PEAK FLOWMETER

Typical Number in Hospital: 10

Cost Bands: 2

References: 2,3,6

This normally refers to a device for measuring the maximum expiratory flow rate as an aid to assessing lung function. It may be a dedicated device such as the Wright peak flowmeter, or the peak flow may be gleaned from a more general test instrument such as the Vitalograph or a recording spirometer.

In the case of the Wright peak flowmeter the peak expiratory flow rate (PEFR) can be measured in the ward or clinic by a simple hand-held instrument into which the patient blows. The flow of air is directed against a movable vane restrained by a spiral spring and as the vane moves further round the dial it uncovers more escape holes. There is a ratchet to hold the vane in the maximum position reached. Typical PEFR for an adult male is 7 l/s.