Renal Replacement Therapy: Key Evidence and Evolving Practice

Renal replacement therapy (RRT) is central to managing severe acute kidney injury (AKI) and end-stage kidney disease, delivered as intermittent hemodialysis, continuous renal replacement therapy (CRRT), peritoneal dialysis, or hemofiltration. Recent evidence has focused on timing of initiation, dosing, and prediction of weaning.

Timing of initiation in AKI

A consistent message has emerged from the major trials: initiating RRT earlier than clinically necessary does not improve survival. In the multinational STARRT-AKI trial, an accelerated strategy produced no mortality difference versus a standard, indication-driven approach (about 44% 90-day mortality in each arm) — and led to more dialysis dependence among survivors and more adverse events such as hypotension and hypophosphatemia. Earlier trials in sepsis-associated AKI (IDEAL-ICU) and in medical AKI (AKIKI and AKIKI-2) reached the same conclusion, and a 2025 meta-analysis reaffirmed no survival benefit from early initiation regardless of illness severity. The practical result is a preference for indication-driven timing — starting for refractory hyperkalemia, acidosis, fluid overload, or uremia rather than by the clock.

Dosing, weaning, and supportive elements

KDIGO recommends a CRRT effluent dose of 20–25 mL/kg/h, individualized to the patient; higher doses provide no mortality benefit and may add risk. Drug dosing (especially antimicrobials) must account for the altered pharmacokinetics of CRRT. Biomarkers (urinary NGAL, proenkephalin) and emerging AI-based decision tools show moderate promise for predicting successful liberation from RRT but need further validation. Patient education about CKD and RRT improves adherence, quality of life, and outcomes.

Further reading: STARRT-AKI (NEJM 2020); IDEAL-ICU (Barbar et al., NEJM 2018); AKIKI-2 (2021); KDIGO AKI/CRRT guidance.