Chronic Obstructive Pulmonary Disease (COPD) Flashcards
Define COPD
Chronic Progressive lung disorder characterised by airflow obstruction, with@
- Chronic bronchitis: chronic cough and sputum production most days for at least 2 months/yr or 2 consecutive yrs
- Emphysema: pathological diagnosis of permanent destruction
Explain the Risk factors of COPD?
- Environmental toxins (e.g. cigarette smoke) cause bronchial and alveolar damage
- Rare α1-antitrypsin deficiency (consider in young pts, may have accompanying cirrhosis symptoms)
What is the Aetiology of COPD?
Chronic Bronchitis:
- narrowing of airways -> bronchiole inflammation (bronchiolitis)
- bronchial mucosal oedema
- mucous hypersecretion
- squamous metaplasia
Emphysema:
- destruction and enlargement of alveoli
- leads to loss of elasticity that keeps small airways open in expiration
- progressively larger spaces develop called bullae (diameter >1 cm)
What is the Epidemiology of COPD?
- Very common (8% prevalence)
- Presents in middle age or later
- More common in males - may change due to rise in female smokers
What are the presenting symptoms of COPD?
- Chronic cough
- Sputum production
- Breathlessness
- Wheeze
- Reduced exercise tolerance
What are the signs of COPD?
Inspection: - respiratory distress - use of accessory muscles - barrel-shaped over-inflated chest - decreased cricosternal distance - cyanosis Percussion: - hyper-resonant chest - loss of liver and cardiac dullness Auscultation: - quiet breath sounds - prolonged expiration - wheeze - rhonchi - rattling, continuous and low-pitched breath sounds that sounds a bit like snoring. Often caused by secretions in larger airways/obstructions - sometimes creptitations Signs of CO2 retention: - bounding pulse - warm peripheries - asterix - late stages: signs of right heart failure (cor Pulmonale) e.g. right ventricular heave, raised JVP, ankle oedema
What are the appropriate Investigations for COPD?
Spirometry and Pulmonary Function tests:
- show obstructive picture
- reduced PEFR
- reduced FEV1/FVC
- increased lung volumes
- decreased carbon monoxide gas transfer coefficient
CXR
- may appear normal
- hyperinflation (>6 anterior ribs, flattened diaphragm)
- reduced peripheral lung markings
- elongated cardiac shadowing
Bloods
- FBC - increased Hb and haematocrit from secondary polycythaemia
- ABG - may show hypoxia, normal/raised CO2
- ECG and Echo - check for cor Pulmonale
- sputum/blood cultures - infective exacerbations
- α1-antitrypsin levels - young, non-smokers
Generate a Management plan for COPD
- Stop Smoking
- Bronchodilators:
- short-acting β2 agonists (e.g. salbutamol)
- anticholinergics (e.g. ipratropium bromide)
- long-acting β2 agonists (if >2 exacerbations a yr)
- Steroids:
- inhaled beclamethasone: considered in all patients with FEV1 < 50% of predicted OR >2 exacerbations/yr
- regular oral steroids should be avoided if possible
- Pulmonary rehabilitation
- Oxygen Therapy:
- only if they stop smoking
- indicated if: PaO2 <7.3kPa on air when clinically unstable or PaO2 7.3-8kPa and signs of secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema or pulmonary hypertension
What is the management plan for Acute exacerbations?
- 24% O2 via venturi mask
- increase slowly if no hypercapnia and still hypoxic (do an ABG)
- corticosteroids
- start empirical antibiotic therapy is evidence of infection
- respiratory physiotherapy to clear sputum
- non-invasive ventilation may be necessary in severe cases
- prevention of infective exacerbations e.g. pneumococcal and influenza vaccination
Identify the possible complications of COPD
- Acute respiratory failure
- Infections
- Pulmonary hypertension
- Right heart failure
- Pneumothorax (secondary to ruptured bullae)
- Secondary polycythaemia
Summarise the prognosis of COPD
- High morbidity
- 3-year survival of 90% if <60yrs, FEV1 >50% predicted
- 3-year survival of 75% if <60yrs, FEV1 40-49% predicted
