Lower versus standard dose-intensity continuous renal replacement therapy: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to evaluate clinical outcomes of lower continuous renal replacement therapy (CRRT) dose-intensity compared with guideline-directed standard dose-intensity CRRT. A comprehensive search of MEDLINE, Embase, CINAHL, and the Cochrane Library was performed from inception to September 19, 2025. Eligible studies included randomized controlled trials (RCTs) and observational studies of adults with acute kidney injury (AKI) receiving CRRT. The primary exposure was delivered lower dose-intensity CRRT (< 20 mL/kg/hr) compared with guideline-directed standard dose-intensity CRRT (≥ 20–40 mL/kg/hr). The primary outcome was intensive care unit (ICU) mortality. Certainty of evidence was assessed using the GRADE approach. (CRD420251135606) Fourteen studies (3 RCTs, 11 cohorts) comprising 5,318 patients were included. RCTs had moderate risk of bias, whereas most cohort studies had serious risk. Lower CRRT dose-intensity was associated with decreased ICU mortality (6 studies) compared with standard dose-intensity (OR 0.77; 95% CI 0.60–0.98; p = 0.04; I2 = 26.9%; very low certainty). However, sensitivity analysis based on a Hartung-Knapp Sidik-Jonkmann model showed no difference in ICU mortality between groups (OR 0.77 [95% CI; p = 0.10, 0.55–1.08]). There were no significant differences between groups for dialysis duration, dialysis dependence at discharge, hospital LOS, or mechanical ventilation duration. In a subgroup analysis, a very low dose-intensity group (< 13 mL/kg/hr) was associated with an increased risk in 90-day mortality (OR 1.72; 95% CI 1.31–2.24; p < 0.001, I2 = 0%; very low certainty). Among critically ill adults with AKI receiving CRRT, lower dose-intensity therapy was not associated with increased ICU mortality. Other key clinical endpoints were comparable, based on very low certainty of evidence. These findings support further research to investigate the impact of lower CRRT dose-intensity.