Abstract
Acute kidney injury (AKI) is the sudden loss of kidney function. It has been referred to as acute 
kidney failure in the past. The primary physiological function of the kidneys is to filter the blood and 
remove the waste, as well as excess salt and water. When AKI occurs, urea nitrogen and creatinine 
levels increase in the blood circulation, the daily urine output falls, and the fluid-electrolyte balance 
and the acid-base balance deteriorate. AKI is associated with prerenal, renal, and postrenal events. 
Although AKI is often reversible, depending on the causes and severity, it may not be. The most 
common adverse events due to AKI are chronic renal failure, chronic kidney disease, and 
cardiovascular events. AKI is a major cause of morbidity and mortality in intensive care units. 
Therefore, early diagnosis of AKI is very important for the prognosis of patients as well as to reduce 
medical costs.