Puncture site patch

[0001] This invention relates to an adhesive patch for use on humans or animals which is adhered to a patient's skin allowing a health care practitioner to puncture the patient's skin while minimizing the risk of contact with the patient's blood.

[0002] It is widely recognized that blood-borne pathogens are an important and serious method of transmission of infectious diseases. Health care practitioners, in particular, are in danger from such exposure because of the need to perform functions that directly expose the practitioner to blood, such as puncturing a patient's skin with a needle to make an injection or to withdraw blood. Typically, when the skin is to be punctured, the target area of the skin is wiped with a disinfectant and the needle (which may be further attached to a syringe) is injected through the skin subcutaneously or intramuscularly. After the skin has been punctured, the needle is withdrawn and a pad of gauze or cotton is placed on the puncture wound to absorb any blood which may emanate therefrom. The practitioner may come into contact with the blood at several points during this procedure, such as when the needle first punctures the skin, when the needle is removed from the skin but before the pad is positioned over the puncture wound, or after the pad is applied over the puncture site because blood may ooze from or seep through the pad.

[0003] Attempts have been made to provide a protective patch that is applied to the skin prior to the skin being punctured. For example, U.S. Pat. Nos. 5,728,071 and 5,738,641, both issued to the present applicant and incorporated herein in their entirety by reference, describe patches that adhere to the patient's skin and minimize the risk of blood contact during injections and blood withdrawal procedures, respectively. The '071 patch is a three layer system comprising a generally annular absorbent pad having a first surface to be placed against the skin of a patient around an intended injection site, a second surface opposite said first surface and a central opening; an elastomeric, self-sealing membrane through which an injection needle can penetrate, said membrane lying against said second surface and closing said central opening, said membrane, in use, being spaced from the patient's skin and forming a cavity between said membrane and said skin surrounded by said absorbent pad; and a cover layer having a central opening substantially aligned with said central opening of said pad and exposing a central portion of said membrane to identify the injection site. The '641 patch is a three layer system comprising an absorbent pad having a first surface to be placed against the skin of a patient around an intended penetration site for injection or withdrawal and a central opening; a transparent, elastomeric, self-sealing membrane through which a needle can penetrate; and a transparent cover layer having an outer surface and an adhesive surface for holding said membrane in said central opening of said pad and for adhering said patch to skin of a patient, and having a central opening substantially aligned with the central opening of said pad to expose a central portion of the membrane allowing visual identification of a selected penetration site whereby a blood vessel can be located through the membrane and cover and a needle can be passed through said membrane and the patient's skin into a vessel for injection or blood withdrawal, and whereby, after injection or withdrawal, the needle is extracted, the membrane wipes the needle and forms a cavity with the pad and the patient's skin to contain blood from the penetration site until after hemostasis. While these patches have been effective for restricting the free flow of blood when the skin is punctured, they are difficult to manufacture because of the need to carefully align the openings in the various layers. Further, the top surface layer of these patches is susceptible to degradation when wiped with an antiseptic. Therefore, each patch must be individually wrapped and sterilized and then carefully maintained sterile by the clinician while using since wiping with alcohol to maintain sterility may degrade the pad. Finally, neither patch provides a means for the blood to coagulate so a nominal risk remains that a practitioner could be exposed to blood oozing from the absorbent pad upon removing the patch from the patient.

[0004] Thus, it would be beneficial to have a protective patch for use during injections and blood withdrawal procedures that does not require complex registering of the layers, that is relatively easy and inexpensive to manufacture, that has a top surface that can be wiped with an antiseptic such as alcohol while using, and that may include a means for coagulating blood collected within the patch, thereby essentially eliminating the risk of unintended blood contact.

[0005] The present invention is for a puncture site patch for use on humans or on animals for confining blood from a needle wound and for a method of making the patch. The patch comprises an essentially transparent membrane layer and a spacer having an aperture. The membrane layer preferably is a transparent, self-sealing, non-coring elastomeric material through which an injection needle can penetrate and which is self-sealing when the needle is removed to prevent blood from flowing out through the puncture hole made by the needle in the membrane. The membrane layer will not degrade if wiped with an antiseptic such as alcohol. This allows the clinician the option of wiping the surface of the patch immediately before injection in case the sterile field is breached and alleviates the need to individually wrap and sterilize each patch. The spacer is a material sheet that is adhered to the membrane and that has an adhesive film on the opposite side to adhere the patch to a patient's skin. When the patch is secured on the patient's skin, a cavity is formed between the skin and the membrane, bounded by the spacer.

[0006] In an alternative embodiment of the patch, a coagulating agent is positioned along the inner edge of the spacer and is included at sufficient concentration that any blood which escapes into the cavity can be coagulated, or gelled, thereby preventing free flow of blood when the patch is removed from the patient's skin.

[0011] Before discussing the structure of the invention in detail, it will be noted that the layers of material used in the structure are quite thin. In the various figures, the thicknesses are exaggerated for clarity of illustration and it will be realized that this exaggeration also exaggerates the curvatures that occur in the drawings at the overlapping intersections of various layers.

[0012] FIGS. 1 and 2 show a puncture site patch indicated generally by the numeral 10 made in accordance with the invention. The patch 10 includes a membrane 12 and a spacer 14, having an aperture 16. In the embodiment shown, the patch 10 is essentially circular, but other shapes can be used without departing from the scope of the present invention. As shown in FIGS. 3A and 3B, the patch 10 is applied to a patient's skin 90 over an intended injection site 92. When the patch 10 is attached to the skin 90, a cavity 20 forms between the skin 90 and the membrane 12 bounded by the spacer 14.

[0013] Referring to FIGS. 1 and 2, the membrane 12 of the patch 10 is an elastomeric material, preferably sterile, self-sealing, non-coring, non-latex and FDA-approved for direct contact with human or animal skin. More preferably, the membrane 12 is sufficiently transparent that the practitioner can observe the patient's skin 90 when the patch 10 is positioned over the intended injection site 92. Further, the membrane material is preferably selected such that it is essentially unaffected chemically or structurally, and therefore will not degrade if cleaned, disinfected and/or sterilized with agents such as ethyl alcohol, betadine, or similar common disinfectants. The membrane 12 has and exterior face 11 and an interior face 13, which faces toward the patient's skin 90 when the patch 10 is applied. The membrane 12 can have any convenient shape, but must have dimensions sufficient to cover the spacer 14. In a preferred embodiment, the exterior peripheries of the membrane 12 and spacer 14 are essentially identical.

[0014] The spacer 14 is a thin material sheet having an outer face 15 and an inner face 17. The spacer 14 can be composed of any material that can be sterilized and that can be used in direct contract with human skin, such as nylon, polyurethane, polyethylene, polypropylene, isoprene, cotton, linen, or combinations thereof. Optionally, the material for the spacer 14 may be selected on the basis of its ability to absorb blood and bodily fluids, although these absorptive properties are not required. However, if an absorbent material is used, it is preferable, but not required, that the material be somewhat resistant to wicking to minimize the risk of blood wicking from the cavity 20 to the outside edge 19 of the spacer 14. The spacer 14 is secured by its outer face 15 to the interior face 13 of the membrane 12. A variety of means known in the art can be used to secure the spacer 14 to the membrane 12, such as glue, hot melt adhesive, pressure sensitive adhesive, thermally sensitive adhesive, chemical bonding, acrylic cement, or a combination thereof, or any other means well known in the art. Preferably, the spacer 14 is positioned on the membrane 12 such that the membrane 12 covers the entire outer face 15 of the spacer 14. The inner face 17 of the spacer 14 is coated with an adhesive film (not shown) for holding the patch 10 against the patient's skin 90. Although a variety of adhesives may perform the desired function, it is preferable that the adhesive be an FDA-approved material because of the direct skin contact. Optionally, a protective sheet or release paper 18 can be used to protect the adhesive coating until the patch 10 is applied to the skin 90, with the release paper 18 being any of a variety of materials known in the art. The release paper 18 may have a similar size and shape as the spacer 14, or it may be slightly larger than the spacer 14 thereby creating tab 28 to allow for easy removal of the release paper 18 from the membrane 12 and spacer 14.

[0015] The spacer 14 further includes the aperture 16 near its center. The aperture 16 must have dimensions adequate to allow the practitioner to insert a needle through the membrane 12 and the aperture 16 without penetrating any part of the spacer 14. When the patch 10 is applied to the skin 90, the aperture 16 bounded by the skin 90, the membrane 12, and the spacer 14 forms the cavity 20. Because the needle passes through the cavity 20 during an injection or blood withdrawal procedure, any blood that is released from the skin will pool in the cavity 20. The blood may dry within the cavity 20 over time, or it may be absorbed by the spacer 14 if the spacer 14 includes an absorbent material, or optionally, a coagulating agent may be applied to the spacer 14 adjacent to the aperture 16 to cause the blood to thicken and gel. In a preferred embodiment, the spacer 14 is made from polyethylene, and the aperture edge of the spacer 14 is coated with oxidized regenerated cellulose or any other suitable coagulant as is generally known in the art to coagulate any blood that enters the cavity 20. In a more preferred embodiment, the dimensions of the aperture are such that the cavity 20 formed can contain up to about 0.3 cc of bodily fluids.

[0016] Ideally, the patch 10 is secured and held directly against the patient's skin 90 along any portion of the inner face 17 of the spacer 14. While the secure attachment is beneficial to prevent blood leakage, it can be problematic for removing the patch from the skin after use. To make removal easier, the patch may further include pull tab 24 that protrude from the spacer 14. The pull tab 24 is preferably unitary with the spacer 14. The pull tab 24 may or may not include adhesive on the inner face 17. Thus, the practitioner can easily grab the loose pull tab 24 to remove the patch from the patient's skin.

[0017] A patch made in accordance with the invention can also be used when inserting a catheter into a patient, when inserting a needle for biopsies, or whenever the patient's skin will be punctured by a sharp, needle-like object. The cavity can accommodate bodily fluids other than blood, and a variety of antimicrobial agents may be substituted on the spacer for the coagulating agent if so desired.

[0018] The patch of the present invention is relatively easy and inexpensive to manufacture. For example, as shown in FIG. 4, the patch 10 may be made using a continuous production process that includes creating apertures 16 at predetermined positions on a sheet of spacer material 14 that is pretreated with adhesive on both faces 15, 17 and that includes one sheet of protective paper 30 on the outer face 15 and the sheet of release paper 18 on the inner face 17, then removing the protective paper 30 using a take-up roll 32 as the punched spacer material continues its forward motion, then securing a sheet of membrane material 12 to the outer face 15, then die cutting 34 the membrane/spacer/release paper in the desired configuration. As is known in the art, the process may be modified in a variety of ways without departing from the scope of the invention, such as applying the first adhesive to the membrane rather than the spacer sheet, applying the second adhesive to the release paper rather than the spacer sheet, using lasers to cut the layered material, layering and cutting the membrane and spacer before adding the release sheet and combinations thereof.

[0019] While certain advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various modifications can be made herein without departing from the scope of the invention.