LCN2 and acute kidney injury: In a recent study by Mishra et al. urinary and plasma NGAL levels were measured in 71 children undergoing cardiac surgery necessitating extra-corporeal cardio-pulmonary bypass.95 Amongst the 20 children developing AKI (defined as an elevation of serum creatinine >50% from baseline), a significant rise in the average urinary NGAL levels was seen as early as 2 hours post-operatively (from 1.6 μg/L SE 0.3, to 147 μg/L SE not available), while a significant change in serum creatinine could only be noted from 24 to 72 hours postoperatively.