The present disclosure relates generally to the recovery of fetal blood from a placenta.
The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain of such illustrative embodiments that are depicted in the figures, in which:
One devastating occurrence in modern neonatal intensive care is intraventricular hemorrhage (IVH). Hemorrhages of this variety virtually always occur during the three days following birth of very low birth weight (VLBW) infants, which are generally defined as infants whose mass is less than 1500 grams. When such hemorrhages are graded as severe (e.g., grade 3 or 4) they generally presage significant, life-long neurodevelopmental handicaps. It is believed that approximately 25 percent of very low birth weight neonates develop an IVH, and about 10 percent of these develop a severe IVH. Although IVH is a multi-factorial condition, in which some of the associated factors are not amenable to correction after birth (e.g., genetic predisposition, the fragile make up of the vascular structure of the germinal matrix, intrauterine complications), other factors may be addressed by the methods and devices disclosed herein, as further discussed below.
For example, phlebotomy followed by red blood cell transfusions using donor blood can cause IVH. Without being limited by theory, it is noted that term infants have pericytes surrounding the fragile capillaries in the germinal matrix of the brain. These are supporting cells giving the capillaries strength and preventing rupture. However, pericytes have not yet formed surrounding capillaries in the premature germinal matrix. Red blood cells can transverse the fragile capillaries in line (i.e., in single file) and can require both deformability and the release of nitric oxide synthase to relax the capillaries for the red blood cells to pass. Banked donor red blood cells can develop a storage lesion involving poor deformability and loss of nitric oxide synthase. The storage lesion can result in a reduced ability of the transfused red blood cells to adequately navigate and dilate the capillaries. If red blood cells get stuck in the unsupported capillaries, pressure can build up and the wall of the capillary can rupture, instituting a brain hemorrhage. It is noted that when a premature neonate is admitted to the NICU, the initial blood tests drawn for laboratory analysis can equate to about 10 percent or more of the blood volume of the neonate, which can contribute to the need for red blood cell transfusions.
Accordingly, it can be desirable to reduce or eliminate the need for red blood cell transfusions in neonates and/or reduce or eliminate the use of donor blood where such transfusions take place. Certain embodiments disclosed herein can achieve one or more of these desirable goals. For example, some embodiments can reduce or eliminate the need for drawing blood from the neonate for initial blood tests, and other or further embodiments can substitute autologous blood transfusions, in which the infant's own fetal blood is used, for standard donor blood transfusions.
As further discussed below, in some embodiments, a method for drawing blood for post-delivery tests comprises drawing all or a substantial portion of blood needed for laboratory tests (e.g., admission blood tests) from fetal blood in the placenta. For example, fetal blood can be drawn from the placenta immediately following placental delivery. Such procedures can eliminate the drawing of any blood directly from the neonate. In other or further embodiments, fetal blood is harvested from the placenta for purposes of autologous transfusion. In some embodiments, the harvested fetal blood is used in such a transfusion immediately or shortly after its collection. Accordingly, certain embodiments disclosed herein can significantly reduce donor blood transfusions into VLBW infants during their first days after birth, and thereby reduce the prevalence of brain hemorrhages.
Other uses and advantages of the methods, systems, and devices disclosed herein are also contemplated. Accordingly, although certain embodiments may provide particular advantages in the context of premature infants, wider applications are possible. For example, fetal blood harvesting such as disclosed herein may be performed for term infants. The use of fetal blood drawn from the placenta for initial blood tests can eliminate the discomfort associated with drawing the blood directly from the infant. Similarly, obtaining fetal blood for an autologous transfusion may be useful in a variety of situations for term infants (e.g., surgery shortly after birth, or those with known antenatal anemia, abruption, or other hemorrhage).
With reference to
The collection fluid path 101 can further include a valved connector 140. In the illustrated embodiment, the valved connector 140 comprises a closed male connector. In particular, the connector 140 comprises a male connector 144 at one end and a female connector 142 at an opposite end. The male connector 144 is a “closed” or “closable” connector, meaning that the connector 144 comprises a valving feature that is configured to be in an open state when the connector 156 is coupled with the male connector 144 and is configured to automatically transition to a closed state when the connector 156 is decoupled from the male connector 144. Many suitable valving male connectors 144 are known. In the illustrated embodiment, the male connector 144 includes a standard male luer lock arrangement for coupling with the female luer lock arrangement of the connector 156.
In
With reference again to
At least a portion of the collection fluid path 106 is defined by the closed female connector 136. A sampling syringe 190 can be coupled to the female connector 136 via a male connector 196. The syringe 190 can include a blood receptacle 192 and a plunger 194 that is movable relative to the blood receptacle 192. In other embodiments, different blood receptacles may be used in the place of the syringe 190. As further discussed below, in some embodiments, the sampling syringe 190 can be used to collect fetal blood for use in laboratory testing. The blood collection can take place when the assembly 100 is in a sample blood harvesting mode, which is discussed further below. In some embodiments, it can be desirable for the syringe 190 to be selectively detachable from the assembly 100 so that the harvested blood within the syringe 190 can readily be transported to a desired location (e.g., a blood laboratory).
In certain embodiments, when the syringe 190 is coupled with the connector 136, the connector 136 is in the open state and permits fluid communication between the syringe 190 and the sampling fluid path 106. When the syringe 190 is decoupled from the assembly 100, the connector 136 can automatically transition to the closed state, and the connector 136 can thereby seal the sampling fluid path 106 from an environment that surrounds the assembly 100.
In addition to a branch of the manifold connector 130, the transfusion fluid path 104 can include a valved connector 120. In the illustrated embodiment, the valved connector 120 is a shut-off valve connector 122, that includes a female connector 126 and a male connector 128 at opposite ends thereof. A transfusion syringe 110, which includes a blood receptacle 112 and a plunger 114, can be connected to the connector 126 via a connector portion 116.
The shut-off valve connector 122 includes a manually operable switch or actuator 124 that can be moved so as to transition the connector 122 between an open orientation and a closed orientation. When in the closed orientation, the connector 122 prevents fluid communication between opposite ends of the connector 122—e.g., can prevent fluid communication between the manifold connector 130 and the transfusion syringe 110. When in the open orientation, the connector 122 permits fluid to pass therethrough. Accordingly, when the assembly 100 is in an appropriate mode, pulling back on the plunger 114 can draw fetal blood through the transfusion fluid path 102 and into the blood receptacle 112 of the syringe 110. Such a mode may be referred to as a transfusion blood harvesting mode, which is discussed further below.
In some embodiments, the transfusion syringe 110 can be pre-loaded with an anticoagulant 208 (see
The delivery fluid path 104 can include the connector 135, as previously mentioned, as well as a tube 160 that includes connectors 162, 164 at either end, a valved connector 170, and/or a filter 180. The valved connector 170 can resemble the valve connector 120 described above. For example, in the illustrated embodiment, the valved connector 170 is a shut-off valve connector 172, which includes a female connector 176 and a male connector 178 at opposite ends thereof and a manually operable actuator 174. When in a closed orientation, the connector 172 prevents fluid communication between opposite ends of the connector 172—e.g., can prevent fluid communication between the manifold connector 130 and the filter 180. When in the open orientation, the connector 172 permits fluid to pass therethrough. Accordingly, depressing the plunger 114 can force fetal blood through the transfusion fluid path 102 and through the delivery path 104 when the assembly 100 is in an appropriate operational mode. Such a mode is referred to herein as a transfusion mode, which is discussed further below.
The filter 180 can be of any suitable variety, and may be configured to prevent particles larger than a predetermined size from being transfused into an infant. For example, various embodiments, the filter 180 can be configured to prevent passage of particles larger than about 40, 150, 170, 200, or 250 microns, while readily permitting the passage of blood cells. In some embodiments, a cap 188 may be connected with filter 180 when the assembly is in a pre-use state.
For any of the connector arrangements discussed above, the specific male-female relationships recited are not intended to be limiting. For example, in some embodiments, the connector 156 is instead a male connector, whereas the connector 144 is a complementary closed or valved female connector. Additionally, connection interfaces other than luer-type interfaces are possible. Moreover, in some embodiments, such as certain embodiments in which a particular component is not intended for removal from the assembly, each connector in a complementary connector pair may be “open.” For example, in some embodiments, both the connector 135 and the connector 162 are open connectors that remain connected to each other at all times during use of the assembly 100, thereby maintaining the entirety of the delivery fluid path 104 coupled to the assembly 100 throughout all stages of a harvesting and transfusion procedure.
Moreover, in some embodiments, many components of the assembly 100 may be permanently affixed and/or integrally connected to each other. For example, in some embodiments, the connector 135 and the connector 162 of the fluid path 104 may be replaced by a single, integrally formed component. As another example, the needle device 150 and the valved connector 140, and/or the valved connector 140 and the manifold connector 130 portions of the fluid path 101 can be permanently affixed to each other, and housing portions of these components may be formed of a single piece of integrally formed material. Certain of such embodiments may reduce the deadspace of the collection fluid path 101 and or may exhibit other distinguishing or desirable features relative to the more modular embodiment depicted in
In some embodiments, a portion of the placenta 200 and/or the umbilical cord 205 has been disinfected prior to insertion of the needle 152 into the placenta 200 at an insertion site 201. For example, in some embodiments, a surface of the placenta 200 and/or a surface of the umbilical cord 205 are swabbed with providone iodine and allowed to dry for about 60 seconds. For ease of discussion, certain references herein to the “placenta” may include one or more of the placenta 200 and the portion of the umbilical cord 205 that remains attached to the placenta 200. Accordingly, it may be said that a surface of the placenta 200 at which an insertion site or access site 201 is to be formed is disinfected prior to inserting the needle 152 into the placenta 200 at the insertion site 201, even where the access site 201 is in fact located at the umbilical cord 205 remnant.
With continued reference to
With reference to
With reference to
As previously noted, the transfusion syringe 110 includes an anticoagulant 208 therein. In some embodiments, the transfusion syringe 110 may be pre-loaded with the anticoagulant 208 and attached to the assembly 100 when the assembly 100 is in a pre-use state. In other embodiments, the transfusion syringe 110 may be loaded with anticoagulant 208 at any point prior to transition of the assembly 100 into the transfusion blood harvesting mode. For example, in some embodiments, the transfusion syringe 110 is loaded with anticoagulant and attached to the assembly 100 at the stage illustrated in
The assembly 100 is loaded onto an automatic syringe pump 250. The pump 250 may be programmable so as to transfuse blood to the infant I in any suitable manner. The pump 250 can include a dispensing arm 252 that is configured to depress the plunger 114 at a desired rate so as to deliver the blood 204 to the infant I at the desired rate.
In some methods, the transfusion procedure depicted in
In some instances, the transfusion procedure can be started immediately or very soon after the transfusion fetal blood has been collected from the placenta 200. For example, the fetal blood may not be placed in sort of storage prior to its use in a transfusion. In various instances, the transfusion procedure may begin no more than about 5, 10, 15, 20, or 30 minutes after the transfusion syringe 110 has been charged with fetal blood. In other or further instances, it can be desirable to complete the transfusion procedure within a certain timeframe of the harvesting of the fetal blood. For example, in various instances, the transfusion procedure may be completed no more than about 1, 2, 3, 4, 5, or 6 hours after the transfusion syringe 110 has been charged with fetal blood.
In other or further embodiments, the kit 260 can include a metabolic screen 280, which may be used in a known manner with a portion of the collected fetal blood. In some instances, a different version of the metabolic screen 280 may be included with the kit 260, as such screens can typically vary from state to state. However, in other embodiments, the kit 260 does not include a metabolic screen 280.
In other or further embodiments, the kit 260 can include any suitable combination of tubes 282, 284, 286 for receiving fetal blood for culture, umbilical venous blood gas analysis, coagulation tests, complete blood cell counts, metabolic screening tests, and/or any other suitable laboratory tests. The kit 260 may be suitable for rapid distribution and use, as certain of such tubes may outdate rapidly (e.g., have a shelf life of a few months). The kit 260 may also include different combinations or types of tubes 282, 284, 286, depending on the hospital to which it is distributed, since the tubes used in certain protocols often vary from hospital to hospital. However, in other embodiments, the tubes are not included in the kit 260.
The kit 260 may also include instructions 290 for using the blood harvesting assembly and/or any other components of the kit 260. The instructions 290 can include directions for performing any and/or all of the steps of any suitable method for harvesting blood using the assembly, such as any of the procedures discussed above. In other or further embodiments, the instructions 290 may provide directions for accessing such directions for use. For example, the instructions may list a web address, a mailing address, and/or a telephone number that can be used to locate instructions for harvesting fetal blood. One or more of the foregoing items can be included in and/or on (e.g., in the case of the instructions) packaging (not shown) in which the kit 260 is distributed.
With reference to
In the illustrated embodiment, the collection fluid path 301 includes a needle 352 that is connected to the stopcock 330 via a connector 341. The sampling fluid path 306 includes an open connector 336 that can be connected with an open connector portion 393 of a valve member 391. The valve member 391 can include a closed connector 395 that can be selectively coupled to the connector portion 196 of the syringe 190. The transfusion fluid path 302 can include an open connector 334 defined by the stopcock 330, which can be selectively connected to the connector portion 116 of the syringe 110. The delivery fluid path 304 can include an open connector 335 defined by the stopcock 330, which can be connected with tubing 360 via a connector 362. The delivery line 360 can further include a filter 380, a connector 383, and a clamp 385 (e.g., a roller clamp). The clamp 385 can selectively close the tubing 360.
With reference to
As illustrated in
In other embodiments, the assemblies 100, 300 are configured for operation in the transfusion blood harvesting mode and the transfusion mode. For example, the assemblies 100, 300 may not include the sample blood fluid paths 106, 306 (e.g., may not be configured for coupling with a sample syringe 190). Such embodiments may be configured primarily for transfusion applications.
In some embodiments the sample syringe 190 may be coupled with a first needle and the transfusion syringe 110 may be coupled with a second needle. Each syringe 110, 190 may be used to separately extract blood from the placenta 200. For example, the sample syringe 190 may be used to draw blood from the placenta 200 through a first access site in the placenta that is formed by the first needle, and the transfusion syringe 110 may be used to draw blood from the placenta 200 through a second access site in the placenta that is formed by the second needle. In various such embodiments, it may be desirable to form the access sites using the needles of the syringes 110, 190 at approximately the same time, or to ensure that both needles have been inserted into a blood vessel before any blood is drawn from the vessel, or to ensure that both needles have been inserted into a blood vessel before the needle of one of the syringes is removed from the vessel. This is because, in some instances, it may be difficult to withdraw blood from a blood vessel after a separate access site has been formed therein and is left open or unsealed, for example, due to bleeding and/or venting at the open or unsealed access site. Moreover, the clamped placental system may no longer be considered “closed” or sterile after a first needle has been used to access the system and is removed from the system. However, in other methods, one syringe 110, 190 may be used to collect blood and then removed from a vessel, and then another syringe 110, 190 may thereafter be inserted into the vessel and used to collect blood from the vessel.
In still further embodiments, a sample syringe 190 may be used on its own, without any transfusion procedures. For example, sample blood may be harvested using the sample syringe 190 or other blood collection device, and the blood can then be tested or otherwise processed. Such methods can prevent any sampling of blood directly from the infant, which may itself reduce or eliminate the need for a transfusion and/or save the infant from pain associated with a blood collection procedure.
As previously mentioned, while the drawings and written description have focused on illustrative devices, systems, and methods related to neonatal applications, it is to be understood that embodiments may be used in any other suitable context, such as contexts involving full-term infants. Moreover, it will be understood by those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. For example, any suitable combination of various embodiments, or the features thereof, is contemplated. Additionally, blood receptacles other than those associated with syringes may be used in some embodiments.
Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.
References to approximations are made throughout this specification, such as by use of the terms “about” or “approximately.” For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, where qualifiers such as “about,” “substantially,” and “generally” are used, these terms include within their scope the qualified words in the absence of their qualifiers. For example, where the term “substantially planar” is recited with respect to a feature, it is understood that in further embodiments, the feature can have a precisely planar orientation.
Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.
The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.
Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US12/38394 | 5/17/2012 | WO | 00 | 8/27/2014 |
Number | Date | Country | |
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61488010 | May 2011 | US |