DIALYSIS DEVICE FOR PERITONEAL DIALYSIS

Description

[0001] The invention relates to a dialysis machine for performing automated peritoneal dialysis (APD) treatment.

[0002] In the implementation of automated peritoneal dialysis treatments, it is known from WO 2013 / 000569 A1 to optimize the treatment while adhering to specified tolerances and time constraints, as well as with regard to the volume of dialysis fluid administered. Essential to this concept are the definitions of a permissible reduction in dwell time, a permissible reduction in inflow volume, a permissible residual volume, and a permissible patient volume.

[0003] The potential use or administration of unused dialysis solution is not taken into account. If fresh dialysis fluid remains at the end of treatment, it is pumped into the drainage system when the solution bags are emptied. However, in practice, it frequently occurs that the total prescribed infusion volume for a treatment cannot be fully administered to the patient. This is primarily due to the differing ranges for the permissible residual volume and the permissible patient volume.

[0004] The permissible residual volume is typically set relatively high in relation to the permissible patient volume so that the patient is not disturbed during sleep by leakage alarms.

[0005] This situation is schematically described in Figure 1The procedure is explained. In the example shown, the permissible patient volume is 120%, while the permissible residual volume is set at 50%. The prescribed total enema volume is 5000 ml (5 cycles of 1000 ml each). However, due to the automatic switching in the residual range, only 4700 ml of solution can be administered. While the system can switch to the next enema once 50% of the outflow volume is reached, the upper limit for the permissible enema volume limits the amount of enema volume administered to 20% more. This leaves dialysis solution unused, which can lead to inadequate treatment results and is also uneconomical.

[0006] To avoid wasting residual fluid—the difference between the connected dialysate volume and the volume actually needed for treatment—a tidal flow treatment could be prescribed. This involves administering a volume-controlled tidal flow. This minimizes the loss of dialysis solution by limiting the permissible residual volume. However, since the patient cannot be emptied to the same extent as with a pressure-controlled flow, as in standard treatment, the efficiency of the treatment is reduced. Therefore, tidal flow treatment is often prescribed not for therapeutic reasons, but simply to minimize disruptions and the loss of dialysis fluid.In this context, the procedure described in WO 2010 / 088360 A1 should be mentioned, whereby, in the event of incomplete drainage, the remaining treatment is replaced by a tidal treatment in order to utilize the prescribed total volume and achieve a target UF rate. The prescribed remaining infusion volume is distributed evenly across the tidal cycles so that the total treatment time is adhered to.

[0007] US 6 558 343 B1 also discloses a method of tidal treatment.

[0008] Furthermore, it would be conceivable to edit the prescription during treatment. If, during the course of treatment, the system frequently switches to the next inflow phase at the limit of the permissible residual volume, the user could increase the subsequent enema volumes using an editor. However, the ability to edit is tied to user rights; the user would have to set an alarm at night, and the adjustment process is relatively time-consuming.

[0009] It would also be conceivable to lower the limit for the permissible residual volume. However, this could lead to the patient being woken more frequently during treatment due to disturbances. The parameter value for the permissible residual volume is regularly set high precisely to avoid this.

[0010] However, due to the aforementioned disadvantages, none of these concepts leads to a truly satisfactory solution. Furthermore, implementing these concepts in devices that model profiled prescriptions, where the patient receives an individualized volume of a customized dialysis solution in each cycle, as in [reference to a specific device / system], would be problematic. Figure 2 schematically represented.

[0011] The object of the invention is to provide an improved concept for the use of residual liquid.

[0012] Against this background, the invention relates to a device for carrying out peritoneal dialysis treatment, comprising a reservoir for fresh dialysis fluid, a connection for connecting to a patient's peritoneal catheter, an outlet for used dialysis fluid, and a control unit connected to actuators, wherein the device is configured to perform several successive inflow-dwell-outflow cycles based on a treatment prescription stored in the control unit, in which dialysis fluid is supplied to the patient from the reservoir and, after a certain residence time in the patient's peritoneum, is drained again through the outlet, and wherein the device is further configured to replace a portion of the dialysis fluid in the patient's peritoneum with fresh dialysis fluid from the reservoir in at least one cycle before the residence time has elapsed.if, in at least one previous cycle, the volume of fresh dialysis fluid prescribed for that previous cycle was not completely used.

[0013] According to the invention, it is therefore intended to use fresh dialysis solution that is no longer expected to be used according to the prescription for a refreshment of the dialysis solution located in the peritoneum of the patient during the residence phase.

[0014] In one embodiment of the premature partial replacement procedure, a maximum of 50%, preferably a maximum of 30%, and more preferably a maximum of 20% of the total volume of dialysis fluid in the peritoneum can be replaced. The invention therefore does not involve the actual integration of further complete drainage and inflow phases, but rather the replacement of only a smaller portion of the dialysis fluid in the peritoneum in order to replenish it somewhat.

[0015] Preferably, the dwell time, i.e., the duration of the dwell phase of the respective cycle, is neither extended nor shortened by the premature partial replacement. The dwell time thus remains constant. When dwell time is mentioned in this context, it refers to the dwell time including the partial replacement procedure. In this way, the total treatment duration remains unchanged.

[0016] In this embodiment, the total volume of dialysis fluid in the patient's peritoneum is not altered by the premature partial replacement. It is therefore intended that the total volume of dialysis fluid in the patient's peritoneum after the partial replacement procedure corresponds to the total volume of dialysis fluid in the patient's peritoneum before the partial replacement procedure. Minor deviations occur during the partial replacement procedure.

[0017] Alternatively, it may be provided that the volume changes slightly, for example, particularly when the partial replacement process begins with an inflow step of fresh dialysis solution.

[0018] The partial replacement procedure can begin with either an inflow or an outflow step, although starting with an outflow step may be preferable, particularly if the total volume in the patient's peritoneum is close to a predetermined maximum volume. On the other hand, starting with an inflow step may reduce potential outflow problems, as the outflow pressure would then be higher.

[0019] Premature partial replacement preferably occurs in several, preferably consecutive, inflow and outflow steps. By dividing the inflow and outflow of dialysis fluid required for partial replacement into several steps, the total fluid volume in the peritoneum can be kept approximately constant. Several smaller partial replacement volumes also minimize the risk of leakage problems. If, nevertheless, a problematic inflow or outflow event occurs, the partial replacement procedure can be stopped and, if necessary, continued at a later time. Alternatively, if a leakage problem occurs, an attempt can be made to continue the partial replacement cycle with an enema to flush out any potentially stuck catheter.

[0020] In this context, for example, three or more, five or more, or a similar number of feed steps can be provided, and / or a maximum of 200 ml can be added with each feed step. A high number of small-volume feed and drain steps during the partial replacement process can increase the effective partial replacement volume.

[0021] Preferably, the early replacement is performed only after at least 50% of the intended dwell time has elapsed and / or is completed before a maximum of 80% of the intended dwell time has elapsed. After half the dwell time has passed, the dialysis fluid in the peritoneum is regularly no longer as effective as at the beginning of the dwell time, so that a significant increase in efficiency can be achieved through partial replacement. Replacing the fluid too late has only a minor impact on the quality of treatment, as the replenished solution can then no longer exert its effect to a noticeable extent.

[0022] In one embodiment, the device is designed to replace a portion of the dialysis fluid in the patient's peritoneum with fresh dialysis fluid from the reservoir during several treatment cycles, even before the residence time has elapsed. This serves both efficiency purposes and because the remaining volume can change during the course of treatment. For example, dialysis solution may need to be discarded if malfunctions occur or pumps need to be repositioned.

[0023] In one embodiment, the device is configured to initiate a partial replacement cycle only if the residence time specified for the respective cycle exceeds a minimum time. For cycles with short residence times, generating a partial replacement cycle may not be practical due to the short exposure time. Suitable minimum times could be set, for example, at 45 minutes or 60 minutes.

[0024] The device typically determines whether a partial replacement will occur at the beginning of a dwell time, as this is when the available and required infusion volume can be calculated. Furthermore, the dwell time can be modified. For example, the predetermined dwell time can be shortened. Subsequently, one or more small-volume infusions and outflows are administered. After the partial replacement, a final dwell time follows. The planned time for the subsequent outflow should still be adhered to in order to avoid prolonging the treatment.

[0025] As part of partial replacement, one could also consider administering a solution with a different glucose concentration than originally planned for the cycle, depending on availability, since the overall concentration would only change slightly due to the relatively small amounts.

[0026] An additional effect is conceivable: due to the fact that the dialysis solution is circulated through the partial replacement in the peritoneum, an additional positive effect on treatment efficiency is achieved.

[0027] The inflow and outflow rates during the partial replacement cycle can generally be set according to the cycle's inflow and outflow rates, or they can be lower or higher. In this context, very low flow rates can also be used to achieve a quasi-continuous partial replacement.

[0028] Any minimum volumes that may apply to a prescription need not be considered when choosing the partial replacement volume, as the partial replacement is not a prescription parameter. Rather, a corresponding patient parameter would apply across all prescriptions.

[0029] The invention further relates to a device for carrying out peritoneal dialysis treatment, comprising a reservoir for fresh dialysis fluid, a connection for connecting to a patient's peritoneal catheter, an outlet for used dialysis fluid, and a control unit connected to actuators, wherein the device is configured to perform several successive cycles, typically inflow-dwell-outflow cycles, based on a treatment prescription stored in the control unit, in which dialysis fluid is supplied to the patient from the reservoir and, after a certain residence time in the patient's peritoneum, is drained again through the outlet, and wherein the device is further configured to increase the total inflow volume in at least one cycle.if, in at least one previous cycle, the volume of fresh dialysis fluid prescribed for that previous cycle was not completely used.

[0030] According to this variant of the invention, it is therefore provided that fresh dialysis solution, which is expected to be no longer needed according to the prescription, is used to top up a later cycle. This variant of the procedure could be advantageous for adapted prescriptions, since cycles with small and large infusion volumes alternate in this treatment mode. The cycles with small infusion volumes could be increased within predetermined limits of, for example, 10%.

[0031] The two variants of the process according to the invention can be combined.

[0032] Generally, the control unit may be configured to specify a maximum volume of dialysis fluid that may be present in the patient's peritoneum. Incomplete use of the fresh dialysis fluid volume intended for the previous cycle is assumed to result from the fact that complete use would have exceeded this maximum volume. Setting this maximum volume is for patient safety. While the prescription is generally designed to prevent exceeding the maximum volume, it is not always possible to adequately account for the fact that the peritoneum may have been only partially emptied during the preceding drainage phase. This means that the prescribed inflow volume, combined with the unpredictable residual volume, can potentially exceed the maximum value.The residual volume results from the fact that the process, especially during the patient's nighttime rest, cannot always take place under ideal conditions, but that a certain residual volume is tolerated so that the patient is not disturbed during sleep by leakage malfunction messages.

[0033] In one embodiment, the device is designed to supply the patient with the total amount of dialysis fluid prescribed during treatment, with any excess fluid not supplied during the regular infusion phases, particularly due to consideration of the maximum volume, being supplied entirely during early replacement during at least one or more cycles. This ensures that the available dialysis solution, or the solution prescribed for administration, is used efficiently overall, which is desirable from both a medical and an economic perspective.

[0034] Further details and advantages of the invention will become apparent from the experiments and exemplary embodiments described below with reference to the figures. The figures show: Figure 1: A schematic representation of the process of an automated peritoneal dialysis treatment, in which the permissible residual volume is set relatively high in relation to the permissible patient volume, and therefore the dialysis solution is not completely consumed; Figure 2: A schematic representation of the process of an automated peritoneal dialysis treatment with profiled prescription, in which solution A is prescribed for enema 1, solution B for enema 2, and solution C for the last enema (profiled solutions), and in which the enema volumes and residence times also vary for the two cycles (profiled volumes and profiled residence times); Figure 3: Schematic representation of the interaction of residual solution present in the patient's peritoneum and fresh solution during the enema; Figure 4: Schematic representation of the mixing of the residual solution and the fresh solution;Figure 5: A schematic representation of an absorption curve for a solution exchanged during peritoneal dialysis treatment; Figure 6: Various absorption curves for different solutions; Figure 7: A filling volume-time diagram for a procedure during peritoneal dialysis treatment using a device according to the invention; Figure 8: A diagram showing the effectiveness of UF generation for solutions with glucose concentrations of 3.86%, 2.27%, and 1.50%; Figure 9: Illustration of the effectiveness of a mixture of fresh and used dialysis solution; Figure 10: A filling volume-time diagram for an alternative procedure during peritoneal dialysis treatment using a device according to the invention; Figure 11: An exemplary representation of proportions of the partial replacement volume in the peritoneum; Figure 12: a filling volume-time diagram for further procedure control in a peritoneal dialysis treatment using a device according to the invention;and Figure 13: a filling volume-time diagram for yet another procedure in peritoneal dialysis treatment using a device according to the invention.

[0035] The advantages of the invention are best explained by the following considerations. How this is achieved from Figure 3As can be seen, during the inflow of fresh dialysis solution 10 in the peritoneum 2 of the patient 1, residual solution 20 and fresh solution 10 mix in each new cycle. The residual solution 20 is formed from residual fluid of the previous cycle and consists of the previously administered dialysate and ultrafiltration fluid. The mass transport properties of the residual solution 20 differ from those of the fresh solution 10. In isolation, it is even conceivable that the residual solution 20 promotes resorption. The question arises as to how quickly the two solutions 10 and 20 mix in the abdominal cavity and what properties this mixed solution possesses. During the inflow, a portion of the fresh dialysate solution 10 mixes with the residual solution 20 due to the inflow.The subsequent diffusion causes the concentrations of the two solutions 10 and 20 to equalize at a certain time x. Presumably, after a relatively short time, a homogeneous mixture 30 will be found in the peritoneum 2, as shown in [reference]. Figure 4 depicted.

[0036] A resorption curve, as exemplified in Figure 5 As shown, this provides information about the effectiveness of detoxification during the dwell phase. The temporal course of the reabsorption curve depends on whether the patient is a high or low transporter. High transport capacity means that a concentration equilibrium of dissolved particles between blood and dialysate is quickly established, corresponding to a steep curve at the beginning and a rapid attainment of steady state. Furthermore, the steepness of the reabsorption curve depends on the glucose concentration or the type of solution used. How this is affected by the Figure 6Different substances have different absorption curves. For large molecules like proteins and insulin, these curves are generally flat and nearly linear.

[0037] What all absorption curves for smaller molecules have in common is that the concentration gradient at the beginning of the residence phase is relatively high and linear. This means that the effective mass transport remains constant in the initial period. The dependence of mass transport on the administered enema volume is in Figure 6 not shown. Rather, the illustrations assume that the patient was ideally filled with fresh solution. In reality, however, the properties of the residual solution 20 and its quantity would also have to be taken into account. In any case, it must be assumed that influencing the residual solution leads to a deterioration of the mass transport properties compared to the idealized considerations of the Figure 6comes.

[0038] According to the present invention, it is now provided to utilize unused inlet volume to exchange small portions of the applied peritoneal solution during the dwell phase in order to achieve additional mass transport. This concept is illustrated in the diagram of the Figure 7The graph visualizes the dialysis volume in the patient's peritoneum, with the y-axis representing the volume of fluid in the peritoneum. In this example, the permissible residual volume is set at 1000 ml (lower horizontal line) and the permissible patient volume at 3400 ml (upper horizontal line). The prescription is shown by the theoretical (lower) treatment curve and does not take residual volume into account. During actual treatment according to the higher treatment curve, dialysis fluid remains unused whenever the prescribed infusion volume, together with the residual volume present in the peritoneum before the start of the respective infusion phase, would result in a total volume exceeding the permissible patient volume.In the example shown, an additional partial replacement takes place during the residence phase in cycles 4, 6, and 8, consuming the unused and therefore excess inlet solution. This is symbolized by the jagged lines. No partial replacement occurs in the odd-numbered cycles because the residence times are relatively short, making the use of the available excess volume in these cycles less effective. No residual volume is available in cycle 2.

[0039] According to the invention, partial replacement should always take place during a dwell period. Preferred times for the start of partial replacement begin after approximately half the dwell time has elapsed and end after approximately 80% of the dwell time has elapsed, since at this point the dialysate is normally no longer as effective as at the beginning of the treatment, and, on the other hand, the replenished solution can still exert its effect sufficiently.

[0040] In one example, the prescribed infusion volume might be 3000 ml, and the residual volume might be set at 50%, or 1500 ml. The maximum volume is set at 110%, or 3300 ml. If a new infusion phase is started immediately upon reaching the residual volume, then a maximum of only 1800 ml may be infused into the patient. The percentage of the residual solution is therefore (1500 / 3300)*100% = 45%. Since the effectiveness of dialysis solutions decreases with the residence time in the peritoneum, as shown in Figure 8 As the relationship shown is evident, this can have significant effects on treatment efficiency.

[0041] Assuming that the residual fluid consists solely of dialysate (no ultrafiltration fraction) and has been in the abdominal cavity for approximately 2 hours on average, the resulting effectiveness of the mixed solution in the example scenario lies between the effectiveness of fresh dialysis solution and that of the 45 / 55 mixture. This is illustrated graphically in Figure 9The figure illustrates where the removal efficiency for ultrafiltration volume (UF volume) is shown for the fresh solution. The UF efficiency of the residual solution results from the UF efficiency curve of the fresh solution shifted 2 hours to the left. The efficiency of the mixed solution is obtained by additive superposition, assuming a mixing ratio of approximately 50%, as in the calculation example above. In reality, the residual solution will still contain ultrafiltration volume, which has zero efficiency. Therefore, the partial replacement of the solution according to the invention increases the blood-dialysate concentration gradient and thus the effectiveness of the treatment.

[0042] An alternative according to the invention to the one described in Figure 7 The process shown is in Figure 10As shown, the partial replacement cycles begin with a run-in phase to generally avoid outlet pressure problems. In this variant, the volume of the previous run-in phase can be reduced by the volume of the run-in phase for the partial replacement cycle, as illustrated in the figure.

[0043] The partial replacement is used in both the embodiment of the Figure 7 as well as the embodiment of the Figure 10 The dialysis solution is distributed across several cycles. This is partly for efficiency reasons, but also because the remaining volume can change during the course of treatment. For example, dialysis solution may need to be discarded if malfunctions occur or pumps need to be repositioned.

[0044] Within the scope of the invention, it may be advantageous to maximize the effective partial replacement volume during the partial replacement process. Figure 11Referring back to the calculation example above, the proportion of fresh solution in the peritoneum is shown as a function of the number and volume of partial replacement cycles. After the regular enema was administered, there were 550 ml of fresh solution and 450 ml of residual solution in the patient's abdominal cavity. The higher the exchange volumes, the higher the proportion of fresh solution at the end, as can also be seen in the following Table 1, which lists the values ​​from the diagram. Figure 11 reflects. Table 1 Partial replacement cycles Fresh solution in the abdominal cavity beforehand Fresh solution in the abdominal cavity afterwards 10 × 100 ml 550 ml 843 ml 5 x 200 ml 550 ml 852 ml 2 x 500 ml 550 ml 887 ml

[0045] A further embodiment of the invention is described in Figure 12 As shown. In this embodiment, partial replacement processes are only carried out within two cycles. For cycles with short residence times, it may not make sense to generate a partial replacement cycle due to the short exposure time.

[0046] In one variant of the concept according to the invention, it is provided that unused enema solution is used alternatively or additionally to slightly increase enemas, as shown in the illustration of the Figure 13 This is evident. The maximum permissible enema volume must, of course, not be exceeded. This variant of the procedure could be advantageous for adapted prescriptions, as cycles with small and large enema volumes alternate in this treatment form. The cycles with small enema volumes could be increased within predefined limits, for example, 10%.

[0047] Advantages of the concept according to the invention include the fact that little or no fluid is directed into the drainage system. The entire connected solution volume can be used effectively for the treatment. Time-consuming and knowledge-intensive workarounds, such as creating Tidal prescriptions or subsequent editing, are no longer necessary. The disadvantages of these workarounds are compensated for. The adaptation is highly dynamic and situation-dependent. The efficiency of the treatment is increased. The patient cannot be overfilled. No time delays in treatments are necessary. No additional disturbances are to be expected, so the patient does not need to be awakened for the procedure. The concept works with profiled treatments.

Claims

1. Apparatus for carrying out a peritoneal dialysis treatment comprising a reservoir for fresh dialysis fluid, a connector for connecting to a peritoneal catheter of a patient, a drain for consumed dialysis fluid, and a control unit connected to actuators, wherein the apparatus is configured to carry out a plurality of consecutive inflow-dwell-outflow cycles for a treatment on the basis of a prescription stored in the control unit, in which inflow-dwell-outflow cycles dialysis fluid is supplied to the patient from the reservoir and is led off through the outflow again after the elapse of a specific dwell time in the peritoneum of the patient, characterized in that the apparatus is further configured to already replace a portion of the dialysis fluid present in the peritoneum of the patient with fresh dialysis fluid from the reservoir before the elapse of the dwell time in at least one cycle if, in at least one preceding cycle, the volume of fresh dialysis fluid provided in accordance with the prescription for this preceding cycle was not completely consumed.

2. Apparatus in accordance with claim 1, characterized in that a maximum of 50%, preferably a maximum of 30%, and further preferably a maximum of 20%, of the total volume of dialysis fluid present in the peritoneum is replaced as part of the premature partial replacement.

3. Apparatus in accordance with one of the preceding claims, characterized in that the dwell time is not extended or reduced by the premature partial replacement and / or in that the total volume of dialysis fluid present in the peritoneum of the patient is not changed by the premature partial replacement.

4. Apparatus in accordance with one of the preceding claims, characterized in that the premature partial replacement is carried out in a plurality of inflow and removal steps, preferably directly consecutive, with at least five inflow steps preferably being provided and / or with a maximum of 200 ml being supplied with each inflow step.

5. Apparatus in accordance with one of the preceding claims, characterized in that the premature replacement is only carried out after the elapse of at least 50% of the provided dwell time and / or that the premature replacement is ended before the elapse of a maximum of 80% of the provided dwell time.

6. Apparatus in accordance with one of the preceding claims, characterized in that the apparatus is configured to already replace a portion of the dialysis fluid present in the peritoneum of the patient in a plurality of cycles over the course of the treatment with fresh dialysis fluid from the reservoir before the elapse of the dwell time.

7. Apparatus in accordance with one of the preceding claims, characterized in that the apparatus is configured only to start a partial replacement cycle when the dwell time provided for the respective cycle in accordance with the prescription exceeds a minimum time.

8. Apparatus for carrying out a peritoneal dialysis treatment comprising a reservoir for fresh dialysis fluid, a connector for connecting to a peritoneal catheter of a patient, a drain for consumed dialysis fluid, and a control unit connected to actuators, wherein the apparatus is configured to carry out a plurality of consecutive cycles for one treatment on the basis of a prescription stored in the control unit, in which inflow-dwell-outflow cycles dialysis fluid is supplied to the patient from the reservoir and is led off through the drain again after the elapse of a specific dwell time in the peritoneum of the patient, in particular an apparatus in accordance with one of the preceding claims, characterized in that the apparatus is further configured to increase the total inflow volume in at least one cycle if, in at least one preceding cycle, the volume of fresh dialysis fluid provided in accordance with the prescription for this preceding cycle was not completely consumed.

9. Apparatus in accordance with one of the preceding claims, characterized in that a maximum volume of dialysis fluid that may be present in the peritoneum of the patient is fixed in the control unit and that the incomplete consumption of the volume of fresh dialysis solution provided for the preceding cycle results from the fact that the complete consumption would have led to an exceeding of the maximum volume.

10. Apparatus in accordance with one of the preceding claims, characterized in that the apparatus is configured to supply the patient with the total volume of dialysis fluid provided in accordance with the prescription in the course of the treatment, with any difference quantity that is not supplied as part of the regular inflow phases being completely supplied, in particular on the basis of a consideration of the maximum volume, as part of the premature replacement during the at least one or more cycles.