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Long-term oxygen therapy (LTOT) in COPD

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

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  • long-term oxygen therapy (LTOT)
    • clinicians should be aware that inappropriate oxygen therapy in people with COPD may cause respiratory depression
    • LTOT can be defined as oxygen used for at least 15 hours per day in chronically hypoxaemic patients
      • chronic hypoxaemia is defined as a PaO2 <=7.3kPa or, in certain clinical situations, PaO2 <=8.0kPa
      • patients with stable chronic obstructive pulmonary disease (COPD) and a resting PaO2 <=7.3kPa should be assessed for LTOT which offers survival benefit and improves pulmonary haemodynamics
      • consider LTOT if patients have a PaO2 above 7.3 and below 8 kPa when stable, if they also have 1 or more of the following: secondary polycythaemia, peripheral oedema, pulmonary hypertension(2)
      • LTOT should be ordered for patients with resting hypercapnia if they fulfil all other criteria for LTOT (2)
    • oxygen concentrators should be used to provide the fixed supply at home for long-term oxygen therapy
    • patients should be warned about the risks of fire and explosion if they continue to smoke when prescribed oxygen
  • ambulatory oxygen therapy
    • people who are already on LTOT who wish to continue with oxygen therapy outside the home, and who are prepared to use it, should have ambulatory oxygen prescribed
    • ambulatory oxygen therapy should be considered in patients who have exercise desaturation, are shown to have an improvement in exercise capacity and/or dyspnoea with oxygen, and have the motivation to use oxygen
    • ambulatory oxygen therapy is not recommended in COPD if PaO2 is greater than 7.3 kPa and there is no exercise desaturation
    • ambulatory oxygen therapy should only be prescribed after an appropriate assessment has been performed by a specialist. The purpose of the assessment is to assess the extent of desaturation, and the improvement in exercise capacity with supplemental oxygen, and the oxygen flow rate required to correct desaturation
    • small light-weight cylinders, oxygen-conserving devices and portable liquid oxygen systems should be available for the treatment of patients with COPD
    • a choice about the nature of equipment prescribed should take account of the hours of ambulatory oxygen use required by the patient and the oxygen flow rate required
  • short-burst oxygen therapy
    • short-burst oxygen therapy should only be considered for episodes of severe breathlessness in patients with COPD not relieved by other treatments
    • short-burst oxygen therapy should only continue to be prescribed if an improvement in breathlessness following therapy has been documented
    • when indicated, short-burst oxygen should be provided from cylinders
  • non-invasive ventilation (NIV)
    • adequately treated patients with chronic hypercapnic respiratory failure who have required assisted ventilation (whether invasive or non-invasive) during an exacerbation or who are hypercapnic or acidotic on LTOT should be referred to a specialist centre for consideration of long-term NIV

For more detailed guidance then see the full BTS guideline.


1. National Institute for Health and Clinical Excellence (NICE) 2018. Chronic obstructive pulmonary disease in over 16s: diagnosis and management.

2. Hardinge M, Annandale J, Bourne S, et al. British Thoracic Society guidelines for home oxygen use in adults. Thorax2015;70:i1-i43.

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