Campbell E J, Lefrak S S
Geriatrics. 1978 Jun;33(6):68-74.
Age-associated changes in the lung resemble emphysema. Progressive loss of the aging lung's static recoil forces produces airway closure at lung volumes in the tidal volume range,which leads to decreased arterial Po2. Under conditions that decrease oxygen content of arterial blood, the increase in both ventilation and cardiac output is smaller in elderly persons than in younger subjects. Therefore, less oxygen may be delivered to the tissues. Muscular strength of the respiratory apparatus consistently declines and the chest wall stiffens with advancing age. Thus, the elderly have weaker muscles to act on a chest wall that becomes progressively harder to move. Both maximal inspiratory and expiratory pressures are significantly decreased. Loss of the functional reserve of the respiratory system with age increases the risk of respiratory failure and leaves elderly subjects with decreased compensatory mechanisms for dealing with even moderate stress. The physician must be aware of these problems and provide early and vigorous respiratory care for elderly patients.
肺部与年龄相关的变化类似于肺气肿。随着年龄增长，肺部静态回缩力逐渐丧失，导致在潮气量范围内的肺容积时气道关闭，进而引起动脉血氧分压降低。在使动脉血含氧量降低的情况下，老年人通气量和心输出量的增加幅度小于年轻受试者。因此，输送到组织的氧气可能会减少。随着年龄的增长，呼吸器官的肌肉力量持续下降，胸壁也会变硬。这样一来，老年人用于作用于逐渐变得更难移动的胸壁的肌肉变弱。最大吸气和呼气压力均显著降低。随着年龄增长，呼吸系统功能储备的丧失增加了呼吸衰竭的风险，并且使老年受试者应对即使是中度应激的代偿机制也有所减弱。医生必须意识到这些问题，并为老年患者提供早期且积极的呼吸护理。
