Respiratory Failure

Question 1

What is Type 1 respiratory failure?

Answer 1

• Hypoxaemia (PaO2 < 60 mmHg) generally arising from V/Q mismatch/imparied gas exchange

Question 2

What is Type 2 respiratory failure?

Answer 2

• Hypercapnia (>50 mmHg PaCO2) with hypoxia generally due to reduced alveolar ventilation

Question 3

What are the causes of Type 1 respiratory failure?

Answer 3

• V/Q mismatch
  
  • Pneumonia
  • APO
  • PE
  • Asthma
  • Emphysema
  • Pulmonary fibrosis
  • ARDS

Question 4

What are the causes of Type 2 respiratory failure?

Answer 4

• Reduced alveolar ventilation
  
  • Asthma/COPD/pneumonia/OSA
  • Reduced resp drive (drug/trauma)
  • Neuromuscular disease/chest wall abnormalities

Question 5

What general investigations might be needed in a patient suspected to be in respiratory failure?

Answer 5

• ABGs
• FBE (anaemia)
• CXR
• CT/CTPA/VQ
• Lung/sleep function studies

Question 6

What are the management prinicples of a patient with suspected respiratory failure?

Answer 6

• Treat the underlying cause
• Maintain oxygen saturation
• Decrease WOB