(1331) Beyond AKI Staging: Importance of Trajectory of Serum Creatinine in Sepsis-Associated AKI

Introduction: Sepsis-associated Acute Kidney Injury (SA-AKI) is very common and is associated with poor outcomes. Peak SA-AKI stage and its persistence (AKI lasting 48h or more) are known to correlate with outcomes, however, it is unclear if the actual trajectory of creatinine early during AKI impacts outcomes. We aimed to elucidate creatinine trajectories in SA-AKI patients during the first 96 hours of intensive care unit (ICU) admission and determine their impact on clinical outcomes.

Methods: We performed a retrospective study using MIMIC-IV database. We identified patients with sepsis who developed AKI within 48h of their first ICU admission. We excluded patients with age < 18yr, end-stage kidney disease or on dialysis. We used latent class mixed model (LCMM) to identify their creatinine trajectories. We compared dialysis within 7 days of ICU admission and mortality amongst the trajectories using chi squared test.

Results: Among 4694 patients we identified 6 distinct creatinine trajectories:
Trajectory 1(n=1295) had nadir from baseline creatinine followed by peak at AKI stage 1 by 48h, with subsequent recovery.
Trajectory 2(n=1473) had AKI stage 1 on admission with rise in creatinine in next 24h followed by recovery.
Trajectory 3(n=172) had AKI stage 1 on admission with sustained rise leading to persistent stage 2 AKI.
Trajectory 4(n=786) had AKI stage 1-2 on admission with peak at AKI stage 2 by 24h followed by persistent stage 1 AKI.
Trajectory 5(n=778) had AKI stage 2-3 on admission with peak at AKI stage 3 by 48h followed by stage 2-3 persistent AKI.
Trajectory 6(n=190) had admission with AKI stage 3 with its continued persistence.
13.9% patients needed dialysis within 7 days of hospital admission and in-hospital mortality rate was 17.6%. The need for dialysis was highest in trajectory 6(54.2%), followed by 5(34.9%), 4(13.5%), 3(13.4%), 2(6%) and 1(2.8%) (p < 0.001). Mortality was highest in trajectory 3(40.7%) followed by 5(24.8%), 4(20%), 6(19.5%), TRJ2(14.3%) and 1(12.3%) (p < 0.001).

Conclusions: We identified 6 distinct creatinine trajectories with differences in AKI staging, persistence and outcomes. Serum creatinine trajectories provide valuable information and offer a novel approach for studying SA-AKI.