COPD

COPD 1COPD 2

Risk factors:

COPD 3

  • Tobacco smoking (90% of COPD)
  • a1-Antitrpsin deficiency

 

Diagnosis:

  • ABG: chronic pCO2 retention, ↓ pO2, “60-60”
  • CBC: ↑ hematocrit (bc of chronic hypoxia)COPD 4
  • Measure a1-Antitrpsin levels if hx <50 yo

PFTs:

  • ↓ FEV1 and ↓ FEV1\FVC
  • ↑ TLC, RV, and FRC -> air trapping
  • ↓ DLCO in case of emphysema

CXR:

  • Emphysema: hyperinflation, flattened diaphragm, enlarged retrosternal space, diminished vascular markings (hyper-lucent lungs), ↑ AP diameter
  • Useful in acute exacerbations -> rule out pneumonia and pneumothorax

ECG:

  • Changes due to cor pulmonale: right atrial enlargement (peaked P wave = “P pulmonale”), right ventricular hypertrophy (right axis deviation)
  • Other changes:
  1. RBBB (due to RVH),
  2. A fib, multifocal atrial tachycardia (MAT): rapid, irregular atrial tachycardia w\ at least 3 distinct P wave morphologies (associated w\ ↑ mortality COPD)
  • Echo: right atrial\ventricular hypertrophy, pulmn HTN

 

Treatment:

  • Improves mortality: smoking cessation, oxygen, vaccination
  • Smoking cessation: slows the rate of FEV1 decline, but doesn’t completely reverse. Prolongs survival. Resp sx improve after 1 yr
  • Combinations of B-agonists (albuterol) and anti-cholinergics (tiotrpium or ipratropium) -> most effective
  • Inhaled corticosteroid (budesonide, fluticasone): may slows FEV1 decrease overtime. (systemic glucocorticoids are only used for acute exacerbations)
  • Theophylline (controversial) -> may improve mucociliary clearance + central resp drive. Refractory COPD.
  • Oxygen therapy: improves survival + QOL
  • Vaccinations: against S. pneumonaie + influenza to COPD pts > 65 yo (or younger if ds is severe)
  • Antibiotics: in acute exacerbations, change in sputum, worsening SOB
  • Surgery: lung resection, lung transplantation

 

 

Treatment for acute exacerbation:  (↑SOB, sputum, cough)

  • 1st: B-agonist and\or anticholinergic (ipratropium)
  • Systemic corticosteroids: for pts requiring hospitalizations -> IV methylprednisolone, taper w\ oral prednisone
  • Antibiotics (broad spectrum), despite normal CXR
  • Oxygen: nasal cannula\face mask -> keep at 90-93% (if >93% -> V\Q mismatch + loss of hypoxemic resp drive + Haldane effect)
  • Noninvasive positive pressure ventilation (BIPAP or CPAP)
  • If ↑ RR, PaCO2, acidosis -> intubate and mechanical ventilate

 

Combined assessment of COPD: 

CAT score (assessment of symptom severity):

  • < 10: less symptoms
  • ≥ 10: more symptoms

FEV1 (GOLD classification):

  • > 50%: low risk
  • ≤ 50%: high risk

Exacerbations (hx of hospitalization):

  • < 2: low risk
  • ≥ 2: high risk

 

Prognosis:

BODE: 10-point scale

  • BMI: <21 (+1)
  • Obstruction (FEV1): 50-64% (+1), 36-49% (+2), <35 (+3)
  • Dyspnea (MRC scale): walking level (+1), 100 yards (+2), w\ ADL (+3)
  • Exercise capacity (6 min walk): 250-349 m (+1), 150-248 m (+2), <149 (+3)

 


Download the PDF version: here


References: 

  • Pocket medicine
  • Step up to medicine
  • Toronto notes
  • The Johns Hopkins Internal Medicine Board Review

 

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