An 81-year-old man comes to the office after an upper respiratory tract infection. His symptoms have largely resolved except for a mild, nonproductive cough that is especially bothersome at night. Medical history includes hypertension and knee osteoarthritis. The patient is still physically active and plays golf on the weekends. He is a retired insurance executive and has no known environmental exposures. He has no history of smoking. Physical examination is unremarkable, and chest x-ray is normal. Pulmonary function testing is considered in this patient. Compared to midlife, which of the following changes are most likely expected as a result of normal aging in this patient?

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11ec160b_3cdb_025c_9249_9579ac46ad1e_MD0001_00 Aging is associated with a number of changes in pulmonary function. Patients age >35 experience steady decreases in chest wall compliance as a result of stiffening from rib calcification and from increased thoracic curvature due to osteoporosis and osteoarthritis. In contrast, lung compliance increases with age due to a loss of elastic recoil, particularly in the alveolar ducts. The dilation of alveolar ducts is homogenous, as opposed to the emphysema associated with chronic obstructive pulmonary disease, and is not associated with destruction of the alveolar walls. Diminished elastic recoil and the collapse of supporting tissues around the airways cause a significant increase in residual volume (RV). However, total lung capacity (TLC) remains unchanged because the decreased chest wall compliance counterbalances increases in lung compliance (Choices A, D, and E). In addition, as RV becomes a much higher proportion of TLC (due to air trapping), forced vital capacity also decreases (Choice B). Other age-associated changes include decreases in forced expiratory volume in 1 second and diffusing capacity. Educational objective: Aging is associated with steady decreases in chest wall compliance but increases in lung compliance due to a loss of elastic recoil. This results in a marked increase in residual volume, a decrease in forced vital capacity, and relatively unchanged total lung capacity. __________ References: Effect of aging on respiratory system physiology and immunology. (http://www.ncbi.nlm.nih.gov/pubmed/18046878) Physiological changes in respiratory function associated with ageing. (http://www.ncbi.nlm.nih.gov/pubmed/10836348)

An 81-Year-Old Man Comes to the Office After an Upper