Peak expiratory flow rate monitoring in asthma
- Lynn B Gerald, PhD, MSPH
Lynn B Gerald, PhD, MSPH
- Endowed Chair and Professor
- Mel and Enid Zuckerman College of Public Health, University of Arizona
- Tara F Carr, MD, FAAAAI
Tara F Carr, MD, FAAAAI
- Assistant Professor, Medicine and Otolaryngology
- Department of Medicine, University of Arizona
- Section Editors
- Peter J Barnes, DM, DSc, FRCP, FRS
Peter J Barnes, DM, DSc, FRCP, FRS
- Editor-in-Chief — Pulmonary and Critical Care Medicine
- Section Editor — Asthma
- Professor of Medicine
- National Heart and Lung Institute, Imperial College, London
- Robert A Wood, MD
Robert A Wood, MD
- Editor-in-Chief — Allergy and Immunology
- Section Editor — Pediatric Allergy
- Professor of Pediatrics
- Johns Hopkins University School of Medicine
The peak expiratory flow rate (PEFR, also known as a peak flow) is the maximal rate that a person can exhale during a short maximal expiratory effort after a full inspiration. In patients with asthma, the PEFR percent predicted correlates reasonably well with the percent predicted value for the forced expiratory volume in one second (FEV1). Monitoring the PEFR is useful for detecting changes or trends in a patient's asthma control, although significant testing variability makes it important to confirm or exclude airflow limitation with a more reliable test, such as spirometry.
The management of asthma depends in part on the ability of patients to monitor their condition on a regular basis. Self-monitoring can be performed by subjectively evaluating the frequency and severity of symptoms (figure 1). Patients can gain further information by monitoring peak expiratory flow rates (PEFRs), which provide an objective measurement of airflow obstruction, and can be performed accurately by most adults and children older than five years of age.
Peak expiratory flow rate monitoring in patients with asthma will be reviewed here. Other aspects of asthma management are presented separately. (See "An overview of asthma management" and "Overview of pulmonary function testing in children" and "Pulmonary function testing in asthma" and "Patient education: Asthma treatment in adolescents and adults (Beyond the Basics)".)
PEFR VARIABILITY FOR THE DIAGNOSIS OF ASTHMA
Documentation of PEFR variability may be used to support the diagnosis of asthma. Patients can be asked to record PEFR upon awakening, in the evening, and before bed. Peak flow variability is calculated as the difference between the maximum and minimum peak flow in a day, expressed as a percentage of that day's minimum PEFR. Within-day or between-day variability in PEFR of >20 percent is characteristic of asthma . (See "Pulmonary function testing in asthma", section on 'Peak expiratory flow'.)
ROLE OF PEFR MONITORING
The optimal role of long- or short-term daily monitoring in the ongoing management of asthma is unknown. The theoretic advantage is that daily PEFR monitoring can provide the patient and clinician with objective data upon which to base therapeutic decisions [2,3]. However, adherence to long-term monitoring is difficult to maintain . According to some reports, adherence with home PEFR recording is satisfactory in the short term, but falls off considerably after several months. This suggests a significant limitation to this form of monitoring [5,6]. While patient adherence to PEFR monitoring is highly variable, connecting its use to the production of data relevant to concrete self-management activities may increase adherence .
- Jamison JP, McKinley RK. Validity of peak expiratory flow rate variability for the diagnosis of asthma. Clin Sci (Lond) 1993; 85:367.
- National Asthma Education and Prevention Program: Expert Panel Report III: Guidelines for the diagnosis and management of asthma. Bethesda, MD. National Heart, Lung, and Blood Institute, 2007. (NIH publication no. 08-4051) www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm (Accessed on March 17, 2016).
- Global Initiative for Asthma. Global strategy for asthma management and prevention. http://www.ginasthma.org/local/uploads/files/GINA_Report_2015_Aug11.pdf (Accessed on October 06, 2015).
- Gibson PG. Monitoring the patient with asthma: an evidence-based approach. J Allergy Clin Immunol 2000; 106:17.
- Côté J, Cartier A, Malo JL, et al. Compliance with peak expiratory flow monitoring in home management of asthma. Chest 1998; 113:968.
- Verschelden P, Cartier A, L'Archevêque J, et al. Compliance with and accuracy of daily self-assessment of peak expiratory flows (PEF) in asthmatic subjects over a three month period. Eur Respir J 1996; 9:880.
- Caress AL, Luker K, Beaver K, Woodcock A. Adherence to peak flow monitoring. Information provided by meters should be part of self management plan. BMJ 2002; 324:1157; author reply 1157.
- Wensley D, Silverman M. Peak flow monitoring for guided self-management in childhood asthma: a randomized controlled trial. Am J Respir Crit Care Med 2004; 170:606.
- 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.
- Garrett J, Fenwick JM, Taylor G, et al. Peak expiratory flow meters (PEFMs)--who uses them and how and does education affect the pattern of utilisation? Aust N Z J Med 1994; 24:521.
- Ignacio-Garcia JM, Gonzalez-Santos P. Asthma self-management education program by home monitoring of peak expiratory flow. Am J Respir Crit Care Med 1995; 151:353.
- Cowie RL, Revitt SG, Underwood MF, Field SK. The effect of a peak flow-based action plan in the prevention of exacerbations of asthma. Chest 1997; 112:1534.
- Turner MO, Taylor D, Bennett R, Fitzgerald JM. 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.
- Lahdensuo A, Haahtela T, Herrala J, et al. Randomised comparison of guided self management and traditional treatment of asthma over one year. BMJ 1996; 312:748.
- Charlton I, Charlton G, Broomfield J, Mullee MA. Evaluation of peak flow and symptoms only self management plans for control of asthma in general practice. BMJ 1990; 301:1355.
- Effectiveness of routine self monitoring of peak flow in patients with asthma. Grampian Asthma Study of Integrated Care (GRASSIC). BMJ 1994; 308:564.
- Jones KP, Mullee MA, Middleton M, et al. Peak flow based asthma self-management: a randomised controlled study in general practice. British Thoracic Society Research Committee. Thorax 1995; 50:851.
- Goldberg S, Springer C, Avital A, et al. Can peak expiratory flow measurements estimate small airway function in asthmatic children? Chest 2001; 120:482.
- Yoos HL, Kitzman H, McMullen A, et al. Symptom monitoring in childhood asthma: a randomized clinical trial comparing peak expiratory flow rate with symptom monitoring. Ann Allergy Asthma Immunol 2002; 88:283.
- Huang TT, Li YT, Wang CH. Individualized programme to promote self-care among older adults with asthma: randomized controlled trial. J Adv Nurs 2009; 65:348.
- Janson SL, McGrath KW, Covington JK, et al. Objective airway monitoring improves asthma control in the cold and flu season: a cluster randomized trial. Chest 2010; 138:1148.
- Gibson PG. Outpatient monitoring of asthma. Curr Opin Allergy Clin Immunol 2002; 2:161.
- O'Brien K, Mendoza G. Peak flow meter versus symptoms. J Allergy Clin Immunol 1994; 94:272.
- Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA). Full text available online at: www.ginasthma.org (Accessed on January 30, 2015).
- Plaut TF. One Minute Asthma: What You Need to Know, Pedipress, Inc, Amherst, MA 1992.
- Hankinson JL, Odencrantz JR, Fedan KB. Spirometric reference values from a sample of the general U.S. population. Am J Respir Crit Care Med 1999; 159:179.
- Pesola GR, O'Donnell P, Pesola GR, et al. Peak expiratory flow in normals: comparison of the mini Wright versus spirometric predicted peak flows. J Asthma 2009; 46:845.
- Gannon PF, Belcher J, Pantin CF, Burge PS. The effect of patient technique and training on the accuracy of self-recorded peak expiratory flow. Eur Respir J 1999; 14:28.
- Reddel HK, Marks GB, Jenkins CR. When can personal best peak flow be determined for asthma action plans? Thorax 2004; 59:922.
- Gautrin D, D'Aquino LC, Gagnon G, et al. Comparison between peak expiratory flow rates (PEFR) and FEV1 in the monitoring of asthmatic subjects at an outpatient clinic. Chest 1994; 106:1419.
- Dinakar C, Oppenheimer J, Portnoy J, et al. Management of acute loss of asthma control in the yellow zone: a practice parameter. Ann Allergy Asthma Immunol 2014; 113:143.