%0 Journal Article %A Akhilesh Jha %A Fangyue Chen %A Sam Mann %A Ravi Shah %A Randa Abu-Youssef %A Holly Pavey %A Helen Lin-Jia-Qi %A Josh Cara %A Daniel Cunningham %A Kate Fitzpatrick %A Celine Goh %A Renee Ma %A Souradip Mookerjee %A Vaitehi Nageshwaran %A Timothy Old %A Catherine Oxley %A Louise Jordon %A Mayurun Selvan %A Anna Wood %A Andrew Ying %A Chen Zhang %A Dariusz Wozniak %A Iain Goodhart %A Frances Early %A Marie Fisk %A Jonathan Fuld %T Physiological effects and subjective tolerability of prone positioning in COVID-19 and healthy hypoxic challenge %D 2021 %R 10.1183/23120541.00524-2021 %J ERJ Open Research %P 00524-2021 %X Background Prone positioning has a beneficial role in COVID-19 patients receiving ventilation but lacks evidence in awake non-ventilated patients, with most studies being retrospective, lacking control populations and information on subjective tolerability.Methods We conducted a prospective, single-centre study of prone positioning in awake non-ventilated patients with COVID-19 and non-COVID-19 pneumonia. The primary outcome was change in peripheral oxygenation in prone versus supine position. Secondary outcomes assessed effects on end-tidal CO2, respiratory rate, heart rate, and subjective symptoms. We also recruited healthy volunteers to undergo proning during hypoxic challenge.Results 238 hospitalised patients with pneumonia were screened; 55 were eligible with 25 COVID-19 patients and 3 non-COVID-19 patients agreeing to undergo proning – the latter insufficient for further analysis. 10 healthy control volunteers underwent hypoxic challenge. Patients with COVID-19 had a median age of 64 years (interquartile range [IQR] 53–75). Proning led to an increase in SpO2 compared to supine position (difference +1.62%; p=0.003) and occurred within 10 min of proning. There were no effects on end-tidal CO2, respiratory rate, or heart rate. There was an increase in subjective discomfort (p=0.003), with no difference in breathlessness. Among healthy controls undergoing hypoxic challenge, proning did not lead to a change in SpO2 or subjective symptom scores.Conclusion Identification of suitable patients with COVID-19 requiring oxygen supplementation from general ward environments for awake proning is challenging. Prone positioning leads to a small increase in SpO2 within 10 min of proning though is associated with increased discomfort.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: Akhilesh Jha has nothing disclose.Conflict of interest: Fangyue Chen has nothing disclose.Conflict of interest: Sam Mann has nothing disclose.Conflict of interest: Ravi Shah has nothing disclose.Conflict of interest: Randa Abu-Youssef has nothing disclose.Conflict of interest: Holly Pavey has nothing disclose.Conflict of interest: Helen Lin-Jia-Qi has nothing disclose.Conflict of interest: Josh Cara has nothing disclose.Conflict of interest: Daniel Cunningham has nothing disclose.Conflict of interest: Kate Fitzpatrick has nothing disclose.Conflict of interest: Celine Goh has nothing disclose.Conflict of interest: Renee Ma has nothing disclose.Conflict of interest: Souradip Mookerjee has nothing disclose.Conflict of interest: Vaitehi Nageshwaran has nothing disclose.Conflict of interest: Timothy Old has nothing disclose.Conflict of interest: Catherine Oxley has nothing disclose.Conflict of interest: Louise Jordon has nothing disclose.Conflict of interest: Mayurun Selvan has nothing disclose.Conflict of interest: Anna Wood has nothing disclose.Conflict of interest: Andrew Ying has nothing disclose.Conflict of interest: Chen Zhang has nothing disclose.Conflict of interest: Dariusz Wozniak has nothing disclose.Conflict of interest: Iain Goodhart has nothing disclose.Conflict of interest: Frances Early has nothing disclose.Conflict of interest: Marie Fisk has nothing disclose.Conflict of interest: Jonathan Fuld has nothing disclose. %U https://openres.ersjournals.com/content/erjor/early/2021/10/28/23120541.00524-2021.full.pdf