Kinetic Estimated Glomerular Filtration Rate and Severity of Acute Kidney Injury in Critically Ill Children.

OBJECTIVE: To study the Kinetic estimated Glomerular Filtration Rate (KeGFR) using serum creatinine (SCr) for the identification of acute kidney injury (AKI), stages of AKI, and extent of agreement with Kidney Disease Improving Global Outcomes (KDIGO) classification in critically ill children.

METHODS: A prospective observational study was conducted in a pediatric intensive care unit (PICU) in a tertiary care institute of South India from July through August 2018. Sixty children were enrolled. The patients with known End-Stage Renal Disease (ESRD), with previous renal transplantation, admission SCr more than 4 mg per dL, expired within 24 h of admission and patients who underwent Renal Replacement Therapy (RRT) before PICU admission were excluded. KeGFR was calculated for the first seven days, and the worst achieved value was determined. AKI staging by KDIGO was compared with AKI by KeGFR value. The requirement of RRT, multi-organ dysfunction syndrome (MODS), mechanical ventilation, cumulative fluid balance, PICU stay, and hospital mortality was recorded.

RESULTS: AKI detection by KeGFR method showed a sensitivity of 93% (95% CI 80% - 98.2%) and specificity of 76% (95% CI 49.8% - 92.2%) compared to KDIGO criteria. The good agreement between KDIGO and KeGFR values for AKI was noted (Kappa = 0.71, p < 0.001). It was observed that 81.3% (n = 13) of Group-I, 56% (n = 14) of Group-II, 77.8% (n = 7) of Group-III and 90% (n = 9) of Group-IV by KeGFR were graded as Stage-0, Stage-1, Stage-2 and Stage-3 of AKI by KDIGO criteria respectively (p < 0.001). There was no significant difference noted in secondary outcomes. The survival of children with AKI and those without AKI (by both KDIGO staging and KeGFR) showed no significant difference.

CONCLUSIONS: KeGFR is highly sensitive, and there is a good agreement with KDIGO criteria in the identification of AKI in critically ill children. Further research is required to validate these study results.