Blood and tissue detoxification method

• US 3,878,564 A
• Filed: 04/17/1973
• Issued: 04/22/1975
• Est. Priority Date: 04/14/1972
• Status: Expired due to Term

• Current Assignee: Shang J. Yao, Sidney K. Wolfson
• Original Assignee: Shang J. Yao, Sidney K. Wolfson
• Inventors: Yao, Shang J., Wolfson, Sidney K.
• Primary Examiner(s): Frinks, Ronald L.
• Application Number:
  US05/352,070
• Time in Patent Office: 735 Days
• Field of Search: 3/1 128/1R,214R,DIG.3,419B 210/321
• US Class Current: 604/5.04
• CPC Class Codes: A61F 2/00 Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents as cosmetic articles, see the relevant subclasses, e.g. wigs, hair pieces, A41G3/00, A41G5/00; artificial nails A45D31/00; dental prostheses A61C13/00; materials for prostheses A61L27/00; artificial hearts A61M60/00; artificial kidneys A61M1/14
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/3687 Chemical treatment A61M1/3675 takes precedence

Abstract

Method and apparatus for blood and tissue detoxification by oxidation of excess undesirable or toxic substances such as ammonia, urea, creatinine, alanine, carbon monoxide, drug overdoses, uric acid, acetone, aceto acetate and ethanol in an electrochemical cell which may be implanted or used in an extracorporeal shunt system. The cell may be hybridized with a battery to drive the cell under certain conditions, and the cell may be employed as part of a blood toxic substance level monitoring system. The invention is typified by the case where electrochemical cells convert oxygen and the enumerated toxic substances in the body fluids to harmless products such as CO2, water and nitrogen which are easily dissipated. The cells have hydrophobic cathodes having a membrane thereover of silicone rubber, polyfluorocarbon, polycarbonate, and copolymers thereof which permit diffusion of oxygen therethrough. The anodes may be either hydrophilic or hydrophobic, the former employing a membrane thereover of cellulose or a cation resin and the latter a silicone rubber toxic substance- diffusible membrane. The electrodes are separated by an anion exchange membrane, or inorganic matrix edge-impregnated with a cation exchange membrane. The cells are simple of construction, and typically thin, wafer-like in form which permits ease of implantation at any desired location in the body. In its broadest aspect, the invention involves the use of electrochemical cells in the manner of artificial organs to remove toxic substances the body is unable to metabolize. Ammonia and ethanol, uric acid, urea, drugs such as digitalis glycosides or barbiturates, and toxic agents such as methanol may be oxidized to nontoxic products such as N2, H2O, acetate and CO2. Diabetic acidosis can be improved by oxidizing ketone bodies and aceto acetate to CO2 and water. This method will detoxify or eliminate any substance which is oxidizable to harmless or less harmful products and which can be selectively or non-selectively admitted to the anode by means of specific or non-specific covering membranes. The anode itself may also be selective with respect to the toxic substance to be eliminated. In specific embodiments, the electrochemical cell can be used in an extracorporeal shunt system to rapidly oxidize dialysate-urea and dialysate-ammonia contained in hemodialysis fluid.

Claims

1. A method of treating patients having metabolic imbalances comprising the steps of:

a. selecting a patient having relatively high concentrations of oxidizable toxic substances which their bodies are unable to metabolize or remove to substantially non-toxic levels, b. said toxic substances being present in extracellular fluid in at least one natural bodily fluid zone selected from the circulatory system, the pericardial sac, the abdominal peritoneum, the pleural cavity, and intratissue regions, c. surgically preparing said patient to provide said extracellular fluid from at least one of said natural bodily fluid zones, d. contacting said extracellular fluid with an electrochemical cell system adapted to oxidize said toxic substances to non-toxic or metabolizable substances, e. maintaining said contact for a time sufficient to reduce the amount of said substances to relatively non-toxic substances in said patient, and f. permitting said detoxified extracellular fluid to return to a physiologic environment in said patient.

2. A method as in claim 1 wherein said toxic substances are selected from NH3, NH4 , urea, uric acid, digitalis glycosides, carbon monoxide, barbiturates, ketone bodies, aceto acetate, methanol, creatinine, alanine, ethanol, and mixtures thereof.

3. A method of treating patients as in claim 2 wherein said toxic substances are selected from urea, uric acid, NH3, NH4 and mixtures thereof and said electrochemical cell system is adapted to oxidize said NH3 or NH4 to nontoxic N2 and H2O for a time sufficient to reduce said NH3 or NH4 to relatively safe levels.

4. A method as in claim 1 wherein said step of contacting includes passing some of the blood of said Patient through an extracorporeal shunt in which said electrochemical cell is disposed.

5. A method as in claim 3 which includes the added step of supplying DC current to said cell to increase the rate of oxidation of said toxic substances in said electrochemical cell.

6. A method as in claim 3 wherein said electrochemical cell system includes a cathode assembly, and which method includes the added step of supplying air or oxygen to the cathode assembly of said cell.

7. A method as in claim 3 wherein said cell is adapted for implantation and includes an oxygen permeable membrane in association with a cathode assembly, a membrane permeable to said toxic substances disposed in association with an anode assembly, and an ion transfer membrane between said assemblies, and said cell is disposed in said body so that said membranes are in contact with said extracellular fluid.

8. A method as in claim 7 wherein said cell is implanted in a manner so that said anode membrane is exposed to blood of said patient.

9. A method as in claim 3 which includes the steps of:

a. Monitoring the output of said cell system as a measure of the patient'"'"''"'"'s toxic substance concentration, and b. Selectively supplying current to said cell when said monitored concentration reaches a predetermined level to promote oxidation of said substance.

10. A method as in claim 1 wherein said cell system includes a hydrophobic cathode assembly containing a high surface area metal consisting essentially of silver and an anode assembly containing a high surface area metal comprising platinum.

11. A method as in claim 2 wherein said toxic substances are NH3 and NH4 generated by the action of urease on dialized urea in a hemodialysis fluid.

12. A method as in claim 11 wherein said step of contacting includes passing the dialysate of said patient through urease in a closed loop circuit in which said electrochemical cell is disposed downstream of said urease.

13. A method as in claim 11 which includes the added step of supplying DC current to said cell to increase the rate of oxidation of said NH3 or NH4 generated by the action of urease on urea in hemodialysis fluid in said electrochemical cell.

14. A method as in claim 11 which includes the added step of supplying air or oxygen to the cathode portion of said cell.

15. A method as in claim 1 wherein said toxic substance is urea in a hemodialysis fluid.

16. A method as in claim 15 wherein said step of contacting includes passing the dialysate of said patient in hemodialysis through an extracorporeal shunt in which said electrochemical cell is disposed.

17. A method as in claim 15 which includes the added step of supplying DC current to said cell to increase the rate of oxidation of said urea in the hemodialysis fluid in said electrochemical cell.

18. A method as in claim 15 wherein said electrochemical cell system includes a cathode assembly, and which method includes the added step of supplying air or oxygen to the cathode assembly of said cell.