Beyond diagnosing acute kidney injury: defining what we need from kidney biomarkers

Acute kidney injury (AKI) is common in critically ill children and is associated with worse short- and long-term outcomes. 1 Yet, despite considerable progress in our understanding of AKI, its diagnosis at the bedside still relies largely on serum creatinine and urine output, both of which have known drawbacks. Though, both are useful measures of kidney function, neither tells us whether there is structural kidney injury, what is driving the fall in kidney function, or how likely it is to recover. 2 For the clinician looking after a critically ill child, these are often the questions that matter most.