Reversing Pathophysiologic Changes of Chronic Obstructive Pulmonary Disease with Lung Volume Reduction Surgery and Exercise Rehabilitation

Abstract

Premature disability is associated with the development of chronic obstructive pulmonary disease. The accompanying lung destruction is permanent and promotes premature dyspnea on exertion in the early stages, increasing to dyspnea at rest as the disease progresses. These chronic degenerative changes are amplified with periodic acute exacerbations with accompanying bed rest and/or inactivity. Treatments for dyspnea have focused on medical treatment primarily in the areas of reversing airway dysfunction, controlling inflammatory processes, and smoking cessation, which is paramount. Unfortunately, the disease progresses, and physical limitation complicates the process, amplifies dyspnea, and greatly diminishes quality of life. A recently described surgical procedure, lung volume reduction surgery, has been shown to decrease dyspnea in a limited number of patients. Dyspnea reduction has been attributed to improvement in lung tissue elasticity, better function of the diaphragm at a lung volume 20% to 30% less than the preoperative value, and decreased airway resistance secondary to an improvement in radial traction. It is not yet known whether the improvements seen will persist or whether emphysematous changes will rapidly recur. A medical countermeasure to this debilitating cascade, pulmonary rehabilitation, has been applied with varying degrees of success. The central focus of any rehabilitation program is to increase functional ability to the highest level possible using exercise training. Increases in functional ability and quality of life occur in association with significant reductions in dyspnea and disease morbidity. Increased activity whether formal or informal should be stressed, and there are data to support that higher-intensity training will bring about greater increases in functional ability than those that are less intense.