StatPearls: Acute Kidney InjuryStatPearls. StatPearls Publishing: Treasure Island (FL).BOOK
Acute kidney injury (AKI), previously called acute renal failure (ARF), denotes a sudden and often reversible reduction in kidney function, as measured by glomerular filtration rate (GFR). Although, immediately after a renal insult, blood urea nitrogen (BUN) or creatinine levels may be within the normal range. The only sign of acute kidney injury may be a decline in urine output. AKI can lead to the accumulation of water, sodium, and other metabolic products. It can also result in several electrolyte disturbances. It is a very common condition, especially among hospitalized patients. It can be seen in up to 7% of hospital admissions and 30% of ICU admissions. There is no clear definition of AKI; however, several different criteria have been used in research studies such as RIFLE, AKIN (Acute Kidney Injury Network), and KDIGO (Kidney Disease: Improving Global Outcomes) criteria. Among these, KDIGO is the most recent and most commonly used tool. According to KDIGO, AKI is the presence of any of the following: 1. Increase in serum creatinine by 0.3 mg/dL or more (26.5 micromoles/L or more) within 48 hours. 2. Increase in serum creatinine to 1.5 times or more baseline within the prior seven days. 3. Urine volume less than 0.5 mL/kg/h for at least 6 hours.
