Background: A common symptom perceived by patients with chronic obstructive pulmonary disease (COPD) is breathlessness, which may be partially attributed to diaphragmatic dysfunction. The potential benefits of pulmonary rehabilitation (PR) on diaphragmatic function utilizing direct visualization have not been reported.

Objective: To determine if participation in an 8-week outpatient PR program will increase diaphragmatic function as measured by 2D echocardiography for patients diagnosed with COPD.

Design: Nonexperimental, prospective, longitudinal study.

Methods: Two groups, an exercising group (EG, n = 10) and a nonexercising comparison group (CG, n = 10), were recruited for entry through convenience sampling. EG subjects exercised 3 times per week for 8 weeks in a supervised, hospital-based outpatient PR program for 90 minutes each day, including a 45-minute upper body exercise/coordinated breathing class & a 45-minute exercise class utilizing treadmills & recumbent cycles. CG subjects maintained normal activities.

Main Outcome Measures: Diaphragmatic excursions during normal & maximal inspiratory/expiratory breathing, measured by 2D echocardiographic imaging, prior to & following the 8-week study period.

Results: At baseline unpaired t tests revealed significant differences between the EG & CG for normal & maximal diaphragmatic excursions (P = .048 & .046, respectively). Therefore, ANCOVA was used to determine mean between-group differences following the 8-week study period. Postexercise the EG had significantly greater maximal excursions than the CG (P = .004) with no difference for normal excursions between the groups. Within-group analyses (paired t tests) showed a significant change in maximal excursions pre- to postexercise for the EG (2.2+/-1.6 to 3.5+/-2.4; P = .039) with no change in normal excursions in ether group & no change in maximal excursions for the CG.

Conclusions: These findings suggest participation in outpatient PR improves maximal diaphragmatic excursions as measured by echocardiographic imaging. This improved function may contribute to a reduced sensation of perceived breathlessness during exertional activities.