[Usefulness of peak expiratory flow measurements in assessing degree of bronchial obstruction in patients with chronic obstructive lung diseases].

An analysis was carried of relations between PEF measurements and FEV1 values and between PEF and FEF25-75 in 130 patients with COLD (48 females and 82 males). PEF was assessed using the Wright peak flow meter, while FEV1 and FEF25-75 from the spirographic curve. A positive linear correlation was found between PEF and FEV1 in absolute values, % predicted and standardised residuals (r = 0.91, r = 0.87, p < 0.001). Diagnostic sensitivity of PEF in detecting bronchial obstruction was 82%, while the specificity was 85%. The weakest correlation was found between PEF and FEV1 in standardised residuals of 41 patients with PEF between 50% and 79% predicted (r = 0.41, p < 0.05). In this subgroup of patients, twenty one (51%) had normal FEV1, and twenty (49%) low FEV1 values. Measurements of PEF despite a strong correlation with FEF25-75 did not allow to single out cases without small airway involvement, because in 28% of the patients with PEF 100% predicted lowered FEF25-75 were noted. In 97% of patients with PEF values 80% predicted abnormal low FEF25-75 were demonstrable.