BUN too high to read creatinine 3.3

My cat has been in the ER several days and is now drinking water nonstop. She is 14 and definitely has CKD, but the doctors are in disagreement about whether her azotemia is renal or pre-renal.

First doc said that kidney levels were fine. The next doc said the first doc was wrong, the numbers are awful: BUN too high to read and creatinine 4 something and that the cat had advanced kidney disease. Third doc said, I’m not worried about the BUN levels—that’s from dehydration not kidney disease. Next doc said end stage renal failure.

The ER decided to stop hydrating my cat since the numbers weren’t moving that much. Creatinine came down a little to 3.3 and I pointed out that since BUN levels were hitting the test ceiling, they didn’t really know what as going on there. They could also be inching down.

But they decided to stop IV fluids and said she was hydrated enough. Possibly they are worried about the stress on her heart from the fluids, but since they keep recommending euthanasia, I’m not sure why they’re so worried to take that risk. The only thing they suggested for her was to have an ultrasound and a feeding tube. Since she ate a Churu (and wanted more) when my daughter and I came to see her, I didn’t see the point in the feeding tube. And she is scheduled for an ultrasound, but there didn’t seem to be any point in continuing hospitalization if she wasn’t getting fluids and I didn’t think the feeding tube was worth it.

The vet told me not to give her subcutaneous fluids today, but is the fact that she is drinking so much an indication that she should have at least a small amount of subs fluids (25ml?) today?