Physiologic evaluation of patients for pulmonary rehabilitation

The physiologic evaluation of the patient with pulmonary disease is important. Pulmonary function tests play an important role in evaluating the degree of impairment (Fig. 9), evaluating a patient for rehabilitation, determining the rate of decline in function, and lastly measuring the impact of rehabilitation on slowing or ideally reversing the effect of disease. Although a training effect can be demonstrated in terms of increased exercise tolerance and improved anaerobic threshold, to date the impact of current rehabilitation schemes on pulmonary function has been disappointing. There are reports that a vigorous rehabilitation program can positively alter pulmonary function, but most studies in which pursed lip breathing, breathing exercises, and physical therapy are used show little change in the indices of pulmonary function that were evaluated. This failure is surprising, given the finding that smoking cessation will often improve pulmonary function and returns the subject to the age-related rate of decline in pulmonary function that is observed in non-smoking subjects. The failure of rehabilitation programs to improve pulmonary function is unclear. Undeniably, one of the reasons lies in entering patients into rehabilitation who have proceeded too far into the course of their disease. Accordingly, it would be of great interest to evaluate rehabilitation approaches in much less impaired patients. Another possibility is that the length of most rehabilitation programs is relatively short. It may be that longer courses of training would improve function. It is unexplained why declines in pulmonary function are correlated to declines in work capacity, yet improvements in work capacity achieved by rehabilitation are not associated with improved pulmonary function. A likely factor is that pulmonary function is often optimized through pharmacotherapy prior to entrance into such programs; hence, little further change in function is realized. Lastly, although data for the study groups show little change, some individuals do on occasion improve. One cannot forget that while science deals with populations and statistics, the practicing physician must deal with the individual.