Reference Change Value Based AKI Criteria in Critically Ill Children

Recently, a new criterion for acute kidney injury (AKI), the pediatric reference change value optimized for AKI in children (pROCK criterion), has been introduced, to account for the high analytical and biological variability observed with serum creatinine. However, there is limited information about this novel criterion.

Consecutive children aged 1 month to 18 years admitted to the pediatric intensive care unit (PICU) of a tertiary care center from February 2023 to December 2024 were prospectively enrolled. Using the pROCK criterion, incidence of AKI within 7 days of PICU entry, and the diagnostic performance of this criteria was compared with other AKI criteria.

Of the 907 patients screened, 478 were found eligible and followed up with until discharge. The incidence of AKI as per pROCK, the Kidney Disease: Improving Global Outcomes (KDIGO), the Pediatric Risk, Injury, Failure, Loss of kidney function and End-stage renal disease (pRIFLE), and AKI Network (AKIN) criteria were 25.3%, 30.5%, 37.6%, and 30.5%, respectively. The incidence varied significantly based on the definition used to assume baseline creatinine, with the pROCK criteria identifying less false positives at low baseline creatinine. There was very good agreement between pROCK and KDIGO for identifying any AKI (kappa statistic [K] = 0.91) and No-AKI (K = 0.91), and good agreement for stage 3 AKI (K = 0.76). Whereas KDIGO offered the highest sensitivity (100%), pROCK had the highest specificity (96.2%). The pROCK criteria was an independent predictor of mortality.

The pROCK criteria can effectively diagnose AKI, with the added advantage of specificity, thereby able to better identify "true AKI," especially in infants and young children with lower ranges of serum creatinine. Further refinement in the pROCK definition with incorporation of urine output criteria is warranted.