WO2015192927A1

WO2015192927A1 - Hemofiltration appliance, hose set and use thereof, and method for operating a hemofiltration appliance

Info

Publication number: WO2015192927A1
Application number: PCT/EP2015/000678
Authority: WO
Inventors: Günter Heeke
Original assignee: Günter Heeke
Priority date: 2014-06-16
Filing date: 2015-03-30
Publication date: 2015-12-23
Also published as: DE102014008546A1; DE102014008546B4

Abstract

The invention relates to a hemofiltration appliance with a hemofilter (3), with a feed line (1) for delivering a blood stream from a patient to the hemofilter (3), and with a return line (6) for returning the blood stream to the patient, wherein a first feed point for a substituate to the blood stream is arranged upstream from the hemofilter (3), and wherein a second feed point for a substituate to the blood stream is arranged downstream from the hemofilter (3), and with a delivery device for delivering the substituate from a reservoir (9) to the first and/or to the second feed point, wherein the delivery device has a branched hose line (13) with a first line section (10) running from the reservoir (9) to a branching site and with a first and a second line branch (7, 8) extending from the branching site, wherein a hose pump (11) for conveying the substituate is arranged on the first line section (10), and wherein the first line branch (7) runs from the branching site to the first feed point situated upstream, and wherein the second line branch (8) runs from the branching site to the second feed point situated downstream, and is characterized in that a nonreturn valve (18) is arranged only in one of the two line branches (7, 8) of the hose line (13), and in that a shut-off valve (316), in particular a hose pinch valve, is arranged only in the other of the two line branches (7, 8) of the hose line (13). The invention further relates to a hose set for a hemofiltration appliance and to the use thereof. Finally, the invention relates to a method for operating a hemofiltration appliance.

Description

Haemofiltration device, hose set and its use and

Method for operating a haemofiltration device

Description:

The invention relates to a Haemofiltrationsgerät with a Haemofilter, with a supply line for supplying a blood stream from a patient to the Haemofilter, and a return line for returning the blood stream to the patient, wherein upstream of the Haemofilters a first addition point for a substituate (= substitution liquid) to the Blood flow is provided, and wherein downstream of the Haemofilters a second addition point for a Substituat is provided to the bloodstream, and with a supply means for supplying the substituate from a supply to the first and / or to the second addition point, wherein the supply means a Y-shaped branched hose having a line extending to a branch point line section and extending from the branch point first and second line branch, wherein on the first line section a hose pump for conveying the substituate is arranged, and wherein the first leg extends from the branch to the first upstream point of addition and the second leg branches from the branch to the second downstream point of addition.

The invention further relates to a hose set for a Haemofiltrationsgerät, consisting of a Y-shaped branched hose of flexible material, and its use.

The invention further relates to a method for operating a haemofiltration device.

Extracorporeal therapies based on the principle of haemofiltration filter out some of the blood, eliminating dissolved urine-containing substances or toxins in the broadest sense, while leaving the cellular blood components in the bloodstream. In order not to cause unwanted volume losses

CONFIRMATION COPY a sterile substituate with a suitable electrolyte composition and with the desired volume, the extracorporeal blood circulation fed back in the course of treatment. The medically required balancing accuracy in this addition of substituent is mostly achieved by electronic control devices using control and control systems such as gravimetric or volumetric measuring devices and processor controlled pumps. If such a therapy method is used in patients with kidney failure, in addition to the elimination of urinary substances and the required volume reduction can be achieved by more liquid withdrawn from the circuit than substituted. Such devices for renal replacement therapy are known as artificial kidney, for example from DE 25 52 304 A1.

The delivery of the substituate to the extracorporeal bloodstream may be accomplished downstream of the hemofilter using a standard drip chamber. The filtered blood and the substituate then pass back to the patient via the return line. Since the blood concentrated in the passage through the haemofilter is diluted again behind the filter during this process, this admixing process is referred to as postdilution.

In the course of a mostly several hours, sometimes even several days Haemöfiltrationsbehandlung increases because of the filtration of liquid, the percentage of cellular components in the blood. This increase in hematocrit causes an increase in the viscosity of the blood and often leads to a reduction in the effectiveness of the haemofilter or even to complete blockage of the filter membranes. This effect is also referred to as clotting. By using anticoagulant substances, e.g. Although heparin or citrate solution, the unwanted coagulation effect can be reduced, but for medical reasons, the anticoagulation so effected can not be increased arbitrarily.

An alternative to post-dilution is the supply of the substituate before the hemofilter. This admixing process is known as predilution. It has advantages and disadvantages compared to classical postdilution. It is advantageous that due to the blood dilution before entering the Haemofilter the Clottingeffekte can be significantly reduced or avoided altogether. The disadvantage is that a large part of the added substituate in the filtration process is immediately lost again. On the one hand this reduces the effectiveness of the entire filtration process, on the other hand it increases the treatment costs significantly, because a significant increase in demand for expensive Substituat can arise.

Often medically and technically useful as well as economically viable is a combined procedure that allows both post and predilution. It is usually switched in the course of a longer treatment of initial postdilution from reaching a measurable increased Haematokritwertes or based on experience on predilution.

The simplest form of switching between post and predilution is to manually shut off the typically used tubing of the substituate using temporary shutoff valves, release it from the postdilution port, and connect it to a port intended for predilution. This manual intervention interferes with the operation and poses an additional risk of contamination. In addition, only 100% Postdilution or 100% Predilution can be used with this method. A short-term change between the operating modes is therefore not possible.

Technical arrangements are also known in which the hose line for the transport of the substituate is divided into two branches in a Y-shape, each leading to the point of addition for mail or for predilution. Several commercially available haemofiltration devices offer such a solution, wherein two peristaltic pumps for the independent, defined liquid transport are connected in the two branch lines after the Y-shaped division. These two peristaltic pumps arranged in the branch lines cause a selectively controllable ratio of post- and predilution, as well as a desired closure of a single one of the line branches or both line branches at standstill.

Another technical possibility uses only one peristaltic pump in front of the Y-shaped hose manifold and two separate hose clamp valves downstream of the manifold for the selective closure of one of the two pipe branches after the branching. By opening or closing the typically electrically controllable shut-off valves, post or predilution is made possible. Since, in principle, there is the possibility in this embodiment variant of blood flowing through the hose line when the hose clamping valves are open at the same time, check valves must be provided in both line branches. A defined Relation from pre- to post-dilution with simultaneous opening of both shut-off valves is not possible because the delivery rates in the two transport branches are counter-pressure-dependent and this back pressure is influenced by the changing filter state and the blood flow rate. The synchronization of the opening and closing operations requires careful timing and is fraught with the risk of unwanted pressure spikes. Since the peristaltic pump usually runs continuously, the pressure in the hose increases immediately when the first shut-off valve is already closed and the second shut-off valve is not yet open. Such an arrangement with correspondingly complex pressure sensors and control is described, for example, in US Pat. No. 7,744,553.

The object of the invention is to provide a hemofiltration apparatus and a corresponding hose set, which allow a simple and safe switching of the addition of a substituate between pre- and post-dilution. Furthermore, the object of the invention is to provide an improved method for operating a Haemofiltrationsgeräts.

The object is achieved according to the invention by a Haemofiltrationsgerät with a Haemofilter, a supply line for supplying a blood stream from a patient to the Haemofilter, as well as with a return line for returning the blood stream to the patient, upstream of the Haemofilters a first addition site for the substituate the blood stream is arranged, and wherein downstream of the Haemofilters a second addition point for the Substituat is arranged to the bloodstream, and with a supply means for supplying the substituate from a supply to the first and / or the second addition point, wherein the supply means is a Y-shaped branched hose having a line extending to a branch point line section and extending from the branch point first and second line branch, wherein on the first line section a hose pump for conveying the substituate is arranged, and wherein the the first leg extends from the branch to the first point of addition, and wherein the second leg extends from the branch to the second point of addition, which is further developed in that only in one of the two branches a check valve is arranged, and that only in the other of the two Line branches a shut-off valve, in particular a hose clamp valve, is arranged. In this embodiment of the invention Haemofiltrationsgeräts manual switching to the device is no longer required for switching between pre- and post-dilution. At the same time only one shut-off valve must be switched while the check valve automatically opens or closes by switching the shut-off valve from the open to the closed state and vice versa. The control and sensor effort is low. In addition, the required equipment is reduced, since only one check valve and only one shut-off valve is needed. Compared to embodiments with two peristaltic pumps and a significant reduction in size can be achieved.

For the purposes of the invention, a Y-branched hose line is understood to mean any hose line whose lumen splits from a lumen leading to the branching into two lumens leading away from the branching. The branch may also be T-shaped or asymmetric, without departing from the invention.

In an advantageous development of the invention, an infusion heating is arranged along the first line section of the hose line. This allows the substituate to preheat to body temperature or slightly higher so as to avoid hypothermia of the patient.

In a particularly advantageous embodiment of the invention, the hose line in the region of the hose pump and / or the shut-off valve has a higher load capacity, for example a higher elasticity, than in the remaining hose area. As a result, the hose can be designed to be optimally optimized for the stress in its particularly stressed area, without the entire hose being made of such a material, which is adapted to the stresses required only in regions. The increased elasticity can be achieved, for example, by the use of a silicone material, a modified PVC material and / or by changing wall thicknesses of the hose line. A particularly stressed area is, for example, the area of action of the peristaltic pump. There, the hose must be walkbar and reliably withstand the replacement of the hose set of the sometimes several days of stress. This applies analogously to the area of action of the shut-off valve, for example a clamping valve. The check valve is designed to be spring-loaded according to a particularly advantageous embodiment of the invention, that is, the closed position is left only after concerns a spring force exceeding the opening force, and the valve automatically returns to the closed position, when the spring force is higher than the applied opening force again. This ensures that the check valve is not unintentionally opened by the back pressure of the substituent flowing through the opened shut-off valve. The spring load is preferably set so that the peristaltic pump can open the check valve with closed shut-off valve against the pressure in the filtration circuit problem-free. Typical opening pressures at which the check valve should open are, for example, in the range of 200-500 mbar. The term "spring-loaded" is to be interpreted broadly here, for example, plastic or rubber diaphragms with spring action or even lip valves with suitable shaping and sufficient prestressing in a suitable installation structure can be used.

The first leg of the tubing, which is connected to the first addition point, is provided in a preferred embodiment of the invention with the shut-off valve. In this embodiment, the predominant in typical treatment course postdilution is carried out by the preferably in the de-energized state opening shut-off valve, while the rarer predilution takes place through the check valve, which is arranged in the second leg, leading to the second addition point.

In a particularly advantageous embodiment of the invention, the first point of addition and / or the second point of addition are designed as drip chambers. This allows a bubble-free and visually verifiable addition of the substituate.

The object is further achieved by a hose set for a Haemofiltrationsgerät according to one of the embodiments described above, consisting of a Y-shaped branched hose of flexible material, wherein in only one of the line branches behind the Verzeigung the hose, in particular a spring-loaded check valve is arranged.

In a particularly advantageous embodiment of the hose set according to the invention, the first line section of the hose line and / or the line branch, in which the check valve is not arranged, an area with increased strength, eg with increased elasticity. According to a further aspect of the invention, the stated object is achieved by the use of a hose set according to the invention in a Haemofiltrationsgerät.

According to an additional aspect of the invention, the stated object is further achieved by a method for operating a hemofiltration apparatus comprising the steps of providing a hemofiltration apparatus according to the invention, performing haemofiltration with addition of a substituate through the Y-shaped branched tubing at the first addition site or at the second addition point, and switching the addition of the Substituats between the first addition point and the second addition point by opening or closing the shut-off valve.

The invention is explained below with reference to exemplary embodiments, which are illustrated in the schematic drawings. Show it:

1: a Haemofiltrationsgerät according to the prior art,

Fig. 2: another Haemofiltrationsgerät according to the prior art, and

Fig. 3: a Haemofiltrationsgerät according to the invention.

FIG. 1 shows a hemofiltration apparatus 100 according to the prior art. A supply line 1 passes a blood stream from the patient, not shown, through a first drip chamber 2 to a hemofilter 3, in which unwanted blood constituents are filtered out and removed via a filtrate line 4. The purified blood stream is passed through a second drip chamber 5 and returned to the patient via a return line 6.

The transport of the blood stream through the haemofiltration device 100 is typically done using a blood pump, not shown here, with the blood taken from a vein and also returned to a vein.

To compensate for the volume removed by filtration, a substituate is added to the bloodstream. This is supplied from a supply 9 via a Y-shaped branched hose 13 by means of two peristaltic pumps 14, 15 of the first drip chamber 2 or the second drip chamber 5 and there added to the blood stream. The Drip chambers 2, 5 serve the bubble-free mixing and the visual inspection by the treatment staff.

At a first line section 10 of the hose 13, which extends from the supply 9 to the branch point, an infusion heater 12 is arranged for preheating the substituate. The infusion heater 12 may be e.g. be designed as a biocompatible heat exchanger, infrared radiator or as Heizplatten-Heizungsbeutel combination.

A first line branch 7 of the hose line 13 leads from the branching point to the first drip chamber 2. At this first line branch, a first peristaltic pump 15 is arranged to supply the substituate via the first drip chamber 2 to the blood stream. The first peristaltic pump 15 is activated when predilution is desired and taken out of service when post-dilution is required. When put out of operation first peristaltic pump 15, the first line branch 7 of the hose 13 is closed.

A second line branch 8 of the hose line 13 leads from the branching point to the second drip chamber 5. At this second line branch 8, a second hose pump 14 is arranged to supply the substituate via the second drip chamber 5 to the blood stream. The second peristaltic pump 14 is activated when post-dilution is desired and taken out of service when predilution is required. When decommissioned second peristaltic pump 14, the second leg 8 of the hose 13 is closed.

Figure 2 shows another Haemofiltrationsgerät 200 according to another prior art, which is similar to the Haemofiltrationsgerät 100 gem. Figure 1 is constructed. A repeated description of the same components is therefore omitted here.

Unlike in the embodiment of FIG. 1, a peristaltic pump 1 1 is arranged in the first line section 10 of the hose 13, which causes the delivery of the substituate from the supply 9 both in postdilution and in predilution.

Both in the first leg 7 and in the second leg 8 of the hose 13 shut-off valves 16, 17 are arranged, which in order to avoid an unwanted bypass flow of the blood past the filter 3 each with associated return impact valves are executed. The shut-off valves 16, 17 thus allow the substituate to flow only in the direction of the drip chambers 2, 5 in the opened state, but not in the opposite direction.

During operation of the hemofiltration apparatus 200, the shut-off valve 17 is first closed to work with post-dilution and the shut-off valve 16 is opened. The substituate is conveyed by the hose pump 11 from the supply 9 through the pipe sections 10 and 8 of the hose 13 to the second drip chamber 5, where it is mixed with the blood stream.

If, due to an increased Haematokritwertes to be switched to predilution, the shut-off valve 6 is closed and the shut-off valve 17 is opened. The substituate is then conveyed through the conduit sections 10 and 7 of the tubing to the first drip chamber 2 where it is mixed with the blood stream.

The switching of the shut-off valves 16 and 17 must be synchronized. If e.g. the shut-off valve 17 is opened too late, after the shut-off valve 16 is already closed, a pressure peak builds up in the hose line between the hose pump 11 and the shut-off valves 16, 17, which after opening the shut-off valve 7 on the supply line 1 and the Haemofilter acts and can lead to damage of Haemofilters 3. If, however, the shut-off valve 17 is opened before the shut-off valve 16 is closed, both shut-off valves 16, 17 are opened at short notice and a bypass flow can briefly emerge past the line branches 7 and 8 on the haemofilter 3, which are only interrupted by the shut-off valves 16, 16. 17 provided check valves is interrupted.

FIG. 3 shows a hemofiltration apparatus 300 according to the invention. The haemofiltration device 300 in turn comprises a supply line 1, which directs a blood flow from the patient, not shown, through a first drip chamber 2 to a hemofilter 3, in which unwanted blood constituents are filtered out and removed via a filtrate line 4. The purified blood stream is returned to the patient through a second drip chamber 5 via a return line 6.

The blood flow through the Haemofiltrationsgerät 300 again typically takes place by a separate, not shown, blood pump, wherein the blood is removed from a vein and returned to a vein. The substituate is supplied from the supply 9 via a Y-shaped branched hose 13 by means of a peristaltic pump 11 of the first drip chamber 2 or the second drip chamber 5 and admixed there to the blood stream.

As already described for the previous figures, an infusion heater 12 for preheating the substituate is arranged on the first line section 10 of the hose line 13 which runs from the supply 9 to the branching point.

A first line branch 7 of the hose line 13 leads from the branch point to the first drip chamber 2. In this first line branch 7, a check valve 18 is arranged. A second line branch 8 of the hose line 13 leads from the branch point to the second drip chamber 5. At this second line branch 8, a shut-off valve 316 is arranged, which in this illustrated embodiment of the invention must have no check function and is therefore designed as a simple hose clamp valve.

The operation of this hemofiltration apparatus 300 according to the invention is as follows:

At the beginning of the Haemofiltrationsbehandlung the blood of the patient has a normal Haematokritwert, so that it can be used because of a low risk of clotting with post-dilution. For this purpose, the shut-off valve 316 is opened. Since this is the predominantly present operating state, the shut-off valve 316 is designed as a passively opening valve, which closes when energized.

In this operating state, the peristaltic pump 1 1 conveys the substituate at low pressure and with a delivery rate, not shown, through the second line branch 8 and the second drip chamber 5 into the blood returning to the patient. Because of the low delivery pressure and because of the pressure gradient prevailing at the same time over the Haemofilter 3, the check valve 18 remains securely closed. By using a spring-loaded check valve 18, the security against unwanted opening is further increased.

Increasing hematocrit of the blood due to haemofiltration increases the risk of clotting, so that at some point from post-dilution to predilution should be switched. At this time, the shut-off valve 316 is closed by energizing.

Since the substituate can no longer flow through the second line branch 8, which is closed by the shut-off valve 316, a rising delivery pressure successively builds up in the hose line 13 behind the hose pump 11, e.g. from about 200-500 mbar. This pressure is sufficient to open the check valve 18 against the spring tension, so that the substituate is now conveyed through the first line branch 7 of the hose 13 through the first drip chamber 2 and mixed there with the blood stream.

This described arrangement is without additional pressure sensor and associated software control. However, the provision of sensors can be done to e.g. provide additional pressure controls and safety precautions,

By electrical actuation of the shut-off valve 316 in sufficiently short time intervals, a quasi-simultaneous predilution and postdilution can be achieved with a variable duty cycle to one another. Interchanging the positions of the check valve 18 and the check valve 316 is possible and may be useful for technical reasons. However, since in practice the postdilution mostly outweighs the predilution in terms of time and volume, the illustrated arrangement is preferable for energetic reasons, because the typically solenoid-operated shut-off valve 316 consumes no energy in the normally open state and thus generates no loss-related heat.

The advantage of the invention described lies in particular in the special technical simplicity. In particular, only one peristaltic pump 11 and only one shut-off valve 316 are required as machine components for dilution control. As a result, the thus-equipped hemofiltration apparatus 300 can be produced less costly than conventionally equipped equipment due to a reduced number of components. Furthermore, there is a significant weight and volume reduction, which contributes to the desired reduction of the devices. The elimination of a pump segment in the hose 13 also results in a simpler handling of the device, since only one pump segment is to be inserted into the associated peristaltic pump 11, while in the prior art were two pump segments. One Another advantage is that existing devices that allow, for example, only post-dilution can be easily retrofitted.

The hose line, which is typically designed as a disposable article, is also technically simpler and thus less expensive. Instead of a second pump segment only one miniaturized check valve 18 is integrated in one of the two line branches. Such components are available in the field of medical technology industrial mass products and as inexpensive, sterilizable disposable items.

The dilution control according to the invention has in addition to the previously known arrangements in addition the advantage that they can work independently and thus can be implemented as a separate retrofit unit for such Haemofiltrationsgeräte, which were originally designed only for post-dilution. Since, in particular, the safety-related fluid balance of the devices is not affected, no change in the device software and no control-technical electrical intervention is required. Only the hose line, which is usually designed as a disposable article anyway, must be modified by integration of the check valve 18.

LIST OF REFERENCE NUMBERS

1 feed line

2.5 drip chamber

3 haemofilters

4 filtrate line

6 return line

7,8,10 line sections, first and second line branch

9 stock

11, 13,14 peristaltic pump

12 infusion heating

13 hose line

16,17,316 stop valve

18 check valve

100,200,300 haemofiltration device

Claims

claims:

A hemofiltration apparatus comprising a hemofilter (3), a supply line (1) for delivering a blood stream from a patient to the hemofilter (3), and a return line (6) for returning the blood stream to the patient, upstream of the hemofilter ( 3) a first addition site for a substituate to the bloodstream is arranged, and wherein downstream of the haemofilter (3) a second addition site for a substituate to the bloodstream is arranged, and with a supply means for supplying the substituate from a supply (9) to the first and / or to the second addition point, wherein the feed device has a branched hose line (13) extending from the supply (9) to a branch point first line section (10) and extending from the branch point first and second line branch (7 , 8), wherein at the first line section (10) arrange a hose pump (11) for conveying the substituate t, and wherein the first leg (7) extends from the branch to the first upstream point of addition, and the second leg (8) extends from the branch to the second downstream point of addition, characterized in that only in one the two line branches (7, 8) of the hose line (13) a check valve (18) is arranged, and that only in the other of the two line branches (7, 8) of the hose line (3) a shut-off valve (316), in particular a hose clamp valve, is arranged.

2. Haemofiltration device according to claim 1, characterized in that along the first line section (10) of the hose line (13) an infusion heater (12) is arranged.

Haemofiltration device according to one of the preceding claims, characterized in that the hose line (13) in the region of the hose pump (11) and / or the shut-off valve (316) has a higher load capacity, in particular a higher elasticity than in the remaining hose area.

Haemofiltration device according to one of the preceding claims, characterized in that the check valve (18) is designed to be spring-loaded.

Haemofiltrationsgerät according to any one of the preceding claims, characterized in that the shut-off valve (316) in the first line branch (7) of the hose line (13) is arranged, wherein the shut-off valve is preferably designed to energize switching, wherein the shut-off valve is further preferably designed so that it is energized in the open position.

Haemofiltration device according to one of the preceding claims, characterized in that the first addition point and / or the second addition point is designed as a drip chamber (2.5) or are.

Hose set for a haemofiltration apparatus according to one of the preceding claims, consisting of a branching hose line (13) of flexible material, the hose line (13) extending to a branch point first line section (10) and extending from the branch point first and second line branches ( 7, 8), wherein at the first line section (10) a peristaltic pump (11) for conveying the substituate can be arranged, and wherein in only in the first or only in the second line branch (7, 8) of the hose line (13) in particular spring-loaded check valve (8) is arranged.

Hose set according to claim 7, characterized in that at least one line region of the hose line (13), in which the check valve (18) is not arranged, a higher resistance, in particular a higher elasticity than the rest of the hose region, namely for the action of a peristaltic pump and / or a shut-off valve provided hose area.

Use of a tubing set according to claim 7 or claim 8 in a hemofiltration device.

10. A method for operating a Haemofiltration device, characterized by the steps:

Provision of a Haemofiltrationsgeräts according to any one of claims 1 to 6,

Performing haemofiltration with addition of a substituate through the branched tubing at the first addition site (predilution) or at the second addition site (postdilution),

- Switching the addition of the substituate between the first addition point and the second addition point by opening or closing the shut-off valve.

11. The method according to claim 10, characterized in that several times and alternately switched back and forth between the addition of the substituate on the first and on the second addition point.

12. The method according to claim 11, characterized in that the switching times are in the range of seconds.

13. The method according to claim 11 or 12, characterized in that the addition of the substituate by post-dilution over a multiple longer period of time than the addition by predilution, in particular by a 2-20-fold longer period of time.

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