tailieunhanh - Aging of the Respiratory System: Impact on Pulmonary Function Tests and Adaptation to Exertion

Age-related hearing loss or presbycusis is mainly caused by changes in the inner ear. However, your genes and loud noises (such as from rock concerts or music headphones) may play a large role. Initially there is difficulty in hearing high-frequency sounds, such as someone talking. As hearing gets worse, it may become difficult to hear sounds at lower pitches. Hearing aids Telephone amplifiers and other assistive devices may be helpful. A cochlear implant (Surgery) may be recommended for certain women with very severe hearing loss. The implant makes sounds seem louder, but does not restore normal hearing | ELSEVIER SAUNDERS Clin Chest Med 26 2005 469 - 484 CLINICS INCHEST MEDICINE Aging of the Respiratory System Impact on Pulmonary Function Tests and Adaptation to Exertion Jean-Paul Janssens MD Outpatient Section of the Division of Pulmonary Diseases Geneva University Hospital 1211 Geneva 14 Switzerland Life expectancy has risen sharply during the past century and is expected to continue to rise in virtually all populations throughout the world. In the United States population life expectancy has risen from 47 years in 1900 to 77 in 2001 for the male and for the female population 1 . The proportion of the population over 65 years of age currently is more than 15 in most developed countries and is expected to reach 20 by the year 2020. Healthy life expectancy at the age of 60 is at present years for the male population and years for the female population 2 . These demographic changes have a major impact on health care financially and clinically. Awareness of the basic changes in respiratory physiology associated with aging and their clinical implication is important for clinicians. Indeed age-associated alterations of the respiratory system tend to diminish subjects reserve in cases of common clinical diseases such as lower respiratory tract infection or heart failure 3 4 . This review explores age-related physiologic changes in the respiratory system and their consequences in respiratory mechanics gas exchange and respiratory adaptation to exertion. Structural changes in the respiratory system related to aging Most of the age-related functional changes in the respiratory system result from three physiologic events progressive decrease in compliance of the E-mail address chest wall in static elastic recoil of the lung Fig. 1 and in strength of respiratory muscles. Age-associated changes in the chest wall Estenne and colleagues measured age-related changes in chest wall compliance in 50 healthy subjects ages 24 to 75 .