Method and device for the removal of partially protein bound substances
A method and a device to increase the efficiency of dialysis for the removal from blood of substances that are more or less tightly bound to carriers such as albumin. According to the invention this is accomplished by a simultaneous significant increase of the flow rate of the dialysis fluid and of the area of the membrane that separates the blood from the dialysis fluid, compared to conventional dialysis.
1. A method for removing partially carrier bound substances from blood comprising a blood circuit, a fluid circuit, and a filter having a semipermeable membrane separating a fluid compartment from a blood compartment, where blood is directed through the blood compartment and a cleaning fluid is directed through the fluid compartment wherein:
a mass transfer coefficient k o A of the filter is at least 2000 ml/min;
a ratio between the mass transfer coefficient k o A of the filter and a blood flow rate is at least 5;
a cleaning fluid flow rate is at least 2000 ml/min; and
a ratio between the cleaning fluid flow rate and the blood flow rate is at least 5.
2. A method according to claim 1 , wherein
the ratio between the mass transfer coefficient k o A of the filter and the blood flow rate is at least 10; and
the ratio between the cleaning fluid flow rate and the blood flow rate is at least 10.
3. A method according to claim 1 , wherein
the mass transfer coefficient k o A of the filter is at least 5000 ml/min; and
the cleaning fluid flow rate is at least 5000 ml/min.
4. A method according to claim 1 , wherein, parameters are chosen in relation to the product of a blood flow rate Q b and a factor α denoting the total amount of substance to be removed in relation to the fraction dissolved in plasma,
the mass transfer coefficient k o A of the filter is at least 10% of said product; and
the cleaning fluid flow rate is at least 10% of said product.
5. A method according to claim 4 , wherein
the mass transfer coefficient k o A of the filter is at least 100% of said product; and/or
the cleaning fluid flow rate is at least 100% of said product.
6. A device configured to remove partially carrier bound substances from blood comprising a blood circuit, a fluid circuit, and a filter having a semipermeable membrane separating a fluid compartment from a blood compartment, where blood is directed through the blood compartment and a cleaning fluid is directed through the fluid compartment wherein:
a mass transfer coefficient k o A of the filter is at least 2000 ml/min;
a ratio between the mass transfer coefficient k o A of the filter and a blood flow rate is at least 5;
a cleaning fluid flow rate is at least 2000 ml/min; and
a ratio between the cleaning fluid flow rate and the blood flow rate is at least 5.
7. A device according to claim 6 , wherein
the ratio between the mass transfer coefficient k o A of the filter and the blood flow rate is at least 10; and
the ratio between the cleaning fluid flow rate and the blood flow rate is at least 10.
8. A device according to claim 6 , wherein
the mass transfer coefficient k o A of the filter is at least 5000 ml/min; and
the cleaning fluid flow rate is at least 5000 ml/min.
9. A device according to claim 6 , wherein parameters are chosen in relation to the product of a blood flow rate Q b and a factor α denoting the total amount of substance to be removed in relation to the fraction dissolved in plasma,
the mass transfer coefficient k o A of the filter is at least 10% of said product; and
the cleaning fluid flow rate is at least 10% of said product.
10. A device according to claim 9 , wherein
the mass transfer coefficient k o A of the filter is at least 100% of said product; and/or
the cleaning fluid flow rate is at least 100% of said product.