Nocturnal hypoxaemia in interstitial lung disease: a systematic review

Abstract

BackgroundPatients with interstitial lung disease (ILD) are at risk of developing nocturnal hypoxaemia due to ventilatory restriction and impaired gas exchange that worsen with supine posture and reduced ventilatory drive during sleep. This systematic review synthesised literature on the diagnostic evaluation, epidemiology, associations, management and prognosis of nocturnal hypoxaemia in ILD.MethodsOvid MEDLINE, Embase and CENTRAL databases were searched for eligible studies. Meta-analyses with subgroup analyses were conducted, where possible.ResultsFifty-three studies were included (total participant number=2590). The most common definition for clinically significant nocturnal hypoxaemia was ≥10% of total sleep time with oxyhaemoglobin saturation <90%, with pooled prevalence of 37%. There were no significant differences in pooled prevalence according to ILD subtype and comorbid obstructive sleep apnoea status. Study heterogeneity precluded meta-analysis of associations and prognosis. Diffusing capacity for carbon monoxide (DLCO) and echocardiographic features for pulmonary hypertension were consistently associated with nocturnal hypoxaemia. There were inconsistent associations between nocturnal hypoxaemia with ILD subtype and severity. Multivariable analyses in most studies demonstrated significant associations of nocturnal hypoxaemia with survival. Two small short-term intervention studies demonstrated that supplemental oxygen of 1–3 L/min corrected nocturnal hypoxaemia, with improved heart rate control during in-laboratory observation and increased serum antioxidant levels after 1 month of therapy.ConclusionNocturnal hypoxaemia is common, associated with DLCO impairment and markers suggestive of pulmonary hypertension, and a potential prognostic factor in patients in ILD. There is a need to establish a consensus definition of nocturnal hypoxaemia and evaluate long-term effects of nocturnal supplemental oxygen in ILD.

Treatment of idiopathic pulmonary fibrosis and progressive pulmonary fibrosis: A position statement from the Thoracic Society of Australia and New Zealand 2023 revision

“…A number of studies have confirmed the high degree of sleep‐related hypoxaemia in IPF/ILD patients, and furthermore, have shown associations between nocturnal hypoxaemia and the development of PH and increased mortality in these cohorts 110,124,125 . Nocturnal oxygen desaturation occurs as a direct consequence of OSA but may also relate to other physiologic derangements of ventilation and gas exchange in patients with IPF/ILD 126 …”

“…110,124,125 Nocturnal oxygen desaturation occurs as a direct consequence of OSA but may also relate to other physiologic derangements of ventilation and gas exchange in patients with IPF/ILD. 126 Whilst very little high-quality IPF/ILD-specific evidence is available, general OSA interventional studies provide a framework for initiating therapy. It is reasonable for continuous positive airway pressure (CPAP) to be considered for patients with moderate to severe OSA, particularly in those with daytime somnolence.…”

“…[167][168][169] Nocturnal hypoxaemia, even in the absence of OSA, is a common observation in ILD patients, with multiple studies consistently linking this phenomenon with poorer outcomes. 110,126 To date, very little data have been published on the impact of nocturnal oxygen supplementation in ILD patients. Nocturnal oxygen may be considered for patients with SpO 2 <88% for >30% of sleep time, as for patients with other chronic respiratory diseases.…”

“…Nocturnal hypoxaemia, even in the absence of OSA, is a common observation in ILD patients, with multiple studies consistently linking this phenomenon with poorer outcomes 110,126 . To date, very little data have been published on the impact of nocturnal oxygen supplementation in ILD patients.…”

“… 110 , 124 , 125 Nocturnal oxygen desaturation occurs as a direct consequence of OSA but may also relate to other physiologic derangements of ventilation and gas exchange in patients with IPF/ILD. 126 …”