COPD Flashcards
Define what COPD is
- It is a common progressive disorder characterised by airway obstruction (FEV1 < 80% & FEV1/FVC ratio < 0.7) with little or no reversibility.
- It encompasses both chronic bronchitis and emphysema
What is COPD characterised by ?
- Characterised by airflow reduction that is in some patients partially reversible (with bronchodilators) but which progressively worsens as assessed by FEV1 and exacerbation of symptoms including cough and mucus production
Define what chronic bronchitis is
- It is a clinical term defined clinically as cough and sputum production on most days for 3 months of 2 successive years.
Define what emphysema is
- This is a pathological term defined histologically as enlarged air spaces distal to terminal bronchioles, with destruction of alveolar walls.
What are the potential causes of COPD?
- Smoking! – 90% of cases
- Occupational exposure - cadmium (used in smelting), coal, cotton, cement, grain
- Genetics - alpha1-antitrypsin deficiency
What are the general symptoms of COPD?
- Chronic cough: often productive (sputum production)
- Dyspnoea
- Wheeze
What are the general signs of COPD?
- Tachypnoea – use of accessory muscles of respiration
- Hyperinflation
- Decreased cricosternal distance (<3cm)
- Decreased chest expansion
- Hyperresonant percussion note
- Quiet breath sounds
- Wheeze
- Cyanosis
- In severe cases, right-sided heart failure may develop resulting in peripheral oedema
What features are generally suggestive someone has COPD rather than asthma:
- Age of onset > 35
- Smoker (active or passive)
- Or pollution related
- Minimal diurnal or day-to-day FEV1 variation
How should you view COPD patients?
- As being on a spectrum with one side being chronic bronchitis and the other side being emphysema
What are the signs/symptoms which would suggest more of a chronic bronchitis or emphysema aspect to someone’s COPD?
- Pink puffers have near normal PaO2 & a normal or low PaCO2. They are breathless but not cyanosed. They may progress to type I resp failure.
- Blue bloaters have a low PaO2 & a high PaCO2. They are cyanosed but not breathless. They may go on to develop cor pulmonale. They’re respiratory centres are insensitive to CO2 and they rely on hypoxic drive to maintain respiratory effort è supplementary O2 should be given with care (these are the ones a venturi mask is key for)
What complications of COPD may arise?
- Acute exacerbations +/- infection
- Polycythaemia
- Respiratory failure
- Cor pulmonale (oedema, increased JVP)
- Pneumothorax
- Lung carcinoma
What should be considered as the potential diagnosis in patients over 35 years of age who are smokers or ex-smokers and have symptoms such as exertional breathlessness, chronic cough or regular sputum production?
COPD
What investigations should be done in someone with suspected COPD?
- CXR – hyperinflation (> 6 anterior ribs seen above hemidiaphragm), bullae, flat hemidiaphragm. Also, important to exclude lung cancer or other pathologies e.g. TB, bronchiectasis & HF
- FBC: to investigate for secondary polycythaemia caused by COPD, or anaemia
What is the key investigation used to diagnose COPD?
- Spirometry (measured post-bronchodilator administration) – confirmation made if obstructive pattern seen – FEV1/FVC ratio < 70%
How is the severity of COPD graded?