Key learning points

  • The British Thoracic Society (BTS) recommends home oxygen in adults with chronic hypoxaemia
  • Patients with resting oxygen saturations above 92% are unlikely to require long-term oxygen therapy (LTOT)
  • The Part A home oxygen order form (HOOF) should be used when ordering temporary palliative home oxygen

The BTS guidelines for home oxygen in adults recommend that oxygen therapy for home use is most useful in chronic hypoxaemia.1,2 Long-term oxygen therapy (LTOT) is prescribed to improve survival in patients with hypoxia. LTOT is a treatment for hypoxia but not for breathlessness,2 yet many people with breathlessness are unnecessarily prescribed oxygen and will not benefit. Patients with resting saturations above 92% are unlikely to require LTOT.2

Risks of LTOT

Oxygen as a therapy has some risks. There is the danger of the ‘carbon dioxide retainer’ in chronic obstructive pulmonary disease (COPD). For such patients, too little carbon dioxide is removed from the blood by the lungs, leading to increased levels of CO2 in the blood (hypercapnia).3 There is an increased risk of hypercapnia in patients with COPD taking oxygen.3

Other situations in which oxygen therapy has risks include myocardial infarction, in which oxygen administration can lead to dangerous undesirable circulatory changes and increased myocardial ischaemia.4,5 In addition, there is a reported increase in mortality among ventilated stroke patients with higher blood oxygen levels, leading to suggestions that unnecessary oxygen administration should be avoided in stroke patients.6

It is also worth thinking about patients who travel regularly because air travel reduces resting saturations due to pressurised cabins.7 The BTS recommend a pre-flight assessment involving a clinical history and examination to identify risk of flying and need for in-flight oxygen.7 A hypoxic challenge test should be conducted within this assessment, with an arterial oxygen tension of <6.6kPa (<50mmHg) or an oxygen saturation of less than 85% indicating the need for in-flight oxygen.7

Of course, if assessment indicates that the person requires oxygen for travel, it may increase their insurance payments and they will need to arrange oxygen for overseas, as equipment supplied in the UK is not covered if taken out of the country.

Oxygen forms 

Temporary oxygen is ordered on a Part A HOOF form.8 This form is for non-specialist healthcare professionals or for temporary supply pending specialist review. The Part A HOOF is used to order a static concentrator or cylinder for use in the home, and flow rate and either a mask or a nasal cannula should be specified. This is then sent to the oxygen provider.

Consent needs to be obtained from the patient on a home oxygen consent form, which allows data sharing. This is stored with the patient’s records, together with a risk assessment on an initial home oxygen risk mitigation form.

The initial home oxygen risk mitigation form ensures that the patient and/or carer understands the safety advice regarding the use of home oxygen, including the dangers of smoking cigarettes and e-cigarettes, naked flames, the use of paraffin-based ointments and pressure-relieving mattresses. They are then referred to the oxygen assessment team.

The Part B HOOF is a restricted document for home oxygen assessment and review services, paediatric and other specialist teams. The Part B HOOF can be used to order ambulatory oxygen equipment in addition to any LTOT equipment.

For information on the evidence for LTOT see the article by Jane Scullion on The evidence for long-term oxygen therapy

Jane Scullion, respiratory nurse consultant, University Hospitals of Leicester, and a respiratory clinical lead within the East Midlands working with the Clinical Senate

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