Registered Nurses' Association of Ontario

Peak Flow Monitoring Tips

1. Monitoring Peak Expiratory Flow (PEF) may be useful in some persons, particularly those who are poor perceivers of airflow obstruction.

2. Caution should be exercised in interpreting PEF results, as they are extremely effort-dependent. They should be used in conjunction with other clinical findings.

3. The person’s PEF technique should be observed until the practitioner is satisfied that the technique produces accurate readings. (See “How to Use a Peak Flow Meter,” above.)

4. Home PEF monitoring should be linked to the assessment of symptoms in the action plan.

5. Persons who are using a PEF meter should be instructed on how to establish their personal best PEF and use it as the basis of their action plan.

6. PEF devices must be checked regularly for accuracy and reproducibility of results.

7. Baseline morning and evening monitoring should be carried out over a number of weeks and continued regularly, with the frequency adjusted to the severity of the disease.

8. Persons should be alerted to the significance of increased diurnal variation (i.e., evening to morning changes) in PEF that are greater than 15–20%.

9. The accuracy of a person’s peak flow meter should be determined at least once per year or whenever there is a question about its accuracy. Values from spirometry or another portable meter should be compared.


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