The Renal Angina Index (RAI) developed at Cincinnati Children’s can predict whether a child will develop severe acute kidney injury (AKI) within three days of admission to the pediatric intensive care unit (PICU).

Researchers validated the novel risk stratification system in a 2016 study. Now, clinicians are integrating the RAI with an automated clinical decision support program to improve its ease of use at the bedside.

A three-year prospective trial called TAKING FOCUS 2 (TF2) is testing the program. First-year TF2 data demonstrate improved prediction of severe AKI when the urinary biomarker neutrophil gelatinase-associated lipocalin (NGAL) is evaluated in patients with an RAI >8 in critically ill children. These data have just been published in Kidney International Reports.

AKI occurs in about 25% of critically ill children admitted to the PICU. Severe AKI is independently associated with morbidity and 28-day mortality. RAI results let clinicians:

• Direct diagnostic tests
• Quickly guide therapy as needed for patients likely to develop severe AKI
• Avoid unnecessary interventions for patients unlikely to develop AKI

The RAI system “provides real-time data that helps intensivists and nephrologists support patients with severe AKI in a standardized way earlier than they did before,” says pediatric nephrologist Stuart Goldstein, MD, Director of the Center for Acute Care Nephrology at Cincinnati Children’s. He spent over 10 years developing and studying the RAI.

“We hypothesize that if you start continuous renal replacement therapy (CRRT) earlier in high-risk patients, you can prevent the ill effects of fluid overload, reduce the duration of CRRT, and shorten ICU and overall length of stay,” Goldstein says. “This approach could lead to higher survival rates for these patients.”

Integrating the RAI for Clinical Decision Support

TF2 integrates the RAI into the Epic™ electronic medical record at Cincinnati Children’s.

Epic™ automatically calculates the RAI in the first 12 hours of admission to the PICU. If the RAI >8, a clinician simply releases a standard order for an NGAL test. Clinicians use the results to guide treatment, which can include fluid management and renal replacement therapy initiation.

Goldstein hopes that the TF2 study leads to the universal availability of an automated RAI tool that clinicians everywhere can use.

What Is the RAI?

The RAI assigns points for AKI risk factors:

• PICU admission (one point)
• Transplantation status (three points)
• Intubation and vasoactive medication administration (five points)

The total points are multiplied by a factor representing creatinine changes over baseline or fluid accumulation during the first 12 hours of an ICU admission. Patients with an RAI <8 have a small (<2%) chance of developing severe AKI.

Patients who score eight or higher are tested for the urinary biomarker NGAL. A concentration greater than 150 ng/ml indicates a 60% chance the child will develop severe AKI within 72 hours of PICU admission.

The Center for Acute Care Nephrology Research Team is now evaluating the clinical outcomes of TF2, comparing the four years before and after implementation. They expect that TF2 era patients who are RAI+ (> 8) and NGAL+ (>150 ng/ml) may have shorter time to CRRT initiation and less fluid overload with resultant decreased time on mechanical ventilation and in the PICU.