Centriacinar emphysema is associated with cigarette smoking, characterized by enlarged airspaces found (initially) in association with respiratory bronchioles.
First, cigarette smoke directly affects the cells in the airway responsible for clearing mucus and other secretions. Occasional smoking temporarily disrupts the sweeping action of tiny hairs called cilia that line the airways. Long-term exposure to cigarette smoke causes the cilia to disappear from the cells lining the air passages. Without the constant sweeping motion of the cilia, mucous secretions cannot be cleared from the lower respiratory tract. Furthermore, smoke causes mucous secretion to be increased at the same time that the ability to clear the secretions is decreased. The resulting mucous buildup can provide bacteria with a rich source of food and lead to infection. Secondly, cigarette smoke affects the immune cells in the lung (macrophage, neutrophil…) that can not fight bacteria as effectively or clear the lungs of the many particles (such as tar) that cigarette smoke contains. In addition, enzymes released during this persistent inflammation destroy small distinct airspaces.
Panacinar emphysema refers to abnormally large airspaces evenly distributed within and across acinar units. Panacinar emphysema is usually observed in patients with alpha1-AT deficiency.
Alpha-1-antitrypsin is a substance that fights a destructive enzyme in the lungs called trypsin. Trypsin is a digestive enzyme, most often found in the digestive tract, where it is used to help the body digest food. It is also released by immune cells in their attempt to destroy bacteria and other material. People with alpha-1-antitrypsin deficiency cannot fight the destructive effects of trypsin once it is released in the lung. The destruction of tissue by trypsin produces similar effects to those seen with cigarette smoking. The lung tissue is slowly destroyed, thus decreasing the ability of the lungs to perform appropriately.
Symptom:
One of the hallmark signs of emphysema is "purse-lipped breathing". The person with emphysema is struggling to exhale completely, with airways that close when the chest wall collapses during expiration. They purse the lips, leaving only a small opening. Then, when they exhale, the lips block the flow of air, increasing pressure in the collapsed airways, and opening them, allowing the person to fully exhale.
Barrel chest, poor diaphragmatic excursion,
Systemic wasting is associated with both inadequate oral intake and elevated levels of inflammatory cytokines (TNF-alpha).
Paradoxical inward movement of the rib cage with inspiration (Hoover’s sign).
Signs of cor pulmonale ( heart disease due to lung disease).
Patients with predominant emphysema, termed "pink puffers," are thin and noncyanotic at rest and have prominent use of accessory muscles.
Laboratory examination:
Reduction in FEV1 and FEV1/FVC and an increase in total lung capacity, functional residual capacity, and residual volume.
Arterial blood gases and oximetry are not sensitive and may demonstrate resting or exertional hypoxemia.
X-ray: Obvious bullae, paucity of parenchymal markings, or hyperlucency suggest the presence of emphysema. However, the x-ray also may show the presence of an infection.
Measurement of the serum alpha1AT level.
Treatment:
Medical therapy:
Bronchodilators: anticholinergic agents, beta agonists, methylxanthine.
Steroid medication: glucocorticoids. A trial of inhaled glucocorticoids should be considered in patients with frequent exacerbations, defined as two or more per year, and in patients who demonstrate a significant amount of acute reversibility in response to inhaled bronchodilators.
Antibiotics.
Supplemental oxygen therapy.
Non-medical therapies
General Medical Care: influenza vaccine and pneumococcal vaccine.
Pulmonary rehabilitation: include improving exercise tolerance and dyspnea, and may improve quality of life and decrease the frequency of exacerbations.
Surgery:
Lung volume reduction surgery: Target areas for surgical resection consist of large peripheral focal areas of severe emphysema.
Giant bullectomy is considered in patients with COPD and dyspnea in whom a bulla or bullae occupy approximately one-third to one-half of the hemithorax.
Lung transplantation is indicated in patients with very severe expiratory airflow obstruction and severe limitations in quality of life.