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?
What is the general management of COPD?
- Smoking cessation advice: including offering nicotine replacement therapy, varenicline or bupropion
- annual influenza vaccination
- one-off pneumococcal vaccination
- pulmonary rehabilitation to all people who view themselves as functionally disabled by COPD (usually Medical Research Council [MRC] grade 3 and above)
What is 1st line the treatment of COPD?
1st line = a short-acting beta2-agonist (SABA) or short-acting muscarinic antagonist (SAMA)
Note - this is for patients with minimal symptoms, preserved lung function (FEV1 > 80% predicted) and few (if any) exacerbations, a SAMA or SABA should be prescribed as monotherapy (without the need for any other inhaled treatment)
For patients who remain breathless or have exacerbations despite 1st line treatment of COPD, what does the next steps in treatment choice depend on ?
Whether the patient has ‘asthmatic features/features suggesting steroid responsiveness’ or not
What different features/criteria can be used to determine if a COPD patient has asthmatic features suggesting steroid responsiveness or not ?
- Any previous, secure diagnosis of asthma or of atopy
- a higher blood eosinophil count (blood eosinophilia > 4%) - note that NICE recommend a full blood count for all patients as part of the work-up
- substantial variation in FEV1 over time (at least 400 ml)
- substantial diurnal variation in peak expiratory flow (at least 20%)
Note - in lectures this overlap of the 2 syndromes if referred to as ACO (asthma COPD overlap syndrome)
What is the further treatment of COPD after 1st line treatment if they have No asthmatic features/features suggesting steroid responsiveness?
- 1st line = add a long-acting beta2-agonist (LABA) + long-acting muscarinic antagonist (LAMA) + SABA (if already taking a SAMA stop and switch to SABA)
- 2nd line = consider adding in ICS
Guidelines and licensing authorities generally indicate that co-administration of ICS should be considered in patients with FEV1 < 60% predicted (in a combination inhaler with a LABA) who experience frequent (≥2 per year) exacerbations
What is the further treatment of COPD after 1st line treatment if they have asthmatic features suggesting steroid responsiveness?
- 1st line = LABA + inhaled corticosteroid (ICS) (+ SAMA or SABA)
- 2nd line = if patients remain breathless or have exacerbations offer triple therapy i.e. LAMA + LABA + ICS (if already taking a SAMA, discontinue and switch to a SABA)
What are the signs of an acute exacerbation of COPD?
- increase in dyspnoea, cough, wheeze
- there may be an increase in sputum suggestive of an infective cause
- patients may be hypoxic and, in some cases, have acute confusion
What is the treatment of acute exacerbations of COPD?
- Give oxygen use a 28% Venturi mask at 4 l/min and aim for an oxygen saturation of 88-92%
- 1st line = Increase frequency of bronchodilator use and consider giving via a nebuliser (salbutamol & ipratropium) + Give prednisolone daily for 5 days
- Review if they need to be given antibiotics
What Ix’s should be carried out in somoene with a possible exacerbation of COPD ?
- ABG’s
- CXR
- ECG
- Baseline bloods including CRP
Why is it important to perform a CXR in someone with suspected exacerbation of COPD ?
To look for signs of pneumonia, and because they may have a pneumothorax which would influence their Mx.
When should antibiotics be given in an acute exacerbation of COPD and what are the 1st & 2nd line choices:
Give antibiotics if ↑ sputum purulence. If no ↑ sputum purulence, then no antibiotics unless consolidation on CXR or signs of pneumonia
- 1st line = amoxicillin
- 2nd line = doxycycline
What is the main causative organism of infective exacerbations of COPD?
- Haemophilus influenzae (most common cause)
Even if a patient has COPD if they are critically ill (anaphylaxis, shock etc) how should oxygen be delivered?
- It should be given via a reservoir mask at 15 l/min (high flow). Hypoxia kills.
Go over this summary slide
