BTW - Rowan's medical staff were quite pleased with his progress regarding breathing on his own.

The first day they had him breathing on his own for an hour, but he was very tired by the end of that. They've explained to me that breathing actually does take some effort.

By the next day he did 8 hours on his own, and then the following day, he started breathing on his own and has just continued.

I've chatted with them about it, and we think that Rowan's fitness level (all the cycling!) helped.