Patent Application
20220287604
The present technology relates to a device for trapping an initial flow of blood during a blood collection process.
A blood culture test is presently the preferred method for identifying bacteremia and septicemia (sepsis). Sepsis is a body-wide response to a bacterial infection of the blood stream that can cause organ failure and death. Sepsis kills every one in six infected patients. Moreover, half of all in-hospital deaths involve sepsis. In fact, sepsis kills more people than AIDS, breast cancer and prostate cancer combined. Sepsis affects more hospital patients than any other diagnosis.
Unfortunately, the United States healthcare system spends over $4 billion each year on unnecessary treatment associated with false positive blood culture results. See Oren Zwang & Richard K. Albert, Analysis of Strategies to Improve Cost Effectiveness of Blood Cultures, 1 J. Hosp. Med. 272 (September 2006). Moreover, “[i]t is currently accepted that most organisms identified as contaminants in blood cultures originate from the skin of the patient.” Robert A. Garcia et al., Multidisciplinary Team Review of Best Practices for Collection and Handling of Blood Cultures to Determine Effective Interventions for Increasing the Yield of True-Positive Bacteremia, Reducing Contamination, and Eliminating False-Positive Central Line Associated Bloodstream Infections, 43 Am. J. Infect. Control 1222 (November 2015).
Thus, during a blood collection process, there is a need for a device capable of diverting and trapping an initial flow of blood from a patient that might contain contaminants from the skin of that patient in order to reduce the number of false positives. One such device is described in WO2019018324 to Milan Ivosevic, which was filed on Jul. 17, 2018 as PCT/US2018/042367 and is incorporated by reference herein.
Various embodiments of the present disclosure describe a diversion device that traps an initial flow of blood in a diversion chamber of the diversion device. The diversion chamber may be defined, in part, by a flow path defined by a channel or series of channels that terminate in a diversion chamber valve. The diversion chamber valve is a passage configured to permit the flow of air therethrough but that does not permit a liquid such as the collected blood to flow through it. After the diversion chamber is filled, the collected blood begins to flow through a collected sample valve and is drawn through a bypass flow chamber of the diversion device and into a collection vessel in fluid communication with and downstream from the diversion device.
One aspect of the present disclosure relates to a diversion device comprising: (1) a housing having an inlet conduit and an outlet conduit, wherein the housing is configured to receive an initial flow of blood and a subsequent flow of blood through the inlet conduit, and wherein the housing is configured to allow the subsequent flow of blood to exit the diversion device through the outlet conduit; (2) a diversion chamber defined by a flow path defined by a channel or series of channels that terminate in a diversion chamber valve; (3) a collected sample valve; and (4) a bypass flow chamber, wherein the collected sample valve is configured to permit the subsequent flow of fluid to enter the bypass flow chamber, and the bypass flow chamber is configured to permit the subsequent flow of fluid to exit the diversion device through the outlet conduit.
Both the diversion chamber valve and the collected sample valve deploy hydrophobic material and smaller diameter passages or channel to increase flow resistance to the flow of blood through the channel. Non-limiting examples of hydrophobic materials include, e.g., polytetrafluoroethylene (PTFE), polypropylene, or other conventional non-polar polymers. Suitable polymers will have sufficient thermal stability so that the device can be sterilized.
The diversion chamber valve is configured to completely prevent the flow of liquid through the valve. When the diversion chamber is filling with the initial portion of blood, the collected sample valve is configured to provide a flow resistance that will not pass the initial portion of blood collected into a collection vessel. When the diversion chamber is full, the flow resistance of the diversion chamber valve is such that the subsequent portion of blood flowing into the diversion device will “break through” the flow resistance of the collected sample valve and flow into the bypass flow chamber and through the outlet conduit.
In some embodiments, a portion of the housing comprises a hydrophilic material. Hydrophilic materials are optionally used to enhance the motive force for the fluid by, for example, wicking the liquid to drive it through the device. In some embodiments, the hydrophilic material is carboxymethylcellulose (“CMC”).
In some embodiments, a cross-sectional area of the diversion chamber is larger than a cross-sectional area of the bypass flow chamber. In some embodiments, the bypass flow chamber comprises a tube. In some embodiments, the housing comprises a housing shell, wherein the housing shell contains the inlet conduit on one end and the outlet conduit on the opposite end. In some embodiments, a vacuum pressure created by a collection vessel coupled to the diversion device draws the initial flow of blood into the diversion chamber. In some embodiments, the bypass flow chamber is configured to permit the subsequent flow of fluid to exit the diversion device using only the vacuum pressure created by the collection vessel coupled to the diversion device.
Another aspect of the present disclosure relates to a blood collection kit comprising: instructions to assemble a blood collection pathway from a patient to a collection vessel, wherein the blood collection pathway comprises a first needle piercing the skin of the patient and a diversion device, and wherein the collection vessel has a sub-atmospheric internal pressure that draws (a) an initial flow of blood from the patient through the first needle and into the diversion device and (b) a subsequent flow of blood through the first needle and the diversion device, respectively, and into the collection vessel, and wherein the blood collection pathway is a closed system that prevents an initial flow of air through the diversion device from being vented into the atmosphere.
In some embodiments, the blood collection pathway further comprises a holder having a second needle piercing a cap of the collection vessel. In some embodiments, the diversion device is integrated with the holder. In some embodiments, the diversion device and the holder are separate units. In some embodiments, the diversion device is integrated with a first needle used to pierce a vein or an artery of the patient. In some embodiments, the diversion device and the first needle are separate units that are in close proximity to each other, or in some embodiments, right next to each other. In some embodiments, the collection vessel contains one or more bacterial growth media, an antibiotic scavenger, or a pH sensor.
Yet another aspect of the present disclosure relates to a blood collection method comprising: assembling a blood collection pathway from a patient to a collection vessel, wherein the blood collection pathway comprises a first needle piercing the skin of the patient and a diversion device, and wherein the collection vessel has a sub-atmospheric internal pressure that draws (a) an initial flow of blood from the patient through the first needle and into the diversion device and (b) a subsequent flow of blood through the first needle and the diversion device, respectively, and into the collection vessel, and wherein the diversion device comprises: (1) a housing having an inlet conduit and an outlet conduit, wherein the housing is configured to receive an initial flow of blood and a subsequent flow of blood through the inlet conduit, and wherein the housing is configured to allow the subsequent flow of blood to exit the diversion device through the outlet conduit; (2) a diversion chamber defined by a flow path defined by a channel or series of channels that terminate in a diversion chamber valve; (3) a collected sample valve; and (4) a bypass flow chamber, wherein the collected sample valve is configured to permit the subsequent flow of fluid to enter the bypass flow chamber, and the bypass flow chamber is configured to permit the subsequent flow of fluid to exit the diversion device through the outlet conduit.
In some embodiments, the blood collection pathway is a closed system that prevents an initial flow of air through the diversion device from being vented into the atmosphere. In some embodiments, the blood collection pathway further comprises a holder having a second needle piercing a cap of the collection vessel. In some embodiments, the diversion device is integrated with the holder. In some embodiments, the diversion device and the holder are separate units. In some embodiments, the diversion device is integrated with a first needle used to pierce a vein or an artery of the patient. In some embodiments, the diversion device and the first needle are separate units that are in close proximity to each other, or in some embodiments, right next to each other.
A diversion device for collecting a biological sample is described herein. The diversion device has an inlet for receiving a biological sample collected from a patient. The diversion device has an outlet for delivering the collected biological sample to a collection vessel, the collection vessel being under sub-atmospheric pressure. The diversion device also has a first channel into which a first portion of the collected biological sample flows upon commencement of sample collection. The first channel has a first valve such that air in the first channel exits the first channel through the valve as the collected sample fills the first channel. The device also has a second channel into which a second portion of the collected sample flows after the first channel is substantially filled with collected sample. The second channel is in fluid communication with the first channel through a second valve. The diversion device outlet is adapted for attachment to a needle with a lumen. The needle is adapted to pierce a seal on the collection vessel, such that the sub-atmospheric pressure of the collection vessel draws the biological sample from the device to the collection vessel.
Optionally, the inlet of the diversion device is adapted for connection to a line set for collecting a biological sample from a patient. Typically, line sets have a sample collection needle and a collection tube. Optionally the sample collection needle is a butterfly needle selected from the group consisting of a single-winged butterfly needle or a dual wing butterfly needle. Optionally, the diversion device is integrated into a wing of the butterfly wing needle.
Optionally the diversion device is adapted to be coupled to an adapter that fluidically couples to a collection vessel. The collection vessel is sealed and has an internal pressure that is less than atmospheric pressure. The adapter is coupled to the diversion device by any conventional coupling (e.g. threaded connection, snap connection, luer connector, etc.
The valves of the diversion device operate as follows. The first valve operates to let air escape from the first channel but retains the sample collected in the first channel. The air that passes from the first channel is received from the second channel is drawn out of the diversion device by the reduced pressure in the collection vessel. The second valve operates such the sample does not flow from the first channel to the second channel until the time when the first channel is filled with sample, which overcomes for liquid flow resistance of the second valve. Optionally, both valves are hydrophobic flow restrictors. Optionally, both valves have a barrier with one or more openings the provided liquid flow resistance. Optionally, the flow restrictors are barriers that have an orifice of about 2 mm or less therein. Optionally, the flow restrictors have multiple barriers with one or more orifices in each barrier. Optionally, the diversion device has an orifice with a diameter of about 0.5 μm or less.
The first channel in the diversion device can be a serpentine channel or a straight channel. Optionally, the first channel has diameter of about 3 to about 4 mm.
Optionally, the first and second valves are hydrophobic membranes. Such membranes are porous and the size of the pores is about 0.45 μm or less. Examples of hydrophobic materials from which the hydrophobic flow restrictors or membranes are made include polytetrafluoroethylene (PTFE) or polypropylene.
Described herein is a diversion device assembly for collecting a biological sample. The assembly includes a butterfly needle and a diversion device integrated on the butterfly needle. the diversion device has an inlet for receiving a biological sample collected from a patient. The diversion device has an outlet for delivering the collected biological sample to a collection vessel. The collection vessel is typically under sub-atmospheric pressure (i.e. the inside of the container has a pressure that is less than atmospheric pressure. The diversion device has a first channel into which a first portion of the collected biological sample flows upon commencement of sample collection. The first channel has a first valve such that air in the first channel exits the first channel through the valve as the collected sample fills the first channel. The valve is in fluid communication with the outlet of the diversion device so that any air exiting the first channel is drawn from the device into the collection vessel. That is, the diversion device is not vented to the atmosphere. The diversion device has a second channel into which a second portion of the collected sample flows after the first channel is substantially filled with collected sample, the second channel is in fluid communication with the first channel through a second valve. The second channel is also in fluid communication with an adapter wherein the adaptor receives the collected biological sample from the second channel and wherein the adapter outlet is adapted for attachment to a needle with a lumen, the needle adapted to pierce a seal on a collection vessel, such that the sub-atmospheric pressure of the collection vessel draws the biological sample from the diversion device into the collection vessel. The first and second valves are as described previously.
Embodiments of the present disclosure are described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. It is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
In some embodiments, the blood collection system of
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In some embodiments, Diversion Device 130 may include an indicator for providing feedback relating to the amount of collected blood. For example, Diversion Device 130 may include a flow meter that indicates how much blood has been collected inside Collection Bottle 150. The flow meter could minimize potentially false negative blood cultures by helping to ensure that health care workers collect an adequate amount of blood. Furthermore, in some embodiments, a transmitter may be communicatively coupled to the indicator for wirelessly transmitting information relating to the amount of collected blood to a receiver. In such embodiments, the receiver may be communicatively coupled to a display device configured to display information relating to the amount of collected blood.
Collection Bottle 150 may be constructed of glass, plastic, or other suitable materials. In some embodiments, Collection Bottle 150 may be implemented using one of BD's BACTEC™ culture vials or one of BD's Vacutainer® blood collection tubes. In some embodiments, Collection Bottle 150 may contain liquids and/or solid additives, such as a bacterial growth media, an antibiotic scavenger, or a pH sensor. In some embodiments, Collection Bottle 150 may contain one of BD's blood culture medias, such as BD's BACTEC™ Peds Plus™ medium, BD's BACTEC™ Plus Aerobic medium, BD's BACTEC™ Plus Anaerobic medium, BD's BACTEC™ Lytic Anaerobic medium, BD's BACTEC™ Standard Aerobic medium, or BD's BACTEC™ Standard Anaerobic medium.
As mentioned above, most organisms identified as contaminants in blood cultures originate from the skin of the patient. These contaminants are typically introduced into a patient's blood sample by the venipuncture and the initial flow of blood from the patient into a collection bottle. In the blood collection system of
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In some embodiments, the housing for the diversion device and/or a holder may be constructed of a plastic material, such as Acrylonitrile Butadiene Styrene (“ABS”). In some embodiments, tube may be constructed of a hydrophobic material. For example, in some embodiments, tube may be constructed of a plastic material, such as Polyethylene. In some embodiments, housing shell may be attached to a housing base by an ultrasonic welding process.
An initial flow of blood bypasses Collected Sample Valve 560 and flows into Diversion Chamber 530. Such a path reflects the path of least flow resistance for the blood, since, as noted above, flow through the Collected Sample Valve 560 requires that the flow resistance of the Collected Sample Valve 560 be overcome. Thus, the flow of the initial portion of blood into the Diversion Chamber 530 is the preferred flow path for the initial portion of the collected blood sample flowing into the Diversion Device 500.
Diversion Chamber 530 has a channel or series of channels that terminate in Diversion Chamber Valve 550. In some embodiments, the channel or series of channels of Diversion Chamber 530 have a diameter of about 3 to about 4 mm. In some embodiments, the length of the path through Diversion Chamber 530 is minimized to prevent unnecessary airflow restriction. In some embodiments, Diversion Chamber Valve 550 is of such a diameter that it is able to hold back the momentum of a column of liquid, thereby preventing any of the blood from passing through the Diversion Chamber Valve 550 and into the Bypass Flow Chamber 570. In some embodiments, Diversion Chamber Valve 550 has a diameter that is much smaller than about 0.2 mm. In alternate embodiments, Diversion Chamber Valve 550 is a membrane with multiple pores or holes. In some embodiments, each pore or hole of the membrane of Diversion Chamber Valve 550 has a diameter of about 5 μm. In alternate embodiments, each pore or hole of the membrane of Diversion Chamber Valve 550 has a diameter of about 0.45 μm. In some embodiments, the membrane of Diversion Chamber Valve 550 is made of a hydrophobic material. Non-limiting examples of hydrophobic materials used to construct the membrane of Diversion Chamber Valve 550 include, e.g., Polytetrafluoroethylene (PTFE) or polypropylene. In some embodiments, Diversion Chamber Valve 550 holds back much more static pressure than Collected Sample Valve 560.
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An air gap between flow restrictors may also be present in other embodiments of diversion chamber valve. In some embodiments, a diversion chamber valve may contain more than one set of air gap.
In some embodiments, the diversion device is a distance away from the first needle, and is close to the holder or adapter connected to a collection bottle. In some embodiments, the diversion device is close to the first needle and far away from the holder or adapter connected to a collection bottle. In a preferred example, the diversion device is part of winged butterfly first needle.
The volume of blood diverted into the diversion device may be changed depending on the proximity of the diversion device to the first needle. For example, in some embodiments, if the diversion device is immediately behind the first needle (e.g., as part of the winged butterfly first needle), the diversion device may be configured to direct less than about 150 μL of blood into its diversion chamber. In some embodiments, the diversion device may be configured to direct less than about 30-50 μL of blood into its diversion chamber.
As demonstrated above, some embodiments of the present invention provide significant advantages. Most organisms identified as contaminants in blood cultures originate from the skin of the patient. These contaminants are typically introduced into a patient's blood sample by the venipuncture and the initial flow of blood from the patient into a collection bottle. Therefore, by diverting and trapping an initial flow of blood, a diversion device in accordance with the present technology can potentially reduce the number of false positive blood cultures.
Furthermore, a diversion device in accordance with the present technology provides a versatile solution. For example, the distance of a diversion device to a first needle can be readily changed, so that any predetermined amount of blood, such as less than about 150 μL, can be diverted and trapped.
Moreover, the inclusion of a diversion device in accordance with the present technology in a blood collection system, does not introduce additional workflow steps for health care workers relative to presently conventional techniques for collecting blood samples. For example, health care workers do not need to wait for a conduit or a chamber to partially or completely fill before inserting a collection bottle into a holder. This advantage is achieved, in large part, because some embodiments of a diversion device in accordance with the present technology operate using the vacuum pressure created by a collection bottle. As a result, some embodiments of a diversion device in accordance with the present technology do not rely on a separate power source or the venous pressure of a patient for trapping an initial flow of blood or for collecting a subsequent flow of blood in a collection bottle.
As noted above, some embodiments of a blood collection system with a diversion device in accordance with the present technology represent closed system solutions. In these embodiments, the air that precedes the liquid blood flow is not vented out of the system and into the atmosphere. Instead, these embodiments use the vacuum pressure created by a collection bottle to immediately draw blood from a patient. A diversion device in these embodiments can be used inside the closed system to balance pressure and air flow along the flow path. For example, a diversion chamber valve can be used to allow any air preceding the blood sample to flow out of the diversion chamber and into an outlet conduit. In such embodiments, the diversion chamber valve may prevent flow therethrough of a liquid such as blood.
From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, a diversion device in accordance with the present technology can be positioned anywhere along the flow path. For example, a diversion device in accordance with the present technology could be attached to the body of a first needle. As another example, a diversion device in accordance with the present technology could be positioned along tubing between a holder and a second needle.
Furthermore, a blood collection system in accordance with the present technology may not include all of the components illustrated in the above embodiments. For example, the needle, the diversion device, and the holder may be integrated into one device without any tubing. For example, a diversion device in accordance with the present technology could be integrated with BD's Vacutainer® Eclipse™ blood collection needle.
Moreover, in many of the embodiments discussed above, collection bottles having a sub-atmospheric internal pressure were used to collect blood from a patient. However, a wide variety of collection vessels having a sub-atmospheric internal pressure may be used with the present technology. For example, a collection tube may be used with the present technology. As another example, a collection vial may be used with the present technology.
While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
This application claims the benefit of priority from U.S. Provisional Application No. 62/883,941 filed Aug. 7, 2019, the contents of which are incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/044993 | 8/5/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62883941 | Aug 2019 | US |
