COPD Flashcards
Define
Progressive disorder of the lower respiratory tract characterised by airway obstruction with little or no reversibility
Includes chronic bronchitis and emphysema:
- Clinical definition of chronic bronchitis: cough and sputum production on most days for 3 months of 2 successive years.
Symptoms improve with smoking cessation
Narrowed airways due to bronchitis and ↑mucus - Emphysema: Pathological diagnosis of permanent destructive enlargement of air spaces distal to the terminal bronchioles
Epidemiology
Very common, prevalence up to 8%
Favoured by:
- Age of onset >35 years
- Males
- Smoking/pollution
Causes
- Bronchial and alveolar damage is caused by environmental toxins (e.g. cigarette smoke)
- RARE CAUSE: a1 antitrypsin deficiency
Chronic Bronchitis
- Narrowing of the airways resulting in 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)
Symptoms
Chronic cough
Sputum production
Breathlessness
Wheeze
Reduced exercise tolerance
Signs
Inspection
- Respiratory distress: tachypnoea
- Use of accessory muscles
- Barrel-shaped over-inflated chest
- Decreased cricosternal distance
- Cyanosis
Palpation:
- decreased expansion
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. They are often caused by secretions in larger airways or obstructions
- Sometimes crepitations
Signs of CO2 Retention
- Bounding pulse
- Warm peripheries
- Asterixis
LATE STAGES: signs of right heart failure (cor pulmonale)
Right ventricular heave
Raised JVP
Ankle oedema
Investigations
- Spirometry and Pulmonary Function Tests
- Shows 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 silhouette
- Bloods
- FBC - increased Hb and haematocrit due to secondary polycythaemia
- ABG - may show hypoxia, normal/raised PCO2
- ECG and Echocardiogram - check for cor pulmonale
- Sputum and Blood Cultures - useful in acute infective exacerbations
- a1 antitrypsin levels - useful in young patients who have never smoked
Management
- STOP SMOKING
- Bronchodilators
- Short-acting beta-2 agonists (e.g. salbutamol)
- Anticholinergics (e.g. ipratropium bromide)
- Inhaled corticosteroids (beclamethasone)
- Long-acting beta-2 agonists (if > 2 exacerbations per year)
- Steroids
Regular oral steroids should be avoided if possible
- Pulmonary rehabilitation
- Oxygen therapy (Only for those who stop smoking)
Treatment of Acute Exacerbations
- 24% O2 via Venturi mask
- Increase slowly if no hypercapnia and still hypoxic (do an ABG)
- Corticosteroids
- Start empirical antibiotic therapy if evidence of infection
- Respiratory physiotherapy to clear sputum
- Non-invasive ventilation may be necessary in severe cases
- Prevention of infective exacerbations: pneumococcal and influenza vaccination
Complications
Acute respiratory failure
Infections
Pulmonary hypertension
Right heart failure
Pneumothorax (secondary to bullae rupture)
Secondary polycythaemia
Prognosis
High morbidity
3-year survival of 90% if < 60 yrs, FEV1 > 50% predicted
3-year survival of 75% if > 60 yrs, FEV1: 40-49% predicted
