I read an article a while back where they said there are a few bands of severity (this was how they treating in China). First level of seriousness was oxygen /

I read an article a while back where they said there are a few bands of severity (this was how they treating in China). First level of seriousness was oxygen / respirator. Then for even more serious cases they had to actually oxygenate the blood outside their body. Basically the problem was people can’t breath because of fluid or maybe it’s damage in their lungs so all the treatments of the severe patients were to help that.