Domiciliary positive expiratory pressure improves pulmonary function and exercise capacity in patients with chronic...

This study assessed how positive expiratory pressure (PEP) affected pulmonary function, functional capacity, and subjective cough difficulty in individuals with chronic obstructive pulmonary diseases (COPD).

This 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.

Subjects 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.

Four-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.