Domiciliary Positive Expiratory Pressure Improves Pulmonary Function and Exercise Capacity in Patients with Chronic Obstructive Pulmonary Disease

Background/purposeThis study assessed how positive expiratory pressure (PEP) affected pulmonary function, functional capacity, and subjective cough difficulty in individuals with chronic obstructive pulmonary diseases (COPD).MethodsThis was a prospective, randomized, controlled study. Subjects were recruited from an outpatient department at a university hospital. Thirty-two patients with COPD were allocated to either PEP + FET (forced expiratory technique) group (n = 16) or FET only group (n = 16). Subjects in PEP + FET and FET groups were in a clinically stable condition before and during the study. Subjects in the PEP + FET group received PEP breathing using a mouth adjunct to FET, and the FET group was administered FET for 4 weeks only. Patients received weekly follow-up during the study period. Pulmonary function, 6-minute walk tests, and subjective cough difficulty scores were measured before and after the 4-week interventions.ResultsSubjects in the PEP + FET group had a significantly increased diffusing capacity (DLCO) compared to preintervention (p < 0.05) and after intervention in the FET group (p < 0.05). DLCO significantly increased in the PEP + FET group from 18.0 ± 7.3 to 20.1 ± 7.2 mL/min/mmHg. The 6-minute walking distance (6MWD) also increased significantly from 516.8 ± 94.1 to 570.6 ± 60.4 m in the PEP + FET group (p < 0.001) after intervention, compared to that for the FET group (p < 0.05). Additionally, the PEP + FET group had significantly lower cough difficulty scores compared to those at baseline and in the FET group.ConclusionFour-week PEP therapy as an adjunct to FET further enhanced DLCO and 6MWD, and reduced cough difficulty compared to FET only in COPD patients with mucus hypersecretion. [J Formos Med Assoc 2007;106(3):204-211