What is the role of peak expiratory flow (PEF) measurement in the evaluation of status asthmaticus?

Updated: Jun 17, 2020
  • Author: Constantine K Saadeh, MD; Chief Editor: John J Oppenheimer, MD  more...
  • Print

Also see Pulmonary Function Testing.

The most important and readily available test to evaluate the severity of an asthma attack is the measurement of peak expiratory flow (PEF). PEF monitors are commonly available to patients for use at home and they provide asthmatic patients with a guideline for changes in lung function as they relate to changes in symptoms. In most patients with asthma, a decrease in peak flow as a percentage of predicted value correlates with changes in spirometry values.

Although the forced expiratory volume in one second (FEV1) is also used to monitor the degree of airway obstruction, in patients who are acutely ill, PEF monitoring is more commonly performed. Note that spirometry is more accurate (sensitive and reproducible).

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!