Early diagnosis of acute kidney injury in critically ill patients.

Acute kidney injury (AKI) is a common and serious problem in critically ill patients. Tests currently used to detect AKI (i.e., serum creatinine, serum urea and various urinary indices) often result in delayed detection of injury--becoming abnormal at 48-72 h after the initial insult. This delayed detection translates into a potential missed opportunity for therapeutic interventions at a time when kidney damage may be limitable or reversible. This may also, in particular, account for the poor clinical outcomes commonly associated with AKI. The development of novel serum and urinary biomarkers capable of detecting AKI at an earlier phase of illness is therefore vital. This article will review the pitfalls of current conventional testing in kidney injury and discuss the emergence of novel biomarkers with the potential to revolutionize the field of critical care nephrology.