Blood collection syringe with protection against hemolysis

Abstract

A blood collection device may include a syringe with hemolysis protection. The hemolysis-protected syringe can be attached to a catheter assembly and used for blood collection. The blood collection device may include the syringe, which may include a distal end and a flow restrictor. The flow restrictor may include a distal end and a proximal end. The proximal end of the flow restrictor can be attached to the distal end of the syringe, which may provide hemolysis protection.

Description

Blood collection syringe with protection against hemolysis CROSS REFERENCE TO RELATED APPLICATION This application claims priority over the United States provisional application serial no. 63 / 090.602, entitled Blood Draw Syringe with Hemolysis Protection, filed on October 12, 2020, the full disclosure of which is incorporated herein by reference. BACKGROUND A catheter is commonly used to infuse fluids into a patient's vasculature. For example, the catheter can be used to infuse normal saline solution, various medications, or total parenteral nutrition. The catheter may include a peripheral intravenous (IV) catheter. In this case, the catheter may be mounted on an introducer needle with a sharp distal tip. The catheter and introducer needle may be assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter, with the bevel of the needle facing upward and away from the patient's skin. The catheter and introducer needle are typically inserted at a shallow angle, through the skin, into the patient's vasculature. To verify that the introducer needle and / or catheter have been properly inserted into the blood vessel, the physician will typically confirm that blood flows back into a return chamber of the catheter assembly. Once needle placement has been confirmed, the physician can remove the introducer needle, leaving the catheter in place for future fluid infusion. Blood collection via peripheral intravenous catheters is not routinely performed, largely due to the risk of hemolysis of a blood sample drawn through the catheter. When blood is drawn via a peripheral intravenous catheter, a commonly used collection container is a VACUTAINER® blood collection tube, marketed by Becton Dickinson & Company. In some cases, a syringe may be used instead. However, the syringe has not been shown to reduce the risk of hemolysis compared to VACUTAINER®. Unfortunately, when blood is drawn into a syringe or VACUTAINER®, red blood cells are subjected to high shear stress and are susceptible to hemolysis due to a high pressure differential between the vein and the syringe or VACUTAINER®. Hemolysis can result in rejection and discarding of a blood sample. The high pressure differential can also result in catheter tip folding, vein collapse, or other complications. The subject matter claimed herein is not limited to implementations that overcome a disadvantage or that function only in the environments described above. Instead, this background information is provided only to illustrate a technological area where some of the implementations described herein may be put into practice. BRIEF DESCRIPTION This disclosure generally relates to a blood collection device and related devices, systems, and methods. In some embodiments, a blood collection system may include a catheter assembly, which may include a catheter adapter and a catheter extending distally from the catheter adapter. In some embodiments, the blood collection system may include the blood collection device coupled to the catheter assembly. In some embodiments, the blood collection device may include a syringe, which may include a distal end. In some embodiments, the blood collection device may include a flow restrictor, which may include a distal and a proximal end. In some embodiments, the proximal end of the flow restrictor may be coupled to the distal end of the syringe. In some embodiments, the catheter assembly may include an extension tube. In some embodiments, a distal end of the extension tube may be integrated into the first catheter adapter. In some embodiments, the blood collection device may be attached to a proximal end of the extension tube. In some embodiments, the distal end of the syringe may include a first Luer adapter. In some embodiments, the proximal end of the flow restrictor may include a second Luer adapter coupled to the first Luer adapter. In some embodiments, the flow restrictor may be monolithically formed as a single unit. In these and other embodiments, the distal end of the flow restrictor may include a third Luer adapter. In some embodiments, the distal end of the flow restrictor may include the third Luer adapter. In these and other embodiments, the flow restrictor may include an extension tube disposed between the second and third Luer adapters. In these and other embodiments, the flow restrictor may include a first piece formed monolithically as a single unit and a second piece formed monolithically as a single unit. In some embodiments, a proximal end of the extension tube may be integrated within the first piece. In some embodiments, a distal end of the extension tube may be integrated within the second piece. In some embodiments, the first piece may include the second Luer adapter. In some embodiments, the second piece may include the third Luer adapter. In some embodiments, a geometric factor of the flow restrictor is represented by Gr. In some embodiments, Gf can be 1.43E7 l / in³ ± 30%. In some embodiments, Gf can be 3.70E6 l / in³ ± 30%. In some embodiments, Gf can be between 1.43E7 and 3.70E6. In some embodiments, Gr can be 1.43E7 l / in³ ± 10% or 3.70E6 l / in³ ± 10%. In some embodiments, the flow restrictor may include a fluid path extending through the flow restrictor. In some embodiments, the diameter of the fluid path may be uniform along its entire length. In these embodiments, the diameter is represented by D, the length is represented by L, and D⁴ / L may be 2.7E⁻⁷ or 7.0E⁻⁸. It should be understood that both the preceding general description and the following detailed description are illustrative, not restrictive, examples of the invention as claimed. It should be understood that the various embodiments are not limited to the arrangements and instruments shown in the drawings. It should also be understood that the embodiments may be combined, or that other embodiments may be used, and that structural changes, unless so claimed, may be made without departing from the scope of the various embodiments of the present invention. The following detailed description should therefore not be taken in a limiting sense. BRIEF DESCRIPTION OF THE DRAWINGS The illustrative realizations will be described and explained in additional specificity and detail by means of the accompanying drawings, in which: Figure 1A is a top perspective view of an example of a blood collection device that includes protection against hemolysis, according to some embodiments; Figure 1B is a cross-sectional view of the blood collection device of Figure 1A, according to some embodiments; Figure 2A is a top perspective view of another example of a blood collection device that includes protection against hemolysis, according to some embodiments; Figure 2B is a cross-sectional view of the eoLfrnn / eznz / B / Yi blood extraction device of Figure 2A, according to some embodiments; Figure 3 is a top perspective view of an example of a blood collection system, according to some embodiments; Figure 4 is a bar chart illustrating blood collection rates with different catheter gauges and flow limiters under different syringe withdrawal rates, according to some realizations; Figure 5 is a bar chart illustrating the maximum shear stress with different catheter gauges and flow restrictors under different syringe withdrawal speeds, according to some embodiments; and Figure 6 is a graph illustrating free plasma hemoglobin for catheter assemblies with and without flow limiter, according to some realizations. DESCRIPTION OF THE ACHIEVEMENTS In some embodiments, a blood collection device 10 may include a syringe 12, which may include a distal end 14 and a proximal end 16. In some embodiments, the syringe 12 may include a sliding plunger 18 that fits snugly into a cylinder or tube 20. In some embodiments, the sliding plunger 18 can be pulled proximally relative to the tube 20, allowing the syringe 12 to draw a fluid, such as blood, through an orifice 22 in the distal end 14. In some embodiments, the sliding plunger 18 can be pushed distally relative to the tube 20, allowing the syringe 12 to then expel the fluid through the orifice 22. In some embodiments, the syringe 12 can be configured to hold between approximately 1 and 20 milliliters of the fluid. In some embodiments, the blood collection device 10 may include a flow restrictor 24, which may include a distal end 26 and a proximal end 28. In some embodiments, the proximal end 28 of the flow restrictor 24 may be coupled to the distal end 14 of the syringe 12. In some embodiments, the flow restrictor 24 may be removably coupled to the distal end 14 of the syringe 12. In other embodiments, the flow restrictor 24 may be permanently coupled to the distal end 14 of the syringe 12. In some embodiments, the distal end 14 of syringe 12 may include a first Luer adapter 30. In some embodiments, the proximal end 16 of flow restrictor 24 may include a second Luer adapter 32 coupled to the first Luer adapter 30. In some embodiments, the first Luer adapter 30 may include a male Luer adapter, which can be screwed on or slid into a fitting with the second Luer adapter 32, which may include a female Luer adapter. In some embodiments, a threaded connection between the first Luer adapter 30 and the second Luer adapter 32 may prevent accidental detachment of syringe 12 from flow restrictor 24 during blood collection. In some embodiments, the flow restrictor 24 can be formed monolithically as a single unit, as illustrated, for example, in Figures 1A-1B. In these and other embodiments, the distal end 26 of the flow restrictor 24 can include a third Luer adapter 34. In some embodiments, the third Luer adapter 34 can include a male Luer adapter. In some embodiments, the distal end 26 of the flow restrictor 24 can be configured to attach to a catheter assembly, which can be inserted into a patient's vasculature. In some embodiments, the sliding plunger 18 can be pulled in a proximal direction to draw blood from the patient's vasculature into the syringe 12 tubing 20. In some embodiments, the length of the flow restrictor 24 may be shorter than the length of the syringe 12 to facilitate user handling. In some embodiments, the flow restrictor 24 may include a fluid pathway 36 that extends through the flow restrictor 24. In general, blood cells experience shear stress when blood flows through a fluid pathway. The maximum shear stress occurs along the blood cell wall, also referred to as wall shear stress. Wall shear stress on blood cells is considered a major source of hemolysis and mechanical damage to them. In some embodiments, the flow limiter 24 can provide protection against hemolysis. More specifically, the flow limiter 24 can limit a maximum blood collection rate, which in turn can limit the maximum shear stress during blood collection and reduce hemolysis. In some embodiments, the flow limiter 24 can be configured to limit the maximum shear stress to which blood cells are exposed during syringe collection to a target or predetermined value. The fluid flow in a flow restrictor with a tubular fluid path through it can be analyzed using Poiseuille's equation: πΰ4ΔR ΔR Q =----= —v128μί Rf where P is a change in the pressure gradient across the flow restrictor, D and L are the inside diameter and length, respectively, of the fluid path 36 through the flow restrictor, μ is the viscosity of a fluid, and Rf = is the fluid resistance. Since μ is the viscosity of the fluid and is not part of the geometry of the flow restrictor, a geometric factor G is defined such that Rf (the fluid resistance) is Rf= Gf, where Gf = In some embodiments, the flow restrictor may include flow restrictor 24 or flow restrictor 38 (see, for example, Figures 2A-2B). In response to fluid path 36 which has multiple sections with lengths (L1, L2, L3) and inner diameters of (D1, D2, D3), the fluid resistance is: „ L1 L2 L3 (jf — ---- ' ----- I ----rDI4£>24D34 In some embodiments, the flow limiter can be configured to limit Gf and thus limit hemolysis. For example, for flow limiter 24, Gf can be approximately 1.43E7 L / in3. In some embodiments, for flow limiter 24, Gf can be 1.43E7 L / in3 ± 10% or 1.43E7 L / in3 ± 30%. In some embodiments, the inner diameter of the fluid path 36 may be uniform along its entire length. In some embodiments, D4 / L is approximately 2.7E-7, which may reduce wall shear stress to minimize hemolysis when the flow restrictor 24 is used with a 20G catheter. In some embodiments, D4 / L is approximately 7.0E-8, which may reduce wall shear stress to minimize hemolysis when the flow restrictor 24 is used with a 22G catheter. Referring to Figures 2A-2B, in some embodiments, the blood collection device 10 may include a flow limiter 38. In some embodiments, the flow limiter 38 may be similar or identical to the flow limiter 24 in terms of one or more features and / or operation. In some embodiments, the flow limiter 38 may also be configured to limit Gf and thereby limit hemolysis. For example, for flow limiter 38, Gf may be approximately 3.70E6 L / in³. In some embodiments, for flow limiter 38, Gf may be 3.70E6 L / in³ ± 10% or 3.70E6 L / in³ ± 30%. In some embodiments, a particular flow restrictor, such as, for example, flow restrictor 24 or flow restrictor 38, may have a Gf between 1.43E7 and 3.70E6. In some embodiments, the inside diameter of the fluid path 36 may be variable along the fluid path 36.In these and other embodiments, the flow limiter 38 may include multiple sections formed with tubes having different inner diameters that are joined together or a single tube with a variable inner diameter along its length. In some embodiments, the distal end 26 of the flow restrictor 38 may include the third Luer adapter 34. In these and other embodiments, the flow restrictor 38 may include an extension tube 44 disposed between the second Luer adapter 32 and the third Luer adapter 34. In these and other embodiments, the flow restrictor 38 may include a first piece 40 formed monolithically as a single unit and / or a second piece 42 formed monolithically as a single unit. In some embodiments, the proximal end of the extension tube 44 may be integrated within the first piece 40. In some embodiments, a distal end of the extension tube 44 may be integrated within the second piece 42. In some embodiments, the first piece 40 may include the second Luer adapter 32. In some embodiments, the second piece 42 may include the third Luer adapter 34. In some embodiments, the length of flow restrictor 38 may be shorter than the length of syringe 12 to facilitate user handling. In some embodiments, flow restrictor 38 may include fluid path 36 extending through flow restrictor 24. In some embodiments, the inside diameter of fluid path 36 may be uniform along its entire length. In some embodiments, the inside diameter is represented by D, the length by L, and D⁴ / L is 2.7E⁻⁷, which may reduce wall shear stress to minimize hemolysis when flow restrictor 38 is used with a 20G catheter. In some embodiments, the inside diameter is represented by D, the length by L, and D⁴ / L is 7.0E⁻⁸, which may reduce wall shear stress to minimize hemolysis when flow restrictor 38 is used with a 22G catheter. Referring to Figure 3, a flow restrictor, such as flow restrictor 24 (see, for example, Figures 1A-1B) or flow restrictor 38 (see, for example, Figures 2A-2B), can be attached to a catheter assembly 46. In some embodiments, the catheter assembly 46 may include catheter adapter 48 and a catheter 50 extending distally from catheter adapter 48. In some embodiments, the catheter assembly 46 may include an extension tube 52. In some embodiments, a distal end of the extension tube 52 may be integrated into catheter adapter 48. In some embodiments, the blood collection device 10 may be attached to a proximal end of the extension tube 52. In some embodiments, a needle assembly 54 can be attached to the catheter assembly 46. In some embodiments, the needle assembly 54 may include a needle hub 56 and an introducer needle 58 secured within the needle hub 56. In some embodiments, in response to the insertion of the catheter 50 into the patient's vasculature, the needle assembly 54 can be withdrawn from the catheter assembly 46. In some embodiments, the proximal end of the extension tube 52 can be integrated into a side port 60 of the catheter adapter 48. In some embodiments, catheter assembly 46 may include or correspond to any suitable catheter assembly, such as, for example, the closed IV catheter system eoLfrnn / eznz / B / Yi BD NEXIVA™, the BD CATHENA™ catheter system, the BD VENFLON™ Pro Safety Shielded IV Catheter System, the BD NEOFLON™ IV Cannula System, the BD INSYTE™ AUTOGUARD™ BC Shielded IV Catheter System, or another suitable catheter assembly. In some embodiments, the 50 catheter may include a peripheral intravenous catheter (PIVC), a peripherally inserted central catheter (PICC), a midline catheter, or another suitable catheter. In some embodiments, in response to the insertion of catheter 50 into the vasculature, blood may flow proximally through a fluid pathway of catheter assembly 46, which may include one or more of the following: catheter 50, catheter adapter 48, extension tube 52, adapter 62, flow limiter, and syringe 12. The following bar graph, referring to Figure 4, illustrates blood withdrawal rates with different catheter gauges and flow restrictors under varying syringe withdrawal rates, according to several embodiments. Hemoshield 1 refers to a first example of a flow restrictor coupled to a catheter assembly. Hemoshield 1 may include flow restrictor 24 from Figures 1A-1B or flow restrictor 38 from Figures 2A-2B coupled to the catheter assembly. In this example, D4 / L for Hemoshield 1 is approximately 7 e-8, but D4 / L may vary. Hemoshield 2 refers to another example of a flow restrictor coupled to the catheter assembly. Hemoshield 2 may include flow restrictor 24 from Figures 1A-1B or flow restrictor 38 from Figures 2A-2B coupled to the catheter assembly. In this example, D4 / L for Hemoshield 2 is approximately 2.7 e-8, but D4 / L can vary.It does not refer to the catheter assembly that is not coupled to a flow limiter. In the absence of a flow restrictor, the blood flow rate varies significantly with the syringe withdrawal speed. However, with the use of flow restrictors (Hemoshield 1 and Hemoshield 2 in the experiment), the flow rate through the catheter during blood collection becomes independent of the syringe withdrawal speed. This will greatly reduce the variation in blood draws per syringe in the clinical setting, according to some implementations. Figure 5 is a bar graph illustrating the maximum shear stress with different catheter gauges and flow restrictors under different syringe withdrawal speeds, according to some embodiments. Again, Hemoshield 1 refers to the first example of a flow restrictor coupled to the catheter assembly. Hemoshield 1 may include flow restrictor 24 from Figures 1A-1B or flow restrictor 38 from Figures 2A-2B coupled to the catheter assembly. In this example, D4 / L for Hemoshield 1 is approximately 7 e-8, but D4 / L may vary. Hemoshield 2 refers to another example of a flow restrictor coupled to the catheter assembly. Hemoshield 2 may include flow restrictor 24 from Figures 1A-1B or flow restrictor 38 from Figures 2A-2B coupled to the catheter assembly. In this example, D4 / L for Hemoshield 2 is approximately 2.7 e-8, but D4 / L can vary.This does not refer to a catheter assembly that is not coupled to a flow restrictor. UT 21G refers to a previous technique catheter assembly with a 21G catheter. The resulting maximum shear stress for each catheter gauge can be shown as a ratio to the maximum shear stress of a 21G UT with VACUTAINER®, which was previously considered the gold standard for blood draws. Since shear stress leads to mechanical hemolysis, reducing the shear stress of catheter-based blood draws to that of the 21G UT reduces the risk of hemolysis. Data show that for an 18G catheter, the risk of hemolysis is low when using a syringe to draw blood. However, as the catheter gauge increases, the risk of hemolysis also increases. For a 20G catheter, the risk of hemolysis is moderate at low syringe withdrawal speeds but increases at higher withdrawal speeds.With a flow restrictor with a D4 / L of 2.7 x 10⁻⁷, the maximum shear stress with a catheter withdrawal is reduced to the maximum shear stress of a 21G UT catheter for all tested syringe withdrawal speeds. For a 22G catheter, the risk of hemolysis is significant at higher withdrawal speeds. A flow restrictor with a D4 / L of 7 x 10⁻⁸ reduces the shear stress back to the reference value for all tested syringe withdrawal speeds. For a 24G catheter, the tested flow restrictors can reduce the maximum shear stress by 2.5 to 3 times, depending on the syringe withdrawal speed. Figure 6 is a graph illustrating free plasma hemoglobin for catheter assemblies with and without a flow limiter, according to several embodiments. IAG refers to a prior art catheter assembly, specifically the INSYTE™ AUTOGUARD™ BC shielded IV catheter available from Becton Dickinson & Company of Franklin Lakes, New Jersey. IAG+H refers to the prior art catheter assembly coupled with a flow limiter, such as flow limiter 24 in Figures 1A-1B or flow limiter 38 in Figures 2A-2B. UT refers to another prior art catheter assembly. Hemoshield 1 was used in a hemolysis study with 24G IAG where all samples underwent hemolysis (measured by the presence of free plasma hemoglobin) in the absence of a flow limiter. With Hemoshield 1, hemolysis was reduced to the UT 21G level. eoLfrnn / eznz / B / Yi All examples and conditional language listed herein are for pedagogical purposes to assist the reader in understanding the invention and the concepts contributed by the inventor to further the technique, and should be considered without limitation to the specifically listed examples and conditions. Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations may be made to them without departing from the spirit and scope of the invention.

Claims

1. A blood collection device, comprising: a syringe, comprising a distal end; and a flow limiter, comprising a distal end and a proximal end, wherein the proximal end is coupled to the distal end of the syringe.

2. The blood collection device of claim 1, wherein the distal end of the flow limiter is configured to couple to a catheter assembly.

3. The blood collection device of claim 1, wherein the distal end of the syringe comprises a first luer adapter, wherein the proximal end of the flow limiter comprises a second luer adapter coupled to the first luer adapter.

4. The blood extraction device of claim 3, wherein the flow limiter is formed monolithically as a single unit.

5. The blood extraction device of claim 4, wherein the distal end of the flow limiter comprises a third luer adapter.

6. The blood collection device of claim 3, wherein the distal end of the flow restrictor comprises a third luer adapter, wherein the flow restrictor further comprises an extension tube disposed between the second luer adapter and the third luer adapter.

7. The blood collection device of claim 6, wherein the flow limiter comprises a first piece formed monolithically as a single unit and a second piece formed monolithically as a single unit, wherein a proximal end of the extension tube is integrated within the first piece, wherein a distal end of the extension tube is integrated within the second piece, wherein the first piece comprises the second luer adapter, and wherein the second piece comprises the third luer adapter.

8. The blood extraction device of claim 1, wherein a geometric factor of the flow limiter is represented by Gr, wherein Gres 1.43E7 1 / ¡n3± 30 %.

9. The blood extraction device of claim 1, wherein a geometric factor of the flow limiter is represented by Gr, wherein Gres 3.70E6 1 / ¡n3± 30 %.

10. A blood collection system, comprising: a catheter assembly, comprising: a catheter adapter; and a catheter extending distally from the catheter adapter; and a blood collection device coupled to the catheter assembly, the blood collection device comprising: a syringe, comprising a distal end; and a flow limiter, comprising a distal end and a proximal end, wherein the proximal end is coupled to the distal end of the syringe.

11. The blood collection system of claim 10, wherein the catheter assembly further comprises an extension tube, wherein a distal end of the extension tube is integrated into the luer adapter, and wherein the blood collection device is coupled to a proximal end of the extension tube.

12. The blood extraction system of claim 10, wherein the distal end of the syringe comprises a first luer adapter, wherein the proximal end of the flow limiter comprises a second luer adapter coupled to the first luer adapter.

13. The blood extraction system of claim 12, wherein the flow limiter is formed monolithically as a single unit.

14. The blood extraction system of claim 13, wherein the distal end of the flow limiter comprises a third luer adapter.

15. The blood collection system of claim 12, wherein the distal end of the flow restrictor comprises a third luer adapter, wherein the flow restrictor further comprises an extension tube disposed between the second luer adapter and the third luer adapter.

16. The blood collection system of claim 15, wherein the flow limiter comprises a first piece formed monolithically as a single unit and a second piece formed monolithically as a single unit, wherein a proximal end of the extension tube is integrated within the first piece, wherein a distal end of the extension tube is integrated within the second piece, wherein the first piece comprises the second luer adapter, and wherein the second piece comprises the third luer adapter.

17. The blood extraction system of claim 10, wherein a geometric factor of the flow limiter is represented by Gf, wherein Gres 1,43E7 1 / ¡n3± 30 %.

18. The blood extraction system of claim 10, wherein a geometric factor of the flow limiter is represented by Gf, wherein Gres 3.70E6 1 / ¡n3± 30 %.

19. The blood extraction system of claim 10, wherein a geometric factor of the flow limiter is represented by Gf, wherein Gf is between 1.43E7 and eoLfrnn / eznz / B / Yi 3.70E6.

20. The blood extraction system of claim 10, wherein a geometric factor of the flow limiter is represented by Gf, wherein Gres 1.43E7 1 / in3± 10 % or 3.70E6 1 / in3± 10 %.

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