REN and acute kidney injury: Among children with SM, renin levels were higher in children with AKI on admission compared to children without AKI (median 1627 pg/mL (IQR 895, 2612) vs. 900 pg/mL (IQR 557, 1483), p<0.0001) (Figure 2A) and was associated with persistent AKI at the 24-hour follow-up (p<0.0001).