I looked up the percentages, and Snowy's levels are within normal range, other than hemoglobin.I think he is anemic from the hemoglobin reading. What did they say about the CBC? I’m not used to reading things in percentages either...anything from 1.6 to 2.5 or so is considered high normal and they are already at stage two kidney disease...If he is having some sort of injury to his kidneys from whatever is going on with him, it would be better if he could have IV fluids versus subcutaneous.
As far as the creatinine, yes it is considered Stage 2 by IRIS, but not 'dangerous', and if it is acute (vs. chronic) due to toxins, etc. it could come down into normal range with treatment. But, 1.5 is not the top end of a range I am familiar with, so it makes it seem worse than it is from what we know to be the ranges. Perhaps, it reflects the range as it pertains to Stage 1 or below?
IV fluids would probably be better, especially if this acute, but more possible injury to his poor legs at this point is a bad idea. That is why I suggested either jugular IV, or subcutaneous instead. They could also use his back legs that haven't been injured, but that is a gamble depending on who does it.
His hemoglobin is pretty low, so there is anemia going on. I believe it has been going on for a while now (think it was talked about earlier in this thread) - whether that is from some sort of toxin/parasite/etc. is unknown, but should be looked into, if at all possible. Anemia can be affiliated with kidney issues too, but not sure if his kidney values are high enough to cause anemia. I suppose that can vary from cat to cat.