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Peak Expiratory Flow Rate (PEFR)

This is a simple method of measuring airway obstruction and it will detect moderate or severe disease. The simplicity of the method is its main advantage. It is measured using a standard Wright Peak Flow Meter or mini Wright Meter. The needle must always be reset to zero before PEF is measured.

Normal values are related to the patient's height as follows:

Height (cm) PEFR (L/min)*
120 215
130 260
140 300
150 350
160 400
170 450
180 500

* mean; 2 SD = ±100

An easy to remember approximation is: PEFR (L/min) = [Height (cm) - 80] x 5