Abstract 16847: Comparison of Urine Output and Creatinine as Markers for Severe Acute Kidney Injury in the Immediate Post-Operative Period After Pediatric Heart Transplant

Abstract

Background: Urine output (UOP) is an important indicator for acute kidney injury (AKI) in the pediatric critical care setting as it captures approximately 20% of patients who would go undiagnosed with creatinine data alone. We hypothesized that UOP remains clinically relevant indicator of severe AKI in the immediate post-operative period after pediatric heart transplant (HT). Methods: We performed a retrospective descriptive study of all patients who underwent HT at a single, quaternary care pediatric institution between 1/2016-11/2019. Severe AKI was defined as &gt= stage 2 using the Kidney Disease Improving Global Outcomes (KDIGO) criteria and measured at POD 1, 2 and 3, respectively. Baseline creatinine was defined as the lowest creatinine value in the 3 months preceding HT. Results were then subdivided into those who met severe AKI based on KDIGO creatinine criteria alone versus and those meeting criteria only by UOP. Results: During the study period, 94 patients underwent HT. Median age at HT was 7 years (range 1 month - 23 years). Criteria for severe AKI was met by 40%, 49%, and 52% at POD 1, 2 and 3 respectively. Of these, 95%, 93%, and 94% were captured with creatinine criteria (Figure 1.) Comparatively, only 3%, 3% and 4% were captured with only UOP criteria at POD 1, 2 and 3 respectively. Figure 2 illustrates an almost uniform decrease in UOP at hour 11 (median 0.83 ml/kg/hr, IQR 0.59-1.36 ml/kg/hr) with subsequent dispersion over time. Conclusions: Severe AKI is common after OHT and is largely nonoliguric, with significant less capture of severe AKI based on UOP alone. Most patients experience a decline in UOP in the first 12h but were rarely oliguric in the first 48h.