Emphysema:  Abnormal irreversible enlargement of air spaces distal to terminal bronchioles caused by destruction of alveolar walls, resulting in decreased elastic recoil properties of lungs.  Emphysema is the most common cause of death from respiratory disease in the United States.

Cause:  Cigarette smoking, deficiency of alpha,-antitrypsin.
Recurrent inflammation associated with release of proteolytic enzymes from lung cells causes bronchiolar and alveolar wall damage and, ultimately, destruction.  Loss of lung supporting structure results in decreased elastic recoil and airway collapse on expiration.  Destruction of alveolar walls decreases surface area for gas exchange.

Symptoms:

Dyspnea (labored or difficulty breathing)

Chronic cough

Anorexia

Weight loss

Malaise

Barrel chest

Use of accessory muscles of respiration

Prolonged expiratory period with grunting

Pursed - lip breathing

Tachypnea (rapid respiration)

Complications includes:  recurrent respiratory tract infections, cor pulmonale, and respiratory failure

Treatment:

Bronchodilators - to promote mucociliary clearance

Antibiotics to treat respiratory infection;  Influenza vaccine to prevent influenza; and Pneumococcal vaccine to prevent pneumococcal pneumonia

Adequate fluid intake and , in some patients, chest physiotherapy to mobilize secretions

Oxygen therapy to treat hypoxemia

Avoidance of smoking and air pollutants