Application of a standard method to characterize clearance blood flow relationships in hemodialysis.

The effectiveness of solute removal of a hemodialyzer may be judged by the ability of the device to remove solutes over the clinical range of blood flow rates. The expression of solute removal characteristics of hemodialyzers at standard or specific blood flow rates is important for clinical use and comparison. The solute removal at a specific blood flow rate is derived mathematically, usually by the fitting of a curve to the blood flow solute removal characteristics established experimentally over a range of blood flow rates. The commonly used methods of obtaining such a relationship are discussed and a new method of curve fitting is described. This method is derived from the mathematical theory defining the overall dialyzer mass transport relationship which governs the clearance blood flow relationship in any dialyzer. The derived relationship between the blood flow rate and the clearance has been validated using data generated for a commercially produced hemodialyzer.