Continuous renal replacement therapy and neurological dysfunction in septic acute kidney injury

Sepsis-associated acute kidney injury (SA-AKI) is a frequent and severe complication of critical illness and is increasingly recognized as a contributor to remote organ dysfunction, including the brain. Experimental and clinical data suggest that SA-AKI may exacerbate neurological injury through systemic inflammation, blood–brain barrier disruption, impaired cerebral autoregulation, and altered osmotic and metabolic homeostasis, providing a biological basis for a kidney–brain axis in sepsis. Continuous renal replacement therapy (CRRT) is the preferred renal replacement modality in patients with, or at risk of, hemodynamic instability and is central to the management of severe SA-AKI. Beyond its established role in solute and fluid control, CRRT may influence kidney and brain pathophysiology by modulating the inflammatory burden, acid–base balance, and hemodynamics; however, evidence for organ-protective effects remains inconsistent, and optimal prescription strategies remain undefined. This review synthesizes clinical and preclinical evidence examining the impact of CRRT on renal and neurological outcomes in SA-AKI, with a specific focus on treatment timing, intensity, and fluid management. We integrate mechanistic insights to highlight potential pathways linking CRRT prescription to kidney and brain injury, identify critical gaps in current knowledge, particularly regarding neurological and renal outcomes, and propose priorities for future research aimed at optimizing CRRT strategies in sepsis-associated multi-organ dysfunction.

Continuous renal replacement therapy; Brain injury; Acute kidney injury; Septic acute kidney injury; Sepsis; Cognitive function

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