A theoretical ultrafiltration model for albumin-bound toxin dialysis

A theoretical mass transfer model considering the local ultrafiltration across the hollow fiber membrane during the dialysis process of albumin-bound toxins is presented in this paper. Then, this model is compared in detail with the model in the literature, which does not consider the local ultrafiltration when the net ultrafiltration is zero and assumes the local ultrafiltration to be a constant when the net ultrafiltration is not zero. The results show that relatively, the accuracy of the literature model is limited because it neglects the effect of the linear decreasing local ultrafiltration on the toxin transport across the membrane no matter whether the net ultrafiltration is zero. Compared to the model in this study, the literature model always overestimates or underestimates the clearance of toxins, especially when the net ultrafiltration is not zero. The model in this study can be used to accurately predict the clearance of albumin-bound toxins and thereby optimize the dialysis process in artificial liver support systems.