Table 1 Critical illnesses requiring high levels of supplemental oxygen (see section 8.10)

  • The initial oxygen therapy is a reservoir mask at 15 l/min.

  • Once stable, reduce the oxygen dose and aim for target saturation range of 94–98%

  • If oximetry is unavailable, continue to use a reservoir mask until definitive treatment is available.

  • Patients with COPD and other risk factors for hypercapnia who develop critical illness should have the same initial target saturations as other critically ill patients pending the results of blood gas measurements, after which these patients may need controlled oxygen therapy or supported ventilation if there is severe hypoxaemia and/or hypercapnia with respiratory acidosis.

Additional commentsGrade of recommendation
Cardiac arrest or resuscitationUse bag-valve mask during active resuscitationGrade D
Aim for maximum possible oxygen saturation until the patient is stable
Shock, sepsis, major trauma, near-drowning, anaphylaxis, major pulmonary haemorrhageAlso give specific treatment for the underlying conditionGrade D
Major head injuryEarly intubation and ventilation if comatoseGrade D
Carbon monoxide poisoningGive as much oxygen as possible using a bag-valve mask or reservoir mask. Check carboxyhaemoglobin levelsGrade C
A normal or high oximetry reading should be disregarded because saturation monitors cannot differentiate between carboxyhaemoglobin and oxyhaemoglobin owing to their similar absorbances. The blood gas Pao2 will also be normal in these cases (despite the presence of tissue hypoxia)

  • COPD, chronic obstructive pulmonary disease; Pao2, arterial oxygen tension.