Kidney failure gfr question?

I am on kidney dialysis. Have been since Jan 07. Last month my creatinin was 3.7. this gave me a gfr of 18%. This month my creatinin was 4.1 which gave me a gfr of 16%. As we know 15% is the cut off. I only have to go to dialysis 2 times a week. Drs told me when gfr goes down to 15% i go back to dialysis three times a week. My gfr fluctuates from month to month. I wonder why. Four months ago my gfr was 19.9%. What can i do to help keep my gfr above 15%. Is there ANYTHING i can do to help keep it above 15%. I would hate to go back to three days a week. I am using the gfr calculater on davita.com which only uses three factors. My weight and my creatinin and my age. which is taken monthly I know that gfr can be calculated more precisely and possible get a higher rate but I do not know the formula. Neither does any of the dialysis tecnitions. Does anyone know what I'm talking about.?PLEASE respond if you do. Also, is the davita.com gfr calculater a close indicator?

Desperate in Housto

well kidney failure has different stages. depending on the GFR
1. Silent 鈥?GFR up to 50 ml/min.
2. Renal insufficiency 鈥?GFR 25 to 50 ml/min.
3. Renal failure 鈥?GFR 5 to 25 ml/min
4. End-stage renal failure 鈥?GFR less than 5 ml/min.

You belong to stage 3. basically kidney failure is a irreversible disease. ones the nephrons are damage you can never bring them back again. So what can you do? Please follow a strict Diet... the diet usually consist of protein, potassium, sodium, phosphate restrictions. this is to avoid further use of your kidney's function for this substances are being filtered in the kidney. So it's better not to aggravate your condition. your best hope is to avoid further destruction of your kidney. try to maximize your time resting, vitamin supplements (which off course must be approved by your physician) and a strict diet.