PT  - JOURNAL ARTICLE
AU  - Mathieu Marillier
AU  - Anne-Catherine Bernard
AU  - Onofre Moran-Mendoza
AU  - Denis E O'Donnell
AU  - Samuel Verges
AU  - J Alberto Neder
TI  - Beyond the lungs in fibrotic interstitial lung disease: does supplemental O2 improve skeletal muscle oxygenation and fatigue?
AID  - 10.1183/13993003.congress-2020.4405
DP  - 2020 Sep 07
TA  - European Respiratory Journal
PG  - 4405
VI  - 56
IP  - suppl 64
4099  - http://erj.ersjournals.com/content/56/suppl_64/4405.short
4100  - http://erj.ersjournals.com/content/56/suppl_64/4405.full
SO  - Eur Respir J2020 Sep 07; 56
AB  - Background: The severity of exertional hypoxaemia in fibrotic interstitial lung disease (f-ILD) finds no parallel in respiratory medicine. The prevailing view is that supplemental oxygen (O2) may improve exercise tolerance in f-ILD by lessening the hypoxic ventilatory drive and dyspnoea. However, it is conceivable that part of the ergogenic effects of O2 are secondary to improved muscle O2 delivery and fatigue.Methods: Sixteen f-ILD patients (13 males, 73±8 years) performed a constant-load (60% peak) cycle test to symptom limitation on normoxia (Tlimnorm). Fourteen controls cycled up to patients’ Tlimnorm. Later on, patients exercised up to Tlimnorm under supplemental O2 (0.41±0.07). Changes in quadriceps oxyhaemoglobin concentration ([HbO2]) were assessed by near-infrared spectroscopy. A >15% post-cycling fall in quadriceps force response to magnetic nerve stimulation (twitch, Twquad) indicated the presence of muscle fatigue.Results: Patients showed severe exertional hypoxaemia (O2 saturation= 80.7±7.4% after 17±4 min). Fatigue was found in 13/16 patients (Twquad fall= 21.5±8.0%) and was larger than in controls (13.5±9.1%; p<0.05). Supplemental O2 improved quadriceps [HbO2] (+6.9±3.6 vs +2.4±2.6 μmol; p<0.05) leading to a decrease in muscle fatigue (12.7±8.5%; p<0.05): 7/13 patients were no longer considered as ‘fatiguers’. Leg symptoms dropped by at least one Borg unit in 9 of these 13 patients.Conclusion: The beneficial effects of exertional O2 supplementation in patients with f-ILD are not limited to “the lungs”: lessening peripheral muscle fatigue to improve exercise tolerance is a relevant therapeutic target that deserves clinical attention.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4405.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).