Comparison of filter life span and solute removal during continuous renal replacement therapy: convection versus diffusion ‐ A randomized controlled trial

INTRODUCTION: This study aimed to investigate whether continuous veno-venous hemodiafiltration (CVVHDF) has a different filter life span and molecular solutes clearance when compared to continuous veno-venous hemofiltration (CVVH). METHODS: Sixty patients were enrolled in this study and randomly assigned to the CVVHDF (n = 30) or CVVH (n = 30) groups. Demographics, laboratory tests, urea, creatinine, IL-6, β2-microglobulin, and myoglobulin clearance were recorded. RESULTS: Patients in the CVVH group had a shorter median time of filter life span compared with those in the CVVHDF group (20 vs. 37.5 h, p = 0.002). Urea and creatinine clearance were not significantly different between groups over time (p > 0.05). IL-6, β2-microglobulin, and myoglobulin clearance were higher in the CVVH group. The transmembrane pressure (TMP) was significantly higher in the CVVH group. CONCLUSION: The use of CVVHDF may lead to a longer filter life span and lower clearance of medium and large molecules without affecting the small molecular solute clearance. TRIAL REGISTRATION: Chinese Clinical Trial Register (ChiCTR), ChiCTR2000029873. Registered 16 February 2020, http://www.chictr.org.cn/showproj.aspx?proj=49528.