Method for removing fluid from a blood filter after completing a blood treatment session by means of flow increase and treatment device for carrying out said method

Abstract

The present invention relates to a method for removing a first fluid from a blood filter for the blood treatment of a patient and/or for removing blood from the blood filter after completing the blood treatment session. It further relates to a medical treatment apparatus having a control device with which a method for removing a first fluid from a blood filter is executable, a digital storage medium, and a computer program product.

Claims

1. A medical treatment apparatus comprising: at least one extracorporeal blood circuit with a line interior and comprising a blood chamber and an arterial blood line; and a medical blood treatment apparatus comprising: at least one blood pump which is arranged along the extracorporeal blood circuit for conveying blood within the line interior of the extracorporeal blood circuit; at least one device for introducing a second fluid into the arterial blood line; and a control device configured to, after completing a blood treatment session of a patient using the medical treatment apparatus, control the medical blood treatment apparatus to cause blood to be displaced from the blood chamber by introducing the second fluid into the arterial blood line in phases of high-flow followed by phases of low-flow such that the displaced blood is reinfused to the patient at a desired average reinfusion flow rate.

2. The medical treatment apparatus according to claim 1, wherein the control device is further configured to control the medical blood treatment apparatus to cause a subsequent displacing of a first fluid from the blood chamber by an introduced substituate with a predetermined substituate flow rate through a blood filter between 135 ml/min and 165 ml/min.

3. The medical treatment apparatus according to claim 2, wherein the subsequent displacing of the first fluid from the blood chamber by an introduced substituate with the predetermined substituate flow rate through the blood filter is between 135 ml/min and 165 ml/min in average.

4. The medical treatment apparatus according to claim 1, wherein the control device is further configured to control the medical blood treatment apparatus to perform the blood treatment session of the patient using the medical treatment apparatus.

5. The medical treatment apparatus according to claim 1, wherein the medical blood treatment apparatus further comprises a buffer tank for receiving fluid which has been displaced from the blood chamber, wherein the buffer tank is in fluid communication with the blood chamber.

6. The medical treatment apparatus according to claim 5, wherein the buffer tank is arranged downstream of the blood chamber.

7. The medical treatment apparatus according to claim 5, further comprising a blood cassette, and wherein the buffer tank is a single needle chamber of the blood cassette.

8. The medical treatment apparatus according to claim 1, wherein the second fluid is a substituate fluid or a dialysis fluid.

9. The medical treatment apparatus according to claim 1, wherein the at least one extracorporeal blood circuit further comprises a blood filter comprising the blood chamber and a dialysate chamber between which a membrane is arranged.

10. The medical treatment apparatus according to claim 9, wherein the blood chamber is in fluid communication with the arterial blood line and with a venous blood line.

11. The medical treatment apparatus according to claim 9, wherein the dialysate chamber is in fluid communication with a dialysis inlet line and with a dialysate outlet line.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Hereafter, the method is exemplarily described by preferred embodiments with reference to the accompanying drawing. In the drawing, the following applies:

(2) FIG. 1 illustrates in a schematically simplified manner sections of a medical treatment apparatus having a blood cassette for performing the method in a first embodiment;

(3) FIG. 2 illustrates the medical treatment apparatus of FIG. 1 when or while performing the method in a second exemplary embodiment; and

(4) FIG. 3 illustrates the measured transmission (in percent (%)), shown over the reinfusion volume (in milliliter (ml))

DETAILED DESCRIPTION

(5) FIG. 1 shows an extracorporeal blood circuit 1 which is connected, by double-needle access, to the vascular system of the patient (not shown). The blood circuit 1 is disposed in section thereof in or on the blood cassette 2 (exemplarily as described above). The blood circuit 1 is connected to a treatment apparatus 4.

(6) The blood circuit 1 comprises an arterial patient hose clamp 6 and an arterial connection needle 5 (as an example of an access device) of an arterial section or of an arterial patient or line blood line 9. The blood circuit 1 further comprises a venous patient hose clamp 7 and a connection needle 27 (as an example of a further or second access device) of a venous section or of a venous patient line or blood line 23.

(7) A blood pump 11 is provided in the arterial section 9, a substituate pump 17a is connected to a substituate line 17. The substituate line 17a can be connected with a substituate source through a, preferably automatic, substituate port 18. By the substituate pump 17, substituate may be introduced via pre-dilution or via post-dilution through associated lines 13 or 14 into line sections, e.g., into the arterial section 9 or into a venous section 23a (between a blood chamber 19a and a single needle chamber 36 (see below) of the blood circuit 1.

(8) A blood filter 19 is provided in or with the blood circuit 1. It comprises a blood chamber 19a which is connected with the arterial section 9 and with the venous section 23. A dialysate chamber 19b is connected with a dialysis fluid inlet line 31a which leads to the dialysate chamber 19b and with a dialysate outlet line 31b which leads away from the dialysate chamber 19b.

(9) The dialysis fluid inlet line 31a optionally comprises a valve V24 by which the flow within the dialysis fluid inlet line 31a may be stopped. The dialysate outlet line 31b optionally comprises a valve V25 by which the flow within the dialysate outlet line 31b may be stopped.

(10) The dialysis inlet line 31a is further optionally connected to a compressed air source 26 by another internal valve of the apparatus. The compressed air source 26 may be provided as a part or component of the treatment apparatus 4 or as a separate part thereof. A pressure sensor 37 may be provided downstream of the compressed air source 26.

(11) For performing the method aiming to empty the blood chamber 19a of the blood filter 19 after completion of the treatment, the arterial patient hose clamp 6 may be closed, the venous patient hose clamp 7 may be opened and/or the blood pump 11 (exemplarily designed as a roller pump) may be stopped and a substituate or dialysis fluid may be introduced by a substituate pump 17 through the addition point 13 in pre-dilution of the blood circuit 1 and of the blood chamber 19a.

(12) Alternatively or in addition, it is possible not to introduce the substituate by operating the substituate pump 17 but by operating the blood pump 11. Thereto, the arterial patient hose clamp 6 is closed and substituate is introduced into the extracorporeal blood circuit 1 via a supply line 8 from a storage container for the substituate.

(13) The achieved substituate-blood content is conveyed along the line interior of the extracorporeal blood circuit 1 by operating the blood pump 11 and/or the substituate pump 17. It is as well pressed or conveyed through the blood filter 19, the venous air separation chamber 21 and a venous section 23 of the extracorporeal blood circuit 1 in order to remove the blood from the extracorporeal blood circuit 1 in the direction towards the venous connection needle 27 from the blood filter 19.

(14) A venous substituate-blood detector 25 is optionally arranged in the venous section 23 of the extracorporeal blood circuit 1 as a further example of a detection device which detects the occurrence of substituate at a predetermined position of the line interior of the extracorporeal blood circuit 1. The blood pump 11 and/or the substituate pump 17 continue conveying the substituate-blood content until the blood in the venous section 23 of the extracorporeal blood circuit 1 is removed from it and returned to the vascular system of the patient via the venous connection needle 27, and/or until substituate is detected in the line interior at the venous substituate-blood detector 25. The conveying effort of all pumps is stopped at this point. An optical and/or acoustical signal can be output.

(15) Controlling or regulating the treatment apparatus 4 may be carried out by a control or regulating device 29.

(16) The arrangement of FIG. 1 encompasses an optional detector 15 for detecting air and/or blood. The arrangement of FIG. 1 encompasses further one or two pressure sensors 33a, 33b at the illustrated points in FIG. 1.

(17) The introduced substituate may be temporarily stored in a buffer tank or container, from which it will or can be discharged at a lower flow rate than that with which it has been introduced into the buffer tank.

(18) The single needle chamber 36 is particularly taken into consideration as buffer tank in the arrangement of FIG. 1. The single needle chamber 36 may be an active or non-active part in the blood circuit by correspondingly switching an optional single needle valve 35, which separates the single needle chamber 36 preferably from further, in particular from all further blood conducting structures. When the single needle chamber 36 is accessible—by opening the single needle valve 35—for blood or another fluid which flows out of the venous section 23a downstream of the blood filter 19 and when at the same time a flow-through of blood or of fluid along the single needle chamber 36 is prevented exemplarily by closing the patient hose clamp 7, then the blood may first be buffered or stored in the single needle chamber 36 before it leaves, with a desired flow rate, the single needle chamber 36 towards the venous patient hose clamp 7, after the venous patient hose clamp 7 has been opened.

(19) Alternatively, it may exemplarily be proceeded as illustrated in FIG. 2:

(20) The extracorporeal blood circuit 1 is disconnected from the vascular system of the patient by, e.g., removing the arterial connection needle 5 from the arm of the patient. In any case however, the arterial blood line 9 is connected upstream of the blood filter 19 at a connection point 24 with the venous section 23a. The arterial patient hose clamp 6 remains open. Due to the pressure of the substituate pump 17, substituate is conveyed along the directions of the two arrows both through the blood chamber 19a and through the arterial blood line 9. The blood present in the blood chamber 19a and in the arterial blood line 9 is thus removed in this way from both blood chamber 19a and from the arterial line 9.

(21) In FIGS. 1 and 2, the single needle chamber 36 is used as a buffer tank, in particular during or after a double-needle method by which a patient is connected with the extracorporeal blood circuit 1 by two blood lines 9 and 27. However, it is apparent for the skilled in the art that some embodiments may also be carried out or performed without using a buffer tank. In addition, any other buffer tank may be taken into consideration.

(22) FIG. 3 shows the measured transmission (in %) shown over the reinfusion volume (in ml) which was measured by the inventors in an experimental set up using the FX.sub.hdf1000 dialyzer from or made by the applicant at different substituate flow rates, as indicated in the graph of FIG. 3.

(23) Substituate is sucked in or drawn in arterially in the experimental set up. At the venous blood line 23, see FIG. 1 or 2, a photometer, provided for detecting a transmitted light power, is mounted about 10 cm below or downstream of the venous optical detector 25 and of the venous patient hose clamp 7. The sensor of the photometer has been normalized or standardized on clear, bloodless substituate. The transmission has been detected depending on the rinsing or flushing volume at different substituate flow rates. The hematocrit of the used bovine blood is 30% prior to each experiment.

(24) FIG. 3 shows the advantageous efficiency performed by the method by which higher substituate flow rates than usual are used or practiced for rinsing or flushing.

(25) It is evident that with increasing substituate flow used as rinsing flow, the line content gets clear sooner or the measured transmission increases.

(26) The amount of the blood remaining in the extracorporeal blood circuit decreases when having a predetermined or fixed reinfusion volume.

(27) The respectively selected points in the graphs denote the reinfusion volume by which or at which the detection device, e.g. the optical sensor, does not detect any blood anymore.

(28) The present invention is not limited to the embodiments as described above, they are considered only for illustrative purposes. Furthermore, the invention is not limited to emptying the content or parts hereof while a connection with the vascular system still exists.

REFERENCE NUMERAL LIST

(29) 1 extracorporeal blood circuit 2 blood cassette 4 treatment apparatus 5 access device, e.g. arterial connection needle 6 arterial patient tube clamp 7 venous patient tube clamp 8 supply line 9 arterial section or arterial blood line or arterial patient line 11 blood pump 13 addition site for substituate (pre-dilution) 14 addition site for substituate (post-dilution) 15 arterial air/blood detector 17 second conveying device, e.g. a substituate pump 17a substituate line 18 automatic substituate port 29 blood filter 19a blood chamber 19b used dialysate chamber 21 air separator chamber 23 venous section or venous blood line 23a venous section 24 connection site 25 venous substituate blood detector 26 compressed air source 27 access device, e.g. venous connection needle 29 control or regulating unit 31a dialysis inlet line 31b dialysate fluid outlet line 33a, b pressure sensors 35 single-needle valve 36 single needle chamber 37 pressure sensor V24 valve V25 valve