Kidney diseases are common today. Acute kidney failure is a medical term meaning that the kidneys no longer function and are not able to remove toxins from the body, unable to maintain a stable electrolyte balance inside the body and unable to secrete extra fluid under form of urine outside the body. Renal replacement therapy (RRT) or dialysis was discovered in 1913 by Able, Rowntree and Turner in London, United Kingdom. In medicine, dialysis is primarily used to provide artificial support for lost kidney function in people with kidney failure. two types of renal replacement therapy. The original dialysis, which we called hemodialysis, used for patients with chronic kidney disease, requires patients to come to the hospital 2 to 3 times a week. This type of dialysis is called intermittent hemodialysis. However, intermittent hemodialysis is difficult to perform in the acute kidney injury population due to hemodynamic instability and these type of patients are usually the sickest and most critically ill patients in the acute renal failure setting. intensive. units and have multiorgan dysfunction, so it is medically too difficult to give them intermittent hemodialysis. Moreover, intermittent hemodialysis will increase mortality and morbidity among them. In modern intensive care units, a new method of dialysis was developed 30 years ago called continuous renal replacement therapy (CRRT). The definition of (CRRT) is any extracorporeal blood purification therapy intended to replace renal failure over a prolonged period of time. and requested or aimed to be applied 24 hours a day, Bellomo R., Ronco., Mehata R. The CRRT was found because the traditional way of...... middle of paper...... ed trail .Lancet 356(9223), 26-36(2)Saudan,P.,Niederberger,M.,De Seigneux,S.,Romand,J.,Pugin,J.,Pernrger,T.,& Martin,PY(2006 ).Adding a dose of dialysis to continuous hemofiltration increases the survival of patients with acute renal failure. Kidney international,70(7),1312-1317.(3)Bellomo,R.,Cass,A.,Cole,L.,Finer, S., Gallagher, M., Lo, S., McAthur, C., McGuinness, S., Myburgham J., Norton, R., Scheinkestel, C. and Su, S. for the Renal Study Investigators (2009). Intensity of continuous renal replacement therapy in critically ill patients. The New England Journal of Medicine, 361(17), 1627-1638.(4)Bellomo,R., Ronco,C.,Mehata,R.Nomenclature of continuous renal replacement therapies,AJKD,VOL 28,NO.5, Suppl 3, November 1996 (5) Tolwani AJ, Gampbell RC, Stofan BS, Lai KR, Oster RA, Wille KM. Standard versus high-dose CVVHDF for intensive care-related acute renal failure. J Am soc Nephrol 2008;19:1233-8