COPD Flashcards
Define COPD summarising its epidemiology
Definition: COPD- Is a chronic, progressive lung disorder characterised by airflow obstruction, with the following:
- Chronic bronchitis: Chronic cough and sputum production on most days for at least 3 months per year year over 2 consecutive years
- Emphysema:
Pathological diagnosis of permanent destructive enlargement of air spaces distal to the terminal bronchioles
Epidemiology:
- VERY COMMON (8% prevalence)
- Presents in middle age or later
- More common in males- this may change because there has been a rise in female smokers
Explain the aetiology/risk factors of COPD
- Bronchial and alveolar damage is caused by environmental toxins (e.g. cigarette smoke)
- RARE cause: Alpha 1 antitrypsin deficiency. Though this is rare, consider it in young patients, who have never smoked, presenting with COPD type symptoms (and may have accompanying symptoms of cirrhosis)
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 > 1cm)
Describe the history/presenting symptoms of COPD
- Chronic cough
- Sputum production
- Breathlessness
- Wheeze
- Reduced exercise tolerance
What are the signs of COPD upon physical examination?
Inspection:
- Respiratory distress
- Use of accessory muscles
- Barrel- shaped over-inflated chest
- Decreased cricosternal distance
- Cyanosis
Percussion:
- Hyper-resonant
- 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
What are the 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
What investigations are used to identify COPD?
1st line 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
Other investigations to consider:
Sputum and Blood Cultures:
- Useful in acute infective exacerbations
Alpha1 antitrypsin levels:
- Useful in young patients who have never smoked
How is COPD managed generally?
STOP SMOKING
Bronchodilators:
- Short acting beta-2 agonists e.g. Salbutamol
- Anticholinergics (e.g. Ipratropium bromide)
- Long acting beta-2 agonists (if >2 exacerbations per year)
Steroids:
- Inhaled beclomethasone- considered in all patients with FEV1 < 50% of predicted OR > 2 exacerbations per year
- Regular oral steroids should be avoided if possible
Pulmonary rehabilitation
Oxygen therapy:
- Only for those who stop smoking
- Indicated if:
- PaO2 < 7.3 kPa on air during a period of clinical stability- PaO2: 7.3-8 kPa and signs of secondary polycythaemia, nocturnal hypoxaemia, peripheral oedema or pulmonary hypertension.
How are acute exacerbations managed?
Treatment of acute Exacerbations:
- 1st line:
- short-acting bronchodilator
- 24% O2 via Venturi mask - Adjunct:
- systemic corticosteroid
- transition to inhaled corticosteroid
- airway clearance techniques (physio)
- supplemental oxygen
- Non- invasive ventilation may be necessary in sever cases
Summarise the prognosis for patients with COPD
- High morbidity
- 3- year survival of 90% if < 60 yrs, FEV1 > 50% predicted
- 3- year survival 75% if > 60 yrs, FEV1: 40-49%
