Performance evaluation of different filtration fraction during daytime continuous renal replacement therapy

Objective: To investigate the effects of different filtration fractions (FFs) during daytime continuous venovenous hemodiafiltration (CVVHDF) post-dilution. Methods From April to December 2021, forty patients who received CVVHDF in the Second Affiliated Hospital of Nanchang University were randomly assigned to the low FF group (FF: 20–25%) or the high FF group (FF: 25–30%) and then compared with each other. The lifespan of the extracorporeal circuit and other performance metrics were compared between the two groups. Results During treatment, there was no statistically significant difference in arterial pressure between the two groups at 2 hours, 6 hours and the end of treatment compared with that at 1 hour of treatment ( P =  0.30, 0.27, 0.87). There was no statistically significant difference between the venous pressure at 2 hours, 6 hours and the end of treatment compared with that at 1 hour of treatment ( P =  0.55, 0.53, 0.53), and there was also no statistically significant difference in transmembrane pressure ( P =  0.55, 0.63, 0.53). There was no statistically significant difference in the clotted filter or the extracorporeal circulation circuit at the end of CRRT between the two groups ( P =  0.95, 0.31). There were statistically significant differences in the clearance efficiency of serum creatinine ( P  = 0.04). Conclusion For patients with daytime CRRT, CVVHDF treatment with FFs < 25% compared with FFs of 25–30% has no statistically significant difference in the risk of coagulation during cardiopulmonary bypass, while the efficacy seems to be significantly different. This study aims to provide supportive data for the criteria for defining FF in clinical practice.