Impact of CRRT Timing on Mortality in Oliguric Sepsis-Associated Acute Kidney Injury: A Propensity Score Matching...

This study aims to evaluate how the timing of continuous renal replacement therapy (CRRT) initiation influences survival outcomes in oliguric patients with sepsis-associated acute kidney injury (S-AKI) admitted to the intensive care unit (ICU).

Using the MIMIC-IV database, we conducted a retrospective analysis of 2,131 ICU patients with oliguric S-AKI who had CRRT records. Patients were categorized into 2 groups according to the timing of CRRT initiation: early initiation within 48 hours (n = 1,222) and delayed initiation after 48 hours (n = 909) following the onset of oliguria. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were applied to adjust for confounding factors. Baseline characteristics, physiological parameters, and laboratory findings were compared between the 2 groups. Survival outcomes were analyzed using Kaplan-Meier curves and log-rank tests, with a primary focus on 90-day mortality.

Patients who initiated CRRT more than 48 hours after oliguria onset had significantly longer ICU stays compared to those who received early CRRT (17.6 vs. 11.5 days, P < 0.001) and exhibited higher SOFA scores (11.5 vs. 9.14, P < 0.001). After PSM, delayed CRRT was associated with decreased 90-day survival among patients with oliguria, as demonstrated by Kaplan-Meier analysis (P < 0.05). Causal inference showed a 10% increase in the 90-day mortality rate for patients who started CRRT after 48 hours (ATE 0.11, 95% CI: 0.02 - 0.19, P = 0.01).

Early initiation of CRRT, within 48 hours of oliguria onset, in S-AKI patients is associated with improved 90-day survival. These findings suggest that earlier CRRT initiation may be beneficial for improving survival outcomes in this patient population.