PT  - JOURNAL ARTICLE
AU  - Julian Müller
AU  - Mona Lichtblau
AU  - Stéphanie Saxer
AU  - Simon R. Schneider
AU  - Paula Appenzeller
AU  - Meret Bauer
AU  - Elisabeth D. Hasler
AU  - Esther I. Schwarz
AU  - Konrad E. Bloch
AU  - Silvia Ulrich
TI  - Hyperoxia improves exercise capacity in cardiopulmonary disease A series of RCT's
AID  - 10.1183/23120541.00563-2022
DP  - 2023 Jan 01
TA  - ERJ Open Research
PG  - 00563-2022
4099  - http://openres.ersjournals.com/content/early/2022/12/08/23120541.00563-2022.short
4100  - http://openres.ersjournals.com/content/early/2022/12/08/23120541.00563-2022.full
AB  - Background To study the overall and differential effect of breathing hyperoxia (FiO2 0.5) versus placebo (ambient air, FiO2 0.21) to enhance exercise performance in healthy people, patients with pulmonary vascular disease (PVD) with precapillary pulmonary hypertension (PH), chronic obstructive pulmonary disease (COPD), PH due to heart failure with preserved ejection fraction (HFpEF) and cyanotic congenital heart disease (CHD) using data of five RCTs performed with identical protocols.Methods 91 subjects (32 healthy, 22 PVD with pulmonary arterial or distal chronic thromboembolic PH, 20 with COPD, 10 with PH in HFpEF and 7 with CHD) performed 2 cycle incremental (IET) and 2 constant work-rate exercise tests (CWRET) at 75% of maximal load (Wmax), each with ambient air and hyperoxia in single blinded, randomized-controlled cross-over trials. The main outcomes were differences in Wmax (IET) respectively cycling time (CWRET) with hyperoxia versus ambient air.Results Overall, hyperoxia increased Wmax by +12 W (95%CI: 9 to 16, p<0.001) and cycling time by +6:13 min (4:50 to 7:35, p<0.001), with improvements being highest in patients with PVD: (Wmax/min: +18%/+118% versus COPD: +8%/+60%, healthy: +5%/+44%, HFpEF: +6%/+28%, CHD: +9%/+14%).Conclusion This large collective of healthy and patients with various cardiopulmonary disease confirms that hyperoxia significantly prolongs cycling exercise with improvements being highest in endurance CWRET and patients with PVD. These results call for studies investigating optimal oxygen levels to prolong exercise time and effects on training.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: None of the authors has any financial or nonfinancial disclosures in context to this manuscript.