Diffusive Versus Convective Continuous Renal Replacement Therapy for Acute Kidney Injury: A Systematic Review and Meta‐Analysis

INTRODUCTION: This review assesses whether the mode of solute clearance in continuous renal replacement therapy influences mortality and renal recovery. METHODS: The protocol was registered with PROSPERO (CRD420251030433). PubMed, Cochrane Library, and LILACS databases were searched until April 24, 2025. Observational studies and randomized controlled trials comparing diffusive and convective strategies of continuous renal replacement therapy in patients with acute kidney injury were included. Risk of bias was assessed using Cochrane ROB 2 and ROBINS-I tools. RESULTS: Thirteen studies with 1146 patients were included. Diffusive modality had no advantage over convective modality with regards to mortality in intensive care unit (RR = 1.04; 95% CI: 0.83, 1.30; p = 0.73), 28-day mortality (RR = 1.19, 95% CI: 0.89, 1.59; p = 0.25), renal recovery (RR = 1.07; 95% CI: 0.65, 1.75; p = 0.79), or the length of stay in intensive care unit (SMD = 0.16 days; 95% CI: -0.17, 0.49; p = 0.33). Filter clotting was 31% less frequent in diffusive modality (RR = 0.69; 95% CI: 0.58, 0.81; p < 0.001). CONCLUSION: Diffusive modalities of continuous renal replacement therapy are not different from convective modalities in terms of mortality and renal recovery. However, they have the advantage of a longer filter lifespan resulting from less frequent clotting.