(198) Cardiopulmonary Bypass Duration, NephroCheck Test Value, and AKI in Pediatric Patients

Introduction: Acute kidney injury (AKI) is associated with increased morbidity and mortality in the pediatric cardiac population. AKI is associated with a longer duration of cardiopulmonary bypass (CPB). Urinary biomarkers for the early detection of AKI risk, however, are gaining momentum in pediatrics. The NephroCheck Test (bioMérieux, Durham, NC) is a commercially available assay that measures two biomarkers, TIMP-2 and IGFBP-7, that has been shown to predict AKI in adults. We hypothesized that a higher NephroCheck Test result would correlate with the development of AKI and a longer duration of CPB in pediatric patients.

Methods: This was a single-center, retrospective observational IRB-approved study conducted in the cardiac ICU within a children’s hospital. Pediatric patients < 18 years of age who underwent cardiac surgery involving CPB who had a NephroCheck Test result obtained as part of their clinical care were included. Baseline renal function, demographics, NephroCheck Test results and CBP duration were collected. We also compared NephroCheck results between single- and two-ventricle patients. Secondary outcomes included ICU and hospital length of stay (LOS). Postoperative renal function labs and NephroCheck Test results were collected. AKI was defined using the KDIGO guidelines.

Results: Among 141 subjects included, 10 (7.1%) developed AKI. AKI did not correlate with CPB duration and a higher NephroCheck Test result. Using a NephroCheck Test cutoff of 0.55, rather than the recommended 0.30, we found a high specificity of 84.0% and a better AUC of 0.63. More single ventricle patients (37.5%) had a NephroCheck test result >0.30, but the difference was not significant (P=0.056). We did find that our AKI population had a significantly longer ICU and hospital LOS (P < 0.05, respectively).

Conclusions: Although we did not find an association between CPB duration, NephroCheck Test result and AKI, for those that developed AKI, a significantly longer ICU and hospital LOS were seen. Given our low AKI incidence, we conclude that additional subjects may be required to determine an optimal NephroCheck Test AKI risk threshold and that this may vary by cardiac anatomy in pediatrics.