Acute Exacerbations of COPD Flashcards
What is a COPD exacerbation?
An acute worsening of respiratory symptoms (caused by even greater airway inflammation and narrowing) that result in additional therapy
What are causes of COPD exacerbations?
Bacteria, viruses, pollutants
What viruses can lead to COPD exacerbations (30%)?
- Rhinovirus
- Influenza
- Parainfluenza
- Respiratory syncytial virus (RSV)
- Human metapneumovirus
- Coronavirus
- Adenovirus
What are common bacterial causes of COPD exacerbations?
- Haemophilus influenzae
- Moraxella catarrhalis
- Streptococcus pneumoniae
- Staphylococcus aureus
What is a bacterial cause common in severe COPD exacerbations?
Pseudomonas aeruginosa
What are atypical bacterial causes of COPD exacerbations?
Chlamydia pneumoniae, mycoplasma pneumoniae, legionella
What are the clinical symptoms of COPD exacerbations?
- Increased breathlessness
- Increased cough and purulent sputum production
- Change in colour and/or tenacity of sputum
- Wheeze
- Runny nose and shivers
- Mild ankle swelling/pitting oedema
- Confusion
- Impaired daily activities
How would you treat a mild COPD exacerbation?
Short acting bronchodilators (SABDs) only
How would you treat a moderate COPD exacerbation?
SABDs + antibiotics and/or OCS
How would you treat a severe COPD exacerbation?
Hospitalisation
What is classified as frequent COPD exacerbations?
2 or more a year
What are frequent COPD exacerbations associated with?
1) Higher mortality
2) More rapid decline in lung function
3) Poorer QoL
4) Greater airway inflammation
What are the cardiovascular effects of a COPD exacerbation?
- Increased pulmonary arterial pressure
- Decreased RV preload
- Increased LV preload
What can the increased ventilatory drive of a COPD exacerbation lead to?
Decreased PaO2, increased PaCO2 and decreased pH (respiratory acidosis - T2RF)
What are the signs of acute exacerbation of COPD?
- Higher temperature (febrile)
- Tachypnoea
- Tachycardia
- Low saturations even on oxygen
- Polyphonic wheeze
What investigations might you do on someone with an acute COPD exacerbation?
Bloods, ECG, nasal swab and sputum culture, CXR, ABG (to check for T2RF as he is hypoxic)
What would bloods of someone with COPD exacerbation show?
High WCC, neutrophils and CRP and maybe low urea (dehydration)
What would a CXR of a patient with COPD without pneumonia look like?
Hyperinflated, clear lung fields
Why is there no focal abnormality on a CXR of someone with a COPD exacerbation?
Bc a COPD exacerbation is an airway phenomenon (tracheitis, bronchitis or alveolitis) so won’t see consolidation on a CXR
What would the ABG of someone with a COPD exacerbation likely show?
Type 2 respiratory failure → (compensated if bicarbonate is high) respiratory acidosis
What is hypoxia?
PaO2 < 8
What is hypercapnia?
PaCO2 > 6
What is the worst impact of a COPD exacerbation?
Lung attack
What is the most common cause of a COPD exacerbation?
Respiratory infection
What leads to worsening breathlessness (frightening and disabling) in a COPD exacerbation?
- Increased airway inflammation
- Increased mucus production
- Gas trapping
- Worsening of co-morbidities on background of limited reserve e.g. effect of steroids on diabetes
How do you define a COPD exacerbation in terms of symptoms?
- Any 2 of: increased dyspnoea, sputum volume or sputum purulence
- OR any one of the above and any one of: increased cough, wheeze, sore throat or cold
What pollutants can cause COPD exacerbations?
Ozone, particulates, sulfer dioxide, nitrogen dioxide
What is associated with the presence of bacteria in the sputum and so should be treated with antibiotics?
Sputum purulence
When is the effect of pollutants worse?
In warmer weather
Why is pus green in bacterial infection>
Bc polymorphs release myeloperoxidase (green) which is how they engulf and destroy bacteria
When is viral-bacterial co-infection (25%) more likely and what does it lead to?
In winter months → greater fall in lung function and longer hospital admission
What are differential diagnoses of COPD exacerbation?
1) CAP (CXR shows consolidation) → if CXR shows anything abnormal, not just plain COPD exacerbation so need to treat cause
2) PE
3) PTX
4) Acute coronary event
5) Congestive cardiac failure
