Obstructive Lung Disease

Obstructive lung disease is characterized by airflow limitation, primarily affecting exhalation. This limitation occurs due to narrowing, obstruction, or damage to the airways, making it harder for air to flow out of the lungs efficiently.

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Key Features

• Pathophysiology:
  • Airflow is obstructed due to inflammation, excess mucus, airway collapse, or structural changes.
  • Air trapping leads to hyperinflation and increased work of breathing.
• Pulmonary Function Test (PFT) Findings:
  • Decreased FEV1/FVC ratio (<70%).
  • Increased residual volume (RV) and total lung capacity (TLC) due to air trapping.

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Common Conditions

1. Chronic Obstructive Pulmonary Disease (COPD)

• Definition: A progressive disease that includes chronic bronchitis and emphysema.
• Chronic Bronchitis:
  • Persistent inflammation of the bronchi.
  • Symptoms: Chronic productive cough (lasting >3 months in 2 consecutive years), wheezing, dyspnea.
  • Pathology: Hyperplasia of mucus-secreting glands and ciliary dysfunction.
• Emphysema:
  • Destruction of alveolar walls and loss of elastic recoil.
  • Symptoms: Dyspnea, barrel chest, pursed-lip breathing.
  • Pathology: Enlarged airspaces, reduced gas exchange surface area.

Risk Factors: Smoking, air pollution, occupational exposure, alpha-1 antitrypsin deficiency.

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2. Asthma

• Definition: A chronic, reversible inflammatory condition causing airway hyperresponsiveness.
• Triggers: Allergens, exercise, cold air, infections, stress.
• Symptoms: Intermittent wheezing, breathlessness, chest tightness, and coughing.
• Diagnosis:
  • Spirometry with reversible obstruction after bronchodilator use.
  • Peak expiratory flow monitoring.

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3. Bronchiectasis

• Definition: Permanent dilation of the bronchi due to chronic infection or inflammation.
• Causes:
  • Recurrent respiratory infections.
  • Cystic fibrosis.
  • Post-tuberculosis or autoimmune diseases.
• Symptoms: Chronic productive cough, large amounts of sputum, hemoptysis.
• Diagnosis: CT scan showing airway dilation.

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4. Cystic Fibrosis (CF)

• Definition: A genetic disorder affecting chloride channels, leading to thick mucus buildup.
• Symptoms: Recurrent infections, persistent cough, malabsorption, and infertility.
• Diagnosis: Sweat chloride test, genetic testing.

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5. Obstructive Sleep Apnea (OSA) (Related Condition)

• Definition: Intermittent airway obstruction during sleep, leading to hypoxia and disrupted sleep.
• Symptoms: Snoring, daytime fatigue, and poor concentration.
• Diagnosis: Polysomnography (sleep study).

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Symptoms of Obstructive Lung Disease

• Shortness of breath (dyspnea), especially on exertion.
• Chronic cough, with or without sputum production.
• Wheezing, especially during exacerbations.
• Fatigue due to increased effort to breathe.

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Diagnostic Tools

1. Pulmonary Function Tests (PFTs):
   • FEV1: Forced Expiratory Volume in 1 second.
   • FVC: Forced Vital Capacity.
   • FEV1/FVC ratio <70% confirms obstruction.
2. Imaging Studies:
   • Chest X-ray: Hyperinflation, flattened diaphragm in COPD.
   • High-resolution CT: Bronchiectasis or emphysema.
3. Blood Tests:
   • Alpha-1 antitrypsin levels in young patients with COPD.
   • IgE levels or eosinophil count in asthma.

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Management

Lifestyle Changes:

• Smoking cessation is critical to slow disease progression.
• Avoid triggers (allergens, air pollution).
• Regular physical activity to improve lung capacity.

Medications:

• Bronchodilators:
  • Beta-agonists (e.g., albuterol).
  • Anticholinergics (e.g., ipratropium).
• Inhaled Corticosteroids (ICS):
  • Reduce inflammation in asthma and severe COPD.
• Combination Therapy: Long-acting beta-agonists (LABA) with ICS for moderate to severe cases.
• Mucolytics and Antibiotics: For bronchiectasis or cystic fibrosis.

Advanced Therapies:

• Oxygen Therapy: For severe COPD with hypoxemia.
• Surgical Interventions:
  • Lung volume reduction surgery (COPD).
  • Lung transplantation (end-stage CF or COPD).

Rehabilitation:

• Pulmonary rehabilitation programs to improve exercise tolerance and quality of life.

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Prognosis

• Depends on the underlying condition, severity, and response to treatment.
• Early diagnosis and intervention can slow progression and improve quality of life.

Would you like to explore treatment strategies, a specific condition, or diagnostic tools in more depth? Contact NOVA Pulmonary Critical Care and Sleep Associates to learn more.