DE102010045798A1 - The blood collection device - Google Patents

Abstract

The invention relates to a blood collection device, in particular a blood collection device for use in accordance with the aspiration method. The object of the invention is to provide a blood sampling device which is designed in such a way that it enables blood samples to be transported with as little hemolysis as possible, in particular by means of automated transport systems. The object is achieved by a blood sampling device comprising a. a blood collection tube (2), b. a plunger (5) movable in the blood collection tube (2) between a starting position (3) and an end position (4), and c. a cap (7) which closes an opening (6) of the blood collection tube (2) and has a septum (8), wherein in the starting position (4) of the plunger (5) one of a surface (9) of the plunger (5) and the cap ( 7) the limited cavity (10) in which the blood collection tube (2) is essentially filled by at least one insert (11, 12).

Description

The invention relates to a blood sampling device, in particular a blood sampling device for use according to the aspiration method.

For the removal and subsequent preparation and analysis of blood samples, prefabricated blood sampling devices are often used in which a sample tube made of transparent plastic is used, which has at one end a cap that provides a connection option to a suitable adapter, eg. B. a correspondingly configured double cannula, which can be pushed on the one hand in a blood vessel to be punctured, on the other hand by a septum located in the cap to catch the blood in the sample tube. In aspiration sampling, a sample tube constructed similar to a syringe and having a plunger reciprocable in the tube is used. The withdrawal of the stamper creates a negative pressure which draws blood or other body fluid into the tube. The stamp can be bent after complete withdrawal, whereby the sending and storing of the tube is facilitated. For sample tubes according to the negative pressure principle, a negative pressure in the tube has been generated in a suitable manner, for example by complete retraction of the punch before the puncture, so that a stamp is not absolutely necessary. The negative pressure can also be generated by complete retraction of the punch prior to connection to a double cannula.

Blood collection tubes are not only used for hygienic and easy blood collection, but also for the transport and storage of samples. The transport of samples, for example, increases with the ongoing centralization of laboratories, be it by combining individual laboratories within a clinic or from clinical laboratories in supraregional laboratories. In addition, the transport is increasingly using automated transport systems, eg. B. pneumatic tube systems. During transport, the samples are often exposed to strong mechanical stress, for example in the form of alternating accelerations. The same applies, albeit to a lesser extent, to longer trans-regional transports by car, train or plane.

Among other things, this mechanical stress leads to a destruction of the erythrocytes (hemolysis) with a release of intracellular components. However, hemolysis is a significant preanalytical irritant. For example, released hemoglobin can affect a number of laboratory analyzes as a (pre-analytical) disruptive factor (see p. Sodi, R., SM Darn, and A. Stott, 2004, Pneumatic tube system induced haemolysis: assessing sample type susceptibility to haemolysis, Ann Clin Biochem. 41 (3): pp. 237-40 ; Stair, TO, et al., 1995, Hemolysis of blood specimens transported from ED to laboratory by pneumatic tube, Am J Emerg. Med. 13 (4): p. 484 ; Steige, H. and JD Jones, 1971, Evaluation of pneumatic-tube system for delivery of blood specimens, Clin. Chem. 17 (12): 1160-4 ). It is known in this context that the hemolysis depends inter alia on the degree of filling of the sample vessels ( Zanner, R. et al., 2006, Transport of blood gas samples: is the pneumatic tube system safe ?, Anesthetist 55 (10): pp. 1099-104 ,

The object of the invention is to provide a blood sampling device, which is designed so that it enables as low as possible hemolysis transport of blood samples, in particular by means of automated transport systems.

The object is achieved by a blood sampling device according to claim 1. Advantageous embodiments of the blood sampling device according to the invention are specified in the subclaims.

The blood sampling device according to the invention comprises a) a blood collection tube, b) a stamper movable in a blood collection tube between a starting position and an end position, and c) a cap closing a mouth of the blood collection tube with a septum, in the starting position of the stamper one of a surface of the stamper and the Cap limited cavity in the blood collection tube is filled by at least one insert substantially.

The invention is based on the finding that in the known in the prior art blood collection devices, in particular those that work by aspiration, by design, an air-filled dead volume is present, ie an air volume that enclosed by the stamp, the walls of the blood collection tube and the cap is. This air volume remains after sampling in the blood collection tube, whereby a hemolysis-poor automated transport is excluded from the outset. Although sample vessels without such a dead volume already exist in the form of the classic syringe. However, this can not be used in modern fully automated laboratories, as it can not be opened without a leak ("decapped"). To that in devices according to the state of To minimize the technique to be observed hemolysis, the blood collection device according to the invention is designed so that it has no or a significantly reduced dead volume, but still easily used in modern laboratory operation. This is accomplished by substantially filling the cavity defined by a surface of the punch and cap in the blood collection tube by at least one insert.

The present invention provides a blood sampling device which enables a low-hemodynamic automated transport. "Hemolysis arm" in this context means a blood collection device according to the prior art, preferably a reduced transport-induced hemolysis to a clinically insignificant extent. A "hemolysis which has not been reduced to a clinically insignificant degree" is understood to mean a hemolysis in which the deviation from a sample exposed to no mechanical stress is shown in Table B1 of the Guideline of the German Medical Association for Quality Assurance of Laboratory Medical Examinations (2008). Deutsches Ärzteblatt, Jg. 105, No. 7, 15 February 2008, page A341-355 ; Deutsches Ärzteblatt 105, No. 12, 21 March 2008, Page A 650 and No. 107, 7 January 2010, pages A51-52 ) does not exceed specified values for control measurements. In addition, the blood sampling devices according to the invention make it possible to use transport systems with increased transport speed and thus stronger force, whereby, for example, the throughput can be increased.

In the blood sampling device according to the invention, the dead volume, the u for transport-related hemolysis. a. is minimized without altering the external dimensions and shape of the known blood collection devices. This allows the practitioner or technician to use the modified collection systems without changing the way they work. The application can be done in the usual way on automated analysis platforms. The automatic sortability (eg due to bulk sorter) and the possibility of automatic opening (eg decapper) are retained.

The insert may conveniently be arranged, for example, either on the punch or on or in the cap and / or fixed, but it may also be arranged both on the stamp and on or in the cap and / or fixed. Preferably, at least one insert is provided on or in the cap. This preferably has a fluid-permeable connection to the cap end, on which a septum is usually provided on. For example, blood, but also other body fluid, may be drawn into the sample tube via this connection, which may be in the form of a bore, a channel, a gutter, or the like.

An insert disposed on the cap preferably projects into the blood collection tube such that a surface of the insert substantially transverse to the longitudinal axis of the blood collection tube is spaced from the mouth of the blood collection tube by a distance a. In this way it is ensured that the blood sample always maintains a sufficient distance from the edge of the blood collection tube when the blood collection tube is in a vertical position. It is prevented that in a (manual or automated) opening the sample in a vertical position results in a "brimful" tube, which would be disadvantageous in view of the common sample transport systems of the analyzers, since there to "spill" of the sample and thus to a Contamination of the equipment could come.

The insert can be configured in a variety of ways, as long as the purpose is achieved, at least substantially prevent the dead volume described. For example, the insert may comprise two inserts. These insert parts can be introduced in a substantially H-shaped profile. The H-shaped profile can be made of any suitable materials known to the person skilled in the art, for example a thermosetting plastic.

The blood sampling device according to the invention may comprise one or more inserts. For only one use, this is preferably provided on or in the cap. In a preferred embodiment of the invention, in addition to the arranged on or in the cap insert yet another insert is present, which is preferably arranged on the surface of the punch. The arranged on or in the cap insert has a liquid-permeable connection to the septum of the cap. This embodiment is advantageous, for example, when the stamp is cup-shaped, as is already the case with blood sampling devices according to the prior art. In this embodiment of the present invention, the dead volume is thus closed by two separate inserts. Of course, in an insert which is arranged on or in the cap, also a corresponding region of the insert may be provided, which fits into the stamp cup, so that, alternatively, the dead volume can also be closed with only one insert.

The insert is preferably provided as a separate element. But it is of course also possible and provided according to the invention that the at least one insert is formed integrally with the cap or the stamp. The insert can be integrated in this way, for example, directly into the cap, it being possible that cap and insert are made of the same or different materials.

Preferably, the at least one insert is made of a biocompatible material, preferably a suitable for the analysis and at least short-term storage of blood samples plastic material.

The invention is explained in more detail below with reference to the attached figures and an embodiment for purely illustrative purposes.

1 Schematic longitudinal section of a blood sampling device according to the prior art.

2 Schematic longitudinal sectional view of an embodiment of the invention in the starting position (A) and an end position (B).

3 Schematic longitudinal section of a preferred embodiment of the invention.

4 Schematic longitudinal section of an alternative embodiment of the invention.

5 Box plots of percentage differences between hemolysis indicators (lactate dehydrogenase, LDH, aspartate aminotransferase, AST, potassium, K ⁺ ) in a prior art blood collection device ("Ref.") And a blood collection device ("Invention") each exposed to mechanical stress compared to samples that were not subjected to any mechanical stress, ie transported by foot. The abscissa gives the respective shaking frequencies (in rpm = revolutions per minute), the ordinate the percentage changes compared to the corresponding values for foot transport.

1 schematically shows a blood collection device according to the prior art, as used for example in the form of an S-Monovette ^® (SARSTEDT AG & Co. Kommanditgesellschaft, Nümbrecht, Germany). The blood sampling device 1 includes a blood collection tube 2 , which consists for example of plastic, as well as one in the direction 16 back and forth moving stamp 5 , The blood sampling device 1 is shown here in the delivery condition, ie the stamp 5 is so far in the blood collection tube 2 introduced that he with the stop 17 the blood collection tube 2 touched. The Stamp 5 or one end thereof is cup-shaped here, that is, it has, in addition to a transverse to the longitudinal axis of the blood collection tube 2 or parallel to the edge of the opening 6 of the blood collection tube 2 aligned area 9 one on the wall of the blood collection tube 2 adjoining surrounding wall 18 on. The stamp can be taken from the blood collection tube 2 on a stick 19 until the stop 20 pulled out and in a pull-out direction 16 If necessary, the constriction immediately before it can be bent off and removed. The opposite end of the blood collection tube 2 has an opening 6 on that with a cap 7 is closed. The cap itself also has an opening 21 and before that a septum 8th on. The blood sampling device 1 according to the prior art also points in the starting position, ie at maximum insertion of the punch 5 , a cavity 10 up here from the cap, the septum, the wall of the blood collection tube 2 and the stamp 5 , or its surface 9 and the wall 18 , is limited. The cavity 10 is air-filled and forms a dead volume, which remains even after sampling, regardless of how far the stamp 5 is withdrawn. Sampling is usually done so that on the cap 7 the outside of an adapter is connected to a double cannula, with one end of the double cannula in the blood vessel to be punctured, the other end through the septum 8th to be led. By pulling out the stamp 5 creates a negative pressure, through the blood into the blood collection tube 2 is sucked.

2 shows a schematic representation of an embodiment of the present invention, wherein the stamp 5 in starting position 3 (A) and end position 4 (B) is shown. Like reference numerals designate corresponding elements of FIG 1 described blood collection device 1 , so that here is waived a complete repetition. In the blood collection device according to the invention 1 There is no or only a small dead volume because of the cavity 10 through an insert 11 and a mission 12 is filled. The use 11 is on or in the cap 7 arranged and optionally there in a suitable manner, for example by gluing, fixed. The use 11 can also be completely or partially with the cap 7 connected, z. B. integrally formed therewith. On the stamp 5 is another use 12 intended. The use 12 is in the cup-shaped designed stamp 5 brought in, so its to the cap 7 directed surface 22 with the wall 18 flees. In the starting position 3 is the stamp 5 as far as possible, that is to the stop 17 , into the blood collection tube 2 introduced. In this position lies the surface 22 of the insert 12 on a corresponding surface 14 of the insert 11 at. The use 11 has a connection 13 on, by after piercing the septum 7 Blood in the blood collection tube 2 can get. As in particular from 2 B can be seen, the blood sample passes 23 when pulling out the stamp up to an end position 4 here for the maximum excerpt of the stamp 5 is shown by the connection 13 in the opening space between the two inserts 11 . 12 , Regardless of the extension length of the punch 5 , ie independent of the respective end position 4 of the punch, a dead volume is effectively avoided. The use 11 fills the inside of the cap 7 essentially protrudes and protrudes over the length a into the blood collection tube 2 into it. This results in the vertical position of the blood collection tube 2 a level of the blood sample 23 , from the edge of the opening 6 of the blood collection tube 2 is spaced by the distance a. This will increase the risk of overflowing the blood sample 23 over the edge of the opening 6 of the blood collection tube 2 with removed cap 7 significantly reduced.

In the 3 and 4 are further embodiments of the blood sampling device according to the invention 1 shown schematically. At the in 3 shown blood collection device 1 is the insert located in or on the cap 11 divided in two. The inserts 11a . 11b are in a section H-shaped profile 15 used. The profile 15 forms a divided by a partition on both sides open cylinder and the insert 11 is by inserting the inserts 11a . 11b formed in the openings of the cylinder. The inserts 11a . 11b are made of an elastomeric material, the profile 15 made of a thermosetting plastic. The profile 15 gives the insert increased rigidity. Otherwise corresponds to in 3 illustrated embodiment of 2 ,

In the 4 illustrated embodiment has only one use 11 on or in the cap 7 on. In this embodiment, the stamp is without the wall 18 trained, so here on another mission 12 can be waived. In the 2 and 3 illustrated embodiments with a wall 18 ie a cup-shaped stamp 5 , the use can 11 or the insert part 11a However, also be designed so that the "punch cup" is filled by, so that even in this case could be dispensed with a further use.

embodiment

Blood collection devices of the prior art (S monovette ^®, SARSTEDT AG & Co. Limited Partnership, Nümbrecht, Germany) were compared with an inventive blood sampling device for hemolysis. The blood sampling devices were under controlled conditions on a laboratory shaker exposed (LAB SHAKER, B. BRAUN, model Kühner) mechanical stress, as would occur when using pneumatic tube systems. The forces occurring in pneumatic tube systems were initially determined by appropriate measurements using the pneumatic tube system of the Eppendorf University Hospital, Hamburg, Germany (Ing. Sumetzberger GmbH, Vienna, Austria). The settings were chosen so that the maximum forces occurring in the pneumatic tube system were simulated (295 rpm, 5 minutes). Subsequently, the extent of hemolysis was measured by intraerythrocytic components to be measured in the blood (lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and potassium (K)) (Modular System, Roche). The reference samples were those that were not exposed to any mechanical stress ("foot transport").

The results are shown in Table 1 and 5 played. Table 1 Comparison measurements for hemolysis of mechanically stressed blood samples ( "shaken") using blood collection devices of the prior art (S-Monovette ^®, Sarstedt AG & Co., "reference") and a blood sampling device according to the invention ( "Inv."). The results are shown for lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and potassium (K) as well as the relative deviations in percent. Control: "foot transport". In the "Speed" column, the shaker frequency (240 or 295 rpm = revolutions per minute) and the shaking time (6 min, 10 s, or 5 min) are used to simulate the indicated forces occurring at different pneumatic tube speeds. Same letters in the sample designation represent paired blood samples from the same subjects. speed sample shaken Fußtransport Deviation from foot transport value% LDH K AST LDH K AST LDH K AST U / L mmol / L U / L U / L mmol / L U / L 240 Reference 6'10 A / 112 216 4.2 34 154 3.9 29 40.26 7.69 17.24 B / 113 222 4.3 30 144 4.0 23 54.17 7.50 30.43 C / 114 200 4.4 26 127 3.9 22 57.48 12.82 18.18 D / 115 266 4.7 33 136 4.1 22 95.59 14.63 50,00 I / 116 176 4.0 24 138 3.8 22 27.54 5.26 9.09 F / 117 207 3.9 35 157 3.7 29 31.85 5.41 20.69 240 Comp. 6'10 A / 118 161 4.1 30 154 3.9 29 4.55 5.13 3.45 B / 119 156 4.0 24 144 4.0 23 8.33 0.00 4.35 C / 120 209 4.2 27 127 3.9 22 64.57 7.69 22.73 D / 121 167 42 25 136 4.1 22 22.79 2.44 13.64 I / 122 148 3.9 23 138 3.8 22 7.25 2.63 4.55 F / 123 176 3.8 32 157 3.7 29 12.10 2.70 10.34 295 reference 5 ' G / 124 239 4.3 36 154 3.9 29 55.79 10.26 24.14 H / 125 239 4.5 32 144 4.0 23 65.97 12.50 39.13 1/126 196 4.3 27 127 3.9 22 54.33 10.26 22.73 J / 127 331 4.8 37 136 4.1 22 143.38 17.07 68.18 K / 128 168 3.9 24 138 3.8 22 21.74 2.63 9.09 L / 129 222 4.1 35 157 3.7 29 41,40 10.81 20.69 295 Erf, 5 ' G / 130 * 304 4.4 41 154 3.9 29 97,40 12.82 41.38 H / 131 193 4.2 29 144 4.0 23 34.03 5.00 26,09 1/132 140 4.2 24 127 3.9 22 10.24 7.69 9,09 J / 133 143 4.1 22 136 4.1 22 5.15 0.00 0.00 K / 134 151 3.9 23 138 3.8 22 9.42 2.63 4.55 L / 135 168 3.8 30 157 3.7 29 7.01 2.70 3.45 * The blood sampling devices 130 had defects (foaming)

The results in Table 1 show that hemolysis-poor transport is enabled by the present invention. In addition to the data in Table 1 shows 5 Boxplots of percentage deviations. From this, the differences between the blood sampling device according to the invention ("Erf.") And the blood sampling device according to the prior art ("Ref.") Are particularly clear. In the blood sampling device according to the invention, there are significantly smaller deviations, which can be interpreted as less hemolysis.

The results make it clear that when using the blood sampling device according to the invention, a reduction of hemolysis to a clinically irrelevant level can be achieved. This results when the percentage deviations given in Table 1 are analogous to the specifications given by the Guideline of the German Medical Association for the Quality Assurance of Laboratory Medical Examinations (2008) Table B1 provides for control measurements, evaluated. In Table 2, the requirements according to the Directive and the values from Table 1 are compared. Table 2: Comparison of permissible deviations in individual value measurements according to Table B1 of the Guideline of the German Medical Association for Quality Assurance of Laboratory Medical Examinations, 2008, and deviations in the degree of hemolysis in mechanically stressed blood samples from blood samplers according to the prior art and according to the invention (in each case in percent). Directive setting Blood collection device according to the prior art Inventive blood collection device Aspartate aminotransferase (AST) 11.5% 22.7% (max 68.2%) 4.5% (up to 9.1%) potassium 4.5% 10.8% (max 17.1%) 2.7% (up to 7.7%) Lactate dehydrogenase (LDH) 9.0% 54% (max 143%) 9.4% (max 34%)

LIST OF REFERENCE NUMBERS

1

The blood collection device

2

Blood Collection tubes

3

starting position

4

end position

5

stamp

6

opening

7

cap

8th

septum

9

area

10

cavity

11

commitment

12

commitment

13

Liquid-permeable connection

14

area

15

H-shaped profile

16

Direction of movement of the stamp

17

attack

18

wall

19

stalk

20

attack

21

opening

22

area

23

sample

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Sodi, R., SM Darn, and A. Stott, 2004, Pneumatic tube system induced haemolysis: assessing sample type susceptibility to haemolysis, Ann Clin Biochem. 41 (3): pp. 237-40 [0004]
• Stair, TO, et al., 1995, Hemolysis of blood specimens transported from ED to laboratory by pneumatic tube, Am J Emerg Med. 13 (4): 484 [0004]
• Steige, H. and JD Jones, 1971, Evaluation of Pneumatic Tube System for Delivery of Blood Specimens, Clin. Chem. 17 (12): 1160-4 [0004]
• Zanner, R. et al., 2006, Transport of blood gas samples: is the pneumatic tube system safe ?, anesthetist 55 (10): pp. 1099-104 [0004]
• Deutsches Ärzteblatt, vol. 105, No. 7, 15 February 2008, pages A341-355 [0009]
• Deutsches Ärzteblatt Journal 105, Issue 12, March 21, 2008, Page A 650 and Gen 107, January 7, 2010, pages A51-52 [0009]

Claims (7)

Blood collection device, comprising a. a blood collection tube ( 2 b. one in the blood collection tube ( 2 ) between a starting position ( 3 ) and an end position ( 4 ) movable stamp ( 5 ) and c. an opening ( 6 ) of the blood collection tube ( 2 ) closing cap ( 7 ) with a septum ( 8th ), whereby in starting position ( 4 ) of the stamp ( 5 ) one of a surface ( 9 ) of the stamp ( 5 ) and the cap ( 7 ) limited cavity ( 10 ) in the blood collection tube ( 2 ) by at least one use ( 11 . 12 ) is substantially filled. Blood sampling device according to claim 1, characterized in that an insert ( 11 ) on or in the cap ( 7 ) and a liquid-permeable compound ( 13 ) to the septum ( 8th ) of the cap ( 7 ) having. Blood sampling device according to claim 0, characterized in that the insert ( 11 ) into the blood collection tube ( 2 protrudes so that a substantially transversely to the longitudinal axis of the blood collection tube ( 2 ) running surface ( 14 ) of the mission ( 11 ) from the opening ( 6 ) of the blood collection tube ( 2 ) is spaced by a distance a. Blood sampling device according to claim 0 or 3, characterized in that the insert ( 11 ) comprises two insert parts, which in a section substantially H-shaped profile ( 15 ), wherein the H-shaped profile ( 15 ) preferably consists of a thermosetting plastic. Blood sampling device according to one of claims 0 to 4, characterized in that next to the on or in the cap ( 7 ) arranged use ( 11 ) another use ( 12 ) present at the surface ( 9 ) of the stamp ( 5 ), wherein the on or in the cap ( 7 ) use ( 11 ) a liquid-permeable compound ( 13 ) to the septum ( 8th ) of the cap ( 7 ) having. Blood sampling device according to one of the preceding claims, characterized in that the at least one insert ( 11 . 12 ) in one piece with the cap ( 7 ) or the stamp ( 5 ) is trained. Blood sampling device according to one of the preceding claims, characterized in that the at least one insert ( 11 . 12 ) consists of a biocompatible material.

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