Table 4 Conditions for which patients should be monitored closely but oxygen therapy is not required unless the patient is hypoxaemic (section 8.13)
  • If hypoxaemic, the initial oxygen therapy is nasal cannulae at 2–6 l/min or simple face mask at 5–10 l/min unless saturation is <85% (use reservoir mask) or if at risk from hypercapnia (see below).

  • The recommended initial target saturation range, unless stated otherwise, is 94–98%

  • If oximetry is not available, give oxygen as above until oximetry or blood gas results are available

  • If patients have COPD or other risk factors for hypercapnic respiratory failure, aim at a saturation of 88–92% pending blood gas results but adjust to 94–98% if the Paco2 is normal (unless there is a history of respiratory failure requiring NIV or IPPV) and recheck blood gases after 30–60 min

Additional commentsGrade of recommendation
Myocardial infarction and acute coronary syndromesMost patients with acute coronary artery syndromes are not hypoxaemic and the benefits/harms of oxygen therapy are unknown in such casesGrade D
StrokeMost stroke patients are not hypoxaemic. Oxygen therapy may be harmful for non-hypoxaemic patients with mild to moderate strokes.Grade B
Pregnancy and obstetric emergenciesOxygen therapy may be harmful to the fetus if the mother is not hypoxaemic (see recommendations 14–17)Grades A–D
Hyperventilation or dysfunctional breathingExclude organic illness. Patients with pure hyperventilation due to anxiety or panic attacks are unlikely to require oxygen therapyGrade C
Rebreathing from a paper bag may cause hypoxaemia and is not recommended
Most poisonings and drug overdoses (see table 1 for carbon monoxide poisoning)Hypoxaemia is more likely with respiratory depressant drugs, give antidote if available (eg, naloxone for opiate poisoning)Grade D
Check blood gases to exclude hypercapnia if a respiratory depressant drug has been taken. Avoid high blood oxygen levels in cases of acid aspiration as there is theoretical evidence that oxygen may be harmful in this condition
Monitor all potentially serious cases of poisoning in a level 2 or level 3 environment (high dependency unit or ICU)
Poisoning with paraquat or bleomycinPatients with paraquat poisoning or bleomycin lung injury may be harmed by supplemental oxygenGrade C
Avoid oxygen unless the patient is hypoxaemic
Target saturation is 88–92%
Metabolic and renal disordersMost do not need oxygen (tachypnoea may be due to acidosis in these patients)Grade D
Acute and subacute neurological and muscular conditions producing muscle weaknessThese patients may require ventilatory support and they need careful monitoring which includes spirometry. If the patient’s oxygen level falls below the target saturation, they need urgent blood gas measurements and are likely to need ventilatory supportGrade C
  • COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; IPPV, intermittent positive pressure ventilation; NIV, non-invasive ventilation; Paco2, arterial carbon dioxide tension; Spo2, arterial oxygen saturation measured by pulse oximetry.