[Value of 25-75 percent maximum expiratory flow as compared with vital capacity (ratio of MEF 25-75 to VC) in the detection of ventilatory disorders of the small air passages].

The author has investigated the feasibility of DME 25--75/C.V. as a test for the detection of ventilatory disturbances of the small aerial pathways, by comparing the results with those of other tests considered to be very sensitive, such as Vmax 50% and 25% of C.V., Vmax 50% and 25% of C.V. of an air curve and that of a He-O2 mixture (80%--20%), and the isoflow volume. The study was carried out in 90 subjects, divided in two groups in relation to the values obtained by the DME 25--75/C.V., as follows : 44 subjects with bronchial obstruction and 46 subjects showing functional signs of obstruction of the small aerial pathways. The results have indicated that the two populations classified according to this criterium are statistically different also with regard to other tests applied, indicating the feasibility of the test under study, which, compared to other tests, has the advantage of higher sensitivity in relation to the simplicity of the device.