Some emerging theories of pathology suggest that lung function can be increased by reinflating collapsed alveoli with constant pressure: https://emcrit.org/pulm

Some emerging theories of pathology suggest that lung function can be increased by reinflating collapsed alveoli with constant pressure: https://emcrit.org/pulmcrit/cpap-covid/ https://emcrit.org/pulmcrit/cpap-covid/. This source describes cases where oxygen supplementation could be reduced or eliminated. This development (https://www.isinnova.it/easy-covid19-eng/ https://www.isinnova.it/easy-covid19-eng/) looks very promising for 'sub-intensive' cases -- adapting decathlon masks to provide positive air pressure (to help reinflate lungs) without intubation or leaking contaminated exhaust. I don't know how many of these rapidly improvised ventilators can provide constant pressure, but if the closed mask method could be used successfully to prevent serious cases from progressing to ICU (or more importantly, keep people in their homes a little longer), it could have a huge impact.