Prediction of Severe Acute Kidney Injury using Renal Angina Index in a Pediatric Intensive Care Unit

ABSTRACT

Objectives: To determine the proportion of children in a pediatric intensive care unit with apositive Day 0 Renal angina index who develop severe acute kidney injury (AKI) on Day 3;and to compare the predictive ability of the index with that of individual markers of renal injury,for the development of severe acute kidney injury. Design: Observational study. Setting:Pediatric intensive care unit of a tertiary-care hospital. Participants: Consecutive children, 1month to 12 years, admitted in Level 3 pediatric intensive care unit for a minimum of 8 hours,having weight and intake-output records, were eligible. Children known to have chronickidney disease or already in stage 2/3 acute kidney injury/dialysis were excluded.Procedure Day 0 Renal angina index was calculated from the product of Risk Group score(Pediatric intensive care admission/Ventilation and inotropy) and Renal Injury score (fluidoverload over previous 8 hours or the % fall in estimated creatinine clearance from baseline).Renal angina index ≥8 was considered positive. Main outcome measure: The proportion ofchildren with positive Day 0 Renal angina index who develop severe AKI (Kidney DiseaseImproving Global Outcomes (KDIGO) ≥ Stage 2) on Day 3. Results: Of 162 enrolled children(median (IQR) age 10.5 (3,39) months), 86 (53%) had positive Renal angina index. On Day 3,a higher proportion of children with positive index developed severe AKI, compared tonegative group (RR 95.5; 95% CI 21.7,420.5; P<0.001). Day 0 positive Renal angina indexhad a sensitivity, specificity, positive predictive value and negative predictive value of 96.9%,75.5%, 72% and 97.4% respectively, for predicting severe AKI on Day 3. The ReceiverOperating Characteristic curve of Day 0 renal angina scores showed AUC of 0.90 (95% CI0.85, 0.95), better than the AUC obtained from either Day 0 serum creatinine or Day 0 percentfall in estimated creatinine clearance from baseline. Conclusion: Day 0 Renal angina indexpositivity is a promising tool to identify critically ill children with impending severe AKI.