Incorrect use of peak flow meters: are you observing your patients?

Monitoring peak expiratory flow (PEF) values is one option as part of asthma action plans per national guidelines. PEF assessment is also recommended in emergency department and hospitalized patients. Incorrect use of peak flow meters (PFM) has obvious implications for appropriate decisions by patients and clinicians.

We searched the English literature via PubMed and SCOPUS using the following search terms: PEF maneuver; incorrect use of PFM. When pertinent articles were found, we assessed publications cited in those papers. All studies related to incorrect use of PFM in patients with asthma were included.

Nine studies have reported errors in performing the PEF maneuver, including three pediatric and six adult studies. Errors were found at most steps of the maneuver, and inability to perform all steps correctly was common in these investigations. Examples of errors included failure to inhale fully or give maximum effort on exhalation, accelerating air with the tongue and buccal musculature, and performing only one attempt versus three. Gender differences in correct use of PFM are suggested by three adult studies. One study described falsifying PEF values by manipulating the PFM indicator, and another investigation assessed the PEF maneuver in two positions in bed versus the correct posture of standing.

Many pediatric and adult patients do not use PFM correctly. Clinicians should regularly observe patients use PFM to detect errors and help ensure correct use and accurate PEF measurements.