Geriatric anesthesia: pulmonary changes

Elderly lungs lose tissue elasticity and demonstrate increases in lung compliance (much like emphysema), however, chest wall compliance decreases, so the net pulmonary compliance is virtually unchanged. Breakdown of alveolar septae increases anatomic and alveolar dead space and increases ventilation- perfusion mismatch. Shunting and physiologic dead space also increase. Closing capacity becomes greater than the volume of the lung at rest. Vital capacity is decreased due to increasing residual lung volumes, and inspiratory and expiratory reserve volumes are decreased