Table 2 Serious illnesses requiring moderate levels of supplemental oxygen if the patient is hypoxaemic (section 8.11)

The initial oxygen therapy is nasal cannulae at 2–6 l/min (preferably) or simple face mask at 5–10 l/min unless stated otherwise.
For patients not at risk of hypercapnic respiratory failure who have saturation <85%, treatment should be commenced with a reservoir mask at 10–15 l/min.
The recommended initial oxygen saturation target range is 94–98%.
If oximetry is not available, give oxygen as above until oximetry or blood gas results are available.
Change to reservoir mask if the desired saturation range cannot be maintained with nasal cannulae or simple face mask (and ensure that the patient is assessed by senior medical staff).
If these patients have co-existing 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 previous hypercapnic respiratory failure requiring NIV or IPPV) and recheck blood gases after 30–60 min.
	Additional comments	Grade of recommendation
Acute hypoxaemia (cause not yet diagnosed)	Reservoir mask at 10–15 l/min if initial Spo₂ <85%, otherwise nasal cannulae or simple face mask	Grade D
Acute hypoxaemia (cause not yet diagnosed)	Patients requiring reservoir mask therapy need urgent clinical assessment by senior staff	Grade D
Acute asthma		Grade C
Pneumonia		Grade C
Lung cancer		Grade C
Postoperative breathlessness	Management depends on underlying cause	Grade D
Acute heart failure	Consider CPAP or NIV in cases of pulmonary oedema	Grade D
Pulmonary embolism	Most patients with minor pulmonary embolism are not hypoxaemic and do not require oxygen therapy	Grade D
Pleural effusions	Most patients with pleural effusions are not hypoxaemic. If hypoxaemic, treat by draining the effusion as well as giving oxygen therapy	Grade D
Pneumothorax	Needs aspiration or drainage if the patient is hypoxaemic. Most patients with pneumothorax are not hypoxaemic and do not require oxygen therapy	Grades C and D
Pneumothorax	Use a reservoir mask at 10–15 l/min if admitted for observation. Aim at 100% saturation (oxygen accelerates clearance of pneumothorax if drainage is not required)	Grades C and D
Deterioration of lung fibrosis or other interstitial lung disease	Reservoir mask at 10–15 l/min if initial Spo₂ <85%, otherwise nasal cannulae or simple face mask	Grade D
Severe anaemia	The main issue is to correct the anaemia	Grades B and D
Severe anaemia	Most anaemic patients do not require oxygen therapy
Sickle cell crisis	Requires oxygen only if hypoxaemic (below the above target ranges or below what is known to be normal for the individual patient)	Grade B
Sickle cell crisis	Low oxygen tension will aggravate sickling	Grade B

COPD, chronic obstructive pulmonary disease; CPAP, continuous positive airway pressure; IPPV, intermittent positive pressure ventilation; NIV, non-invasive ventilation; Paco₂, arterial carbon dioxide tension; Spo₂, arterial oxygen saturation measured by pulse oximetry.