The peak flowmeter has been used extensively in the management of asthma. Its use in the hospital and emergency department has been well described.’ In more recent years, the availability of inexpensive, small, portable peak flo>vmeters has increased. These meters have been shown to be helpiul to both physicians and patients in the outpatient management of asthma. By helping to monitor the course of the disease and its response to medication, peak flowmeters allow for early intervention during exacerbations of asthma, many times avoiding the need for hospitalization.
The reproducibility and accuracy of inexpensive hand-held peak flowmeters have been evaluated in the past. These qualities are essential for the accurate monitoring of the disease over time. In this study, we investigated the performance of three currently available peak flowmeters in widespread use.
Portable peak expiratory flowmeters depend on a calibrated spring mechanism for their readings, and springs may stretch and lose elasticity over time, changing the accuracy of the instrument. To evaluate this effect, we studied peak flowmeters before and after 200 uses to assess any change in accuracy that would be expected during the normal use of the instrument.