Automation and optimization of CRRT treatment using regional citrate anticoagulation

• US 20070066928A1
• Filed: 09/21/2006
• Published: 03/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Nikkiso Company Limited
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Lannoy, Jean-Michel
• Granted Patent: US 8,372,025 B2
• Time in Patent Office: Days
• US Class Current: 604/6.70
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3607 Regulation parameters
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3672 Means preventing coagulation
• CPC Class Codes: A61M 1/3675 Deactivation
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3313 used specific wavelengths
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards

Abstract

A system or method automates and optimizes citrate anticoagulant supplementation in a blood filtration circuit during CRRT. A processor-based control system interfaces with a blood filtration circuit to detect patient blood flow into the circuit, detect fluid loss through a hemofilter, and sense vital electrolyte concentrations in the blood flow, and in response, control the addition of citrate, substitution fluid, and electrolyte supplements to ensure stability of plasma concentrations in post-dilution flow returned to the patient. The controller executes the method embodied as process control algorithms for calculating an optimal citrate flow rate as a function of selected, detected, and calculated system parameters. Citrate may be added to the circuit separately, or as part of a substitution solution or a dialysate.

Claims

1. A system for optimizing citrate anticoagulant supplementation in a blood filtration circuit during a CRRT of a patient, comprising:

a citrate pump causing flow of citrate solution into the blood filtration circuit;

an electrolyte sensor detecting electrolyte concentration in blood flow from the patient; and

a controller controlling the flow from the citrate pump as a function of the sensed electrolyte concentration.

2. The system of claim 1 wherein the controller further comprises

a processor;

and

software, executable by the processor, for determining a rate of the citrate pump flow.

3. The system of claim 6 wherein the processor receives input representing the detected electrolyte concentration.

4. The system of claim 1 wherein the electrolyte sensor detects concentration in the blood flow of an ion selected from the group comprising bicarbonate, calcium, chloride, copper, glucose, iron, magnesium, manganese, phosphate, potassium, sodium, and zinc.

5. The system of claim 1 wherein the controller controls citrate pump flow rate, E, according to E(A, B, C, D)=A×

(B+D)/C,

where A is a detected blood flow rate, B is calcium ion concentration detected by the electrolyte sensor, C is concentration of the citrate solution, and D is magnesium ion concentration detected by the electrolyte sensor.

6. The system of claim 1 further comprising a blood flow detector for detecting a flow of blood from the patient, and wherein the controller controls the flow from the citrate pump as a function of the sensed electrolyte concentration, the detected blood flow, and concentration of the citrate solution.

7. The system of claim 6 wherein the citrate solution has a selected citric acid concentration and a selected trisodium citrate concentration, and wherein the controller controls the flow from the citrate pump as a function of the detected blood flow, the sensed electrolyte concentration, the selected citric acid concentration, and the selected trisodium citrate concentration.

8. The system of claim 7 wherein the controller controls citrate pump flow rate, E, according to E(A, B, C, D, G)=A×

(B+D)/(C+G),

where A is the detected blood flow rate, B is calcium ion concentration detected by the electrolyte sensor, C is the selected citric acid concentration, D is magnesium ion concentration detected by the electrolyte sensor, and G is the selected trisodium citrate concentration.

9. The system of claim 1 further comprising:

a blood flow detector for detecting a flow of blood from the patient;

a means for detecting fluid loss rate in the blood filtration circuit;

an electrolyte solution having a selected calcium ion concentration and a selected magnesium ion concentration; and

an electrolyte pump causing flow of the electrolyte solution supplementing post-filtration blood flow;

wherein the controller controls the flow from the electrolyte pump as a function of the detected blood flow, the detected fluid loss rate, the selected calcium ion concentration, and the selected magnesium ion concentration.

10. The system of claim 9 wherein the controller further comprises

a processor;

and

software, executable by the processor, for determining the citrate pump flow rate and the electrolyte pump flow rate, and for calculating an ultrafiltration rate as a function of the detected fluid loss rate, the determined citrate pump flow rate, and the determined electrolyte pump flow rate.

11. The system of claim 10 further comprising

the citrate solution having a selected trisodium citrate concentration;

a substitution solution having a selected sodium concentration;

a substitution solution pump causing flow of the substitution solution supplementing the blood flow; and

a means for detecting substitution solution flow rate;

wherein the controller further determines a post-dilution flow rate as a function of the detected blood flow rate, the selected trisodium citrate concentration;

the calculated ultrafiltration rate, the selected sodium concentration of the substitution solution, and the detected substitution solution flow rate.

12. The system of claim 1 wherein the citrate solution supplements the blood flow as a pre-dilution solution in the blood filtration circuit.

13. The system of claim 1 wherein the citrate solution enters the blood filtration circuit with a dialysate.

14. A method for optimizing citrate anticoagulant supplementation in a blood filtration circuit during a CRRT of a patient, the method comprising steps of:

flowing a citrate solution through the blood filtration circuit;

detecting electrolyte concentration in blood flow from the patient; and

controlling the flow of the citrate solution into the blood filtration circuit as a function of the detected electrolyte concentration.

15. The method of claim 14 wherein the electrolyte concentration detecting step detects an electrolyte from the group comprising bicarbonate, calcium, chloride, copper, glucose, iron, magnesium, manganese, phosphate, potassium, sodium, and zinc.

16. The method of claim 14 wherein the electrolyte concentration detecting step comprises detecting a calcium ion concentration and a magnesium ion concentration.

17. The method of claim 16 further comprising detecting a rate of the blood flow from the patient.

18. The method of claim 17 wherein the controlling step comprises controlling citrate solution flow rate, E, according to

E=A×

(B+D)/C,

where A is the detected blood flow rate, B is the detected calcium ion concentration, C is concentration of the citrate solution, and D is the detected magnesium ion concentration.

19. The method of claim 17 wherein the citrate solution has a known citric acid concentration and a known trisodium citrate concentration,

wherein the controlling step comprises controlling citrate solution flow rate as a function of the detected blood flow, the detected calcium ion concentration, the detected magnesium ion concentration, the known citric acid concentration, and the known trisodium citrate concentration.

20. The method of claim 19 wherein the controlling step comprises controlling citrate solution flow rate, E, according to E=A×

(B+D)/(C+G),

where A is the detected blood flow rate, B is the detected calcium ion concentration, C is the known citric acid concentration, D is the detected magnesium ion concentration, and G is the selected trisodium citrate concentration.

21. The method of claim 14 further comprising:

detecting fluid loss rate in the blood filtration circuit;

adding to the blood flow an electrolyte solution having a selected calcium ion concentration and a selected magnesium ion concentration; and

controlling flow of the electrolyte solution into the blood flow as a function of the detected fluid loss rate, the selected calcium ion concentration, and the selected magnesium ion concentration.

22. A computer-readable storage medium in which the steps of claim 14 are embodied as a series of instructions executable by a computer processor.

23. The method of claim 14 wherein the citrate solution flows from pre-dilution substitution solution.

24. The method of claim 14 wherein the flowing step further comprises flowing the citrate solution through the blood filtration circuit with a dialysate.

25. In a blood filtration circuit adding substitution fluid prior to filtration by pre-dilution flow and after filtration by post-dilution flow, a method for controlling post-dilution flow rate during a CRRT of a patient, the method comprising:

detecting a flow rate of blood, A, from the patient;

selecting a concentration, G, of trisodium citrate for supplementing the blood flow;

calculating an ultrafiltration rate, I;

selecting a sodium concentration, P, for the substitution fluid in the pre-dilution flow;

detecting a flow rate, Y, of the pre-dilution flow; and

controlling post-dilution flow rate as a function of A, G, I, P and Y.