Validation of Renal Angina Index (RAI) to improve the prediction of Acute Kidney Injury (AKI) in critically ill children admitted to paediatric intensive care unit (PICU)

Abstract

Background: Acute Kidney Injury (AKI) is associated with poor outcome in critically ill children. Reliable prediction of severe AKI may optimize treatment. Here we operationalize the concept of renal angina with Renal Angina Index (RAI). The objective of this study was to validate RAI for prediction of severe AKI on Day 3 of admission.Methods: A prospective observational study including children 1 month to 12 years admitted to PICU at ICH and RC, Madurai over 6 months. Clinical data, urine output (ml/kg/hour), serial S. creatinine values were collected. Renal angina positive was defined as RAI score ≥8.Results: Overall incidence of AKI was 27.8%. Day 0 RAI ≥8 was 42.9% of which 56.1% developed day 3 AKI. RAI ≤8 had high NPV of 93% for Day 3 AKI. Renal angina concept using RAI predicts subsequent severe AKI. RAI provides clinically feasible and applicable methodology to identify critically ill children at risk of severe AKI lasting beyond functional injury. RAI may potentially reduce capricious AKI biomarker use.Conclusions: The use of renal angina to stratify patients for enrollment in biomarker or therapy trials may create the uniformity required to properly analyze AKI in pediatric population. We believe that renal angina is a clinical adjunct that will lead to the optimization of AKI biomarker performance across the wide-ranging heterogeneity that exists across the general pediatric PICU population. RAI may potentially reduce capricious AKI biomarker use by identifying patients in whom further testing would be most beneficial.