respiratory failure

Last reviewed 01/2018

Respiratory failure occurs when pulmonary gas exchange is sufficiently impaired to cause hypoxaemia with or without hypercarbia.

Respiratory failure is present if PaO2 is less than 8 kPa - 60 mmHg.

It is sub-classified into one of two types of respiratory failure based on the level of PaCO2:

  • type 1 respiratory failure:
    • PaCO2 is less than 6.5 kPa
    • PaO2 less than 8 kPa

  • type 2 respiratory failure:
    • PaCO2 is greater than 6.5 kPa
    • PaO2 is less than 8 kPa