Long-term continuous oxygen therapy

Assess the need for long-term continuous oxygen therapy only when patients are clinically stable, have had treatment for their condition optimised and have stopped smoking for at least 1 month. Consider performing arterial blood gas analysis if oxygen saturation measured by pulse oximetry (SpO₂) is less than 90%. Arterial blood gas analysis on room air is required to determine eligibility for domiciliary oxygen therapy.

Long-term continuous oxygen therapy has been shown to prolong survival in patients with stable chronic obstructive pulmonary disease (COPD) who have:

• consistent partial pressure of oxygen (PaO₂) of 55 mmHg or less when breathing air at rest and awake
• evidence of complications of hypoxaemia (eg polycythaemia, pulmonary hypertension, right-sided heart failure) and a PaO₂ of 56 to 59 mmHg.

Results from studies in patients with COPD have been extrapolated to recommend long-term oxygen therapy for patients suffering from any illness where chronic hypoxaemia is an important feature.

Prescribe domiciliary oxygen at an initial flow of 2 litres per minute (this is the flow required by most patients). Some patients may need their flow titrated depending on severity of disease (the usual flow is 1 to 3 litres per minute, but can be higher).

Consider increasing the flow by 1 litre per minute overnight and during activity or exercise (including for everyday physical activities such as showering), if required.

Long-term continuous oxygen therapy should be used for at least 15 hours (preferably 18 hours or more) per day, including hours asleep.

Long-term continuous oxygen therapy should be supplied from an oxygen concentrator. A portable oxygen device (portable concentrator or oxygen cylinder) (see Oxygen delivery systems and devices used in domiciliary oxygen therapy) may be considered, particularly for patients who demonstrate an objective improvement in exercise endurance (eg measured using a treadmill, cycle ergometer, 6-minute walk test or shuttle walk test).

Regularly review patients receiving long-term continuous oxygen therapy (see Monitoring domiciliary oxygen in adults).