reliability of the questions and categories. Intra-class correlation coefficients were calculated to determine inter-rater reliability. After receiving their peer evaluations, each physician rated the process's usefulness to the individual and the department. RESULTS: 225 surveys were completed on 16 physicians. Factor analysis did not distinguish the nonclinical and academic categories as distinct; therefore, the survey questions fell into 3 domains, rather than the 4 hypothesized. The overall intra-class correlation coefficient was 0.43 for emergency physicians, indicating moderate, but far from perfect, agreement. This suggests that variability exists between physician evaluators, and that multiple reviewers are probably required to provide a balanced physician evaluation. The intra-class correlation coefficient for emergency nurses was 0.11, suggesting poor reliability. Overall, 11 of 15 physicians reported the process valuable or mostly valuable, 3 of 15 were unsure and 1 of 15 reported that the process was definitely not valuable. CONCLUSION: Physician evaluation by a single individual is probably unreliable. A useful physician peer evaluation tool can be developed. Most physicians view a personalized, broad-based, confidential peer review as valuable.

Is early discharge safe after naloxone reversal of presumed opioid overdose?

INTRODUCTION: Patients with suspected opioid overdose frequently require naloxone treatment. Despite recommendations to observe such patients for 4 to 24 hours after naloxone, earlier discharge is becoming more common. This prospective, observational study of patients with presumed opioid overdose examines the safety of early disposition decisions and the accuracy of outcome prediction by physicians 1 hour after the administration of naloxone. METHODS: The study was carried out at St. Paul's Hospital, an inner city teaching centre that cares for most of the injection drug users in Vancouver, BC. Patients were formally assessed 1 hour after receiving naloxone for presumed opioid overdose. Demographics, medical history and physical examination were documented on specific data forms, and physicians recorded their comfort with early discharge. Patients were followed up, and those who required a critical intervention or suffered a pre-defined adverse event (AE) within 24 hours of their 1-hour assessment were identified. RESULTS: Of 573 patients, 48% were discharged in less than 2 hours, 23% in 2-4 hours and 29% in >4 hours. 94 patients who were held in the emergency department (ED) or admitted required a critical intervention, including supplemental oxygen for hypoxia (74), repeat naloxone (52), antibiotics administered intravenously (IV) (14), assisted ventilations (13), fluid bolus for hypotension (12), charcoal for associated life-threatening overdose (6), IV inotropic agents (2), antiarrhythmics for sustained tachycardia >130 beats/min (1), and administration of bicarbonate for arterial [HCO3] <5 or venous CO2 <5 (1). Physicians predicted adverse events with 94% sensitivity and 59% specificity. No discharged patients suffered a serious AE within 24 hours of ED discharge. CONCLUSIONS: Emergency physicians can clinically identify patients at risk of deterioration after naloxone reversal of suspected opioid overdose. Prolonged observation or hospital admission is not usually required. Selective early discharge of patients with presumed opioid overdose is feasible and appears safe. A clinical prediction rule may be useful in identifying patients eligible for early discharge.

The NARC (nonsteroidal anti-inflammatory in renal colic) trial. Single-dose intravenous ketorolac versus titrated intravenous meperidine in acute renal colic: a randomized clinical trial.

OBJECTIVES: Intravenous (IV) opioid titration is an accepted method of relieving acute renal colic. Studies have shown that nonsteroidal anti-inflammatory drugs (NSAIDs) are also effective in this setting. Our objective was to compare single-dose ketorolac and titrated meperidine, both administered intravenously, with respect to speed and degree of analgesia, adverse effects and functional status. Our primary hypothesis was that these agents provide equivalent analgesia within 60 minutes. Our secondary hypotheses were that ketorolac-treated patients would experience fewer adverse effects and would be better able to resume usual activity. METHODS: This was a multicentre, double-blind randomized equivalence trial in a convenience sample of patients age 18-65 with moderate or severe renal colic, documented by intravenous pyelogram, ultrasound or stone passage. Meperidine-treated patients received 50 mg IV meperidine at 0 minutes, then 25-50 mg every 15 minutes as needed for ongoing pain. Ketorolac-treated patients received 30 mg IV ketorolac at 0 minutes and placebo injections every 15 minutes as needed. Pain levels and adverse effects were assessed every 15 minutes, and functional status was evaluated at 60 minutes. Our primary outcome was the proportion of patients with mild or no pain at 60 minutes. RESULTS: Overall, 49 of 77 meperidine-treated patients (64%; 95% confidence interval [CI], 53%-75%) and 47 of 65 ketorolac-treated patients (72%; 95% CI, 61%-83%) achieved successful pain relief at 60 minutes (p value for equivalence = 0.002). Ten percent of meperidine-treated patients and 44% of ketorolac-treated patients were able to resume usual activity at 60 minutes (p = 0.001). CONCLUSIONS: In the doses studied, single-dose IV ketorolac is as effective as titrated IV meperidine for the relief of acute renal colic and causes less functional impairment.

Do emergency physicians know the costs of medical care?

OBJECTIVES: To estimate the level of knowledge that Canadian emergency physicians have of the costs of common diagnostic tests and interventions in the emergency department (ED). METHODS: In a cross-sectional survey, 75 emergency physicians from 7 community and academic EDs were asked to estimate the cost of 60 of the most commonly ordered imaging modalities, laboratory tests and pharmaceuticals. Their estimates were compared to actual costs obtained from hospital finance departments. For each test or pharmaceutical, physician error was calculated as a percentage of the actual value, using the formula [(actual - estimated) / actual] yen 100. For each item, the proportion of responses that were underestimates, the proportion that were overestimates and the proportion that were accurate within 25% were reported. RESULTS: Mean error of the physicians' estimates was 40% (95% confidence interval [CI], 35%-45%) for imaging studies, 153% (95% CI, 128%-178%) for lab investigations, and 218% (95% CI, 179%-257%) for pharmaceutical costs. Rates of underestimation vs. overestimation were 68% vs. 16% for imaging modalities, 23% vs. 56% for laboratory tests, and 21% vs. 64% for pharmaceuticals. CONCLUSIONS: Emergency physicians have a limited knowledge of the costs of the tests and interventions they use on a daily basis. They tend to overestimate lab and pharmaceutical costs but underestimate imaging costs. Cost-awareness programs for emergency physicians are most likely to be beneficial if they focus on imaging modalities.

How accurately do we estimate patients' weight in emergency departments?

OBJECTIVE: To assess the accuracy of estimates of patients' weight made by physicians, nurses, and patients themselves in emergency departments. DESIGN: Observational prospective study. SETTING: Tertiary referral centre in Vancouver, BC. PARTICIPANTS: Eleven attending physicians, 26 nurses, and a convenience sample of 117 patients. INTERVENTIONS: Patients themselves, attending physicians, and nurses independently estimated the weight of 117 patients. An investigator weighed each patient. MAIN OUTCOME MEASURES: Mean error was determined by subtracting actual weight from estimated weight and dividing by actual weight; 95% confidence intervals (CI) were calculated. RESULTS: Mean error in estimates was 3.1% (95% CI 2.7 to 3.5) for patients, 8.4% for nurses (CI 7.6 to 9.2), and 8.1% (CI 7.1 to 9.1) for physicians. Weight was estimated within 5% of actual weight by 32% of nurses, 39% of physicians, and 82% of patients. Weight was estimated within 10% of actual weight by 66% of nurses, 66% of physicians, and 97% of patients. Estimates out by more than 15% were made by 11% of nurses, 16% of physicians, and 1% of patients. CONCLUSIONS: Patient estimates were most accurate. Physician and nurse estimates were unreliable.

Sudden death of a young hockey player: case report of commotio cordis.

Despite the use of protective gear, a 15-year-old hockey player died when he was struck in the chest by a puck. This is the fifth recorded hockey death related to so-called commotio cordis, that is, blunt chest injury without myocardial structural damage. In light of inadequacies of commercial chest protectors currently in use for hockey, the authors hope to educate players and coaches about the danger of blocking shots with the chest. Physicians should be aware that commotio cordis represents a distinctive pathological condition, in the event of which immediate recognition, precordial thump, CPR, and defibrillation are potentially lifesaving. Appropriate medical supervision at amateur hockey games, 911 telephone access, and on-site automated external defibrillators are issues that deserve careful consideration.

Procedural sedation and analgesia in the emergency department. Canadian Consensus Guidelines.

Procedural sedation and analgesia are core skills in emergency medicine. Various specialty societies have developed guidelines for procedural sedation, each reflecting the perspective of the specialty group. Emergency practitioners are most likely to embrace guidelines developed by people who understand emergency department (ED) skills, procedures, conditions, and case mix. Recognizing this, the Canadian Association of Emergency Physicians (CAEP) determined the need to establish guidelines for procedural sedation in the ED. In March, 1996, a national emergency medicine (EM) working committee, representing adult and pediatric emergency physicians, was established. This committee teleconferenced with representatives of the Canadian Anesthetic Society (CAS) to identify problems, perspectives, and controversial issues, and to define a process for guideline development. The EM committee subsequently reviewed existing literature, determined levels of evidence, and developed the document, which evolved based on feedback from the CAS and CAEP Standards Committees. The final version was approved by the CAEP Standards Committee and the CAEP Board of Directors, then submitted for peer review. These guidelines discuss the goals, definitions, and principles of ED sedation, and make recommendations for pre-sedation preparation, patient fasting, physician skills, equipment and monitoring requirements, and post-sedation care. The guidelines are aimed at non-anesthesiologists practicing part-time or full-time emergency medicine. They are applicable to ED patients receiving parenteral analgesia or sedation for painful or anxiety-provoking procedures. They are intended to increase the safety of procedural sedation in the ED.

Dexamethasone prevents relapse after emergency department treatment of acute migraine: a randomized clinical trial.

OBJECTIVE: To determine whether the addition of intravenous dexamethasone to standard emergency department (ED) migraine therapy would decrease the incidence of severe recurrent headache 24 to 48 hours after initial treatment. METHODS: Patients aged 19 to 65 years whose headache was severe enough to require parenteral therapy and who met International Headache Society migraine criteria were eligible for this randomized, double-blind trial. The study was conducted in the ED of 2 community hospitals, 1 of which was a tertiary referral centre. Exclusion criteria included pregnancy, focal findings, fever, meningismus, allergy to the study drug, active peptic ulcer disease and diabetes mellitus. Demographic and clinical data, including headache severity, were recorded. After abortive therapy (antiemetics, intravenous nonsteroidal agents, dihydroergotamine or opioids), blinded nurses administered dexamethasone (24 mg intravenously) or placebo. Patients recorded headache severity on a Visual Analogue Scale (VAS) at time T = 0, T = 30 minutes and T = 60 minutes and at discharge. They were contacted 48 to 72 hours later and asked whether they had suffered a recurrence of their headache, categorized as class A (severe, provoking another physician visit), class B (severe, interfering with daily activity but not provoking a physician visit), class C (mild, requiring self-medication but not limiting activity) or class D (mild, requiring no treatment). RESULTS: Two of 100 patients were lost to follow-up, leaving 98 in the study sample. Placebo recipients were more likely to be female; other baseline characteristics were similar between groups. Median VAS pain score was 83 mm on ED arrival, 35 mm after initial treatment and 12 mm on discharge. At follow-up, 65 of 98 patients had suffered headache recurrence. In the placebo versus dexamethasone groups, respectively, the results were 11 versus 0 in class A, 11 versus 9 in class B, 7 versus 11 in class C and 4 versus 12 in class D. Regarding the primary outcome, 9 of 49 dexamethasone patients (18%) and 22 of 49 placebo patients (45%) had severe (classes A and B) recurrent headache (odds ratio 0.28; 95% CI, 0.11 to 0.69; p = 0 .005). CONCLUSIONS: Migraine recurrence is common after "successful" ED treatment. Inflammation may be a critical factor in migraine genesis. Intravenous dexamethasone decreases the incidence of severe recurrent headache after ED treatment and should be offered to patients thought to be at risk of recurrent headache.