Lung Volume Changes following Pulmonary Rehabilitation

Abstract

Studies evaluating the effects of pulmonary rehabilitation have failed to demonstrate statistically significant changes in spirometric values, lung volumes, and other indices of pulmonary function. However, pursed-lips breathing and the utilization of energy-conserving maneuvers have been shown to facilitate activities of daily living, reduce dyspnea, and improve ventilatory efficiency. We developed a 6-week hospital-based outpatient pulmonary rehabilitation program that places special emphasis on the use of controlled breathing techniques and energy-conserving maneuvers during virtually all activities performed during waking hours. Method: We studied the pulmonary function of the first 30 patients who completed the program to determine whether there were any changes as a result of the rehabilitation process. Results: Student's paired t test revealed statistically significant decreases in residual volume (P = 0.002), functional residual capacity (P = 0.011), and total lung capacity (P = 0.003); statistically significant increases in forced vital capacity (P < 0.001) and expiratory reserve volume (P = 0.028); and no statistically significant changes in slow vital capacity (P = 0.184), forced expiratory volume in 1 second (P = 0.261), or carbon monoxide diffusing capacity (P = 0.683). Conclusions: These results suggest a reduction in the amount of trapped air in the lungs, resulting in increased ventilatory efficiency. We conclude that pulmonary rehabilitation may be successful in reducing trapped air when considerable emphasis is placed on the use of controlled breathing and energy-conserving maneuvers during all forms of activity.