Peak Flow Procedure
Introduction
Peak Flow (PF) is a simple and commonly used measurement of lung function. Peak expiratory flow rate (PEFR) is defined as "The maximum flow achievable from a forced expiration starting at full inspiration with an open glottis" (British Thoracic Society and Association of Respiratory Technicians and Physiologists 1994). This is recorded in litres per minute.
Indications
- As an aid to diagnosis
- Method of determining lung function
- A change or fall in PEFR will detect change in airflow obstruction
- Used for the on-going assessment of Asthma/Chronic Obstructive Pulmonary Disease (COPD)
- Evaluate response to therapy i.e. inhalers and nebulisers
- Used in Asthma Management plans
Equipment List
- Peak flow Meter, single use only eg. Mini Wright
- Peak flow chart
New Meters
Mini-Wright peak flow meters presently in use utilise the Wright McKerrow scale New Mini-Wright peak flow meters are being introduced with the new European Standard (EN 13826) scale these may also be identified by their distinctive yellow dial. This scale differs from the present peak flow meters that are in use. This change has the potential to cause confusion so please ensure you know which peak flow meter you are using and then refer to the correct chart to predict peak flow. The old type peak flow meters will eventually be phased out.