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Originally posted by inservice mary:
does anyone know how to calculate the KoA of dialyzers? What does the "A" stand for? How does it correlate to urea clearance?

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Originally posted by Dialysis Rat:

quote:

Originally posted by inservice mary:<br />does anyone know how to calculate the KoA of dialyzers? What does the "A" stand for? How does it correlate to urea clearance?

<br /><br /><br />KOA is the coeficient of Area. You can take different blood flow rates and dialysate flow rates, along with the urea removal and get a KOA number. The higher the number the better. This is a formula that uses a Ln function. I have put it in Exel spreadsheet to determine KOA for different dialyzers. You would think that dialyzer manufacturers measure each flow rate that they quote in there specifications. This may not be so. Some manufacturers get a single KOA and then use it to calculate the different flow rates and clearances. You see, the formula can be manipulated to work either way. Either giving you a KOA or the dialyzer clearance.<br /><br />There is a study guide published by NANT that has the formula in it, I believe. Philip Varughese is the editor. <br /><br />This is a better way to analyze dialyzer performance, rather than looking at different flow rates. Flow rates may not compare between different dialyzers, but the KOA will be a single number for the dialyzer performance. Industry stays away from giving out this number as then you could really compare dialzers. You could divide KOA by cost and find the most cost effective dialyzer, for example.