Peak Expiratory Flow (PEF)

Peak Expiratory Flow (PEF)

  • Definition: Maximal flow produced during forced expiration.

  • Measurement:

    • Can be measured using handheld peak flow meters.

    • Commonly used in Emergency Departments (EDs) and clinics.

  • Purpose:

    • Quickly and objectively assess the effectiveness of bronchodilators in acute asthma attacks.

    • Can be used at home by asthma patients to monitor chronic therapy.

  • Relation to FEV1:

    • Changes in PEF generally parallel those of FEV1.

    • PEF is less reproducible than FEV1.

  • Normal Ranges:

    • Average healthy young adult male: 550 to 700 L/minute.

    • Peak flow meters provide charts for predicted normal PEFs based on gender, age, and height.