Effect of Aging on the Respiratory System
Change that occurs in the muscles and skeleton with aging can decrease lung function. The elderly client may have kyphosis/scoliosis that decreases respiratory movement. Osteoporosis of the ribs and verte-brae and calcification of the cartilage may contribute to stiffness of the chest wall. The respiratory muscles (diaphragm, intercostals, etc.) weaken, reducing the efficiency of breathing.
With age, elastic tissue in the lungs alter, with a re-duction in the lung’s elastic recoil. This compensates for the stiffness of the chest wall, making it easier for the lungs to expand. The alveoli become larger with age, re-ducing the surface area for exchange. The capillaries in the alveoli also decrease. In general, the work of breath-ing increases, and the elderly tend to rely on the move-ment of the diaphragm more than chest wall move-ment. As a result, small changes in intra-abdominal pressure, such as a heavy meal or change in body posi-tion, tend to compromise breathing.
All of the above anatomic changes have significant effects on lung function. More air remains in the lung after expiration; forced expiratory volume and vital capacity decrease. The small airways tend to collapse during shallow breathing, reiterating the importance of deep breathing exercises in older individuals.
Changes also occur in the respiratory centers, with the response to reduced oxygen and increased carbon dioxide levels blunted. The cough reflex is impaired, with reduced force, volume, and air flow rate expelled during a cough. Cilia in the mucosa decrease with age, reducing the lung’s capacity to clear mucus and foreign agents that have settled on the mucus. The activity of the macrophages that wander in the lungs is also decreased, together with a reduction in anti-bodies secreted in the lungs. All this makes the el-derly more prone to respiratory diseases.
The changes that occur with aging are worsened when associated with smoking, obesity, and immo-bility.