Hemodialyzer dialysate solution

The dialysate solution is recirculated through the hemodialyzer system. In hospitals where multiple patients are treated, central dialysate supply systems are normally used. The flow rates of blood and dialysate through a hollow-fiber-type dialyzer are approximately 200-300 ml min-1 and 500 ml min-1, respectively. The more recently developed hemodialyzers have all been disposable that is, they are presterilized and used only once. Normally, a patient will undergo dialysis for 4—5 h per day, for three days each week. 

Hemodialyzer performance is analyzed using a number of indices solute transfer efficiency i/ , clearance C, and dialysance Db. The solute transfer efficiency i/ (Michaels, 1966),... 

In Section 4.3.1, we were introduced to a hemodialyzer with blood on one side of the membrane and the dialyzing solution on the other side. Solutes (metabolic waste products) from blood diffused through the liquid filled pores of the membrane to the dialysate side. Using a simple lumped analysis based on the overall solute mass-transfer coefficient Ku, we will develop an expression for the solute removal efficiency of a hemodialyzer in which blood as well as the dialyzing solution are in steady cocurrent flow (Section 8.1.7 treated countercurrent dia-lyzers). The analysis is valid for any other system, not just hemodialysis. 

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