oxygen therapy in chronic obstructive pulmonary disease (COPD)

Last edited 02/2021 and last reviewed 05/2021

  • 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 15h 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
      • LTOT should be ordered for patients with stable COPD with a resting PaO2 <=8kPa with evidence of peripheral oedema, polycythaemia (haematocrit >=55%) or 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. NICE (June 2010). Chronic obstructive pulmonary disease
  2. Hardinge M, Annandale J, Bourne S, et al.British Thoracic Society guidelines for home oxygenuse in adults.Thorax2015;70:i1-i43.