Prediction of Severe Acute Kidney Injury by Positive Renal Angina Index and Cystatin C in Children with Septic Shock: A Diagnostic Accuracy Study.

OBJECTIVE

To evaluate the predictive performance of Renal Angina Index (RAI) for the development of severe acute kidney injury (AKI) in children with septic shock and to compare its performance with serum and urine cystatin C.

METHODS

This diagnostic accuracy study enrolled 60 consecutive children admitted to the Pediatric Intensive Care Unit (PICU) with septic shock. The primary outcome was the proportion of children with positive RAI who developed severe AKI within seven days of admission. Secondary outcomes included comparing the performance of RAI with serum and urine cystatin C for early prediction of severe AKI, and evaluating its predictive ability for the need for renal replacement therapy (RRT), mechanical ventilation (MV), and 28-day mortality.

RESULTS

Renal angina index was positive in 29 (48.3%) patients. Positive RAI showed a sensitivity of 81.8% and specificity of 92.6%, with an area under the receiver operating characteristic curve (AUROC) of 0.81(95% CI, 0.69-0.90) for predicting severe AKI. The AUROCs of serum and urine cystatin C were 0.89 (95% CI, 0.86-0.99) and 0.72 (95% CI, 0.60-0.84), respectively. The combination of RAI and serum cystatin C yielded an AUROC of 0.99 (95% CI, 0.98-1.00). The AUROCs of RAI for predicting need for RRT, MV, and mortality were 0.84 (95% CI, 0.71-0.96), 0.73 (95% CI, 0.59-0.86) and 0.74 (95% CI, 0.58-0.89), respectively.

CONCLUSION

Renal angina index has good accuracy for predicting severe AKI within seven days of admission in children presenting with septic shock. RAI combined with serum cystatin C provides better predictability for severe AKI.