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Kidney Week

Abstract: PO2283

Modification of the Renal Angina Index for Identifying Need for Renal Replacement Therapy in Critically Ill Pediatric Patients

Session Information

Category: Pediatric Nephrology

  • 1700 Pediatric Nephrology


  • Stenson, Erin K., Children's Hospital Colorado, Aurora, Colorado, United States
  • Soranno, Danielle, Children's Hospital Colorado, Aurora, Colorado, United States
  • Brinton, John T., Children's Hospital Colorado, Aurora, Colorado, United States
  • Gist, Katja M., Children's Hospital Colorado, Aurora, Colorado, United States

Severe acute kidney injury (AKI) is a common and serious problem affecting critically ill children that lacks effective treatment options. Currently, there are no treatment options for AKI other than supportive care. Continuous renal replacement therapy (CRRT) is employed to reduce fluid overload (FO) burden and treat metabolic disturbances in AKI. Identifying patients upon admission who may require CRRT has potential clinical care implications.


The analytic cohort consisted of patients who required CRRT and illness severity score matched controls who did not require CRRT at a single center. Patients who required CRRT had higher mortality rates, length of stay, and use of ventilatory and inotropic support. Test characteristics assessed and compared the discriminatory accuracy of three scores: 1) the renal angina index (RAI), 2) serum-creatinine based AKI on day 0 (Day0AKI) and 3) modified RAI created with an additional RAI injury tranche that corresponded to severe stage 3 AKI serum creatinine (sCr) elevation.


The optimal cutoff for creatinine-based Day0AKI was found to be stage 3; the optimal cutoff for RAI was identified as ≥ 8. AUCs were comparable at 0.78 (95% CI: 0.70, 0.87) and 0.76 (95% CI: 0.69, 0.82) respectively, although each scoring measure differed in sensitivity and specificity. The modified RAI had an optimal cutoff of ≥ 10 and had the highest AUC (0.79; 95% CI 0.72, 0.85) with a high sensitivity and moderate specificity for prediction of CRRT requirements (table 1).


As a more accurate tool for discriminating patients in need of CRRT, a modified RAI has numerous potential implications. Identifying patients who ultimately require CRRT at an earlier timepoint may influence timing of CRRT initiation in an attempt to avoid further FO, or may influence nephrotoxin administration. Furthermore, the diagnostic capabilities of the modified RAI may be further refined by the addition of urinary biomarkers. These findings should be validated in a larger cohort.

Table 1
PredictorThresholdSensitivity (95% CI)Specificity (95% CI)PPV (95% CI)NPV (95% CI)YoudenAUC (95% CI)
Day0 AKIStage 30.63 (0.45, 0.79)0.93 (0.87, 0.97)0.76 (0.56, 0.90)0.89 (0.82, 0.94)0.570.78 (0.70, 0.87)
RAI 12 hours≥80.94 (0.81, 0.99)0.57 (0.47, 0.66)0.41 (0.30, 0.52)0.97 (0.89, 1.00)0.510.76 (0.69, 0.82)
Modified RAI 12 hours≥100.91 (0.77, 0.98)0.65 (0.56, 0.75)0.46 (0.34, 0.58)0.96 (0.89, 0.99)0.570.79 (0.72, 0.85)

Abbreviations: Renal Angina Index (RAI)