Effects of filter membranes adsorbing inflammatory mediators in hemofiltration

Objective: In this study, an in vitro hemofiltration model was set up to investigate adsorptive saturation time of different membrane under different blood flow rate (Q_B) and filtrate rate (Q_F). Methods: Anticoagulated cattle blood (2000 mL per bag) was stimulated with 1μg · mL^-1 endotoxin to induce inflammatory mediators before hemofiltration (HF) using AN69, PS and PMMA filters in vitro. Adsorptive saturation time of membrane was observed using data bridge in different Q _B and different Q_F. TNF was measured by radioimmunoassays. Results: Before the resistance level reached the peak value in the same group, resistance level increased significantly (P <0.01). After the peak value, there was no difference (P>0.05). It was suggested that the resistance level reached plateau at 150, 120, 90, 120, and 150 minutes in Q_F of 100 mL · minute^-1, 200 mL · minute^-1, 300 mL · minute^-1, respectively and in Q_F of 1L · hour^-1, 2L · hour^-1, 4L · hour^-1, respectively. And with the Q_B and Q_F increasing, resistance level increased significantly (P<0.01) among different groups at the same time point in A, B, C, D and E group. Conclusion: Membrane resistance level online measured by Data Bridge can instantly reflect the degree of membrane adsorption. Adsorptive saturation time of filter membrane in different filtration flow rate and blood flow rate are different.