COPD

Chronic Obstructive Pulmonary Disease

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Chronic Obstructive Pulmonary Disease, Chronic Obstructive Lung Disease, COPD

  • Epidemiology
  1. COPD Incidence in U.S.: 15 Million patients
  2. COPD affects 6% of adults in U.S.
  3. COPD results in 126,000 deaths per year in U.S. (4th leading cause of death)
  • Risk Factors
  1. Age over 35 years old (esp. >45 years old)
  2. Cigarette smoking and Exposure to Tobacco smoke
    1. Active, continuous smoking confers COPD absolute risk of 25%
    2. Tobacco use >40 pack years has LR+ 7.3
    3. Tobacco Abuse is responsible for >80% of COPD cases
    4. Women have a greater degree of lung damage and Impairment for a given exposure
      1. Increased hyper-responsiveness to exogenous toxins
      2. Chapman (2004) Clin Chest Med 25:331-41 [PubMed]
  3. Domestic or Occupational pollutants
    1. See Irritant-induced Asthma
    2. See Allergic Occupational Asthma
    3. Mineral Dust (e.g. Mining of coal or hard rock, Concrete manufacture, Silica)
    4. Organic Dust (e.g. Cotton, hemp, grains)
    5. Gas Fumes (e.g. heavy metals, welding, sulfur dioxide, isocyanates)
    6. Boschetto (2006) J Occup Med Toxicol 1:11 [PubMed]
  4. Recurrent respiratory infections (especially Infancy)
  5. Atopic Patients
  6. Family History of COPD
  7. Alpha-1-Antitrypsin Deficiency
    1. Suspect in patients under age 45 without other risk
    2. Other protease deficiencies may also be related
  • Definition
  • Chronic Obstructive Pulmonary Disease
  1. See Emphysema and Chronic Bronchitis
  2. Progressive chronic airflow obstruction
  3. Irreversibility distinguishes COPD from Asthma
  4. Types
    1. Chronic Bronchitis ("Blue Bloater")
    2. Emphysema ("Pink Puffer")
  • Diagnosis
  • Symptoms
  1. Risk factors (see above) AND
  2. At least one of the following
    1. Dyspnea at rest or Dyspnea on exertion
    2. Chronic Cough with or without Sputum production
    3. Wheezing
  1. See Emphysema and Chronic Bronchitis
  2. GOLD criteria
    1. Post-Bronchodilator FEV1 to FVC ratio: 0.7
  3. GOLD and NICE Severity stratification
    1. Mild: FEV1 80% or greater than predicted
    2. Moderate: FEV1 <80% of predicted
    3. Severe: FEV1 <50% of predicted
    4. Very Severe: FEV1 <30% of predicted
  4. Other findings
    1. DLCO diminished in Emphysema
    2. Increased Total Lung Capacity
    3. Increased Residual Volume
    4. Peak Flow <350 L/min
  • Staging
  • Labs
  1. See Emphysema and Chronic Bronchitis
  2. Arterial Blood Gas
    1. Indicated in severe or very severe COPD
  3. Alpha-1-antitrypsin indications
    1. Age under 45 years
    2. No prior smoking history
    3. Family History of Alpha-1-Antitrypsin Deficiency
    4. Comorbid Cirrhosis
  1. See Emphysema and Chronic Bronchitis
  2. Lung hyperinflation
  3. Diaphragm flattening
  4. Distal pulmonary vessel tapering
  5. Increased basilar markings in Chronic Bronchitis
  • Differential Diagnosis
  1. Asthma
  2. Bronchiectasis (associated with recurrent Pneumonia)
  3. Bronchiolitis Obliterans
  4. Diffuse panbronchiolitis (associated with Immunodeficiency in asian descent)
  5. Congestive Heart Failure
  6. Lung Cancer
  7. Cystic Fibrosis
  8. Interstitial Lung Disease (e.g. Idiopathic Pulmonary Fibrosis, Sarcoidosis)
  9. Tuberculosis
  10. Kyphoscoliosis and other chest wall disorders (e.g. severe Pectus Excavatum)
  11. Pulmonary Arterial Hypertension
  12. Upper airway obstruction (tracheal stenosis, tracheal mass)
  13. Vocal Cord Dysfunction
  • Complications
  1. Severe Chronic Dyspnea (66%)
  2. Severe total body pain (25%)
  • Screening
  1. COPD Screening is not recommended in asymptomatic patients (ACP, GOLD, AAFP, USPTF)
  2. Prior proposed recommendations for screening: Spirometry in 10 pack year smokers over age 40 years
    1. Zielinski (2001) Chest 119:731-6 [PubMed]
  • Prognosis
  1. See BODE Index
  2. Factors associated with a worse prognosis (mortality)
    1. FEV1 < 750 cc (<50% of predicted)
    2. Rapid FEV1 decline
    3. Lower diffusion capacity
    4. Hypoxia with PaO2 <55 mmHg
    5. Older patients
    6. Continued Tobacco Abuse
    7. Hypercapnia with PaCO2 > 45 mmHg
    8. Right-sided Heart Failure
    9. Malnutrition
    10. Resting Tachycardia
  3. Factors associated with a better prognosis
    1. Post-Bronchodilator FEV1 shows reversible component
    2. Atopy history