A single-center randomized controlled trial in the Annals of Thoracic Surgery found a significant reduction in the  90-day mortality with early initiation of renal replacement therapy (RRT) in patients diagnosed with acute kidney injury (AKI) after surgery for acute type A aortic dissection. 
The trial enrolled 212 patients who developed severe postoperative AKI, classified as Kidney Disease: Improving Global Outcomes (KDIGO) stage 2, and had elevated plasma neutrophil gelatinase-associated lipocalin levels (>150 ng/mL). Patients without immediate life-threatening complications from renal failure were randomly assigned to either early or standard RRT groups.
The early RRT group received treatment within six hours of KDIGO stage 2 diagnosis, whereas the standard group began RRT within eight hours of reaching stage 3. The primary outcome assessed was 90-day mortality.
Early RRT significantly lowered 90-day mortality to 30.2%, compared to 51.9% in the standard group (P = .001). The early intervention group also had a reduction in in-hospital mortality (24.5% vs. 38.7%; P = .03) and 30-day mortality (28.3% vs. 43.4%; P = .02). However,  no statistically significant difference between the two groups was reported in terms of organ dysfunction, ICU stay, or total hospital length of stay.