Prospective Observational Comparison of oXiris-Based Continuous Renal Replacement Therapy and Sustained Low-Efficiency Dialysis in Sepsis-Associated Acute Kidney Injury

BackgroundSepsis-associated acute kidney injury (AKI) frequently requires renal replacement therapy (RRT).Sustained low-efficiency dialysis (SLED) and oXiris-based continuous renal replacement therapy (CRRT) are established options, but prospective comparative data remain limited.This study compared ICU mortality and survival to hospital discharge without ongoing RRT between patients treated with oXiris-based CRRT and SLED. MethodsThis prospective observational study included 60 adults with septic shock-associated AKI requiring RRT in a tertiary ICU between March 2020 and March 2021; 30 received SLED and 30 received oXiris-based CRRT.Baseline characteristics, illness-severity scores, organ-support requirements, biochemical parameters, and clinical outcomes were assessed.Between-group comparisons were unadjusted; no multivariable or propensity-based adjustment was performed. ResultsPatients selected for oXiris-based CRRT had greater baseline hemodynamic and organ-support requirements, including lower mean arterial pressure (74.3 ± 11.9 vs 86.3 ± 9.6 mmHg; p < 0.001), more frequent use of three or more vasopressors (80.0%vs 20.0%; p < 0.001), and more frequent use of invasive mechanical ventilation (90.0%vs 63.3%; p = 0.015).Baseline Sequential Organ Failure Assessment (SOFA) scores were 11.0 ± 2.6 and 10.0 ± 1.7, respectively (p = 0.083), but this non-significant difference does not establish baseline equivalence.ICU mortality was higher with oXiris-based CRRT (83.3% vs 50.0%;RR 1.67, 95% CI 1.13-2.47;p = 0.006).Survival to discharge without ongoing RRT was lower with oXiris-based CRRT (10.0%vs 40.0%;RR 0.25, 95% CI 0.08-0.80;p = 0.007), but this endpoint was inherently survival-dependent.At 72 hours, SLED was associated with higher bicarbonate and lower lactate values; these comparisons used available observations and were not adjusted for baseline biochemical differences.ICU stay and RRT duration also differed, but interpretation was limited by high and unequal mortality. ConclusionSLED was associated with more favourable unadjusted outcomes, but these findings do not establish superiority.Non-randomised treatment allocation, marked baseline severity imbalance, survival-dependent outcome assessment, and differential mortality preclude causal attribution of the observed differences to RRT modality.