What can cause exacerbations of COPD?
- Infective organisms
- Expansion of large bullae
- Sputum retention
- Temperature change
What bacteria can cause COPD exacerbation?
- H. influenzae
- S. pneumoniae
- M. catarrhalis
What viruses can cause acute exacerbations of COPD?
What are features of acute COPD exacerbation?
Increase in symptoms:
- Sputum volume +/- purulence
- 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?
- Bedside - NEWS scores, ECG, Peak flows
- Bloods - FBC, CRP, U+E's, ABG, Blood glucose, BCs (if febrile)
- Imaging - CXR,
- Orifices - Suptum culture
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
- Co-trimoxazole (IV), then switch to
- Co-trimoxazole/Doxycyline (Oral)
- 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?
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?
O A SHIT PB
- Oxygen (24-28% via Venturi mask)
- Antibiotics - as per local guidelines
- Salbutamol (2.5-5mg) nebulised
- Hydrocortisone (200mg) IV AND Prednisolone (30mg) PO
- Ipratroprium bromide (500mcg) nebulised
- Theophylline/Aminophylline infusion
- Physiotherapy -
- Bipap - consider if becoming more acidotic despite intervention
What oxygen concentration would you want to give someone with COPD through a venturi mask?
How long after initial therapy would you do an ABG to determine need for further therapy?
When would you consider putting someone on BiPAP?
If you cannot get enough oxygen into them to maintain 88-92% without decreasing resp. drive and causing hypercapnic acidosis
What dose of salbutamol nebulisers would you give in an acute asthma attack, and at what rate?
2.5-5mg back to back nebulisers at 5-10 mg/hour
What dose of IV hydrocortisone would you give in an acute asthma attack, and at what frequency?
200mg - 6 hourly infusions
What dose of oral prednisolone would you give someone with an acute asthma attack, and how often would you give it?
30mg Orally - once daily
Why can you give oral prednisolone at longer intervals than IV hydrocortisone?
Prednisolone has a longer half life
What dose of ipratropium Bromide Nebuliser would you give someone having an acute asthma attack?
0.5 mg (500mcg) nebulisers - 4-6 hourly
If someone with fixed bronchospasm (unchanged after salbutamol/ipratroium nebs and steroid treatment) what would you consider giving?
IV Aminophylline and B2 agonist
What is the first line treatment of choice for those with type II resp failure with COPD exacerbation for treating hypoxia?
Why would you do U+E's as part of investigation in AECOPD?
Look for dehydration and renal failure
Why would you perform FBC as part of investigations for AECOPD?
Look for leucocytosis, anaemia or polycythaemia (chronic respiratory failure)
Why would you perform pulse oximetry and ABG's as investigations in AECOPD?
Assess degree of respiratory failure and pH, and guide appropriate O2 treatment
What is a septic screen?
- Sputum culture
- Blood cultures
- Stool cultures
- Urine cultures
Why might you perform peak flows in AECOPD?
To compare to patients baseline
When would you consider NIV/BiPaP/Intubation in AECOPD?
If no response to medical treatment and in Type II respiratory failure (no response = RR >30 or pH < 7.35, or rising PaCO2)
What can be used if NIV is not available?
Doxapram - respiratory stimulant
What is different in terms of steroid treatment between AECOPD and acute asthma treatment?
Doses - Hydrocortisone is 200mg IV in AECOPD, and prednisolone is 30 mg PO