Here's just a theory, take it with a grain of salt...
When I'm on IVs, I get very tired out. I don't know if it's my organs/body trying to keep up, or what? This is virtually the only time when I take regular naps.
And, obviously, we are taking in more fluids via the IVs.
So, possibly she needs to get rid of some of the fluid but is just so tired & in such a deep sleep, that she isn't picking up on that "Hey, get up & pee!" brain signal??
Like Ferris said, her blood sugars may be high-ish and this can cause increased urination too.
I'm sure this can be frustrating for you both--the joys of CF, huh?<img src="i/expressions/face-icon-small-wink.gif" border="0">
If you figure out what's causing this, let us know!