JPH01303155A - Dewatering stopping device for blood dialysis - Google Patents

Abstract

PURPOSE:To prevent a substantial amt. of dewatering from taking place and to eliminate surplus operations so as to enhance safety by providing a pressurizing device which pressurizes the dialysis liquid of a flow passage by the air pressure of a pressure transducer and an air pressure transmission path which communicates both the air layers of the pressure transducer and the pressurizing device. CONSTITUTION:The air layer in the upper part in a hermetic vessel connected in series to a blood circuit is made to exist in the pressure transducer 6 and the pressure transducer indicates the pressure value of the blood detected via the air layer by a pressure gauge 6a. The other end of an air tube 16 is connected to the pressurizing device 15. The pressurizing device 15 is used to generate the pressure on the down stream side of a dialyzer 3 in a dialysis liquid circuit and is inserted into a flow passage 8b for stopping the dewatering. Said device generates the same pressure as the pressure in the pressure transducer 6. The differential pressure between the blood side and the dialysis liquid in the dialyzer 3 is eliminated in the state of exocirculation in this way and the progression of the dewatering is nearly completely stopped. A substantial amt. of the dewatering is prevented from taking place in case of carrying out the operation of stopping the dewatering. The need for the surplus operations during the operation to stop the dewatering is thus eliminated and the safety is enhanced.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a water removal stop device in hemodialysis using a negative pressure method, and is used to save labor, improve safety, and further automate hemodialysis. .

(Prior art) Artificial kidney device i! Hemodialysis, which is performed using a dialysis machine, is widely used to purify the blood by removing waste products from the body or taking in what is needed instead of the kidneys when the human body suffers from renal failure. ing.

The main function of the kidneys is to produce urine, and most of this urine is water, so in hemodialysis, removing water from the blood, so-called water removal, is an important issue. Water in the body moves into the blood via cells, between cells, and blood vessels in this order, but it is necessary to remove water at a rate commensurate with this transfer rate.

Recently, however, dialysis membranes used in dialyzers have been improved, and the membrane thickness has become much thinner, improving waste removal efficiency. This has also greatly improved the ultrafiltration coefficient (UFR), which may cause the patient to experience a drop in blood pressure due to the rate of water removal during dialysis becoming too fast. As a countermeasure in this case, or as a temporary stop operation during normal operation, the following operation is performed to stop water removal. In the positive pressure method, the throttle device (auto-cleaner) on the downstream side of the dialyzer in the blood circuit is released, and in the positive pressure method, the negative pressure of the dialysate is reduced to near zero.

Now, the blood that comes out of the dialyzer returns to the patient's venous blood vessels,
Many patients have various problems in the vascular lumen due to a complex intertwining of factors such as remodeling of the vascular shunt, deformation due to long-term cannula puncture, and lesions due to the underlying disease, resulting in venous vascular resistance. increases, and when dialyzed blood returns to the venous blood vessels, a resistance force proportional to the amount of blood returned (
A natural venous pressure (commonly referred to as natural venous pressure) is generated in the venous blood vessels. Therefore, even when the operation to stop water removal is performed as described above, this natural venous pressure is applied to the dialyzer as residual pressure, and in reality, a considerable amount of water is removed. For example, when the blood volume is 150 to 200 m1/min (the normal extracorporeal circulating blood volume during dialysis), the blood volume is 30 to 120 m/min depending on the patient.
120-480 ml/hr when using a dialyzer with an effective UFR of 11 g/hr and a natural venous pressure of 2001 ug or more.
body fluids are excessively dehydrated.

(Problem to be solved by the invention) In this way, in the past, a considerable amount of water was being removed even during the water removal stop operation, so the nurse had to check the amount of water removed while the water removal was stopped. It is necessary to replenish the patient with scented replacement fluid, and this work requires a great deal of effort, and most of this work relies on experience and intuition, making it difficult to ensure the safety of the patient during dialysis. The current situation is that there are still problems with sexuality.

The present invention has been made in view of the above-mentioned problems, and is intended to prevent a considerable amount of water from being removed as in the past when an operation to stop water removal is performed in hemodialysis using a positive pressure method. The purpose is to eliminate the need for extra work during the water removal stop operation and to improve safety.

(Means for Solving the Problems) The configuration of the present invention adopted to achieve the above object is to provide a dialyzer with a supply pump and a dialysate supply path having a downstream throttling means, and a dialyzer with a suction pump. A water removal stop device connected to a fluid discharge path and used to perform hemodialysis by the positive pressure generated on the dialysate side of the dialyzer based on the throttle of the dialysate suction side by the throttle means. A pressure detector is installed in the blood circuit upstream of the dialyzer to detect the pressure of the blood on the upstream side, and a pressure detector is installed in the blood circuit downstream of the dialyzer to detect the pressure of the blood on the downstream side. a pressure converter that converts the pressure of & into air pressure, a means for releasing the positive pressure, and a water removal stop flow path connected to the discharge path and configured to discharge the dialysate to the outside of the system without passing through the suction pump. a switching means for switching the flow of the dialysate to be discharged from one of the water removal stop flow path and the steady flow path passing through the suction pump; A water removal stop in hemodialysis, comprising: a pressurizer that pressurizes the dialysate in the channel using the air pressure of a pressure transducer; and a pneumatic transmission path that communicates both air layers of the pressure transducer and the pressure transducer. On the device.

(Function) If a patient experiences a drop in blood pressure due to excessive water removal during hemodialysis, a pressure detector will detect an abnormal pressure drop in the blood circuit upstream of the dialyzer, and based on this, automatic or Measures to stop water removal are taken by the person in charge. This measure simply releases the positive pressure on the dialysate side, similar to conventional positive pressure hemodialysis, but as previously mentioned, a considerable amount of water continues to be removed due to the patient's natural venous pressure. In contrast, in the present invention, this natural venous pressure is also applied to the dialysate side via the pressure transducer and pressurizer, so that the differential pressure between the blood sample in the dialyzer and the dialysate side is almost eliminated, and the ultrafiltration pressure is increased. The water removal based on the dialysis fluid stops almost completely, and only the dependent dialysis action, that is, the mass transfer based on the concentration gradient between dialysate and blood, continues.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a dialysis apparatus using the control device of the present invention. In the same figure, la and tb are cannulae, 2 is a blood pump, 3 is a dialyzer, 4 is a pressure detector, and 5
is a tube, and 6 is a pressure transducer. Dialysis machine [[[
In addition to these, an infusion needle and a heparin syringe are connected to the 1/& circuit, but these are not shown. The dialyzer 3 is connected to a dialysate supply path 7 and a dialysate discharge path 8 . The supply passage 7 includes a throttle passage 7a into which a flow rate adjustment valve 9 is inserted and a bypass valve 1.
It has a positive pressure regulating device 11 configured with a branching and merging channel that branches into a bypass channel 7b in which a 0 is inserted and joins on the downstream side, and a supply pump 12 is installed on the upstream side of this regulating device 11.
is the provision. The discharge path 8 includes a steady flow path 8a having a suction pump 13, an on-off valve 14, and a pressurizer 1 downstream thereof.
5 is inserted into the water removal stop channel 8b.

The pressure sensor 4 has a structure similar to a general air chamber, and has an air layer in the upper part of a sealed container connected in series to the blood circuit, and the blood detected by the pressure gauge 48 through the air layer. It is designed to display the pressure value. This pressure value is a nearly constant negative pressure while dialysis is being performed normally, but if excessive water removal is performed, this negative pressure increases further, so it is not necessary to stop water removal. It can be determined based on the pressure value. In addition, in such a pressure detector 4, a pressure value at which water removal should be stopped may be set, and a detection signal may be output when this detected pressure value reaches a set pressure value. Based on this detection signal, it is possible to automatically perform deep pruning when water removal is stopped, which will be described later, via a control mechanism, or to issue a warning to the person in charge with a buzzer or lamp lighting. It is. Also pressure detector 4
It is also possible to provide the pump upstream of the blood pump 2 to reduce the influence of pressure fluctuations caused by the operation of the pump.

The pressure transducer 6 has the same structure as a general air chamber except that an air tube 16 is connected to the air layer, and the air layer is located at the upper part of a sealed container connected in series to the blood circuit. , the blood pressure value detected through the air layer by a pressure gauge 68 is displayed. The other end of the air tube 16 is connected to a pressurizer 15, which will be described below.

The pressurizer 15 is for generating pressure on the downstream side of the dialyzer in the dialysate circuit when water removal is stopped, and is inserted into the water removal stop flow path 8h to convert the pressure in the pressure converter 6 mentioned above. They are designed to generate the same pressure. This pressurizer 15
As shown in FIG. 2, two container members 17a and 17b with the same curved surface shape are placed facing each other, a diaphragm 18 with the same outer circumference is sandwiched between the brim portions of both, and the two container members 17a and 17b are connected to each other. A sealed container 17 is formed by welding, and the interior is divided into a liquid chamber a and an air chamber by a diaphragm 18, and is provided with an inlet 19a, an outlet 19b, and connection ports 19c and 19d. ing. The inlet 19a and the outlet 19b are provided with a tube 8c of the flow path 8b for stopping water removal.
, 8d, and the aforementioned air tube 1 is connected to the connection port 19C.
6 are connected to each other, and a blind plug 20 is attached to the connection port 19d.

The container members 19a and 19b are made of relatively hard polymeric material such as vinyl chloride, polycarbonate, or silicone rubber, and are integrally molded. The diaphragm 18 has appropriate elasticity and is attached to the container member 19a to facilitate welding.

The same material as 19b is used. Container member 19a.

19b Furthermore, if the diaphragm 18 is made transparent,
It is convenient because the internal status can be monitored.

To perform normal hemodialysis using a dialysis machine with the above configuration,
On the dialysate side, both the bypass valve 10 of the supply path 7 and the on-off valve 14 of the discharge path 8 are closed, the bypass path 7b and the flow path 8b for stopping water removal are closed, and the supply pump 12 and the suction pump are closed. 13, and on the blood side patient A
An extracorporeal circulation circuit is constructed by puncturing the veins of the patient with cannula la, lh, and blood circulation through the dialyzer 3 is caused by the operation of the blood pump 2. Thus, the dialysate is fed into the dialyzer 3 through the supply path 7 passing through the throttle channel 7a, and is discharged from the dialyzer 3 to the outside of the dialyzer through the steady flow path 8a of the discharge channel 8. By appropriately restricting the flow path regulating valve 9, ultrafiltration pressure is generated by positive pressure on the dialysate side in the dialyzer 3. In this way, inside the dialyzer 3, water is transferred from the blood side to the dialysate side due to the ultrafiltration pressure described above, and ζ water removal is performed, and mass transfer is performed due to the concentration gradient on both sides of the dialysis membrane, and the blood The waste products inside are removed, and the pressure on the blood circuit side during dialysis is detected by the pressure sensor 4. This normal dialysis is exactly the same as the conventional hemodialysis using the negative pressure method.

Next, a case will be described in which a patient receiving dialysis has a drop in blood pressure and removal has to be stopped.

When a patient's blood drops, the negative pressure detected by the pressure detector 4 will be greater than the negative pressure during normal dialysis. or automatically based on a detection signal from a pressure detector, the dialysis machine is switched from a normal dialysis state to a water removal stop state. The operation of the suction pump 13 is stopped, and the dialysate passes through the bypass path 7b, enters the dialyzer 3 from the supply path 7, and passes through the water removal stop flow path 8b of the discharge path 8. Outside the system...
As a result, the positive pressure set by the operation of the suction pump 13 and the restriction of the flow rate adjustment valve 9 is released.

Here, if the pressurizer 15 is not inserted into the flow path 8b for stopping water removal, the patient's natural venous pressure will be added to the blood circuit as a residual pressure even in this positive pressure release state, and this residual pressure will be applied to the blood circuit as a residual pressure. The pressure acts as a positive pressure on the blood side in place of the positive pressure on the dialysate side in the dialyzer 3, and as in hemodialysis in a positive pressure method (a considerable amount of water continues to be removed). In the configuration, the above residual pressure is transferred to the pressure transducer 6
The air pressure is converted into air pressure at the pressurizer 15.
The pressure is directly applied to the filtrate in the discharge path 8 through the dialysis machine 3, and is measured by the pressure gauges 68 of the pressure transducer 6 on both sides of the dialysis membrane, the blood side and the dialysate side. The same pressure applied will create no differential pressure, and therefore water removal will be completely stopped. Note that even under this water removal stop state, the supply pump 12 continues to operate and supply dialysate compared to during normal dialysis, so that within the dialyzer 3, the dialysis action in a narrow sense, that is, the interaction between blood and dialysate, takes place within the dialyzer 3. Concentration gradient based mass transfer and dialysate renewal continues.

When the patient's blood loss recovers, the pressure sensor 4
The normal dialysis state may be restored again when the negative pressure detected by the dialysis becomes smaller or when this pressure returns to a predetermined value.

In addition, in the event of an emergency situation such as the tip of Caniere 1a adhering to the sac tube and blocking the blood circuit during dialysis,
Since the negative pressure in the pressure detector 4 becomes even greater than the value that requires stopping water removal, the blood pump 2 is stopped based on this pressure change and the necessary measures are taken under this stopped state. good.

In this embodiment, an air chamber is used as the pressure transducer 6, but instead of this, a closed container with a diaphragm having the same structure as the pressurizer 15 of this embodiment is used, and its liquid chamber is connected in series with the blood circuit. The air chamber is connected to the pressurizer 1.
The five air chambers may be connected to each other through an air tube 16. Also, for the pressure detector 4, instead of the illustrated air chamber structure, a closed container having the same structure as the pressurizer 15 of this embodiment is adopted, and its liquid chamber is connected to the blood circuit, and the air chamber side is connected to the blood circuit. A pressure gauge 48 and, if necessary, means for outputting a detection signal when the pressure reaches a value that requires stopping water removal may be provided.

Furthermore, in the present invention, structures other than those illustrated can be used as a pressure detector, a pressure transducer, and an IE adding device, and also as a means for switching between a steady flow path of a dialysate discharge path and a flow path for stopping water removal. Instead of the on-off valve 14, a switching valve may be provided at the branch portion.

On the other hand, in this embodiment, the bypass valve IO of the supply path 7 is kept closed and deaf during normal dialysis, but the bypass valve 10 is intermittently opened for short periods of time during normal dialysis. It is also possible to adopt a method in which the rapid flow of dialysate into the dialyzer 3 when the dialyzer 3 is opened periodically destroys the fluid membrane of the dialysis membrane to prevent a decrease in mass transfer efficiency.

(Effects of the Invention) According to the water removal stop device of the present invention, when blood is being circulated extracorporeally, the differential pressure between the blood side and the dialysate in the dialyzer is eliminated, and the progress of water removal is almost completely stopped. Therefore, even when the water removal is stopped, a considerable amount of water is not removed as in the conventional method, and unnecessary work during the water removal stop operation is unnecessary and safe. This makes it possible to improve sexuality.

In addition, the water removal stop device of the present invention has a mechanism for eliminating the above-mentioned pressure difference, and uses a pressure transducer to convert the patient's natural venous pressure, which is applied to the blood circuit, into pneumatic pressure under the condition where the positive pressure at the time of water removal stop is canceled. The system uses a structure in which this air pressure is directly applied to the dialysate using a pressurizer, so the device configuration is extremely simple and there is no risk of operational errors or malfunctions, and there is no risk of malfunction due to power outages. It has the advantage that it can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a diagram showing a dialysis apparatus using the water removal and stop device of the present invention, and FIG. 2 is a diagram showing the main part of FIG. 1. 3...Dylyzer, 5...Tube (blood circuit), 4.
... Pressure detector, 6... Pressure transducer, 7... Supply path, 8... Discharge path, 8a... Steady flow path, 8b... Water removal stop flow path, 9. ...Flow rate adjustment valve (throttling means), 10
... Bypass valve (positive pressure release means), 12 ... Supply pump, 13 ... Suction pump, 14 ... Opening/closing valve (switching means), 15 ... Pressurizer, 16 ... Air Tube (air pressure transmission path) Air chamber.

Claims (1)

[Scope of Claims] A dialysate supply path having a supply pump and a downstream throttling means and a dialysate discharge path having a suction pump are connected to the dialyzer, and the dialysate suction side by the throttling means is connected to the dialyzer. A water removal stop device used to perform hemodialysis using negative pressure generated on the dialysate side of the dialyzer based on a restriction, which is installed in the blood circuit upstream of the dialyzer and is installed on the upstream side of the dialyzer. a pressure detector that detects the blood pressure; a pressure converter that is installed in the blood circuit downstream of the dialyzer and converts the downstream blood pressure into air pressure; a means for releasing the negative pressure; and the discharge. a flow path for stopping water removal and discharging the dialysate out of the system without passing through the suction pump; the flow of the dialysate to be discharged is connected to the flow path for stopping water removal and the suction pump; a switching means for switching from one side of the steady flow path to the other; a pressurizer that is installed in the water removal stop flow path and pressurizes the dialysate in the flow path using the air pressure of the pressure converter; and a pneumatic transmission path that communicates both air layers of a pressurizer; and a water removal stop device for hemodialysis.