I heard about your brother, and I wanted to pop in.
I know that you have many physicians in your family, so what I'm saying may be superfluous. In Canada it's the Cardiac Surgeons that decide on putting in and taking off ECMO, so we see and do a lot.
I assume your brother is in ARDS, and they are doing VV (Veno venous) ECMO. I only wanted to say...please don't give up to early! I know that you live in the US, and I have no concept of how insurance works (in Canada you just keep going until you know it's futile because health is free and all inclusive) ....so maybe the limitations of resources in US makes a difference.
We've kept patients on VV-ECMO between 4-6 weeks, with COMPLETE recovery. As long as he avoids the complications of ECMO, and the rest of his organs are reasonably well, he stands a good chance. I know the 50/50 statistic is commonly quoted, but it really doesn't accurately reflect the reality. There's the question of the pathology, the comorbidities he had before etc.
I think the hardest thing for us, is when a family insists that we stop ECMO after 1-2 weeks, because they don't see an improvement. We have to abide by their wishes. But in reality, I personally don't think "amount of time spent on ECMO" should, determine anything. I think when patients are on ECMO, the only time we should give up is a) when death is 100% certain even on ECMO (and there's only a few conditions when that happens b) there's a complication where only partial functional recovery (which would be unacceptable to the patient) were to occur.
Keeping you in my thoughts. Don't forget to take care of yourself as well. Sending you lots of positive thoughts.