Method for determining the intraperitoneal volume and device for peritoneal dialysis

• US 20020107474A1
• Filed: 10/09/2001
• Published: 08/08/2002
• Est. Priority Date: 10/10/2000
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius SE & Co. KGaA)
• Inventors: Noack, Joachim
• Granted Patent: US 7,507,219 B2
• Time in Patent Office: Days
• US Class Current: 604/29
• CPC Class Codes: A61M 1/1607 before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1609 after use, i.e. downstream of dialyser
• CPC Class Codes: A61M 1/1635 with volume chamber balancing devices between used and fresh dialysis fluid
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/281 Instillation other than by gravity
• CPC Class Codes: A61M 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes

Abstract

A method and device are provided for determining a intraperitoneal volume during peritoneal dialysis. The method and device can be used in conjunction with a dialysis machine wherein a first circuit peritoneal solution from a patient'"'"'s peritoneal cavity is carried past one side of a semipermeable membrane and dialyzing fluid in a second circuit is carried past the other side of the membrane. The concentration of an endogenous substance (which during peritoneal dialysis passes through the peritoneum into the peritoneal cavity) is measured during the treatment. The intraperitoneal volume is calculated from the measured variation in concentration of the endogenous substance in the peritoneal solution. Preferably, the endogenous substance is albumin. The concentration of the endogenous substance preferably is measured at two successive times. After the first measurement, a predetermined volume of fluid ΔV is withdrawn from or added to the first circuit.

Claims

1. A method for determining an intraperitoneal volume during peritoneal dialysis, which comprising the steps of

passing peritoneal solution from a peritoneal cavity in a first circuit adjacent a first side of a semipermeable membrane;

passing dialyzing fluid in a second circuit adjacent a second side of the semipermeable membrane;

measuring the concentration of an endogenous substance that passes through a peritoneum into the peritoneal solution in the peritoneal cavity; and

determining the intraperitoneal volume from the variation in the concentration over time.

2. The method according to claim 1, wherein the measuring step further comprises:

measuring the concentration co of the endogenous substance in the peritoneal solution at a time t₁;

withdrawing or delivering a predetermined volume Δ

V of fluid in the first circuit;

measuring concentration c₁ the of the endogenous substance in the peritoneal solution at a time t₂; and

wherein the determining step further comprises;

determining the intraperitoneal volume from the equation;

$V=\frac{\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>V}{1-c_0/c_1}.$

3. The method according to claim 2, which further comprises the step of determining an ultrafiltration rate V (t₁)/t₁ from the variation in intraperitoneal volume in the time t₁-t₂;

withdrawing fluid from the first circuit at the ultrafiltration rate.

4. The method according to claim 3, which further comprises the step of:

determining continuously the variation in intraperitoneal volume during peritoneal dialysis for determination of the ultrafiltration rate.

5. The method according to claim 1, wherein the endogenous substance is albumin.

6. An apparatus for peritoneal dialysis comprising:

a dialyzing fluid source;

a dialyzer, the dialyzer divided by a semipermeable membrane into a first compartment and a second compartment, where the first compartment is part of a first circuit for peritoneal solution and the second compartment is part of a second circuit for dialyzing fluid;

a balancer for withdrawing or delivering fluid in the first circuit;

a measuring unit configured to determine the concentration of an endogenous substance in the peritoneal solution, which during peritoneal dialysis passes through the peritoneum into the peritoneal cavity; and

a calculating and evaluation unit configured to determine the intraperitoneal volume from a variation in concentration of the endogenous substance.

7. The apparatus according to claim 6, further comprising:

a control unit for controlling the balancer, the measuring unit, and the calculating and evaluation unit;

wherein the control unit controls the measuring unit such that a first concentration co of the endogenous substance in the peritoneal solution is measured at time t₁, and a second concentration c₁ of the endogenous substance in the peritoneal solution is measured at time t₂; and

wherein the control unit controls the balancer such that between time t₁, and time t₂ a predetermined volume Δ

V of fluid is withdrawn or delivered in the first circuit.

8. The apparatus according to claim 7, wherein the control unit controls the calculating and evaluation unit to determine the intraperitoneal volume from the concentrations c₀ and c₁ and the volume Δ

V.

9. The apparatus according to claim 7, wherein the calculating and evaluation unit is configured to determine a ultrafiltration rate V (t₁)/t₁ from the variation in intraperitoneal volume in the time period from time t₁ to time t₂, and wherein the control unit controls the balancer to withdraw or deliver fluid in the first circuit at the ultrafiltration rate.

10. The apparatus of claim 6, wherein the endogenous substance is albumin.