Acute Exacerbation of COPD Flashcards
What can cause exacerbations of COPD?
- Infective organisms
- Allergens
- Pneumothorax
- Expansion of large bullae
- Sputum retention
- Temperature change
- Co-morbidities
What bacteria can cause COPD exacerbation?
- H. influenzae
- S. pneumoniae
- M. catarrhalis
What viruses can cause acute exacerbations of COPD?
- Rhinovirus
- Influenza
- Parainfluenza
- Coronavirus
- Metapneumonovirus
- Adenovirus
What are features of acute COPD exacerbation?
Increase in symptoms:
- Cough
- Sputum volume +/- purulence
- Dyspnoea
- Wheeze
- Chest tightness
- Peripheral oedema
What is the pathophysiology of acute AECOPD?
Increased airway resistance due to bronchospasm, mucosal oedema and sputum production. This worsens expiratory airflow, therefore expiration takes longer. Shallow rapid breathing further limits time for expiration - this promotes dynamic hyperinflation, leading to mechanical compromise.
What investigations would you do if someone presented with an acute exacerbation of COPD?
- Observations - pulse oximetry
- Bloods - FBC, CRP, U+E’s, ABG
- Blood glucose
- ECG
- CXR
- Peak flows
- Blood cultures - if febrile
- Sputum microscopy
If somone with an acute exacerbation of COPD was found to be hypoxic, what would you do?
Give controlled 24-28% oxygen via venturi mask - aim for sats of 88-92%
Why do you want to aim for an oxygen saturation of 88-92% in those with COPD?
Chronic hypercapnia leads to desensitisation of central chemoreceptors, which means that when oxygen is given, the drop in carbon dioxide decreases respiratory drive. At levels where oxygen is at what is regarded as normal (94-98%), reduced PCO2 in those with COPD will suppress respiratory drive, leading to hypercapnia and respiratory acidosis
What antibiotics would you use in someone with infective exacerbation of COPD?
1st line - Amoxicillin
2nd line - Clarythromycin/Doxycycline
Severe
-
1st line
- Co-trimoxazole (IV), then switch to
- Co-trimoxazole/Doxycyline (Oral)
-
2nd line
- Clarythromycin (IV), then switch to oral
If someone with an infective exacerbation of COPD presented with no pnemonic signs on CXR, what antibiotic would you give them?
Doxycycline
If someone who came in with acute exacerbation of COPD presented with pneumonic signs on CXR, what antibiotics would you use?
As per pneumonia treatment
What mnemonic can you use to think about the treatment of COPD exacerbation?
I AM POSH
- Ipratroprium bromide (500mcg) nebulised
- Aminophylline infusion
- Chest Physiotherapy
- Oxygen (24-28% via Venturi mask)
- Salbutamol (2.5-5mg) nebulised
- Hydrocortisone (200mg) IV AND Prednisolone (30mg) PO
What oxygen concentration would you want to give someone with COPD through a venturi mask?
24-28%
How long after initial therapy would you do an ABG to determine need for further therapy?
When would you consider putting someone on BiPAP?
http://www.oscestop.com/Asthma_COPD_acute.pdf
If you cannot get enough oxygen into them to maintain 88-92% without decreasing resp. drive and causing hypercapnic acidosis