Indications for acute oxygen therapy

Target oxygen saturation levels for acute oxygen therapy may be different for children in some clinical situations (eg cyanotic congenital heart disease, severe chronic lung disease)—seek specialist advice.

Oxygen therapy is generally not indicated if the patient is not hypoxaemic. In particular, in the absence of hypoxaemia, oxygen therapy is no longer recommended for acute coronary syndromes, stroke, hyperventilation or dysfunctional breathing, most poisonings and drug overdoses (excluding carbon monoxide), or pregnancy and obstetric emergencies.

Oxygen therapy is indicated for patients who are hypoxaemic (according to oxygen saturation measured by pulse oximetry [SpO₂]), specifically patients with:

• pretreatment SpO₂ less than 92%
• pretreatment SpO₂ less than 88% in patients at risk of hypercapnia.

Oxygen therapy is also recommended for some critical conditions in which patients are likely to be hypoxaemic. These include cardiac arrest, shock, sepsis, major trauma or head injury, anaphylaxis, major pulmonary haemorrhage, status epilepticus, near drowning, scuba diving accidents (see Decompression sickness) and carbon monoxide poisoning. Patients with these critical conditions should be given high-flow oxygen through a reservoir mask at 15 L per minute until stable.

In patients with hypoxaemia who are not critically ill, the oxygen delivery system should be chosen to maintain the target oxygen saturation; see Pulse oximetry to monitor acute oxygen therapy for target oxygen saturations.

Pulse oximetry readings may be misleading in some clinical scenarios; see Pulse oximetry to monitor acute oxygen therapy.