eMedicine Specialties > Emergency Medicine > Pulmonary

Asthma

Author: Barry E Brenner, MD, PhD, FACEP, Professor of Emergency Medicine, Professor of Internal Medicine, Program Director, Emergency Medicine, University Hospitals, Case Medical Center
Contributor Information and Disclosures

Updated: Jul 2, 2009

Introduction

Background

Asthma is a common disorder that accounts for almost 2 million ED visits each year in the United States. In 2005, 1.8 million ED visits were for acute asthma. On average, this represents approximately 2% of all ED visits. In urban centers, however, acute asthma may comprise up to 10% of all ED visits.

Asthma Resources from Medscape and eMedicine

Pathophysiology

Asthma is a condition characterized by paroxysmal narrowing of the bronchial airways due to inflammation of the bronchi and contraction of the bronchial smooth muscle. The inflammatory component is central to the pathogenesis of symptoms: dyspnea, cough, and wheezing.

Another important mechanism underlying acute asthma involves antigen-antibody interactions, which activate membrane phospholipase and result in production of arachidonic acid. Arachidonic acid is metabolized by cyclooxygenase to vasoactive prostaglandins (eg, thromboxanes, prostacyclins) or leukotrienes and their precursors. Several are potent smooth muscle contractors that produce airway hyperresponsiveness and inflammation. The pharmacologic inhibition of leukotriene synthesis and/or action has a beneficial effect on induced and spontaneous asthma, demonstrating that leukotrienes can be important mediators of acute asthma and reactive airway disease (RAD).

Aspirin, a cyclooxygenase inhibitor, produces severe bronchospasm in sensitive individuals. Leukotriene inhibitors reverse this sensitivity, providing further evidence that leukotrienes are important mediators of asthma.

A balance between the adrenergic and cholinergic systems controls bronchomotor tone. Beta-agonist stimulation induces bronchodilation, and beta-blockers cause bronchoconstriction. More specific beta2-agonists have been developed to avoid the tachycardia associated with nonspecific beta-agonist agents. Cholinergic stimulation may cause bronchoconstriction. Anticholinergic agents (eg, ipratropium) produce bronchodilation.

The airway narrowing in acute asthma manifests itself most commonly in adults as wheezing; in children, nocturnal cough is a very common presentation. The initial component is generally rapidly reversible bronchospasm of the smooth muscles that develops into more refractory inflammation of the airways characterized by bronchial edema, tenacious viscid secretions, mucous plugging, and atelectasis. Common causes of acute asthma include viral upper respiratory infections; exposure to allergens (eg, dustmites, animal dander); smoke inhalation; and cold, dry weather. A strong association had been thought to exist in women between the perimenstrual phase of their cycle and asthma symptoms, but the latest data suggest a more complex association between female sex hormones and asthma.

Frequency

United States

Incidence of acute asthma, defined as the number of persons who develop asthma within a specific time period, is approximately 0.2-0.4% annually. Childhood asthma persists into adulthood in approximately 50% of cases. Those with symptoms persisting into the second decade of life usually have asthma throughout adulthood. Asthma prevalence is 6-10% (ie, 20-25 million persons); one half of these cases are children (ie, 8-20% of all children). Overall, acute asthma represents about 2% of all ED visits with the national rate rising from 1993-1998 but stable from 1998-2005. The asthma epidemic seems to be plateauing.1

International

Asthma prevalence varies from 1-30% across nations; the prevalence increases with increased urbanization and affluence. Over the past decade, asthma mortality has been stable in many countries, including Australia, Israel, New Zealand, and the United Kingdom.

Mortality/Morbidity

The death rate from acute asthma increased from 13 deaths per million in 1982 to 19 deaths per million in 1991. Since the early 1990s, however, US asthma mortality rates have been on the decline and continue on the decline based on recent studies.2 Approximately 4,500 Americans die from asthma each year.

Race

Prevalence of asthma in African American and Puerto Rican Hispanic populations is higher than that in Caucasians. The lower average socioeconomic condition of these groups helps to explain the increased prevalence; however, in other countries, asthma is associated with affluence.

Sex

In children younger than 10 years, the male-to-female ratio is 2:1. Between the ages of 18 and 54 years, the ratio is reversed, with women being affected twice as often as men. Women visit the ED and are hospitalized for acute asthma twice as often as men. Previous data suggested that 40% of these hospitalizations occur during the premenstrual phase of the cycle; more recent data from larger studies have not borne out these initial findings. Indeed, some studies suggest a peak in asthma exacerbations shortly before ovulation, when estrogen levels are rising (and not falling).3,4

Age

Asthma symptoms usually begin in early childhood (eg, 80-90% experience symptoms by age 6 y); however, asthma can present at any age, including elderly persons. Children younger than 10 years constitute approximately 50% of all cases.

Clinical

History

Asthma may be classified based on the history of frequency and severity of attacks.

Mild intermittent asthma

  • Symptoms of cough, wheeze, chest tightness, or difficulty breathing less than twice a week
  • Flare-ups brief, but intensity may vary
  • Nighttime symptoms less than twice a month
  • No symptoms between flare-ups
  • Lung function test FEV1 equal to or above 80% of normal values
  • Peak flow less than 20% variability am-to-am or am-to-pm, day-to-day.

Mild persistent asthma

  • Symptoms of cough, wheeze, chest tightness, or difficulty breathing 3-6 times a week
  • Flare-ups may affect activity level
  • Nighttime symptoms 3-4 times a month
  • Lung function test FEV1 equal to or above 80% of normal values
  • Peak flow less than 20-30% variability

Moderate persistent asthma

  • Symptoms of cough, wheeze, chest tightness, or difficulty breathing daily
  • Flare-ups may affect activity level
  • Nighttime symptoms 5 or more times a month
  • Lung function test FEV1 above 60% but below 80% of normal values
  • Peak flow more than 30% variability

Severe persistent asthma

  • Symptoms of cough, wheeze, chest tightness, or difficulty breathing continual
  • Nighttime symptoms frequently
  • Lung function test FEV1 less than or equal to 60% of normal values
  • Peak flow more than 30% variability
Specific historical factors are key in the assessment of acute asthma. The patient should be asked about the following aspects of their disease to help gauge the severity of this episode.

  • Precipitating factors may include the following:
  • Current medications and compliance (eg, frequency of inhaled beta-agonist treatments, use and dose of inhaled corticosteroids)
  • Past asthma-related healthcare utilization, including both the frequency of events in last 12 months and the length of time since most recent event:
    • Systemic corticosteroids for an asthma exacerbation
    • ED visits for asthma exacerbation
    • Overnight hospitalization or other admissions for asthma exacerbation
    • ICU admission for severe asthma exacerbation
    • Endotracheal intubation
  • Duration of present symptoms (eg, hours to days): Duration of more than 2 days is associated with a higher admission rate than duration of less than 2 days. Sudden-onset exacerbations (ie, £ 3 hours since symptom onset) tend to be more severe but also tend respond better to treatment in the ED and an inpatient setting.
  • Degree of dyspnea, cough, wheezing; whether new productive cough is present
  • Ask about a patient's baseline peak flow or personal best peak flow. Many patients know these values, and they can serve as a comparison against current peak flow and help set a goal for improvement in the ED.
  • The clinician should address whether the condition is truly asthma. Many other causes of dyspnea, cough, and wheezing exist and include the following:
  • Presence of chest pain or pleuritis, which may suggest a complication of more severe exacerbations

Physical

  • Level of alertness
  • Ability to lie flat: Patients with mild acute asthma are able to lie flat. In more severe cases, the patient assumes a sitting position. As the severity increases, the patient increasingly assumes a hunched-over sitting position with the hands supporting the torso, termed the tripod position. If symptomatology becomes more severe, profuse diaphoresis occurs. The diaphoresis presents concomitantly with a rise in PCO2 and hypoventilation. In the most severe form of acute asthma, the patient may struggle for air, act confused, agitated, pulling off his oxygen stating, "I can not breathe." These are signs of life-threatening hypoxia. With advanced hypercarbia, bradypneic, somnolence, and profuse diaphoresis may be present; almost no breath sounds may be heard, and the patient is willing to lie recumbent.
  • Ability to speak/staccato speech
  • Stridor
  • Accessory muscle use - In children, also look for supraclavicular and intercostal retractions and nasal flaring as well as abdominal breathing.
  • Central cyanosis
  • Peripheral edema
  • Subcutaneous emphysema as there may be concomitant pneumothorax or pneumomediastinum
  • Bilateral breath sounds
  • Wheezing: Inspiration-expiration ratio reveals prolongation of the expiratory phase (eg, 1:1 mild, 1:3 severe). Wheezing may be absent both during a severe presentation with very poor air exchange or in mild exacerbations. In a situation with mild exacerbation, request rapid forced expiration to see if a wheeze becomes audible.
  • Peak flow measurements: A peak flow value should be obtained early in the course of the ED visit to document severity as well as to serve as a baseline against which improvement may be measured.

Causes

  • Respiratory infections (most common reason for exacerbations)
  • Allergen exposure, particularly cats
  • Exercise
  • Weather, including cold and dry air, weather changes, significant increases in humidity
  • Air pollution
  • Aspirin ingestion
  • Yellow dyes, particularly tartrazine, found in yellow gelatins
  • Organic particle exposure, including the following:
    • Cotton (byssinosis)
    • Detergent manufacture (Bacillus subtilis)
    • Red cedar
    • Grains
  • Chemical irritants (ie, toluene diisocyanate) may be related to nocturnal asthma.
  • The worst bronchospasm is usually at about 4 am, and the best airflow is at approximately 4 pm; therefore, asthma control is labile. The explanation for this circadian pattern is not clear, but it involves factors beyond acid reflux, sinusitis, or postnasal dripping during sleep. Nonetheless, all of these nocturnal factors can worsen asthma status.

More on Asthma

Overview: Asthma
Differential Diagnoses & Workup: Asthma
Treatment & Medication: Asthma
Follow-up: Asthma
References
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References

  1. Ginde AA, Espinola JA, Camargo CA Jr. Improved overall trends but persistent racial disparities in emergency department visits for acute asthma, 1993-2005. J Allergy Clin Immunol. Aug 2008;122(2):313-8. [Medline].

  2. Epidemiology and Statistics Unit. Trends in asthma morbidity and mortality. January 2009. New York. American Lung Association. Available at http://www.lungusa.org/atf/cf/%7B7a8d42c2-fcca-4604-8ade-7f5d5e762256%7D/ASTHMA%20JAN%202009.PDF.

  3. Brenner BE, Holmes TM, Mazal B, Camargo CA Jr. Relation between phase of the menstrual cycle and asthma presentations in the emergency department. Thorax. Oct 2005;60(10):806-9. [Medline].

  4. Zimmerman JL, Woodruff PG, Clark S, Camargo CA. Relation between phase of menstrual cycle and emergency department visits for acute asthma. Am J Respir Crit Care Med. Aug 2000;162(2 Pt 1):512-5. [Medline].

  5. Workgroup on EMS Management of Asthma Exacerbations. A model protocol for emergency medical services management of asthma exacerbations. Prehosp Emerg Care. Oct-Dec 2006;10(4):418-29. [Medline].

  6. [Guideline] National Asthma Education and Prevention Program. Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma - Update on Selected Topics 2002. June 2003. [Full Text].

  7. [Guideline] National Asthma Education and Prevention Program. Guidelines for the Diagnosis and Management of Asthma (EPR-3). July 2007. [Full Text].

  8. Starobin D, Bolotinsky L, Or J, Fink G, Shtoeger Z. Efficacy of nebulized fluticasone propionate in adult patients admitted to the emergency department due to bronchial asthma attack. Isr Med Assoc J. Aug-Sep 2008;10(8-9):568-71. [Medline].

  9. [Guideline] Rodriguez-Trigo G, Plaza V, Picado C, Sanchis J. [Management according to the Global Initiative for Asthma guidelines of patients with near-fatal asthma reduces morbidity and mortality]. Arch Bronconeumol. Apr 2008;44(4):192-6. [Medline].

  10. [Guideline] Reddel HK, Taylor DR, Bateman ED, et al. An official American Thoracic Society/european Respiratory Society statement: asthma control and exacerbations: standardizing endpoints for clinical asthma trials and clinical practice. Am J Respir Crit Care Med. Jul 1 2009;180(1):59-99. [Medline].

  11. Alvarez GG, Schulzer M, Jung D, Fitzgerald JM. A systematic review of risk factors associated with near-fatal and fatal asthma. Can Respir J. Jul-Aug 2005;12(5):265-70. [Medline].

  12. Appel D, Karpel JP, Sherman M. Epinephrine improves expiratory flow rates in patients with asthma who do not respond to inhaled metaproterenol sulfate. J Allergy Clin Immunol. Jul 1989;84(1):90-8. [Medline].

  13. Banerji A, Clark S, Afilalo M, et al. Prospective multicenter study of acute asthma in younger versus older adults presenting to the emergency department. J Am Geriatr Soc. Jan 2006;54(1):48-55. [Medline].

  14. [Best Evidence] Baren JM, Boudreaux ED, Brenner BE, et al. Randomized controlled trial of emergency department interventions to improve primary care follow-up for patients with acute asthma. Chest. Feb 2006;129(2):257-65. [Medline].

  15. Boychuk RB, Yamamoto LG, DeMesa CJ, Kiyabu KM. Correlation of initial emergency department pulse oximetry values in asthma severity classes (steps) with the risk of hospitalization. Am J Emerg Med. Jan 2006;24(1):48-52. [Medline].

  16. Brenner BE, Chavda KK, Karakurum MB, et al. Circadian differences among 4,096 emergency department patients with acute asthma. Crit Care Med. Jun 2001;29(6):1124-9. [Medline].

  17. Browne GJ, Penna AS, Phung X, Soo M. Randomised trial of intravenous salbutamol in early management of acute severe asthma in children. Lancet. Feb 1 1997;349(9048):301-5. [Medline].

  18. Camargo CA, Smithline HA, Malice MP, et al. A randomized controlled trial of intravenous montelukast in acute asthma. Am J Respir Crit Care Med. Feb 15 2003;167(4):528-33. [Medline].

  19. Camargo CA, Spooner CH, Rowe BH. Continuous versus intermittent beta-agonists in the treatment of acute asthma. Cochrane Database Syst Rev. 2003;CD001115. [Medline].

  20. Cates CC, Bara A, Crilly JA, Rowe BH. Holding chambers versus nebulisers for beta-agonist treatment of acute asthma. Cochrane Database Syst Rev. 2003;CD000052. [Medline].

  21. Chapman KR, Verbeek PR, White JG, et al. Effect of a short course of prednisone in the prevention of early relapse after the emergency room treatment of acute asthma. N Engl J Med. Mar 21 1991;324(12):788-94. [Medline].

  22. Cheuk DKL, Chau TCH, Lee SL. A meta-analysis on intravenous magnesium sulfate for treating acute asthma. Arch Dis Child. 2005;90:74-7.

  23. Cydulka RK, Emerman CL, Schreiber D, et al. Acute asthma among pregnant women presenting to the emergency department. Am J Respir Crit Care Med. Sep 1999;160(3):887-92. [Medline].

  24. Edmonds ML, Camargo CA, Pollack CV, Rowe BH. Early use of inhaled corticosteroids in the emergency department treatment of acute asthma. Cochrane Database Syst Rev. 2000;CD002308. [Medline].

  25. Edmonds ML, Camargo CA, Saunders LD, et al. Inhaled steroids in acute asthma following emergency department discharge. Cochrane Database Syst Rev. 2000;CD002316. [Medline].

  26. Emerman CL, Cydulka RK, Crain EF, et al. Prospective multicenter study of relapse after treatment for acute asthma among children presenting to the emergency department. J Pediatr. Mar 2001;138(3):318-24. [Medline].

  27. Emerman CL, Woodruff PG, Cydulka RK, et al. Prospective multicenter study of relapse following treatment for acute asthma among adults presenting to the emergency department. MARC investigators. Multicenter Asthma Research Collaboration. Chest. Apr 1999;115(4):919-27. [Medline].

  28. Emond SD, Camargo CA, Nowak RM. 1997 National Asthma Education and Prevention Program guidelines: a practical summary for emergency physicians. Ann Emerg Med. May 1998;31(5):579-89. [Medline].

  29. Gibbs MA, Camargo CA, Rowe BH, Silverman RA. State of the art: therapeutic controversies in severe acute asthma. Acad Emerg Med. Jul 2000;7(7):800-15. [Medline].

  30. Gorelick MH, Stevens MW, Schultz T, Scribano PV. Difficulty in obtaining peak expiratory flow measurements in children with acute asthma. Pediatr Emerg Care. Jan 2004;20(1):22-6. [Medline].

  31. Griswold SK, Nordstrom CR, Clark S, et al. Asthma exacerbations in North American adults: who are the "frequent fliers" in the emergency department?. Chest. May 2005;127(5):1579-86. [Medline].

  32. Gupta VK, Cheifetz IM. Heliox administration in the pediatric intensive care unit: an evidence-based review. Pediatr Crit Care Med. Mar 2005;6(2):204-11. [Medline].

  33. Hess DR, Acosta FL, Ritz RH, et al. The effect of heliox on nebulizer function using a beta-agonist bronchodilator. Chest. Jan 1999;115(1):184-9. [Medline].

  34. Keahey L, Bulloch B, Becker AB, et al. Initial oxygen saturation as a predictor of admission in children presenting to the emergency department with acute asthma. Ann Emerg Med. Sep 2002;40(3):300-7. [Medline].

  35. Kelly AM, Kyle E, McAlpine R. Venous pCO(2) and pH can be used to screen for significant hypercarbia in emergency patients with acute respiratory disease. J Emerg Med. Jan 2002;22(1):15-9. [Medline].

  36. Kikuchi Y, Okabe S, Tamura G, et al. Chemosensitivity and perception of dyspnea in patients with a history of near-fatal asthma. N Engl J Med. May 12 1994;330(19):1329-34. [Medline].

  37. Lahn M, Bijur P, Gallagher EJ. Randomized clinical trial of intramuscular vs oral methylprednisolone in the treatment of asthma exacerbations following discharge from an emergency department. Chest. Aug 2004;126(2):362-8. [Medline].

  38. Lee DL, Hsu CW, Lee H, et al. Beneficial effects of albuterol therapy driven by heliox versus by oxygen in severe asthma exacerbation. Acad Emerg Med. Sep 2005;12(9):820-7. [Medline].

  39. Mannino DM, Homa DM, Akinbami LJ, et al. Surveillance for asthma--United States, 1980-1999. MMWR Surveill Summ. Mar 29 2002;51(1):1-13. [Medline].

  40. Martin TG, Elenbaas RM, Pingleton SH. Use of peak expiratory flow rates to eliminate unnecessary arterial blood gases in acute asthma. Ann Emerg Med. Feb 1982;11(2):70-3. [Medline].

  41. McFadden ER, Kiser R, DeGroot WJ. Acute bronchial asthma: Relations between clinical and physiologic manifestations. New Engl J Med. 1973;288:221-225. [Medline].

  42. [Best Evidence] Mitra A, Bassler D, Goodman K, et al. Intravenous aminophylline for acute severe asthma in children over two years receiving inhaled bronchodilators. Cochrane Database Syst Rev. 2005;CD001276. [Medline].

  43. Nowak RM, Pensler MI, Sarkar DD, et al. Comparison of peak expiratory flow and FEV1 admission criteria for acute bronchial asthma. Ann Emerg Med. Feb 1982;11(2):64-9. [Medline].

  44. Parameswaran K, Belda J, Rowe BH. Addition of intravenous aminophylline to beta2-agonists in adults with acute asthma. Cochrane Database Syst Rev. 2000;CD002742. [Medline].

  45. Plotnick LH, Ducharme FM. Combined inhaled anticholinergics and beta2-agonists for initial treatment of acute asthma in children. Cochrane Database Syst Rev. 2000;CD000060. [Medline].

  46. Pollack CV, Pollack ES, Baren JM, et al. A prospective multicenter study of patient factors associated with hospital admission from the emergency department among children with acute asthma. Arch Pediatr Adolesc Med. Sep 2002;156(9):934-40. [Medline].

  47. Radeos MS, Camargo CA. Predicted peak expiratory flow: differences across formulae in the literature. Am J Emerg Med. Nov 2004;22(7):516-21. [Medline].

  48. Rowe BH, Bretzlaff JA, Bourdon C, et al. Magnesium sulfate treatment for treating exacerbations of acute asthma in the emergency department. Cochrane Database Syst Rev. 2000;2:CD001490.

  49. Rowe BH, Camargo CA. The use of magnesium sulfate in acute asthma: rapid uptake of evidence in North American emergency departments. J Allergy Clin Immunol. Jan 2006;117(1):53-8. [Medline].

  50. Rowe BH, Edmonds ML, Spooner CH, et al. Corticosteroid therapy for acute asthma. Respir Med. Apr 2004;98(4):275-84. [Medline].

  51. Scarfone RJ, Fuchs SM, Nager AL, et al. Controlled trial of oral prednisone in the emergency department treatment of children with acute asthma. Pediatrics. Oct 1993;92(4):513-8. [Medline].

  52. Singer AJ, Camargo CA, Lampell M, et al. A call for expanding the role of the emergency physician in the care of patients with asthma. Ann Emerg Med. Mar 2005;45(3):295-8. [Medline].

  53. Singh AK, Cydulka RK, Stahmer SA, et al. Sex differences among adults presenting to the emergency department with acute asthma. Multicenter Asthma Research Collaboration Investigators. Arch Intern Med. Jun 14 1999;159(11):1237-43. [Medline].

  54. [Best Evidence] Teach SJ, Crain EF, Quint DM, et al. Improved asthma outcomes in a high-morbidity pediatric population: results of an emergency department-based randomized clinical trial. Arch Pediatr Adolesc Med. May 2006;160(5):535-41. [Medline].

  55. Travers A, Jones AP, Kelly K, et al. Intravenous beta2-agonists for acute asthma in the emergency department. Cochrane Database Syst Rev. 2001;CD002988. [Medline].

  56. Tuxen DV. Permissive hypercapnic ventilation. Am J Respir Crit Care Med. Sep 1994;150(3):870-4. [Medline].

  57. Weber EJ, Silverman RA, Callaham ML, et al. A prospective multicenter study of factors associated with hospital admission among adults with acute asthma. Am J Med. Oct 1 2002;113(5):371-8. [Medline].

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Further Reading

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Keywords

asthma, asthma attack, asthma symptoms, asthma treatment, asthma evaluation, asthma assessment, asthma causes, airway obstruction, asthma management, asthma exacerbation, airway inflammation, bronchial asthma, asthma triggers, dyspnea, wheezing, shortness of breath, asthmatic, reactive airway disease, wheeze, bronchiolitis, acute asthma, asthma prevention, allergies, bronchial airways, bronchial airway narrowing, inflammation of the bronchi, bronchial smooth muscle contraction, airway narrowing, noisy breathing, difficult breathing, difficulty breathing, inhalers, lung disease

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Contributor Information and Disclosures

Author

Barry E Brenner, MD, PhD, FACEP, Professor of Emergency Medicine, Professor of Internal Medicine, Program Director, Emergency Medicine, University Hospitals, Case Medical Center
Barry E Brenner, MD, PhD, FACEP is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Chest Physicians, American College of Emergency Physicians, American College of Physicians, American Heart Association, American Thoracic Society, Arkansas Medical Society, New York Academy of Medicine, New York Academy of Sciences, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Edward Bessman, MD, Chairman, Department of Emergency Medicine, John Hopkins Bayview Medical Center; Assistant Professor, Department of Emergency Medicine, Johns Hopkins University
Edward Bessman, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Paul Blackburn, DO, FACOEP, FACEP, Program Director, Department of Emergency Medicine, Maricopa Medical Center; Assistant Professor, Department of Surgery, University of Arizona
Paul Blackburn, DO, FACOEP, FACEP is a member of the following medical societies: American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, American Medical Association, and Arizona Medical Association
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Robert E O'Connor, MD, MPH, Professor and Chair, Department of Emergency Medicine, University of Virginia Health System
Robert E O'Connor, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Physician Executives, American Heart Association, American Medical Association, Medical Society of Delaware, National Association of EMS Physicians, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

 
 
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