His blood gasses (the amount of carbon dioxide in his blood) have been wonky today, and he wasn't responding well to all the normal interventions (raising his oxygen level, giving him extra breaths on his ventilator) so he had to be switched to a new kind of ventilator.
Here's a good overview I got from here
The sickest and tiniest babies and those who are no longer responding well to traditional ventilators are sometimes put on high frequency ventilators. These ventilators come in four types, but the one most frequently used in the NICU is the high frequency oscillatory ventilator, otherwise known as an oscillator. An oscillator uses a very high respiratory rate, typically between 120 and 480 breaths per minute, to move very small volumes of air. Babies on an oscillator appear to be vibrating from this rapid movement of air.
We're lucky really, this isn't a HUGE setback. It's not devastating news, it's not anything that he can't bounce back from. It's helping him, more than anything, and it's actually kind of a good thing.
It's just that he HATES it. He's fighting against it, and you can totally tell that he's not comfortable and REALLY not happy. They gave him some morphine to help calm him down a little and (hopefully) give him some time to get used to it.
In the NICU, the doctors and nurses all warn you that there will be bad days. You try to brace yourself for these bad days. You hold your breath, you say your prayers, you think you're ready... And then a bad day comes. And it hits you like a ton of bricks. And you realize you WEREN'T ready for it. There's no way anyone could every be ready for it. Watching your child in pain now nowthing there is NOTHING you can do to help him is the worst feeling in the entire world.
So please, when you say your prayers tonight, say a little one for my little guy. We'd all appreciate it.