Obstructive Lung Disease 4

Emphysema

• Emphysema is characterized by permanent enlargement of airspaces distal to terminal bronchioles and destruction of their walls without fibrosis.
• Panacinar emphysema is associated with α1-antitrypsin deficiency.
• Centriacinar emphysema is the most common type in the upper lobes and is associated with smoking.
• Protease-antiprotease imbalance is involved in the pathogenesis of emphysema.
• Neutrophils are the primary source of protease in emphysema.
• Severe emphysema patients often have a barrel-chested appearance.
• Cor pulmonale is a common cause of death in patients with emphysema.

Chronic Bronchitis

• Chronic bronchitis is defined as a persistent productive cough for at least 3 consecutive months in 2 consecutive years.
• About 90% of chronic bronchitis patients are smokers.
• Chronic obstructive bronchitis is characterized by airflow obstruction usually with associated emphysema.
• Mucous glands hypertrophy and hyperplasia are hallmarks of chronic bronchitis.
• Weight loss is not typically associated with chronic bronchitis.
• Patients with severe chronic bronchitis are often referred to as "blue bloaters".

Bronchial Asthma

• Extrinsic asthma is mediated by IgE and TH2 responses.
• Intrinsic asthma is triggered by viral infections, exercise, and other factors.
• Mast cells and eosinophils are involved in the airway inflammation of asthma.
• Airway inflammation, intermittent airway obstruction, and bronchial hyper-responsiveness are components of asthma's pathophysiology.
• Chest tightness is a main feature of an acute asthma attack.
• Status asthmaticus is a severe asthma attack that does not respond to therapy.
• Bronchial wall thickening is a characteristic of airway remodeling in asthma.
• Aspirin is a major mediator in non-atopic asthma.

Bronchiectasis

• Bronchiectasis is characterized by permanent dilation of bronchi and bronchioles.
• Tumors, foreign bodies, and cystic fibrosis are causes of bronchiectasis.
• Staphylococcus aureus and Klebsiella spp. are microorganisms commonly associated with necrotizing pneumonia leading to bronchiectasis.
• Productive cough with mucopurulent sputum is a common clinical feature of bronchiectasis.
• Clubbing of the fingers and pulmonary hypertension are complications of bronchiectasis.
• Chronic persistent infection and bronchial obstruction are primary pathogeneses of bronchiectasis.

General Knowledge on Obstructive Lung Diseases

• Emphysema, chronic bronchitis, and asthma are considered obstructive lung diseases.
• Pulmonary fibrosis is not considered an obstructive lung disease.
• Increased resistance to airflow is a common feature of obstructive lung diseases.
• Pulmonary function test (PFT) is crucial for diagnosing obstructive lung diseases.
• In obstructive lung diseases, the FEV1/FVC ratio is typically reduced.
• Airway hyperresponsiveness is a hallmark of chronic obstructive bronchitis.
• Chronic airflow obstruction with emphysema is a characteristic of chronic obstructive bronchitis.