Im now stage 4 renal failure...gfr 25 and creatinine 2.19. my first nephrologist appt is thursday .....what are the chances he will put me in hospital?

Not likely: Unless there is more going on it is not likely. You can be managed with those numbers for some time if they are not getting worse quickly. See what nephrologist has to say.

Stage 4 ckd: It is not likely you will require hospitalization unless the kidney insufficiency is progressive rapidly. Otherwise, tests will be done to determine cause, like ultrasound and urine tests and other blood tests.