Nocturnal oxygen therapy

Nocturnal oxygen therapy can be used in patients with chronic hypoxaemia who do not meet the criteria for long-term continuous oxygen therapy.

Before considering nocturnal oxygen therapy, perform a sleep study (polysomnogram) to identify or exclude sleep-disordered breathing (eg obstructive sleep apnoea or obesity hypoventilation syndrome). Hypoxaemia at night may be related to sleep-disordered breathing and may require use of continuous positive airway pressure (CPAP).

In patients unlikely to have sleep-disordered breathing, perform overnight pulse oximetry to detect nocturnal hypoxaemia.

Nocturnal oxygen therapy can be considered if SpO₂ is 88% or less for more than one-third of sleep duration, particularly in patients with complications of hypoxaemia (eg pulmonary hypertension, polycythaemia).