Peak Expiratory Flow Rate

Peak expiratory flow (PEF) measurement should be performed on all patients that are capable of performing the test. PEFR is effort dependent and the best of three attempts should be recorded. This process should not be performed in hypoxic patients and should be stopped if a patient becomes hypoxic during testing. Serial measurements allow response to therapy to be assessed.

The benchmark for comparison should be the patients best PEFR in the last 2 years. Patients commonly cannot recall their best PEFR and this may have to be predicted from charts based on their age, sex and height.