Risk factors:
- Tobacco smoking (90% of COPD)
- a1-Antitrpsin deficiency
Diagnosis:
- ABG: chronic pCO2 retention, ↓ pO2, “60-60”
- CBC: ↑ hematocrit (bc of chronic hypoxia)
- 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:
- RBBB (due to RVH),
- 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:Â
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:Â
- Pocket medicine
- Step up to medicine
- Toronto notes
- The Johns Hopkins Internal Medicine Board Review