Effect of Oxygen on Sleep and Breathing in Patients with Interstitial Lung Disease at Moderate Altitude

Abstract

Objective: To investigate the impact of oxygen on sleep and breathing in patients with interstitial lung disease (ILD) in Mexico City, at 2,240 m of altitude. Participants: Nineteen ILD patients with a mean FVC of 58 ± 17% pred. (SD) and a mean PaO₂ of 51 ± 6 mm Hg were recruited from a pulmonary clinic in a tertiary referral center. In addition, 14 normal control subjects, matched for age and gender, were studied. All patients underwent two consecutive full polysomnographies (PSG), one breathing room air and one breathing supplementary oxygen through nasal prongs, in random order. Controls were studied for one night breathing room air. Results: The mean oxygen saturation (SaO₂) in ILD patients was 82.3 ± 9.1% during sleep on air and 94.8 ± 2.9% on oxygen (p < 0.001). In controls it was 92.9 ± 1.9% (p < 0.001). Sleep efficiency was similar in patients and controls (75 vs. 82%, p > 0.05) and did not change with oxygen (77%). Arousal index was 12.4 ± 6.9·h^–1 in ILD patients breathing room air and 12.9 ± 9.1·h^–1 breathing oxygen while in controls it was 11.4 ± 5.4·h^–1. Breathing frequency (f) during sleep was 24.7 ± 4.2 in ILD patients and decreased breathing oxygen to 22.5 ± 3.6 (p < 0.001) but was still higher than in controls (15.6 ± 2.7; p < 0.001). Similarly, the heart rate (HR) in ILD and controls was 79 ± 12 and 68 ± 8, respectively (p < 0.001), and decreased to 68 ± 4 when patients breathed oxygen (p < 0.001). Conclusions: Oxygen substantially decreases HR and f, but does not normalize the f in ILD patients. The impact of hypoxia on sleep efficiency and arousal index was not demonstrable in our patients acclimatized to moderate altitude.

Managing passengers with stable respiratory disease planning air travel: British Thoracic Society recommendations

“…In a study examining the effects of oxygen on sleep and breathing in patients with ILD living at 2240 m in Mexico City (and thus acclimatised to moderate altitude), no difference in sleep efficiency or arousal index was observed between patients and controls 203. Oxygen reduced heart rate and breathing frequency in patients during sleep but did not normalise breathing frequency.…”

British Thoracic Society guidelines for home oxygen use in adults: accredited by NICE

“…Evidence is limited in this area and no studies have examined the long-term use of nocturnal oxygen or its effects on mortality, pulmonary haemodynamics or healthcare utilisation in ILD. Only one study has prospectively examined the effect of NOT in patients with ILD compared with air 79. This was a 2-night study comparing room air with NOT titrated at 1–3 L/min via nasal prongs to give an oxygen saturation reading of >90%.…”

Treatment of idiopathic pulmonary fibrosis in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand and the Lung Foundation Australia

“…Pulmonary haemodynamics may be improved in COPD patients receiving long‐term nocturnal oxygen; however, this has not been investigated in IPF populations . In two single‐night studies in ILD subjects, oxygen reduced breathing frequency and heart rate through elimination of sleep‐associated desaturation; however, sleep quality and arousal index were not significantly altered …”