Measuring peak expiratory flow rate: what the nurse needs to know.

Rationale and key points This article provides information on monitoring a patient's peak expiratory flow rate. It explains the rationale for measuring the peak expiratory flow rate, provides guidance for nurses to undertake this investigation and offers advice on how to instruct patients in the use of this technique. » Measuring the peak expiratory flow rate is an inexpensive, straightforward and useful clinical investigation that enables fluctuations in the patient's respiratory effort to be monitored over time. » The peak expiratory flow rate is used for the diagnosis, monitoring and assessment of the severity of respiratory compromise, particularly in patients with asthma. » The nurse can enable significant improvements in patient care by providing patient education on the correct technique, and by accurate assessment and recording of the peak expiratory flow rate. » The nurse should advise the patient on the action required if variation between readings occurs, where the patient is required to monitor their condition at home.