Oxygen therapy


The British Thoracic Society updated its guidelines on emergency oxygen therapy in 2017. The following selected points are taken from the guidelines. Please see the link provided for the full guideline.

In patients who are critically ill (anaphylaxis, shock etc) oxygen should initially be given via a reservoir mask at 15 l/min. Hypoxia kills.


Oxygen saturation targets
  • acutely ill patients: 94-98%
  • patients at risk of hypercapnia (e.g. COPD patients): 88-92% (see below)
  • oxygen should be reduced in stable patients with satisfactory oxygen saturation

Management of COPD patients
  • prior to availability of blood gases, use a 28% Venturi mask at 4 l/min and aim for an oxygen saturation of 88-92% for patients with risk factors for hypercapnia but no prior history of respiratory acidosis
  • adjust target range to 94-98% if the pCO2 is normal

Situations where oxygen therapy should not be used routinely if there is no evidence of hypoxia:
  • myocardial infarction and acute coronary syndromes
  • stroke
  • obstetric emergencies
  • anxiety-related hyperventilation