JP2000245828A - Blood dialyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dialyzer which can prevent endotoxin from transferring to the side of blood by blocking the reverse filtration of a dialysis liquid during the dialysis of blood and the operation of the dialyzer. SOLUTION: An operation mode is arranged to always meet Qb/Qd>=0.4 in a relationship between the flow rate Qb of blood and the flow rate Qd of a dialysis liquid at any value of the flow rate Qb of blood. During the dialysis of blood, this can block reverse filtration of the dialysis liquid to the side of blood thereby preventing endotoxin from transferring to the side of blood.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dialysis device. More specifically, the present invention relates to a hemodialysis apparatus having a specific operation mode.

[0002]

In recent years, in the hemodialysis for chronic renal failure patients, urea, as well as removal of small molecular weight substances such as creatinine, beta ₂ microglobulin, by'll also remove low molecular protein such as myoglobin, long dialysis Attempts have been made to treat patient complications. These improvements are largely due to the advancement of hemodialysis membranes.However, as dialysis membranes, cellulose, cellulose acetate, polyacrylonitrile, polysulfone, polyamide, polyimide, polymethyl methacrylate, and polysiloxane with improved permeability of low molecular weight proteins are used. , Polyolefin, hollow fiber formed from ethylene vinyl alcohol and the like as a raw material,
Flat membranes have been put to practical use. On the other hand, since the pore size of the membrane is larger than before, when the dialysate flows into the blood side through the dialysis membrane, so-called back filtration occurs, the endotoxin contained in the dialysate moves to the blood side. It exerts a physiological activity and is likely to adversely affect patients. In normal hemodialysis, the endotoxin is prevented from migrating into the blood by using the dialysate after filtering using an endotoxin cut filter. However, the coupler and hose connecting the hemodialyzer and the dialysate cannot be kept completely sterile.
It was difficult to completely prevent endotoxin, a component of the bacterial body. In a conventional dialysis method, first, the blood side of a hemodialyzer is washed with a physiological saline solution, and then the dialysate flows while the arterial circuit and the venous circuit are clamped. Usually 50
Flow at a flow rate of 0 mL / min and continue flowing until dialysis is completed. Thereafter, blood is introduced, and the blood flow rate is gradually increased to a target blood flow rate. Usually 20
0 mL / min, but maintain this flow rate until end.
However, with the conventional dialysis method, it has been difficult to prevent the above-mentioned back filtration of endotoxin. In other words, the dialysis fluid is primed while the dialysis fluid is flowing at a high flow rate from the beginning, and the blood is introduced at a low flow rate as it is. Back-filtration had occurred. The degree of back-filtration is higher for membranes with higher water permeability, and the permeability of endotoxin increases the permeability of low-molecular-weight proteins, and the membrane with larger pore size is higher. The inflow to the side has become apparent as technology advances.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to prevent dialysate from being back-filtered to the blood side and to prevent endotoxin from migrating to the blood side. It is in. Then, it is an object of the present invention to provide a dialysis device and an operation method of the dialysis device for achieving the above object.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that the blood flow (Q
In the relationship between b) and the dialysate flow rate (Qd), Qb / Q
By operating the dialysis device such that the value of d becomes 0.4 or more at any value of Qb, it was found that almost no endotoxin transfer to the blood side occurred, and the present invention was accomplished. That is, the present invention provides a blood flow (Qb)
Is a hemodialysis apparatus having an operation mode in which the relationship between the blood flow rate (Qb) and the dialysate flow rate (Qd) is always Qb / Qd ≧ 0.4.
Ratio of blood flow to dialysate flow Qb at any Qb
It is not clear why the endotoxin hardly migrates to the blood side by operating the dialysis machine with / Qd of 0.4 or more. However, when the blood flow rate is low, the dialysate flow rate is reduced, so carelessness is required. It is considered that since the reverse filtration of the dialysate is suppressed, the dialysis membrane is coated with the protein in the blood, and the endotoxin is hardly permeated due to a change in the charge of the membrane or a decrease in the pore size.

Hereinafter, the present invention will be described in more detail. The blood flow rate (Qb) in the present invention is a flow rate of blood flowing into a dialyzer generally used for treating renal failure patients, and is controlled by a blood pump by setting a hemodialysis apparatus. The dialysate flow rate (Qd) is the flow rate of the dialysate flowing into the dialysate side of the dialyzer,
It is controlled by the dialysate pump by setting the hemodialysis machine. The operation mode with Qb / Qd ≧ 0.4 referred to in the present invention is a control mode on the hemodialysis apparatus side that controls the above-mentioned Qb and Qd in conjunction with each other, and Qb / Qd ≧ 0 regardless of the setting of Qb. .4 refers to the control mode of the hemodialysis apparatus that controls the blood pump and the dialysate pump so that When the value of Qb / Qd is less than 0.4, the back-filtration of the dialysate to the blood side tends to occur, which is not suitable for the purpose of the present invention. On the other hand, if the value of Qb / Qd is more than 0.4, the dialysis efficiency deteriorates, which is not preferable. The preferable value of Qb / Qd is a value as close to 0.4 as possible. However, while Qb is small, a slightly large value may take a large value since the dialysis efficiency does not decrease so much. Rather, while Qb is small, the amount of adsorbed protein is small, so that Qb / Q
The value of d preferably ranges from 0.5 to 0.7 in order to prevent back-filtration of the dialysate. From the viewpoint of easy control, the most preferable relationship between Qb and Qd in the present invention is Qb / Qd = 0.
4. Hemodialysis usually primes the dialyzer before moving on to the dialysis operation. The dialyzer includes a hollow fiber type and a laminated type, but any type can be used. The material of the film is not limited, but the present invention is particularly useful for a dialyzer using a film called a high performance membrane. The dialyzer usually has a blood inlet, a blood outlet, a dialysate inlet, and a dialysate outlet. Priming refers to an operation of washing the blood chamber and the dialysate chamber of the dialyzer with a physiological saline solution or a dialysate. Usually, the blood chamber side is washed with a physiological saline solution, and the dialysis chamber side is washed with a dialysate. In the present invention, priming on the dialysis chamber side is preferably omitted in order to prevent back filtration of endotoxin. Next, blood is introduced into the blood chamber side of the dialyzer. Usually, the blood flow is gradually increased, and then gradually increased to the set flow rate. Usually, the set flow rate is often selected to be 200 mL / min. In the present invention, the dialysate flow rate (Qd) must satisfy Qb / Qd ≧ 0.4 at any blood flow rate (Qb) at this time. It is the most important in the present invention that this condition is satisfied at the stage of this operation. As a means for achieving the operation mode on the hemodialysis apparatus side for satisfying the above condition, that is, the control mode, when the blood flow rate (Qb) is set, the dialysate flow rate (Qd) automatically becomes Qb / Qd ≧ 0.4. This can be achieved by control means for setting the range, for example, by keeping the ratio of the voltage sent to the blood pump to the voltage sent to the dialysate pump constant. The signal for determining the flow rate according to the type of the pump can be appropriately selected. An arithmetic circuit is set up within a range satisfying Qb / Qd ≧ 0.4, and when Qb is a small value, Q
It is also recommended that b / Qd be set slightly larger. After the blood flow reaches the set flow rate, normal dialysis is performed and can be brought to the end. The present invention is suitable for conventional hemodialysis and hemofiltration dialysis.

[0006]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

[Embodiment 1] A hemodialysis apparatus modified as a hemodialysis mode so that the ratio between the blood flow rate (Qb) and the dialysate flow rate (Qd) can always be controlled so that Qb / Qd ≧ 0.4. The device was used. A polysulfone membrane was used as a dialyzer, with a membrane area of 1.6 m ² and an ultrafiltration rate of 83 mL / mmHg. hr (bovine plasma used, transmembrane pressure difference 5
0 mmHg), sieving coefficient β ₂ microglobulin 0.8
2. Using a dialyzer with albumin 0.009 (using bovine plasma, ultrafiltration rate 25 mL / min · m ² )
A normal blood circuit was attached. As the dialysate, a dialysate to which endotoxin was previously added was prepared and used as a contaminated simulated dialysate. The dialysate is A made by Shimizu Pharmaceutical Co.
Using K. Solita and DL, endotoxin concentration is 153
00 EU / liter. Endospecy manufactured by Seikagaku Corporation was used to measure the endotoxin concentration. First, 1000 mL of physiological saline was added to the blood chamber of the dialyzer.
Then, the blood chamber side was primed. Thereafter, a catheter was attached to both the blood inlet side and the outlet side of the circuit. Next, add 4 liters of pooled blood to 50m
L / min blood flow (Qb) into the dialyzer,
The saline on the blood side was returned to the blood pool. At this time, since the operation mode of the hemodialysis apparatus was set so that Qb / Qd = 0.4, the dialysate flow rate (Qd) was controlled at 125 mL / min. After 5 minutes, the blood flow rate is set to 100 mL / min,
The mixture was refluxed for another 5 minutes. Similarly, the dialysate flow rate at this time is 25
It was controlled at 0 mL / min. Next, the blood flow rate was adjusted to 200 mL / min as a set flow rate, and dialysis was performed for 2 hours.
At this time, the dialysate flow rate was controlled at 500 mL / min. When the endotoxin concentration of the pooled blood was sampled and measured 5 minutes, 10 minutes, 1 hour, and 2 hours after the start of blood flow, all were detected at the detection limit (9.0 EU /
Liter).

[0007]

Comparative Example 1 A commercially available hemodialysis machine was used as the hemodialysis machine. The same dialyzer and dialysate as in Example 1 were used, and the same operations as in Example 1 were performed until priming of the blood chamber. Next, dialysate flow rate (Qd) is set to 500 mL
Per minute, 4 liters of pooled blood was introduced into the dialyzer at 50 mL / min (Qb / Qd = 0.1), and the saline on the blood side was returned to the blood pool. After 5 minutes, the blood flow rate was adjusted to 100 mL / min (Qb / Qd = 0.2), and the blood was refluxed for another 5 minutes. Next, the blood flow rate is 200 m as the set flow rate.
L / min was adjusted (Qb / Qd = 0.4) and dialysis was performed for 2 hours. The endotoxin concentration of the pooled blood was sampled and measured at 5 minutes, 10 minutes, 1 hour, and 2 hours after the start of the blood flow.
Liters, 37 EU / liter, 39 EU / liter,
It was 39 EU / liter.

[0008]

As described above, by using the hemodialysis apparatus of the present invention, the dialysate is reversed to the blood side even when a dialyzer using a membrane having a high ultrafiltration flow rate and a large pore diameter is used. Filtration can be prevented, and endotoxin can be prevented from migrating to the blood side.

Claims (3)

[Claims] 1. An operation mode in which the relationship between the blood flow rate (Qb) and the dialysate flow rate (Qd) is always Qb / Qd ≧ 0.4 at any value of the blood flow rate (Qb). Hemodialysis machine. 2. The hemodialysis apparatus according to claim 1, having an operation mode in which Qb / Qd = 0.4. 3. A hemodialysis apparatus characterized in that the relation between the blood flow rate (Qb) and the dialysate flow rate (Qd) is always Qb / Qd ≧ 0.4 at any value of the blood flow rate (Qb). Driving method.