In critically ill septicemic patients ARF acute renal failure is common initially low output renal failure then converted to high output renal failure despite more than normal urine output urea and creatinine still increasing next option we use peritoneal dialysis urea and creatinine still remain in high level then we started hemodialysis that also could not decrease urea creatinine and K level nephrologist said that he have used fresh dialyzer and fluids. What could be the reason for this what other steps could be taken?