Hyperbaric chambers are not usually intended for long term use, but needs must. Which makes me wonder about ECMO, which the Japanese were reporting early on was being used successfully. But ECMO is a brutal therapy, and you would really want to avoid it. So indeed, maybe there is a middle ground where a hyperbaric room ie where the partial pressure of oxygen was low, but the absolute pressure high - 3 atmospheres say, and patients were on oxygen masks. So you can have a room that was generally safe, and not a bomb waiting to go off, where you could keep patients monitored etc, and keep blood oxygen up. Lots of interesting logistic problems, but not impossible.