Good luck tomorrow. Here's an excellent primer on giving subQ fluids if you haven't already seen it: http://www.weirdstuffwemake.com/weir.../catjuice.html
Growler and I can also help you if you have any questions. One thing the vets never seem to mention is that it really helps if you warm the fluids first.
Also, it's time to get some mirtazapine. And if the fPLI shows pancreatitis, some better pain meds. If those don't work, perhaps a feeding tube would be the way to go.