What is the best dialysis regimen for severe AKI to allow kidney function recovery?

Acute kidney injury (AKI) recovery is a major determinant of long-term renal and patient outcomes. While transient AKI is associated with a more favorable prognosis, persistent or incomplete recovery increases the risk of chronic kidney disease, dialysis dependence, cardiovascular complications, and mortality. Renal recovery after AKI reflects the balance between adaptive repair processes and maladaptive pathways leading to fibrosis and nephron loss. Experimental and clinical evidence highlights the roles of tubular epithelial regeneration, macrophage phenotypes, inflammatory mediators, complement activation, and aging-related decline in regenerative capacity in determining recovery trajectories. Recurrent injury and persistent hemodynamic stress may further impair renal repair and promote progression to chronic kidney disease. Renal replacement therapy (RRT) may itself contribute to delayed renal recovery through "dialytrauma", a concept that encompasses all harmful adverse events related to RRT. Major mechanisms of dialytrauma include hemodynamic instability and organ ischemia, blood-membrane inflammatory activation, metabolic and osmotic perturbations, and access-related complications. Intermittent hemodialysis is particularly associated with circulatory and osmotic stress, whereas continuous RRT may expose patients to prolonged extracorporeal circulation, anticoagulation-related complications, and cumulative metabolic derangements. Peritoneal dialysis avoids extracorporeal blood contact but has other potential risks. This review summarizes the current understanding of dialytrauma as a potentially modifiable determinant of nonrecovery of renal function in patients with AKI receiving RRT. No single modality is universally superior, and minimizing unnecessary exposure, excessive intensity, and hemodynamic instability is essential. In this article, we discuss strategies to minimize the risk of dialytrauma to guide individualized RRT strategies with the aim to promote renal recovery and preserve long-term kidney health.