Clinical Application Of Negative Expiratory Pressure Technique In Chronic Obstructive Pulmonary Disease Patient

Objective To evaluate the relationship between expiratory flow limitation (EFL) and chronic dyspnea in patients with chronic obstructive pulmonary disease (COPD).Methods EFL was detected by using negative expiratory pressure technique(NEP) in 59 patients with COPD at the sitting and the supine position.Results 49 cases of 59 patients successfully completed each target tests, of which 10 patients with severe dyspnea or severe cough can not accomplish the routine pulmonary function test. EFL was detected in 22 (44.9%) of the 49 COPD patients in both seated and supine positions and in 20 (40.8%) only in supine position. And 7 patients were not flow-limted either seated or supine. The values of FEV1% of the patients in the moderate, severe and very severe EFL group were all significantly lower than that of them in NO EFL group(P< 0.000). And the values of FEV1% of them in very severe EFL group were the lowest, which is significantly different with that of the patient in the mild, the moderate, severe EFL group(P<0.005).five-point EFL were significantly correlated with FEV1 (r=-0.934, P<0.000). There was a significant correlation between MRC dyspnea score and five-point EFL score (r=0.903, P<0.01). the multiple regression analysis showed that 6-min walking distance, FEV1% and five-point EFL score were correlated with MRC dyspnea score among the variables of sexes, age, height, body weight,FEV1%,6-min walking distance and five-point EFL score, and five-point EFL score showed the best correlativity with MRC dyspnea score. (regression coefficient was 0.47,P<0.005).Conclusions There was a significant relationship between expiratory flow limitation (EFL) and chronic dyspnea in patients with chronic obstructive pulmonary disease (COPD). EFL are measured by negative expiratory pressure (NEP) technique may be more reliable in the evaluation of dyspnea in COPD. Negative expiratory pressure technique is a is simple, non-invasive test, which dos not require any initiative cooperation from the patients, it can be applied in the patients who can not accomplish routine pulmonary function tests.