JPH059110B2 - - Google Patents

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) Hemodialysis, which is performed using an artificial kidney device (dialysis device), is used to purify blood by eliminating waste products from the body or taking in what is needed instead of the kidneys when the human body suffers from kidney failure. It is widely used to carry out. The main function of the kidneys is to produce urine, and most of this urine is water, so in hemodialysis it is important to remove water from the blood, so-called water removal. This will be a challenge. Water in the body moves into the blood via intracellular, intercellular, and blood vessels, and 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 also greatly improves the ultrafiltration coefficient (UFR), which can cause water removal during dialysis to occur too quickly, which can cause patients to experience a drop in blood pressure. As a process in this case, or as a temporary stop operation during normal operation, the following operation is performed to stop water removal. That is, in the positive pressure method, the throttling device (auto-cleaner) downstream of the dialyzer in the blood circuit is released, and in the negative 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, but in many patients, there are complex factors such as changes in the shunt of the blood vessel, deformation due to long-term puncture of the cannula, and lesions due to the underlying disease.
There are various problems in the vascular lumen, which increases venous vascular resistance, and when dialyzed blood returns to the venous blood vessel, a resistance force proportional to the amount of blood returned (generally called natural venous pressure) is applied. It is supposed to occur in venous blood vessels. For this reason, even when the above-mentioned operation to stop water removal is performed, this natural venous pressure is applied to the diaphragm as a residual pressure, and in reality, a considerable amount of water is removed. For example, 150-200
Blood volume in ml/min (extracorporeally circulating blood volume during normal dialysis)
30-120mmHg depending on the patient, rarely 200mmHg
A natural venous pressure of more than
When using a mmHg/hr dialyzer, 120~
Excessive body fluid removal of 480ml/hr.

[Problems to be solved by the invention] Conventionally, even when water removal is being stopped, a considerable amount of water is being removed. It is necessary to replenish the ivy collection solution to the patient, and this work requires a great deal of labor.Moreover, this work relies mostly on experience and knowledge, and it is important to ensure the safety of patients during dialysis. The current situation is that there are still problems.

The present invention was made in view of the above problems, and
In hemodialysis using a negative pressure method, when an operation to stop water removal is performed, a considerable amount of water is not removed as in the conventional method, and unnecessary work is unnecessary and safe during the operation to stop water removal. The purpose is to enable you to enhance your sexuality.

(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 connected to a fluid discharge path and used to perform hemodialysis by the negative pressure generated on the dialysate side in the dialyzer based on the throttling of the dialysate suction side by the throttle means. The device includes a pressure sensor installed in a blood circuit upstream of the dialyzer to detect the pressure of the upstream blood, and a pressure detector installed in the blood circuit downstream of the dialyzer to detect the pressure of the downstream blood. a pressure converter that converts pressure into air pressure; a means for releasing the negative pressure; a water removal stop flow path that is connected to the discharge path and discharges 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 device for hemodialysis, comprising: a pressurizer that pressurizes the dialysate in the flow channel using the air pressure of the device; and an air pressure transmission path that communicates both the air layers of the pressure transducer and the pressurizer. To.

(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 a person's operation. This measure simply releases the negative pressure on the dialysate side, similar to conventional negative pressure hemodialysis, but as previously mentioned, a considerable amount of water continues to be removed by 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 converter and pressurizer, so that the differential pressure between the blood side and the dialysate side in the dialyzer is almost eliminated.
Water removal based on ultrafiltration pressure is almost completely stopped, and only dialysis action in a narrow sense, that is, mass transfer based on the concentration gradient between dialysate and blood, continues.

(Example) Hereinafter, an example of the present invention will be described 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, 1a, 1
b is a cannula, 2 is a blood pump, 3 is a dialyzer,
4 is a pressure sensor, 5 is a tube, and 6 is a pressure transducer. In addition to these, an infusion needle and a heparin injector are connected to the blood circuit of the dialysis machine, but these are not shown. The dialyzer 3 is connected to a dialysate supply path 7 and a dialysate discharge path 8 . The supply path 7 is a negative pressure adjustment device configured by a branching and merging path that branches into a throttle path 7a in which a flow rate adjustment valve 9 is inserted and a bypass path 7b in which a bypass valve 10 is inserted and which merge on the downstream side. 11, and a supply pump 12 is provided upstream of this regulating device 11. The discharge path 8 includes a steady flow path 8a having a suction pump 13 and an on-off valve 14.
It branches into a water removal stop flow path 8b downstream of which a pressurizer 15 is inserted.

The pressure sensor 4 has a similar structure to a general air chamber, and has an air layer in the upper part of the airtight container connected in series to the blood circuit, and the pressure sensor 4a detects the pressure through the air layer. It is designed to display the blood pressure value. This pressure value is
While the dialysis is being performed normally, the negative pressure is almost constant, but if excessive water removal is performed, this negative pressure becomes even greater, so whether or not to stop water removal is determined by this pressure. It can be determined by the value. In addition, in such a pressure detector 4, a pressure value at which water removal should be stopped may be settable, and a detection signal may be output when this detected pressure value reaches a set pressure value. Based on this detection signal, the operation for stopping water removal, which will be described later, can be automatically performed via a control mechanism, or a warning can be issued to the person in charge by means of a buzzer or lighting of a lamp. is possible. Further, the pressure detector 4 can be provided 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 present at the upper part of the sealed container connected in series to the blood circuit. , the blood pressure value detected through the air layer by the pressure gauge 6a is displayed. The other end of the air tube 16 is connected to a pressurizer 1 which will be described next.
5.

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 8b to generate pressure equal to the pressure inside the pressure transducer 6 described above. It is designed to generate pressure. This pressurizer 15, as shown in FIG.
7b facing each other, a diaphragm 18 having the same outer circumference is sandwiched between the respective brim portions of the two, and these are welded together to form a closed container 17. The inside of the container 17 is It is divided into a liquid chamber a and an air chamber b, and has an inlet 19a,
An outflow port 19b and connection ports 19c and 19d are provided. Tubes 8c and 8d of the water removal stop channel 8b are connected to the inlet 19a and outlet 19b, the aforementioned air tube 16 is connected to the connection port 19c, and a blind plug 20 is attached to the connection port 19d. There is.

The container members 19a and 19b are made of a relatively hard polymeric material such as vinyl chloride, polycarbonate, or silicone rubber, and are integrally molded. The diaphragm 18 has appropriate elasticity and is made of the same material as the container members 19a and 19b to facilitate welding. Container members 19a, 19b and further diaphragm 18
It is convenient to make it transparent so that its internal state can be monitored.

In order to perform normal hemodialysis using the dialysis apparatus configured as described above, on the dialysate side, the bypass valve 10 of the supply path 7 must be
and the on-off valve 14 of the discharge passage 8 are both closed,
The bypass path 7b and the water removal stop flow path 8b are closed, and the supply pump 12 and the suction pump 13 are closed.
On the blood side, cannulae 1a and 1b are inserted into the veins of patient A to form an extracorporeal circulation circuit, and blood circulation through dialyzer 3 is caused by operation of 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 system through the steady flow path 8a of the discharge path 8. By appropriately restricting the flow path regulating valve 9, an ultrafiltration pressure due to negative pressure is generated on the dialysate side of the dialyzer 3. In this manner, in the dialyzer 3, water is transferred from the blood side to the dialysate side by the ultrafiltration pressure described above, and water is removed, and at the same time, substances are transferred due to the concentration gradient on both sides of the dialysis membrane. Waste products in the blood 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 conventional hemodialysis using a negative pressure method.

Next, a case will be described in which a patient undergoing dialysis has a drop in blood pressure and the removal must be stopped.

When the patient's blood decreases, the negative pressure detected by the pressure sensor 4 becomes larger than the negative pressure during normal dialysis. Therefore, the dialysis machine can switch from the normal dialysis state to the water removal stop state automatically by reading the change in pressure value or by the person in charge who received the alarm, or based on the detection signal from the pressure detector. It will be done. This switching is to open the bypass valve 10 and on-off valve 14 on the dialysate side and stop the operation of the suction pump 13, so that the dialysate flows from the supply path 7 to the dialyzer 3 through the bypass path 7b. Enter the water removal stop flow path 8 of the discharge path 8
The negative pressure set by the operation of the suction pump 13 and the restriction of the flow rate regulating 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 negative 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 negative pressure on the dialysate side within the dialyzer 3, and a considerable amount of water continues to be removed as in hemodialysis in a positive pressure method. However,
In the configuration of the present invention, the above residual pressure is transferred to the pressure transducer 6.
The air pressure is converted into air pressure at the pressurizer 15 and directly applied to the dialysate in the discharge path 8.In the dialyzer 3, the blood side and the dialysate side with the dialysis membrane in between are connected. Pressure transducer 6 on both sides
The same pressure measured by the pressure gauge 6a is applied and no differential pressure is generated, so water removal is 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 negative pressure detected by the pressure detector 4 becomes smaller, or when this pressure returns to a predetermined value, the original normal dialysis state can be resumed. .

In addition, in the event of an emergency situation such as the tip of the cannula 1a adhering to a blood vessel and occluding the blood circuit during dialysis, the negative pressure in the pressure detector 4 will be lower than the above-mentioned value that requires stopping water removal. Since the pressure also increases further, the blood pump 2 may be stopped based on this pressure change, and necessary measures may be taken under this stopped state.

In this embodiment, an air chamber is used as the pressure transducer 6, but instead, 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 may be connected to the air chamber b of the pressurizer 15 via the 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. pressure gauge 4
A and, if necessary, means for outputting a detection signal when the pressure reaches a pressure value that requires stopping water removal may be provided.

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

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

(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. This makes it possible to prevent a considerable amount of water from being removed as in the past even when an operation is performed to stop water removal, and eliminates unnecessary work during the operation to stop water removal. Moreover, it becomes possible to improve safety.

In addition, the water removal stop device of the present invention has a mechanism for eliminating the above-mentioned differential pressure, in which the natural venous pressure of the patient that is applied to the blood circuit is converted into pneumatic pressure using a pressure transducer under the condition where the negative pressure at the time of stopping water removal is released. 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 is less likely to cause operational errors or breakdowns, and there is no risk of malfunction due to power outages. It also has the advantage of being able to be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a diagram showing a dialysis machine using the water removal stop device of the present invention;
The figure shows 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...
... Channel for stopping water removal, 9 ... Flow rate adjustment valve (throttling means), 10 ... Bypass valve (negative pressure release means), 12
...Feeding pump, 13...Suction pump, 14...
Opening/closing valve (switching means), 15... Pressurizer, 16...
Air chamber (air pressure transmission path) air chamber.

Claims (1)

[Scope of Claims] 1. A dialyzer is connected to a dialysate supply path having a supply pump and a downstream throttling means, and a dialysate discharge path having a suction pump, 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 the restriction of the dialyzer, which is installed in the blood circuit upstream of the dialyzer and a pressure detector that detects the pressure of the blood on the upstream side; a pressure converter that is installed in the blood circuit downstream of the dialyzer and converts the pressure of the blood on the downstream side into air pressure; and a means for releasing the negative pressure. a water removal stop flow path connected to the discharge path and for discharging the dialysate out of the system without passing through the suction pump; a switching means for switching from one side to the other with a steady flow path passing through; a pressurizer installed in the water removal stop flow path and pressurizing the dialysate in the flow path using the air pressure of the pressure converter; A water removal stop device for hemodialysis, comprising: an air pressure transmission path that communicates both air layers of a converter and a pressurizer.