Prognosis of Severe Acute Kidney Injury Requiring Renal Replacement Therapy: A Systematic Review

Abstract

Introduction. Acute kidney injury (AKI) requiring renal replacement therapy (RRT) represents the most severe spectrum of
AKI in critically ill patients and is associated with high mortality and long-term morbidity. To systematically review short- and
long-term outcomes and prognostic factors in adult patients with severe AKI requiring RRT in intensive care settings.
Methods. A systematic search of PubMed, Embase, and the Cochrane Library was conducted from January 2000 to June
2024 in accordance with PRISMA 2020 guidelines. Adult studies reporting mortality and/or renal outcomes in AKI requiring RRT
were included. Data were synthesized narratively.
Results. Thirty-two studies involving over 80,000 patients were included. Short-term mortality ranged from 40% to 70%, with
hospital mortality frequently exceeding 50%. Long-term mortality remained high, approaching 70 to 80% at 5 to 10 years. Renal
recovery occurred in approximately 30 to 40% of survivors, while 10 to 20% remained dialysis-dependent at discharge. Prognosis
was predominantly influenced by sepsis, multi-organ failure, illness severity scores, advanced age, and fluid overload.
Conclusions. Severe AKI requiring RRT is associated with poor short- and long-term outcomes. Prognosis is driven primarily by
the severity of critical illness rather than dialysis-related factors, highlighting the need for early risk stratification and structured
post-ICU follow-up.