JP7183584B2 - dialysis machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dialysis device and a replacement fluid control method using the dialysis device.

In dialysis treatment, a pump is used to extract blood from the patient's arterial side and send it to a blood purification means such as a dialyzer or a hemodiafilter. Reverting is done.
Generally, in dialysis treatment, the blood is purified over a period of about 4 hours per treatment, and as the dialysis time elapses, the blood is purified and excess water in the body is removed. Since this blood purification reduces the amount of circulating blood flowing through the patient's body, it is not uncommon for patients to exhibit symptoms of hypotension in the latter half of dialysis treatment.

When the circulating blood volume decreases, the normal biological reaction is to maintain the central circulating blood volume by constricting the peripheral blood vessels by the action of the autonomic nerves. In addition, when the blood is concentrated by dehydration, plasma refilling occurs in which plasma components move from the interstitium into the blood vessel due to the difference in osmotic pressure, thereby maintaining the circulating blood volume. However, there are cases in which such biological reactions are not performed normally in some patients, and it is sometimes difficult to continue dialysis treatment due to a drop in blood pressure.

In the event of such symptoms of hypotension, measures such as fluid replacement using physiological saline or purified dialysate in the blood are taken in order to quickly increase the circulating blood volume. .
In recent years, in order to prevent the occurrence of a drop in blood pressure due to a decrease in circulating blood volume due to water removal, in the treatment of hemodialysis (so-called HD) and hemodiafiltration (so-called HDF), for example, 150 mL to 200 mL every 30 minutes An “intermittent replenishment type hemodiafiltration method” has been proposed in which fluid replacement is repeatedly performed and water is removed by adding the amount of water equivalent to the replacement fluid to the original amount of water removed (see Non-Patent Document 1 and Non-Patent Document 2).

Japanese Journal of Dialysis Medicine, Vol. 40, No. 9, pp. 769-774 "New HDF Therapy and its Clinical Effects" Japanese Journal of Dialysis Medicine, Vol. 42, No. 9, pp. 695-703, "Invention and clinical evaluation of intermittent replacement fluid hemodialysis in automatic mode using reverse filtration dialysate"

As mentioned above, the occurrence of hypotension can be suppressed by systematically replacing fluids during dialysis treatment. It is thought that the injection amount and injection interval are different. In addition, even in the same patient, blood hemodynamics (circulating blood volume, plasma refilling speed, etc.) change during the course of dialysis treatment. Therefore, if fluid replacement is performed under uniform conditions that do not depend on the patient's condition, there is a risk that excessive fluid replacement will lead to a sudden increase in blood pressure, and insufficient fluid replacement will result in a sudden drop in blood pressure. may not be obtained in the future.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a dialysis apparatus and a fluid replacement control method capable of performing proper fluid replacement.

The present invention comprises a blood circuit, a blood purification means arranged in the blood circuit and capable of removing water in the blood, and a dialysate connected to the blood purification means for introducing and discharging the dialysate to and from the blood purification means. a circuit, a measuring means for measuring the rate of change in the circulating blood volume, a replenishing solution injection means for injecting a replenishing solution into the blood circuit for recovering the circulating blood volume that has decreased due to dehydration, and a predetermined level in the blood circuit. a control unit that controls the replacement fluid injection means to intermittently inject a predetermined amount of replacement fluid at intervals, wherein the control unit controls the most recent Based on the rate of change in the circulating blood volume due to the injection of the replacement fluid, the next replacement fluid injection amount and/or injection interval is determined so that the rate of change in the circulating blood volume due to the next injection of the replacement fluid is within a predetermined range. and controls the water removal speed of the blood purification means so as to recover at least the water equivalent to the total amount of replacement fluid injected into the blood circuit from the start to the end of dialysis.

Further, it is preferable that the blood purification means and the dialysate circuit are used as the replacement fluid injection means, and the dialysate reverse filtered by the blood purification means is used as the replacement fluid.

Further, the present invention includes a blood circuit, a blood purification means arranged in the blood circuit and capable of removing water in the blood, a dialysate circuit connected to the blood purification means, for introducing and discharging a dialysate, measuring means for measuring the rate of change in the circulating blood volume; replenishing fluid injection means for injecting a replenishing fluid into the blood circuit for recovering the circulating blood volume that has been reduced by water removal; and a controller for controlling the replacement fluid injection means to inject a predetermined amount of replacement fluid, wherein the rate of change measured by the measurement means is used. The rate of change in the circulating blood volume due to the injection of the most recent replenisher is calculated, and based on the rate of change, the rate of change in the circulating blood volume due to the next infusion of the replenisher is within a predetermined range. The injection amount and/or injection interval of the replacement fluid is adjusted, and the blood purification means is removed so as to recover at least the water content corresponding to the total amount of the replacement fluid injected into the blood circuit from the start to the end of dialysis. It relates to a replacement fluid control method for controlling water velocity.

Further, if the rate of change in the circulating blood volume due to the most recent replenishment injection is within the predetermined range, the next replenishment injection amount is set to the same amount as the most recent injection amount, and the rate of change is within the predetermined range. If it is larger than the rate of change, the next injection amount of the replenisher is set to be less than the most recent injection amount, and if the rate of change is smaller than the predetermined range, the next injection amount is adjusted according to the rate of change. It is preferable to set the injection amount of the replenisher to be larger than the most recent injection amount.

Further, if the rate of change in the circulating blood volume due to the injection of the most recent replenisher is within the predetermined range, the interval until the injection of the next replenisher is set as a predetermined injection interval, and the rate of change is within the predetermined range. If it is larger, the interval until the next replenisher is injected is made longer than the predetermined injection interval according to the change rate, and if the change rate is smaller than the predetermined value, the next injection is made according to the change rate. The interval until the replenisher is injected is shorter than the predetermined injection interval, and the interval between the injection of the most recent replenisher and the injection of the next replenisher corresponds to the injection amount of the most recently injected replenisher. It is preferable to control the water removal speed of the blood purifying means so that the removed water is recovered as replacement fluid recovery.

Also, the predetermined range is preferably 5% to 10%.

ADVANTAGE OF THE INVENTION According to this invention, since it can perform appropriate fluid replacement according to the circulatory body movement of the blood during dialysis treatment, a sudden change in blood pressure can be reduced.

It is a figure which shows schematic structure of a dialysis apparatus. FIG. 2 shows a dialysis process carried out in a dialysis machine; It is a figure which shows the replacement|fluid replacement process implemented with a dialyzer. FIG. 4 is a diagram showing the rate of change in circulating blood volume when fluid replacement is performed during dialysis. 4 is a flowchart for explaining a fluid replacement control method of the present invention; 4 is a flowchart for explaining a method for setting fluid replacement conditions in the first embodiment; FIG. 4 is a diagram for explaining a method of injecting and recovering a replenisher in the first embodiment; FIG. 4 is a diagram for explaining another method of injecting and recovering a replenisher in the first embodiment; 9 is a flowchart for explaining a method for setting fluid replacement conditions in the second embodiment; FIG. 10 is a diagram for explaining a method of injecting and recovering a replenisher in the second embodiment;

Preferred embodiments of the dialysis apparatus and replacement fluid control method of the present invention will be described below with reference to the drawings.
The fluid replacement control method of the present invention can be applied to intermittent fluid replacement during dialysis treatment such as hemodialysis (so-called HD) and hemodiafiltration (so-called HDF). As an application example of the present invention, a case of performing intermittent replenishment type hemodiafiltration in which backfiltered dialysate is intermittently replenished will be described.

<First Embodiment>
FIG. 1 is a diagram showing a schematic configuration of a dialysis apparatus 100 according to the first embodiment of the present invention.

As shown in FIG. 1, the dialyzer 100 includes a blood circuit 110 for flowing blood, a blood purification means 120, a dialysate circuit 130, a circulating blood volume measuring means 140 arranged in the blood circuit 110, and a control unit. a portion 150;

The blood circuit 110 has an arterial line 111 , a venous line 112 , a drug line 113 and a priming fluid drain line 114 . The arterial line 111, the venous line 112, the drug line 113, and the priming fluid discharge line 114 are mainly composed of soft tubes having flexibility through which fluid can flow.

One end of the arterial line 111 is connected to a blood inlet 122a of the blood purification means 120, which will be described later. The arterial line 111 is provided with an arterial connecting portion 111a, an arterial air bubble detector 111b, a blood pump 111c, and circulating blood volume measuring means 140, which will be described later.
The artery-side connecting portion 111 a is arranged on the other end side of the artery-side line 111 . A needle that punctures a patient's blood vessel is connected to the artery side connection portion 111a.
The arterial air bubble detector 111b detects the presence or absence of air bubbles in the tube.
The blood pump 111 c is arranged downstream of the arterial air bubble detector 111 b in the arterial line 111 . The blood pump 111c pumps the blood inside the arterial line 111 and a liquid such as a priming liquid by squeezing the tube forming the arterial line 111 with a roller.

One end of the venous line 112 is connected to a blood outlet 122b of the blood purification means 120, which will be described later. The venous line 112 is provided with a venous connector 112a, a venous bubble detector 112b, a drip chamber 112c, and a venous clamp 112d.
The venous connecting portion 112a is arranged on the other end side of the venous line. A needle to be punctured into a patient's blood vessel is connected to the vein side connection portion 112a.
The venous air bubble detector 112b detects the presence or absence of air bubbles in the tube.
The drip chamber 112c is arranged upstream of the venous air bubble detector 112b. Drip chamber 112c stores a certain amount of blood in order to remove air bubbles, coagulated thrombus/coagulum, etc. that have entered venous line 112, and to measure venous pressure.
The venous clamp 112d is arranged downstream of the venous air bubble detector 112b. The vein side clamp 112 d is controlled according to the result of air bubble detection by the vein side bubble detector 112 b to open and close the flow path of the vein side line 112 .

The drug line 113 supplies drugs required during hemodialysis to the arterial line 111 . One end of the drug line 113 is connected to a drug pump 113a that delivers the drug, and the other end is connected to the arterial line 111 . The drug line 113 is provided with clamping means (not shown), and the flow path is closed by the clamping means except when the drug is injected. In this embodiment, the other end of drug line 113 is connected upstream of circulating blood volume measuring means 140 in arterial line 122 .

The priming liquid discharge line 114 is connected to the drip chamber 112c. A priming liquid discharge line clamp 114 a is arranged on the priming liquid discharge line 114 . The priming liquid discharge line 114 is a line for draining the priming liquid in the priming process, which will be described later.

The blood purification means 120 includes a cylindrical container body 121 and a dialysis membrane (not shown) housed inside the container body 121. The inside of the container body 121 is filled with blood by the dialysis membrane. It is divided into a side channel and a dialysate side channel (both not shown). The container body 121 has a blood inlet 122a and a blood outlet 122b communicating with the blood circuit 110, and a dialysate inlet 123a and a dialysate outlet 123b communicating with the dialysate circuit .

According to the blood circuit 110 and the blood purification means 120 described above, the blood taken out from the artery of the subject (dialysis patient) flows through the artery side line 111 by the blood pump 111c and flows through the blood side flow path of the blood purification means 120. introduced into The blood introduced into the blood purification means 120 is purified by the dialysate flowing through the dialysate circuit 130, which will be described later, through the dialysis membrane. The blood purified by the blood purification means 120 flows through the venous line 112 and is returned to the subject's veins.

In this embodiment, the dialysate circuit 130 is configured by a so-called closed capacity control type dialysate circuit 130 . The dialysate circuit 130 includes a dialysate supply line 131a, a dialysate drain line 131b, a dialysate inlet line 132a, a dialysate outlet line 132b, and a dialysate feed section 133.

The dialysate delivery unit 133 includes a dialysate chamber 1331 , a bypass line 1332 and a water removal/backfiltration pump 1333 .
The dialysate chamber 1331 is composed of a hard container capable of accommodating a certain amount of dialysate (for example, 300 ml to 500 ml). It is partitioned into a housing portion 1331b.
Bypass line 1332 connects dialysate outlet line 132b and dialysate drain line 131b.

A dewatering/backfiltration pump 1333 is located in the bypass line 1332 . The water removal/backfiltration pump 1333 circulates the dialysate in the bypass line 1332 toward the dialysate drain line 131b side (water removal direction) and to the dialysate outlet line 132b side (backfiltration direction). It is composed of a pump driven to be able to send liquid to.

The dialysate supply line 131 a is connected to a dialysate supply device (not shown) at its proximal end and to the dialysate chamber 1331 at its distal end. The dialysate supply line 131 a supplies the dialysate to the dialysate chamber 1331 to the liquid supply storage portion 1331 a.

The dialysate introduction line 132a connects the dialysate chamber 1331 and the dialysate introduction port 123a of the blood purification means 120, and the dialysate contained in the liquid supply storage portion 1331a of the dialysate chamber 1331 is used for dialysis of the blood purification means 120. It is introduced into the liquid side channel.

The dialysate lead-out line 132b connects the dialysate outlet 123b of the blood purification means 120 and the dialysate chamber 1331, and leads the dialysate discharged from the blood purification means 120 to the waste liquid container 1331b of the dialysate chamber 1331. do.

The dialysate drain line 131b is connected at its proximal end to the dialysate chamber 1331 and discharges the dialysate drained from the drain storage part 1331b.

According to the dialysate circuit 130 described above, the inside of the hard container that constitutes the dialysate chamber 1331 is partitioned by a soft diaphragm (diaphragm), so that the amount of dialysate discharged from the dialysate chamber 1331 (liquid supply and accommodation) The amount of the dialysate supplied to the portion 1331a) and the amount of the waste fluid collected in the dialysate chamber 1331 (the waste fluid storage portion 1331b) can be the same amount.
As a result, when the water removal/backfiltration pump 1333 is stopped, the flow rate of the dialysate introduced into the blood purification means 120 and the amount of dialysate (drainage) discharged from the blood purification means 120 are the same. can be done.

Further, when the water removal/backfiltration pump 1333 is driven to send liquid in the backfiltration direction, part of the waste liquid discharged from the dialysate chamber 1331 flows through the bypass line 1332 and the dialysate lead-out line 132b. The dialysate chamber 1331 collects the dialysate through the dialysate chamber 1331 again. Therefore, the amount of dialysate drawn out from blood purification means 120 varies from the amount collected in dialysate chamber 1331 (that is, the amount of dialysate flowing through dialysate introduction line 132a) to the amount of dialysate flowing through bypass line 1332. It is the amount obtained by subtracting the amount of liquid. As a result, the amount of dialysate drawn out from the blood purification means 120 flows through the dialysate introduction line 132a by the amount of the dialysate (waste liquid) that passes through the bypass line 1332 and is again collected in the dialysate chamber 1331. less than the required dialysate flow rate. That is, when the water removal/backfiltration pump 1333 is driven to send liquid in the backfiltration direction, a predetermined amount of dialysate is injected (backfiltered) into the blood circuit 110 in the blood purification means 120 (Fig. 3).

Thus, in this embodiment, the blood purification means 120 and the dialysate circuit 130 (water removal/backfiltration pump 1333) are used as replacement fluid injection means, and the backfiltered dialysate is used as the replacement fluid. In other words, the dialysate as a replacement liquid is injected from the dialysate circuit 130 into the blood circuit 110 via the blood purification means 120 by driving the water removal/backfiltration pump 1333 in the backfiltration direction. A replacement fluid line may be connected to the blood circuit 110 to serve as a replacement fluid injection means, and physiological saline or the like may be used as the replacement fluid. Alternatively, a replenisher line provided with a replenisher pump may be connected from the dialysate introduction line 132a to the arterial line 111 or the venous line 112 as a replenisher injecting means, and the dialysate may be used as the replenisher.

On the other hand, when the water removal/backfiltration pump 1333 is driven to send liquid in the water removal direction, the amount of dialysate flowing through the dialysate lead-out line 132b is equal to the dialysate collected in the dialysate chamber 1331. (that is, the amount of dialysate flowing through the dialysate introduction line 132 a ) plus the amount of dialysate flowing through the bypass line 1332 . As a result, the amount of dialysate flowing through the dialysate lead-out line 132b is increased by the amount of the dialysate (waste liquid) that passes through the bypass line 1332 and is discharged to the dialysate drain line 131b. It is larger than the amount of dialysate flowing through. That is, when the water removal/backfiltration pump 1333 is driven to send the liquid in the water removal direction, a predetermined amount of water is removed from the blood in the blood purification means 120 (see FIG. 2).

Circulating blood volume measuring means 140 is a sensor that measures the hematocrit value of blood flowing through blood circuit 110 . For example, the hematocrit value can be measured based on the light transmittance of blood obtained by irradiating blood with near-infrared rays. Based on the hematocrit value measured over time by the circulating blood volume measuring means 140, the change rate of the circulating blood volume in the patient's body can be calculated. As shown in FIG. 1, the circulating blood volume measuring means 140 is located downstream of the blood pump 111c in the arterial line 111 and near the blood purification means 120 so as not to be affected by water removal or fluid replacement by the blood purification means 120. Arranged on the upstream side.

The control unit 150 is configured by an information processing device (computer), and controls the operation of the dialysis machine 100 by executing a control program. Also, the control unit 150 calculates the rate of change of the circulating blood volume based on the hematocrit value measured by the circulating blood volume measuring means 140 .
Specifically, the control unit 150 controls the operations of various pumps, clamps, and the like arranged in the blood circuit 110 and the dialysate circuit 130, and various processes performed by the dialyzer 100, such as a priming process and a dehydration process. A blood process, a dialysis process, a fluid replacement process, a blood return process, etc. are executed.

Various steps will be briefly described with reference to FIGS.
In the priming step, the blood circuit 110 and the blood purifying means 120 are washed and purified using a reverse filtration dialysate as a priming liquid.
In the blood removal step, the patient's blood is sucked and the arterial line 111 and the venous line 112 are filled with the blood. After the blood removal process, a dialysis process is performed to purify the blood and remove water (see FIG. 2). In the dialysis process, the patient's surplus water is removed, and the replacement fluid recovery is also removed.
A fluid replacement step is performed intermittently during the dialysis step (see FIG. 3). After the dialysis process is completed, a blood return process is performed to return the blood to the patient.

Among the various processes performed by the dialysis apparatus 100, the dialysis process and fluid replacement process related to changes in the circulating blood volume will be described in detail below.

The dialysis step will be described with reference to FIG.
In the dialysis process, the patient's blood introduced from the arterial side connection portion 111a passes through the arterial side line 111, is purified by the blood purification means 120, passes through the venous side line 112, and is returned to the patient from the venous side connection portion 112a. .

In the dialysis step, as shown in FIG. 2, the artery side connection portion 111a and the vein side connection portion 112a are in a state of being connected to needles that are punctured into the patient's blood vessel, respectively, and the priming fluid discharge line clamp 114a is closed. State, the venous clamp 112d is open.

A dialysate supply device (not shown) supplies and discharges the dialysate to and from the dialysate chamber 1331 at an average liquid feed rate of 500 ml/min, and operates the water removal/backfiltration pump 1333 to feed the liquid in the water removal direction. to operate. By setting the feed rate of the water removal/backfiltration pump 1333 to 10 ml/min as an example, the blood purification means 120 removes 10 ml/min of water.
The blood pump 111c gradually increases the flow rate from 40 to 50 ml/min at the start of the dialysis process to, for example, about 200 ml/min, and sends blood from the artery side connecting portion 111a side to the blood purification means 120 side.
Blood flows into blood purification means 120 from blood inlet 122a at a flow rate of 200 ml/min, is dehydrated at a flow rate of 10 ml/min, and is discharged from blood outlet 122b at a flow rate of 190 ml/min. Also, the dialysis fluid is discharged from the dialysate discharge port 123b.
In this way, water is gradually removed from the blood in the dialysis step, and the circulating blood volume is gradually reduced accordingly.

Next, the fluid replacement process will be described with reference to FIG.
The fluid replacement step is a step of injecting a backfiltration dialysate into the blood circuit 110. In the present embodiment, in order to prevent a drop in blood pressure due to a decrease in circulating blood volume due to water removal, etc., the step is performed intermittently at predetermined intervals. is performed on

In the fluid replacement process, as shown in FIG. 3, the artery side connection part 111a and the vein side connection part 112a are in a state of being connected to needles that are punctured into the blood vessels of the patient, respectively, as in the dialysis process. The side clamp 114a is closed, and the vein side clamp 112d is open.

A dialysate supply device (not shown) supplies and discharges the dialysate to and from the dialysate chamber 1331 at an average rate of 500 ml/min, and operates the water removal/backfiltration pump 1333 to feed the dialysate in the backfiltration direction. to operate. For example, when 200 ml of fluid is to be replaced, the water removal/backfiltration pump 1333 supplies 150 ml/min as an example, so that 150 ml/min of fluid can be replaced in about 80 seconds in the blood purification means 120. will be
The blood pump 111c gradually reduces the flow rate from 200 ml/min to about 50 ml/min during the dialysis step, and sends blood from the artery side connecting portion 111a side to the blood purification means 120 side.
Blood flows into the blood purification means 120 from the blood inlet 122a at a flow rate of 50 ml/min, the reverse filtration dialysate is replenished at a flow rate of 150 ml/min, and 200 ml of diluted blood is supplied from the blood outlet 122b. /min. In this manner, dialysate is rapidly replenished into the blood in about 80 seconds in the fluid replenishment process.

Next, a specific replacement fluid control method in this embodiment will be described with reference to FIGS. 4 to 8. FIG.

First, the effects of intermittent replacement of fluids will be briefly described.
During dialysis treatment, water in the blood (plasma) is removed as water removal progresses, and the circulating blood volume decreases. When the circulating blood volume decreases and the protein concentration in the blood increases, water (plasma) gradually moves from the interstitium into the blood vessels due to the difference in osmotic pressure between the intravascular and extravascular (interstitial) regions ( plasma refill), circulating blood volume is restored and blood pressure is maintained. However, when the plasma refilling rate cannot catch up with the dehydration rate and the circulating blood volume decreases and the blood pressure drops, the autonomic nervous system constricts the peripheral blood vessels to maintain the blood pressure. happens. If this does not work properly, the rate of plasma refilling will be much lower than the water removal rate, and the rate of decrease in circulating blood volume will increase, leading to a rapid drop in blood pressure.

Fluid replacement is performed intermittently to prevent such a rapid drop in blood pressure. Performing dialysis while restoring the blood circulation volume by performing fluid replacement prevents a decrease in blood pressure, improves peripheral circulation, and maintains the rate of plasma refilling. As a result, compared to the case where fluid replacement is not performed, even if the water removal rate is the same (excluding the fluid replacement portion recovered), the rate of decrease in the circulating blood volume after completion of dialysis can be made smaller. An increase in the circulating blood volume due to the replacement of fluids is removed by the blood purification means 120 from the start to the end of dialysis. Therefore, the total amount of water removed is the sum of the patient's surplus water (water weight minus water) and the recovered fluid replacement.
The present invention makes it possible to perform fluid replacement at an appropriate injection amount and injection interval in order to sufficiently obtain the above-mentioned effects of fluid replacement.

Next, changes in circulating blood volume when fluid replacement is performed under general conditions will be described.
FIG. 4 is a diagram showing the rate of change in the circulating blood volume when fluid replacement is performed under the generally practiced conditions of an injection volume of 200 ml and an injection interval of 30 minutes. As shown in FIG. 4, it can be seen that the circulating blood volume increases due to the implementation of fluid replacement every 30 minutes.
The rate of increase in circulating blood volume due to fluid replacement is considered to depend on the amount of fluid replenished from outside the body and the amount of plasma movement into blood vessels due to plasma refilling in the body. Because the rate of plasma refilling varies from patient to patient and during dialysis, the appropriate volume of replacement fluid infusion will vary from one fluid replacement procedure to another. In the case of the present embodiment, water removal by the blood purification means 120 is not performed while the replenisher is being injected, so the decrease due to water removal need not be considered.

As a result of investigations by the present inventors on the appropriate amount of fluid replacement, it is considered desirable that the rate of change (rate of increase) in the circulating blood volume due to one time of fluid replacement be within the range of 5 to 10%. If this rate of change exceeds 10%, the circulating blood volume increases rapidly, which may lead to a rapid increase in blood pressure. In the case of patients with heart disease, the burden of increased blood pressure increases, so the upper limit of the rate of change should be set to a value lower than 10%, and the amount of replacement fluid injected per time should be reduced. Adjustments may be made to increase the number of injections. In addition, if the amount of replacement fluid injected is excessive, the amount of water removed from the recovered replacement fluid will increase, and the total amount of water removed will increase together with the patient's surplus water. As a result, the water removal speed increases, and the risk of blood pressure drop increases. Also, if the rate of change is less than 5%, the aforementioned effect of fluid replacement cannot be sufficiently obtained.

Therefore, a method for controlling the amount of replenishment to be injected will be described so that the rate of change in circulating blood volume due to replenishment is within the range of 5 to 10%.

(First replenisher control method)
In this embodiment, as an example, the injection interval of replacement fluid is fixed at 30 minutes, and a case where fluid replacement is performed a total of 7 times during a 4-hour treatment will be described with reference to FIGS. 5 and 6. FIG.

The control unit 150 measures the hematocrit value by the circulating blood volume measuring means 140, and calculates the change rate of the circulating blood volume over time based on the measured hematocrit value.
For example, the first replacement fluid can be determined according to the patient's basal weight. For example, a patient with a basic body weight of 50 kg or more should be given 200 ml of fluid per injection, and a patient with a weight of less than 50 kg should be given 150 ml of fluid per injection.

The flow of dialysis treatment will be described with reference to FIG.
After starting dialysis, the dialysis machine 100 removes water at a predetermined rate (S100). After a predetermined time has passed (S110), fluid replacement is performed at a predetermined injection amount (S120).
It is determined whether or not the most recent fluid replacement is the last fluid replacement (S130), and if it is not the last fluid replacement, the next fluid replacement condition is set based on the most recent change rate (increase rate) of the circulating blood volume (S140). If it is the last replacement fluid, water is removed at a predetermined water removal speed (S150), and after a predetermined dialysis time has passed (S160), the dialysis treatment is terminated. Here, the predetermined water removal speed in S150 indicates the water removal speed at the start of dialysis treatment, which is set based on the amount of water to be removed from the patient by dialysis treatment (water removal amount). Also, the predetermined dialysis time in S160 similarly indicates the water removal time at the start of dialysis treatment.

With reference to FIG. 6, a method for setting replacement conditions will be described.
The rate of change in the circulating blood volume before the start of the injection of the replacement fluid and after the end of the injection due to the most recent fluid replacement is calculated (S141), and it is determined whether or not the rate of change due to fluid replacement is within a predetermined range (S142). . If the rate of change due to this fluid replacement is within the range of 5 to 10%, it is determined that the amount of replenisher injected is appropriate, and the next fluid replacement after 30 minutes is performed with the same amount as the first injection. (S143). If the rate of change due to fluid replacement exceeds 10%, it is determined that the injection amount is excessive, and the injection amount of the next replacement fluid after 30 minutes is reduced (S144). Specifically, the greater the rate of change in circulating blood volume, the smaller the amount of replacement fluid to be injected, or the amount of infusion of replacement fluid may be reduced by a certain percentage regardless of the rate of change in circulating blood volume. For example, the ratio of the actual rate of change to the upper limit of 10% of the rate of change of the circulating blood volume is calculated, and the amount of replacement fluid to be reduced is calculated by multiplying the calculated ratio by the initial amount of replacement fluid of 200 ml. In the above example, when the rate of change in circulating blood volume due to fluid replacement exceeds a predetermined range, control is performed to change both the fluid replacement injection volume and the injection interval, but one is not changed, and only the other is changed. may be controlled to
If the rate of change due to fluid replacement is less than 5%, it is determined that the injection amount is too small, and the injection amount of the next fluid replacement after 30 minutes is increased (S145). Specifically, the smaller the rate of change in circulating blood volume, the greater the amount of replacement fluid to be injected, or the amount of infusion of replacement fluid may be increased at a constant rate regardless of the rate of change in circulating blood volume. For example, the ratio of the actual rate of change to the upper limit of 10% of the rate of change in the circulating blood volume is calculated, and the amount of replacement fluid to be increased is calculated by multiplying the calculated ratio by the initial amount of replacement fluid of 200 ml.
In this way, based on the rate of change in the circulating blood volume due to the most recent fluid replacement, the controller 150 adjusts the rate of change in the circulating blood volume due to the next fluid replacement to be in the range of 5 to 10%. Adjust injection volume.

The replacement fluid increase in the circulating blood volume can be recovered by adjusting the water removal rate from the start to the end of dialysis. In this embodiment, as shown in FIG. It was to be added to the patient's surplus water (body weight minus water) and collected until the next fluid replacement.
As for the method of collecting the increment of replenishment fluid, as shown in FIG. 8, even if the final replenishment fluid is collected before the final replenishment is performed, instead of collecting the replenishment fluid after the last replenishment is performed, good. In this case, regardless of the rate of change in the circulating blood volume due to the most recent replacement fluid, the last injection volume of the replacement fluid is set to a predetermined amount, and water removal can be carried out ahead of schedule. In order to simplify the explanation, we have shown the case where the injection volume of replacement fluid is constant. Varies based on

According to the dialysis apparatus 100 and the first replacement fluid control method of the first embodiment described above, the following effects are obtained.

(1) The dialyzer 100 comprises a blood circuit 110, a blood purification means 120, a dialysate circuit 130, a circulating blood volume measuring means 140, a replacement fluid injection means for injecting a replacement fluid into the blood circuit 110, a controller 150 for controlling the replenisher injection means to intermittently inject a predetermined amount of replenisher into the blood circuit 110 at predetermined intervals; the controller 150 controls the circulating blood volume measuring means; Based on the rate of change in circulating blood volume due to the most recent replenishment infusion measured by 140, the next replenishment is determined so that the rate of change in circulating blood volume due to the next replenishment is within a predetermined range. The injection amount and the injection interval are adjusted, and the water removal rate of the blood purification means 120 is controlled so as to recover at least the entire amount of the replacement fluid injected into the blood circuit 110 from the start to the end of dialysis. I assumed.
As a result, it is possible to realize appropriate fluid replacement in accordance with the circulatory dynamics of the patient's blood, thereby suppressing a rapid increase in blood pressure due to fluid replacement and suppressing a decrease in blood pressure due to dehydration. Therefore, blood pressure fluctuations during dialysis can be reduced, and dialysis treatment can be performed with a reduced burden on the patient. In addition, by adjusting the amount of replacement fluid to be injected so as not to be excessive, it is possible to reduce the rate of water removal for the amount of replacement liquid recovered, and suppress the occurrence of a drop in blood pressure due to an excessively high rate of water removal.

(2) Using the fluid replacement control method using the dialyzer 100, the rate of change of the circulating blood volume due to the most recent replacement fluid injection is calculated using the rate of change measured by the circulating blood volume measuring means 140, and the most recent fluid replacement fluid is injected. If the rate of change in the circulating blood volume due to the injection of is within a predetermined range, the next replenishment injection amount is the same as the most recent injection amount, and if the rate of change is greater than the predetermined range, the rate of change If the rate of change is smaller than the predetermined range, the next amount of replenisher to be injected is set to the amount of the most recent replenisher according to the rate of change. The amount should be larger than the injection amount.
As a result, if the most recent replacement fluid injection amount was appropriate, the next fluid replacement will be performed in the same way. If the amount is too high, the next fluid replacement amount can be increased to achieve an appropriate fluid replacement in accordance with the patient's blood circulatory dynamics.

<Second embodiment>
Next, a second replacement fluid control method using the dialysis apparatus 100 described in the first embodiment will be described with reference to FIGS. 9 and 10. FIG. This embodiment differs from the first replacement fluid control method in that replacement fluid injection intervals are not constant.

(Second fluid replacement control method)
In this embodiment, as an example, the reference fluid replacement interval is set to 30 minutes, and the second and subsequent injection intervals are adjusted based on the rate of change in the circulating blood volume due to the most recent fluid replacement.

Since the flow of dialysis treatment is the same as that described in the first embodiment, the description will be omitted, and the method for setting the replacement fluid conditions will be described with reference to FIG.
As shown in FIG. 9, the rate of change in the circulating blood volume before the start of the injection of the replacement fluid and after the end of the injection due to the most recent replacement fluid is calculated (S141), and whether the rate of change due to the replacement is within a predetermined range. (S142). If the rate of change due to this fluid replacement is within the range of 5 to 10%, it is determined that the amount of replacement fluid injected is appropriate, and the next fluid replacement will be the same amount as the first injection, and the next fluid replacement will be the same. The injection interval is performed as the standard injection interval (30 minutes). (S146). In addition, if the rate of change due to fluid replacement exceeds 10%, it is determined that the injection amount is excessive, and the injection amount of the next fluid replacement is reduced, and the injection interval until the next fluid replacement is used as a reference injection. The interval is set longer than the interval (30 minutes) (S147). Specifically, the greater the rate of change in circulating blood volume, the longer the injection interval may be, or the fixed percentage injection interval may be lengthened regardless of the rate of change in circulating blood volume. For example, the rate of change of the circulating blood volume is calculated by calculating the ratio of the actual rate of change to the upper limit of 10%, and multiplying the calculated ratio by the reference infusion interval of 30 minutes to calculate the increased time of the injection interval.
In addition, if the rate of change due to fluid replacement is less than 5%, it is determined that the injection amount is too small, and the injection amount of the next fluid replacement is increased, and the injection interval until the next fluid replacement is used as a reference. The injection interval (30 minutes) is shortened (S148). Specifically, the smaller the rate of change in the circulating blood volume, the shorter the injection interval, or the fixed percentage injection interval may be shortened regardless of the rate of change in the circulating blood volume. For example, the rate of change of the circulating blood volume is calculated by calculating the ratio of the actual rate of change to the upper limit of 10%, and multiplying the calculated rate by the reference injection interval of 30 minutes to calculate the reduction time of the injection interval.

In this way, the control unit 150 injects the next replacement fluid so that the rate of change in the circulating blood volume due to the next fluid replacement is in the range of 5 to 10% based on the rate of change in the circulating blood volume due to the most recent fluid replacement. Adjust the amount and adjust the injection interval until the next replacement fluid.
Further, as shown in FIG. 10, the infusion amount of the final replacement fluid may be adjusted by increasing or decreasing as appropriate according to the remaining time of dialysis after the final replacement fluid.

The replacement fluid increase in the circulating blood volume can be recovered by adjusting the water removal rate from the start to the end of dialysis. The amount injected in step 1 was to be collected by the next replacement fluid (see FIG. 10).

According to the second fluid replacement control method of the second embodiment described above, in addition to the above effects (1) and (2), the following effects are obtained.

(3) In the fluid replacement control method using the dialyzer 100, if the rate of change in the circulating blood volume due to the most recent fluid injection is within the predetermined range, the interval until the next fluid injection is set to a predetermined value. If the rate of change is greater than the predetermined range, the interval until the next replenisher is injected is made longer than the predetermined interval according to the rate of change, and if the rate of change is less than the predetermined range. For example, the interval until the next replenisher is injected according to the rate of change is made shorter than a predetermined injection interval, and the most recently injected replenisher is set between the last replenisher injection and the next replenisher injection. The water removal rate of the blood purification means 120 is controlled so as to recover the water equivalent to the amount of replenisher injected.
As a result, when the injection amount of the most recent replacement fluid is excessive, by lengthening the injection interval until the next replacement fluid, the water removal rate for the recovered replacement fluid can be reduced, and the water removal rate is too high. In addition, if the most recent infusion volume is too low, shortening the infusion interval until the next rehydration will accelerate the sufficient recovery of circulating blood volume. , can suppress the occurrence of hypotension.

Although preferred embodiments of the dialysis apparatus and replacement fluid control method of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified as appropriate.
For example, in the above-described embodiments, the case of using backfiltered dialysate as the replacement liquid was described, but physiological saline may be used as the replacement liquid, or the dialysate may be directly connected to the blood circuit without going through the blood purification means. The dialysate may be replenished from the connected dialysate line.

REFERENCE SIGNS LIST 100 dialyzer 110 blood circuit 111 arterial line 111c blood pump 112 venous line 120 blood purification means 130 dialysate circuit 140 circulating blood volume measuring means 150 control unit

Claims (5)

blood circuit,
Blood purification means arranged in the blood circuit and capable of removing water in the blood;
a dialysate circuit connected to the blood purification means for introducing and discharging dialysate to and from the blood purification means;
a measuring means for measuring the rate of change of circulating blood volume;
a replenisher injection means for injecting a replenisher into the blood circuit for recovering the circulating blood volume that has been reduced due to water removal;
a controller for controlling the replacement fluid injection means to intermittently inject a predetermined amount of replacement fluid into the blood circuit at predetermined intervals,
Based on the rate of change in the circulating blood volume due to the most recent replenishment injection measured by the measuring means, the control unit controls the rate of change in the circulating blood volume due to the next injection of the replenisher to be within a predetermined range. Then, the injection amount and/or injection interval of the next replacement fluid is adjusted, and the blood is collected so as to recover at least the water content corresponding to the total amount of the replacement fluid injected into the blood circuit during the period from the start to the end of dialysis. A dialysis device that controls the water removal rate of the purification means. 2. The dialysis apparatus according to claim 1, wherein said blood purification means and said dialysate circuit are used as said replacement fluid injection means, and dialysate back filtered by said blood purification means is used as said replacement fluid. If the change rate of the circulating blood volume due to the most recent replenishment injection is within the predetermined range, the control unit sets the next replenisher injection amount to the same amount as the most recent injection amount , and the change rate is If it is larger than the predetermined range, the next replenisher injection amount will be smaller than the most recent injection amount according to the change rate, and if the change rate is smaller than the predetermined range, the change rate 3. The dialysis machine according to claim 1 or 2, wherein the injection amount of the next replenisher is adjusted to be larger than the most recent injection amount according to . If the rate of change in the circulating blood volume due to the injection of the most recent replenisher is within the predetermined range, the controller determines that the interval until the next replenisher is injected becomes a predetermined injection interval, and the rate of change is If it is larger than the predetermined range, the interval until the next replenisher is injected according to the change rate becomes longer than the predetermined injection interval, and if the change rate is smaller than the predetermined value, the change rate , the interval until the next replenisher is injected is adjusted to be shorter than the predetermined injection interval, and the most recent replenisher is injected between the injection of the most recent replenisher and the next replenisher. 3. The dialysis machine according to claim 1 , wherein the water removal speed of said blood purification means is controlled so as to recover water equivalent to the amount of replenisher injected. The dialysis apparatus according to any one of claims 1 to 4, wherein said predetermined range is 5 to 10%.

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