Emphysema (‘pink puffer’):
- p/c: thin, barrel chested, no cough, pursed lip breathing, accessory muscle use, tripod sitting position, hyper-resonant chest, wheeze, wasted and cachexic.
- o Alveolar septal damage (distal to terminal bronchiole) leaving empty spaces in lung = reduced vascular bed/alveolar contact = minor hypoxia (still perfusing=pink)
- o Elastic damage of lungs = reduced radial traction on bronchioles = collapsing bronchioles on expiration (due to positive pleural pressure) = pursed lips (=gradual release of pressure to increase intra-bronchial pressure and hold airways open.
- o Compensation for reduced perfusion by hyperventilation (=makes pt cachexic).
- o Distension and damage of lung tissue is concentrated around the respiratory bronchioles – alveoli are unchanged.
- o Common. Cause = smoking! Most damage in upper lobes of lung.
- o Distension and destruction appear to involve the whole acinus (from respiratory bronchioles to alveoli).
- o In extreme cases, lung becomes mass of bullae.
- o Severe airflow limitation
- o Ventilation perfusion mismatch
- Occurs partly because of damage and mucus plugging of smaller airways
- Rapid expiratory closure of smaller airways due to lack of elastic recoil
- Fall in pO2
- Increase in work of respiration
- o Cause = alpha-1-antitrypsin deficiency. Most damage in lower lobes and anterior margins.
- o Scarring and damage affecting the lung parenchyma patchily