Use of Peak Expiratory Flow Rate Monitoring for the Management of Asthma in Adults in the Emergency Department

This Policy Resource and Education Paper is an explication of the Policy Statement Use of Peak Expiratory Flow Rate Monitoring for the Management of Asthma in Adults in the Emergency Department.


The purpose of this paper is to identify the medical literature that pertains to the use of PEFR monitoring for ED management of adult patients with asthma.

This PREP is an update of a previous PREP with the same title, Use of Peak Expiratory Flow Rate Monitoring for the Management of Asthma in Adults in the Emergency Department which served as the background information for the policy statement of the same title.1

The previous policy statement on this topic1 originally arose from a number of studies that suggested that peak expiratory flow rate (PEFR) assessment or other spirometric measures were useful in clinical decision-making for patients with acute exacerbations of asthma.2-14 However, other studies did not find measurement of PEFR in the ED useful in management or in predicting the need for hospital admission.15-20 Despite the inconsistency of evidence, practice guidelines at the time of the original policy statement recommended the use of PEFR monitoring for patient care in the ED21 as do more recent guidelines.22

There have been additional publications on this topic since the prior policy statement was approved by the ACEP Board of Directors in June 2000. For this revision, a literature search was performed and recent articles were reviewed. Those references not cited in the prior PREP were systematically graded and may be found in the Evidentiary Table that appears later in this document.

All articles were graded by 2 subcommittee members for strength of evidence and classified by the subcommittee members into 3 classes of evidence on the basis of the design of the study, with design 1 representing the strongest evidence and design 3 representing the weakest evidence for therapeutic, diagnostic, and prognostic clinical reports, respectively (Appendix A). Articles were then graded on 6 dimensions thought to be most relevant: blinded versus nonblinded outcome assessment, blinded or randomized allocation, direct or indirect outcome measures (reliability and validity), biases (eg, selection, detection, transfer), external validity (ie, generalizability), and sufficient sample size. Articles received a final grade (Class I, II, III) on the basis of a predetermined formula taking into account design and quality of study (Appendix B). Articles with fatal flaws were given an "X" grade.

The literature search identified 26 articles not cited in the previous PREP. One Class II study23 and 7 Class III studies were identified.24-30 The remainder of the studies were not applicable to the question of use of PEFR in the ED, either because PEFR was not a studied variable, or the study setting was not the ED.31-48 


Although additional articles were found in the literature update, it appears that the pace of research in this area has slowed. Revisions to the prior policy statement were minor and reflect current evidence-based practices. Many of the critiques noted in the prior PREP remain valid:

  1. Investigators were not blinded to PEFR measurements used for disposition decisions.
  2. Study asthma treatment studies were different from contemporary treatment protocols.
  3. Disposition and outcome criteria were poorly defined.
  4. Study sizes were small.
  5. Studied patient groups potentially lack generalizability to ED patient populations.


The use of PEFR monitoring has not been shown to improve outcomes, reliably predict need for admissions, or limit morbidity or mortality when used during the ED management of adult patients with acute exacerbations of asthma. The decision to perform PEFR monitoring should be individualized for each patient. Although PEFR may aid emergency physicians during their evaluation and treatment of an adult patient with an acute exacerbation of asthma, the evidence does not support requiring PEFR monitoring for all adult patients.

Revised by a subcommittee of the Clinical Policies Committee
J. Stephen Huff, MD, FACEP, Chair
Deborah B. Diercks, MD, FACEP


  1. American College of Emergency Physicians. Use of Peak Expiratory Flow Rate Monitoring for the Management of Asthma in Adults in the Emergency Department. Ann Emerg Med. 2001;38:198.
  2. Banner AS, Shah RS, Addington WW. Rapid prediction of need for hospitalization in acute asthma. JAMA. 1976;235:1337-1338.
  3. Bolliger CT, Fourie PR, Kotze D, et al. Relation of measures of asthma severity and response to treatment to outcome in acute severe asthma. Thorax. 1992;47:943-947.
  4. Brandstetter RD, Gotz VP, Mar DD. Identifying the acutely ill patient with asthma. South Med J. 1981;74:713-715.
  5. Eliakim R, Halperin Y, Menczel J. A predictor index for hospitalization for patients with acute asthmatic attack. Isr J Med Sci. 1984;20:202-206.
  6. Fanta CH, Rossing TH, McFadden ER, Jr. Emergency room treatment of asthma. Relationships among therapeutic combinations, severity of obstruction and time course of response. Am J Med. 1982;72:416-422.
  7. Kelsen SG, Kelsen DP, Fleeger BF, et al. Emergency room assessment and treatment of patients with acute asthma. Adequacy of the conventional approach. Am J Med. 1978;64:622-628.
  8. McCarren M, Zalenski RJ, McDermott M, et al. Predicting recovery from acute asthma in an emergency diagnostic and treatment unit. Acad Emerg Med. 2000;7:28-35.
  9. Nowak RM, Pensler MI, Sarkar DD, et al. Comparison of peak expiratory flow and FEV1 admission criteria for acute bronchial asthma. Ann Emerg Med..1982;11:64-69.
  10. Nowak RM, Tomlanovich MC, Sarkar DD, et al. Arterial blood gases and pulmonary function testing in acute bronchial asthma. Predicting patient outcomes. JAMA. 1983;249:2043-2046.
  11. Rebuck AS, Read J. Assessment and management of severe asthma. Am J Med. 1971;51:788-798.
  12. Rodrigo G, Rodrigo C. Assessment of the patient with acute asthma in the emergency department. A factor analytic study. Chest. 1993;104:1325-1328.
  13. Worthington JR, Ahuja J. The value of pulmonary function tests in the management of acute asthma. CMAJ. 1989;140:153-156.
  14. Nowak RM, Gordon KR, Wroblewski DA, et al. Spirometric evaluation of acute bronchial asthma. JACEP. 1979;8:9-12.
  15. Emerman CL, Cydulka RK. Factors associated with relapse after emergency department treatment for acute asthma. Ann Emerg Med. 1995;26:6-11.
  16. Fiel SB, Swartz MA, Glanz K, et al. Efficacy of short-term corticosteroid therapy in outpatient treatment of acute bronchial asthma. Am J Med. 1983;75:259-262.
  17. Kunitoh H, Nagatomo A, Okamoto H, et al. Predicting the need for hospital admission in patients with acute bronchial asthma. J Asthma.1996;33:105-112.
  18. Martin TG, Elenbaas RM, Pingleton SH. Failure of peak expiratory flow rate to predict hospital admission in acute asthma. Ann Emerg Med. 1982;11:466-470.
  19. Rose CC, Murphy JG, Schwartz JS. Performance of an index predicting the response of patients with acute bronchial asthma to intensive emergency department treatment. N Engl J Med. 1984;310:573-577.
  20. Stein LM, Cole RP. Early administration of corticosteroids in emergency room treatment of acute asthma. Ann Intern Med. 1990;112:822-827.
  21. Janson S. National Asthma Education and Prevention Program, Expert Panel Report. II: overview and application to primary care. Lippincotts Prim Care Pract. 1998;2:578-588.
  22. National Heart, Lung, and Blood Institute. Expert panel report 3: guidelines for the diagnosis and management of asthma, 2007. Accessed at: on August 29, 2007.
  23. 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.1999;115:919-927.
  24. Abisheganaden J, Ng SB, Lam KN, et al. Peak expiratory flow rate guided protocol did not improve outcome in emergency room asthma. Singapore Med J. 1998;39:479-484.
  25. Choi IS, Koh YI, Lim H. Peak expiratory flow rate underestimates severity of airflow obstruction in acute asthma. Korean J Intern Med. 2002;17:174-179.
  26. Diner B, Brenner B, Camargo CA, Jr. Inaccuracy of "personal best" peak expiratory flow rate reported by inner-city patients with acute asthma. J Asthma. 2001;38:127-132.
  27. Piovesan DM, Menegotto DM, Kang S, et al. Early prognosis of acute asthma in the emergency room. J Bras Pneumol. 2006;32:1-9.
  28. Rodrigo G, Rodrigo C. A new index for early prediction of hospitalization in patients with acute asthma. Am J Emerg Med. 1997;15:8-13.
  29. Rodrigo G, Rodrigo C. Early prediction of poor response in acute asthma patients in the emergency department. Chest. 1998;114:1016-1021.
  30. 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. 2002;113:371-378.
  31. Adams RJ, Boath K, Homan S, et al. A randomized trial of peak-flow and symptom-based action plans in adults with moderate-to-severe asthma. Respirology. 2001;6:297-304.
  32. Atta JA, Nunes MP, Fonseca-Guedes CH, et al. Patient and physician evaluation of the severity of acute asthma exacerbations. Braz J Med Biol Res. 2004;37:1321-1330.
  33. 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. 2006;54:48-55.
  34. Brenner B, Kohn MS. The acute asthmatic patient in the ED: to admit or discharge. Am J Emerg Med. 1998;16:69-75.
  35. Cowie RL, Revitt SG, Underwood MF, et al. The effect of a peak flow-based action plan in the prevention of exacerbations of asthma. Chest. 1997;112:1534-1538.
  36. Gibson PG. Monitoring the patient with asthma: an evidence-based approach. J Allergy Clin Immunol. 2000;106:17-26.
  37. Grunfeld A, Beveridge RC, Berkowitz J, et al. Management of acute asthma in Canada: an assessment of emergency physician behaviour. J Emerg Med. 1997;15:547-556.
  38. Karras DJ, Sammon ME, Terregino CA, et al. Clinically meaningful changes in quantitative measures of asthma severity. Acad Emerg Med.. 2000;7:327-334.
  39. Marik PE, Varon J, Fromm R, Jr. The management of acute severe asthma. J Emerg Med. 2002;23:257-268.
  40. McCarren M, McDermott MF, Zalenski RJ, et al. Prediction of relapse within eight weeks after an acute asthma exacerbation in adults. J Clin Epidemiol. 1998;51:107-118.
  41. Newman KB, Milne S, Hamilton C, et al. A comparison of albuterol administered by metered-dose inhaler and spacer with albuterol by nebulizer in adults presenting to an urban emergency department with acute asthma. Chest. 2002;121:1036-1041.
  42. Ng TP. Validity of symptom and clinical measures of asthma severity for primary outpatient assessment of adult asthma. Br J Gen Pract. 2000;50:7-12.
  43. Pesola GR, Xu F, Ahsan H, et al. Predicting asthma morbidity in Harlem emergency department patients. Acad Emerg Med. 2004;11:944-950.
  44. Richmond NJ, Silverman R, Kusick M, et al. Out-of-hospital administration of albuterol for asthma by basic life support providers. Acad Emerg Med. 2005;12:396-403.
  45. Tierney WM, Roesner JF, Seshadri R, et al. Assessing symptoms and peak expiratory flow rate as predictors of asthma exacerbations. J Gen Intern Med. 2004;19:237-242.
  46. Turner MO, Taylor D, Bennett R, et al. A randomized trial comparing peak expiratory flow and symptom self-management plans for patients with asthma attending a primary care clinic. Am J Respir Crit Care Med. 1998;157:540-546.
  47. Varon J, Fromm RE, Jr. Emergency department care of the asthma patient: predicting "bounce-back" patients. Chest. 1999;115:909-911.
  48. Wilson MM, Irwin RS, Connolly AE, et al. A prospective evaluation of the 1-hour decision point for admission versus discharge in acute asthma. J Intensive Care Med. 2003;18:275-285.

Evidentiary Table

Study Year Design Intervention(s)/Test(s)/ Modality Outcome Measure/ Criterion Standard Results Limitations/Comments Class
Emerman et al23 1999 Multicenter prospective cohort PEFR one of the factors assessed during initial ED visit Relapse defined as unscheduled ED return or visit to any physician for worsening symptoms of asthma PEFR at discharge did not predict relapse; 17% of study group did relapse PEFR may have been one of the factors used in decision-making for discharge at first ED visit II
Abisheganaden et al24 1998 Prospective paired cohorts PEFR-driven protocol compared to routine clinical parameter-driven protocol Discharge PEFR; admission rate PEFR-guided protocol does not reduce admission rates or demonstrate improved PEFR response compared to clinically guided treatment Patients not randomized to protocols; treatment periods separated by 1 y; relapse rates not compared III
Choi et al25 2002 Prospective cohort PEFR and FEV1 compared at different times in clinical course from ED presentation to 7 days Spirometric measurements PEFR and FEV1 PEFR underestimates severity of airway obstruction in acute asthma compared to FEV1 measurements Small study size; only 2 time data points of 0 and 1 h relevant to ED patients III
Diner et al26 2001 Prospective cohort PEFR obtained by research assistant compared to patient's self-determined personal best Researcher-obtained PEFR PEFR - personal best - reported by patients not reliable

Not a study of PEFR in the ED

Inner-city population

Piovesan et al27 2006 Prospective cohort PEFR measured at presentation, 15 min, and 4 h Favorable outcome if PEFR >50% at 4 h of treatment Improvement in 15 min PEFR to >40% was predictive of improvement of 4 h PEFR >50% PEFR was the outcome measure, not clinical parameters; admissions not reported III
Rodrigo and Rodrigo28 1997 Prospective cohort Change in PEFR at 30 min (both as percent predicted and absolute flow rate) Discharge at 3 h if free of dyspnea, use of accessory muscles diminished, wheezing minimal or absent, and able to walk 20 meters without increase in signs or symptoms 3 item index developed for application at 30 min after arrival that included accessory muscle use, PEFR measurement, and change in PEFR from baseline to predict need for admission Discharge decision based on clinical criteria at 6 h, not measurement of respiratory function; favorable outcome was discharge from ED III
Rodrigo and Rodrigo29 1998 Prospective cohort Change in PEFR at 30 min (both as percent predicted and absolute flow rate) Discharge at 3 h if free of dyspnea, use of accessory muscles diminished, wheezing minimal or absent, and able to walk 20 meters without increase in signs or symptoms PEFR measurement and change in PEFR from baseline at 30 min used to develop index validated to predict favorable outcome (FEV1 >45%) Discharge decision based on clinical criteria at 3 h, not measurement of respiratory function; favorable outcome was FEV1, not PEFR III
Weber et al30 2002 Prospective cohort PEFR was one of several factors assessed during ED visit Admissions; ED discharges; relapse as defined by unscheduled visit to physician or ED within 72 h PEFR <50% of predicted not reliable for predicting relapses; final PEFR in ED was predictive of admission Retrospective data analysis; PEFR not examined independently for admission decisions; clinicians not blinded to PEFR; admission or discharge decisions not based on PEFR III

ED, emergency department; FEV1, one-second forced expiratory volume; h, hour; min, minute; PEFR, peak expiratory flow rate; y, year.

Appendix A. Literature classification schema.*

Design/Class Therapy† Diagnosis‡ Prognosis§
1 Randomized, controlled trial or meta-analyses of randomized trials Prospective cohort using a criterion standard Population prospective cohort
2 Nonrandomized trial Retrospective observational Retrospective cohort
Case control
3 Case series
Case report
Other (eg, consensus, review)
Case series
Case report
Other (eg, consensus, review)
Case series
Case report
Other (eg, consensus, review)

*Some designs (eg, surveys) will not fit this schema and should be assessed individually.
†Objective is to measure therapeutic efficacy comparing >2 interventions.
‡Objective is to determine the sensitivity and specificity of diagnostic tests.
§Objective is to predict outcome including mortality and morbidity.

Appendix B. Approach to downgrading strength of evidence.


Downgrading 1 2 3
1 level II III X
2 levels III X X
Fatally flawed X X X


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