ABSTRACT
Measures of Pulmonary Function Due to differences among peak flowmeters of different design and manufacture, patients should use a single device for their serial measurements. Patients should measure and record their morning peak expiratory flow rate daily, shortly after arising. Implementation of effective anti-inflammatory therapy is usually associated with improvement in morning PEFR. Several pieces of information can be gleaned from the peak flow record. First, the absolute change in PEFR (attributable to therapy) can be determined by comparing the peak flow in the first day or so of therapy with that recorded at the follow up visit. Second, the variability in peak flow for a given week can be computed. Finally, the PEFR can be normalized to the patient’s individual personal best PEFR as a percentage. According to the EPR II, good control is indicated by PEFR in the “ green zone” of 80% of personal best PEFR or better. “ Yellow zone” values from 50-80% of personal best suggest need for additional therapy. As noted elsewhere (in the discussion of patient education, above, and that of responding to exacerbations, below), PEFR measures consistently less than 50% of personal best indicate a severe exacerbation requiring prompt medical intervention.
