(906) Refining the Epidemiology of Acute Kidney Injury Following Pediatric Cardiac Arrest

Introduction: Nearly 40,000 children suffer cardiac arrest (CA) each year and may experience acute kidney injury (AKI). AKI epidemiology following CA has been poorly characterized, particularly with regards to timing, severity, and identification using urine output (UOP) criteria, which we aimed to describe. Hypotheses: 1) UOP criteria alone will identify 15% of AKI; 2) Unique timing/severity phenotypes will have different outcomes and values of urinary neutrophil gelatinase-associated lipocalin (uNGAL).

Methods: Observational, single-center study of children admitted to a PICU following in-hospital and out-of-hospital (OH) CA from 2018-2022. Subjects were included if they received ≥2 minutes of CPR, were not at baseline neurologic function post-CA, and survived ≥48 hours. KDIGO AKI Stage was determined daily for 7 days post-CA using serum creatinine (SCr) and UOP criteria. Severe AKI was defined as ≥Stage 2 (≥2x baseline SCr or UOP < 0.5 ml/kg/hr for ≥12 hours). Comparisons were made between patients with “No/Mild AKI” (NM-AKI; Stage ≤1 Day 0-4), “Transient Severe AKI” (TS-AKI; Stage ≥2 on Days 0-1 only), and “Persistent Severe AKI” (PS-AKI; Stage ≥2 on Days 0-4).

Results: 77 patients (median age 2.8 years [IQR 0.76-10.5], 64% male, 58% OHCA) were included. AKI developed in 68% in the first week, with 52% severe AKI. AKI prevalence peaked on Day 0 (57% AKI, 40% severe) and decreased until Day 7 (41% AKI, 20% severe). UOP criteria alone diagnosed 11% of AKI events, including 8% of severe events. 43% had NM-AKI, 22% TS-AKI, and 35% PS-AKI. There were no differences in arrest location or duration across groups. uNGAL was higher in PS-AKI compared to TS-AKI and NM-AKI (2399 ng/ml [745-8143] vs.158 [50,783] vs. 50 [50-88], p< 0.001). Only PS-AKI patients received CRRT (n=4). 56% of PS-AKI, 47% of TS-AKI, and 39% of NM-AKI patients experienced mortality (p=0.46); survivor ICU length of stay was 27.5 days [11-46] in PS-AKI, 21 days [12-64] in TS-AKI, and 17 days [8.5-27] in NM-AKI (p=0.46).

Conclusions: Two-thirds of children develop AKI post-CA, including 35% with PS-AKI. AKI prevalence is highest on Day 0, and use of UOP criteria identifies AKI events that are not detected using only SCr. PS-AKI is distinguished by higher uNGAL and appears to trend toward worse outcomes, though larger studies are needed.