DRESSING FOR CATHETER ASSEMBLY
Background of the Invention
[00001] The subject invention relates to a dressing primarily intended for use with a catheter and introducer needle assembly that includes a catheter hub with wings and a side port. Such a catheter and introducer assembly may be designed to include a needle shield that will safely shield the sharp distal tip of the introducer needle after the needle has been used to insert the catheter into a patient. Once the needle is removed, the catheter hub must be secured in position on the patient. The instant invention relates to a dressing that can be readily applied by a caregiver at a proper orientation, that will firmly secure the catheter hub in position, and that will provide access to the side port without jeopardizing the integrity of the dressing or its seal.
[00002] Catheters, particularly intravascular (IV) catheters, are used for infusing fluids, such as normal saline solution, various medicaments and total parenteral nutrition, into a patient, withdrawing blood from a patient or monitoring various parameters of the patient's vascular system. Peripheral IN catheters tend to be relatively short, and typically are on the order of about two inches or less in length. The most common type of IV catheter is an over-the-needle peripheral IN catheter. As its name implies, an over-the- needle catheter is mounted over an introducer needle having a sharp distal tip. At least the distal portion of the catheter tightly engages the outer surface of the needle to prevent peelback of the catheter and thus facilitates insertion of the catheter into the blood vessel. The catheter and the introducer needle are 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 up away from the patient's skin.
[00003] The catheter and introducer needle assembly is inserted at a shallow angle through the patient's skin into a blood vessel. There are many techniques for inserting such a catheter and introducer needle assembly into a patient. In one insertion technique, the introducer needle and catheter are inserted completely into the blood vessel together.
In another technique, the introducer needle is partially withdrawn into the catheter after the initial insertion into the blood vessel. The catheter is then threaded over the needle and inserted completely into the blood vessel. The clinician confirms proper placement of the catheter by observing a flashback of blood in a flashback chamber. Once proper placement of the catheter into the blood vessel is confirmed, the clinician applies pressure to the blood vessel by pressing down on the patient's skin over the blood vessel distal of the introducer needle and the catheter. This finger pressure occludes or at least minimizes further blood flow through the introducer needle and the catheter. The clinician then withdraws the introducer needle, leaving the catheter in place.
[00004] Regardless of the technique employed to insert the catheter into the patient, once the needle is removed, the catheter must be secured in place. Typically, this is done by adhering the catheter hub to the patient's skin. Certain caregivers will use tape, covering the catheter hub and attaching the hub to the patient's skin. See, e.g., U.S. Patent 4,863,432, incorporated herein by reference. Such taping techniques can be time consuming and may not cover the insertion point of the catheter, thereby requiring additional measures to prevent infection at the insertion point. Other caregivers may employ a prepared dressing to secure the catheter hub in place. See, e.g., U.S. Patent 5,380,294, incorporated herein by reference. Such dressings may consist of a relatively large section of flexible, fluid-tight material, with an adhesive, that covers the entire catheter hub and insertion point. These dressings can be applied quickly but may interfere with the operation of the catheter assembly if not placed properly.
Summary of the Invention
[00005] It is therefore an aspect of one implementation of the invention to provide a dressing that can be readily employed to secure a catheter assembly to a patient's skin and that directs the caregiver in proper placement of the dressing.
[00006] It is also aspect of another implementation of the invention to provide a dressing that allows a caregiver to control the placement of the dressing while maintaining flexibility when on the patient.
[00007] It is also an aspect of another implementation of the invention to provide a dressing that resists curling of its edges when in place on the patient.
[00008] In accord with one aspect of the invention, a dressing is provided for use with a catheter assembly including a catheter hub with a side port extending from the catheter hub and wings extending laterally from the catheter hub, such as that disclosed in US
Patents D458,994; D459,802; D458,678; 6,004,294; 6,379,333; Application 09/717,148; and Application 60/390,499, each incorporated herein by reference. Each wing includes a proximal edge and a distal edge that define, at least in part, an edge geometry. A transparent dressing sheet has a substantially square profile and a dressing notch disposed along at least one side of the profile. A release liner has a substantially square profile and a liner handle extending beyond the square profile of the liner. The release liner is removably engaged to the dressing sheet. A reinforcement material has a center portion and arms extending along the center portion. The center portion is positioned at one corner of the dressing sheet and the arms extend along at least two side of the square profile of the dressing sheet. A material notch is disposed along at least one side of the square profile of the material. The material notch is aligned with the dressing sheet notch. The center portion has a distal edge matching the shape of the distal edge of the wings of the catheter hub. A stiffening frame is releasably attached to the dressing sheet and has a substantially square cross section and a center aperture that exposes at least that portion of the dressing sheet disposed between the arms of the reinforcement material.
[00009] In accord with another aspect of the invention, a dressing for use with a catheter assembly including a catheter hub with a side port extending from the catheter hub and a wing extending laterally from the catheter hub. A translucent dressing sheet is releasably engaged to a release liner. The profile of the liner and the profile of the dressing sheet substantially match. A reinforcement material is permanently engaged to the translucent dressing and has a geometry that matches the geometry of the wing. When applied to the patient's skin, the dressing sheet preferably covers the entire catheter, except for the side port and any extension tube extending from the side port.
[00010] Certain aspects of this implementation of the invention provide that a stiffening frame is releasably attached to the dressing sheet. A notch may be disposed in the dressing sheet, the release liner and the reinforcement material. The notch is aligned with the side port when the dressing is applied to the catheter hub and the geometry of the reinforcement material is aligned with the geometry of the wing. When applied to the patient's skin, the side port side port is aligned with the notch such that the catheter hub is covered by the dressing except for the side port (and any extension tube attached thereto). The reinforcement material may be formed from foam, film or fiber and is preferably aligned to resist forces exerted on the catheter hub. An adhesive material may be applied to the dressing sheet or the reinforcement material. The adhesive material disposed at the periphery of the dressing sheet or the reinforcement material may be stronger than the adhesive located elsewhere on the dressing to provide additional resistance to curling of the dressing at the periphery without making removal of the dressing painful or difficult. The adhesive may be selected to bond to a polymer-film forming site preparation solution applied to a patient's skin.
[00011] Other aspect of this implementation of the invention include a stiffening frame releasably attached to the dressing sheet that has a handle that extends beyond the profile of the dressing sheet and a tab on the release liner that extends beyond the profile of the dressing sheet. The handle on the stiffening frame and the tab on the release liner are not aligned. The catheter hub may include a septum port for removing a needle and the dressing sheet is adapted to cover the septum port when placed on a patient's skin, discouraging access to the catheter hub via the septum port. A design or guide may be printed on the dressing sheet that is adapted to direct a caregiver in placing the dressing sheet on the catheter hub. Specifically, the design may be a silhouette shape of the catheter assembly. This design may be translucent to permit the caregiver better visual observation of the placement of the dressing.
[00012] In accord with other aspects of the invention, a method is provided for assembling a dressing. A transparent dressing sheet is provided and has a substantially square profile and a dressing notch disposed along at least one side of the profile. A release liner is releasably engaged to the dressing sheet and has a substantially square
profile and a liner handle extending beyond the square profile of the liner. A reinforcement material is positioned at one corner of the dressing sheet. The reinforcement material has a center portion and arms extending from the center portion. The arms extend along at least two sides of the square profile of the dressing sheet, and a material notch is disposed along at least one side of the square profile of the material. The center portion has a distal edge matching the shape of the distal edge of the wings of the catheter hub. A stiffening frame is releasably attached to the dressing sheet. The stiffening frame has a substantially square cross section and a center aperture that exposes at least a portion of the dressing sheet disposed between the arms of the reinforcement material.
[00013] In accord with yet another aspect of the invention, a method of forming a dressing for use with a catheter assembly is provided. Specifically, a translucent dressing sheet with a sheet profile is provided. A release liner is releasably engaged to the dressing sheet. The release liner has a liner profile substantially matching the sheet profile and a liner handle extending beyond the liner profile. A reinforcement material is permanently attached to the translucent dressing sheet and has a geometry matchmg the edge geometry.
[00014] In accord with yet another aspect of the invention, a method is provided for applying a dressing on a catheter assembly. Such catheter assemblies may include a catheter hub with a side port extending from the catheter hub and a wing extending laterally from the catheter hub including a distal edge with an edge geometry. A dressing sheet with a guide is provided. The guide is aligned with the catheter assembly. The dressing sheet is placed on the catheter assembly and the patient's skin. The dressing sheet is adhered to the patient's skin.
[00015] Certain implementations of this aspect of the invention provide that: the guide is aligned with the catheter assembly after the catheter has been inserted into the patient's skin; a release liner is selectively engaged to the dressing sheet and the method further includes removing the release liner before placing the dressing sheet on the patient's skin; the dressing sheet includes an adhesive material and the release liner is positioned on the adhesive material before removal; a reinforcement material is permanently engaged to the translucent dressing and has a geometry that matches the edge geometry; the guide is formed, at least in part, by the reinforcement material; the guide is a visual outline of the
catheter assembly located on the dressing sheet; the guide is formed, at least in part, by a rib or elevated portion located on the dressing sheet; the guide is formed, at least in part, by an opening in the dressing sheet sized to match the catheter assembly, at least in part.
Brief Description of the Drawings
[00016] Fig. 1 is a top elevation view of a dressing in accord with an aspect of the invention applied to a patient's skin to maintain the catheter hub in place.
[00017] Fig. 2 is a perspective view of the catheter hub (or fitting) for use in accord with aspects of the instant invention.
[00018] Fig. 3 A is an exploded view of a dressing in accord with an aspect of the invention. Fig. 3B is a top view of the dressing of Fig. 3A, shown assembled. Fig. 3C is a top view of the dressing of Fig. 3 A after placement on the patient.
[00019] Fig. 4A is an exploded view of a dressing in accord with another aspect of the invention. Fig. 4B is a top view of the dressing of Fig. 4A, shown assembled. Fig. 4C is a top view of the dressing of Fig. 4A after placement on the patient.
[00020] Fig. 5A is an exploded view of a dressing in accord with another aspect of the invention. Fig. 5B is a top view of the dressing of Fig. 5 A, shown assembled. Fig. 5C is a top view of the dressing of Fig. 5 A after placement on the patient.
[00021] Fig. 6A is an exploded view of a dressing in accord with another aspect of the invention. Fig. 6B is a top view of the dressing of Fig. 6A, shown assembled. Fig. 6C is a top view of the dressing of Fig. 6A after placement on the patient.
[00022] Fig. 7A is a top view of the dressing in accord with another aspect of the invention aligning the dressing with the distal edge of the catheter hub. Fig. 7B is an isolation view of the notch of the dressing of Fig. 7A. Fig. 7C is a top view of a stiffening frame for use in connection with the dressing of Fig. 7A including a placement handle attached to the stiffening frame.
Detailed Description of the Invention
[00023] As used herein, the term "proximal" refers to a location on the dressing and the catheter and introducer needle assembly that, during normal use, is closest to the clinician using the device and farthest from the patient in connection with whom the device is used. Conversely, the term "distal" refers to a location on the dressing and catheter and introducer needle assembly that, during normal use, is farthest from the clinician using the device and closest to the patient in connection with whom the device is used.
[00024] As used herein, the term "top", "up" or "upwardly" refers to a location on the dressing that, during normal use, is away from the patient's skin. Conversely, the term "bottom", "down" or "downwardly" refers to a location on the dressing that, during normal use, toward the patient's skin.
[00025] As used herein, the term "in" or "inwardly" refers to a location with respect to the dressing that, during normal use, is toward the inside of the dressing. Conversely, as used herein, the term "out" or "outwardly" refers to a location with respect to the dressing that, during normal use, is toward the outside or periphery of the dressing.
[00026] As seen in the drawings (specifically, Fig. 2), the catheter hub 100 includes a generally cylindrical body 101 and wings 102. A catheter 110 extends from the distal end of the hub and is in fluid communication with the hub. Each wing includes a distal edge 103 and a proximal edge 104. The edges of the wings define the edge geometry, discussed below. In use, the needle used to insert the catheter into the patient is withdrawn through a septum 105. Preferably, the septum is not used to reaccess the catheter hub. Rather, an extension tube 107 is attached to and in fluid communication with a sideport 106. To deliver fluid to the patient, the caregiver can access a port or valve (not shown) at the end of the tube. Fluid passing through the tube enters the sideport, passes through to the body of the hub and then through to the catheter 110. It will be appreciated that the catheter hub may have any shape and still practice aspects of the invention. Preferably, the guide on the dressing 1, discussed below, is designed to cooperate with the geometry (preferably, the edge geometry) of any given catheter hub to ensure proper placement by the caregiver.
[00027] Referring to Figs. 3A-C, one aspect of the invention is directed to a dressing 1 including a transparent dressing sheet 20, a release liner 10, a reinforcement material 30 and a stiffening frame 40. The dressing sheet has a substantially square profile (preferably, with rounded corners) and is formed of flexible materials such as polyurethane, polyester, or polyether block amide, or elastomers. The square profile of the dressing defines a periphery 22 and a central portion 23. Preferably, the dressing sheet is transparent or translucent. A notch or slit 21 is positioned in the dressing sheet along one side of the square profile. The material of the dressing sheet and its shape are selected in order to provide a flexible structure that is comfortable on the patient and accommodates movement by the patient without pealing off or pulling at the patient's skin. This material is also preferably moisture vapor permeable. It will be appreciated that other shapes and notch locations may be employed and still practice aspects of the invention, as discussed more fully herein. Specifically, the dressing may be shaped to accommodate different catheter designs (including wings of various shapes and hubs with different profiles) and to form fit particular body parts.
[00028] The reinforcement material 30 is preferably made of materials such as nonwoven fabric, reinforced film or foam or the like, and is designed to resist pulling forces exerted by a catheter hub 100 on the dressing sheet 20. Preferably, the reinforcement material is opaque, translucent or otherwise visually or tactibly distinct from the dressing sheet so that the interface between the sheet and the reinforcement material can serve as a guide to the caregiver. Alternatively (or in combination therewith), the reinforcement material may be formed by providing additional thickness of the dressing sheet at its periphery. The additional film thickness provides structural rigidity that can also be provided by a distinct reinforcement material. In accord with one aspect of the invention, the reinforcement material (whether a distinct material or additional film thickness on the dressing sheet) has a base 31 and two arms 32, and is permanently mounted or attached to the dressing sheet 20. The base is shaped to match the profile of a corner of the dressing sheet and the arms are shaped to extend along and align with two sides of the dressing sheet. A notch 33 is disposed in the reinforcement material and is aligned with the notch in the dressing sheet. It will be appreciated that the reinforcement material may have various shapes and still practice aspects of the invention.
Preferably, the reinforcement material is longer in directions aligned with forces expected to be applied to the catheter hub and/or the dressing sheet while still providing a visual alignment guide for the caregiver.
[00029] The stiffening frame 40 is removably attached to the dressing sheet 20 and is preferably made of a material such as polyethylene/vinyl acetate copolymer coated paper or polyester film, and is designed to match the profile of the dressing sheet 20. The material for and shape of the stiffening frame are preferably selected to provide adequate support to the dressing sheet during placement without providing undue bulk, which would interfere with a caregiver' s use of the product. Specifically, in one implementation of the invention, the stiffening frame extends at least to the periphery of the dressing sheet such that the frame prevents the periphery from bending downward during positioning of the dressing. As discussed below, this permits the caregiver to place the dressing more easily. As shown in Fig. 3 A, the stiffening frame is a loop and includes a handle 41 that extends beyond the periphery of the dressing sheet. Other structures may be employed so long as they do not interfere with the guide provided to the caregiver. Further, the stiffening frame may be provided with a roughened surface to permit easy grasping by a caregiver.
[00030] The release liner 10 is preferably made of materials such as kraft paper, polyethylene, polypropylene, polyester, or composites of any such materials, and is designed to match the profile of the transparent dressing. These materials may be coated with release agents such as flourochemicals or silicone. Importantly, the release liner is shaped to cover that portion of the transparent dressing that includes adhesive. Consequently, the release liner is selectively engaged to the dressing sheet, covering and protecting the adhesive from exposure. The release liner includes a release tab 11 that extends beyond the periphery of the dressing sheet when the dressing is assembled. A notch 12 is positioned in the release liner.
[00031] When assembled, the releaser line 10 is releasably secured to the dressing sheet 20 by an adhesive material. The adhesive material may be an acrylate copolymer medical grade pressure sensitive material such that it temporarily adheres to the release liner and
more permanently adheres to the patient's skin. This adhesive may be selected to bond with a polymer film-forming site preparation solution. The adhesive may be applied more densely, or a stronger adhesive may be applied at the periphery of the dressing to prevent curling up at the periphery. As seen in Fig. 3A, the reinforcing material 30 is located on the top side of the dressing sheet, opposite the release liner. It will be appreciated that the reinforcing material can be located on the bottom side of the dressing sheet and the adhesive material would then be applied to the reinforcing material and the dressing sheet. As shown in Fig. 3C, when assembled, the arms 32 of the reinforcing material are aligned with two sides of the dressing sheet. At one corner, the reinforcing material includes a distal edge 34 that is shaped to match the distal edge 103 of the catheter hub, particularly the distal edge of the wings. The reinforcing material may have other shapes for guiding placement of the dressing on the catheter hub. For example, the reinforcing material may include a projection to overlie the hub to help orient the dressing. These projections may be designed to sit in suture holes 111 in the wings. The stiffening frame has a center opening that permits the caregiver to observe the catheter assembly and the insertion point through the dressing sheet while placing the dressing.
[00032] To use the dressing 1 in accord with an aspect of the invention, an over-the- needle catheter assembly is inserted under the patient's skin. The needle is withdrawn through a septum 105 and the catheter 110 left in place. As currently envisioned, the over-the-needle catheter assembly includes a catheter hub 100 including a side port 106 extending from a catheter hub and wings 102 including a distal edge 103 and a proximal edge 104, such as disclosed in Application Serial No. 09/717,148, incorporated herein by reference. The edge geometry is defined by the shapes of the proximal edge and the distal edge. An adhesive material may be applied to the underside of the hub and/or wings to maintain the hub in place on the patient's skin while the caregiver is preparing to apply the dressing. This adhesive may be selected to bond with a polymer film-forming site preparation solution.
[00033] With the catheter 110 and hub 100 in place, the caregiver grasps the tab 11 on the release liner 12, removing it from the dressing sheet 20, thereby exposing the adhesive material. The stiffening frame 40 provides rigidity to the dressing sheet which might
otherwise be difficult to handle due to its flexibility. The caregiver then aligns the distal edge 34 of the reinforcement material with the distal edge 103 of the wings 102 and aligns the side port 106 with the notches 21, 33 and 43. The caregiver can see through the center portion 23 of the dressing sheet to ensure proper alignment and the reinforcing material thereby serves as a guide. As discussed below, other structures may be employed as a guide to positioning the dressing on the catheter hub. Once in place, the caregiver firmly presses the dressing on the patient's skin and the catheter hub. As can be seen in Fig. lc, the portion of the hub where the septum 105 is located is covered by the base 31 of the reinforcing material and the dressing sheet, thereby discouraging reaccess to the hub via the septum. After proper placement, the caregiver grasps the handle of the stiffening frame, pealing it off the dressing sheet and the reinforcement material.
[00034] Referring to Figs. 4A-C, another aspect of the invention includes a modified design for the stiffening frame 40 and the tab of the release liner 10. Specifically, the release liner includes a tab 11 extending from a corner of the liner having a wider portion near the liner and a narrower portion remote from the liner. The stiffening frame is formed as a loop that meets (or slightly overlaps) itself near the notch 43. The handle 41 on the stiffening frame also extends from the corner of the frame, and has a wider portion near the frame and a narrower portion remote from the frame. As seen in Fig. 2b, the narrow portions of the tab and the handle are designed so that they do not overlap, thereby permitting a caregiver easy access to either the tab or the handle. The frame and the release liner may also be of different colors or textures to permit ready distinction by a caregiver. The tab for the release liner may also be wider than the handle throughout its length so that no portion of the handle extends beyond the release liner tab. Such a construction may discourage caregivers from removing the frame before removing the release liner.
[00035] Referring to Figs. 5A-C, another aspect of the invention includes a modified reinforcement material 30 that provides a two-edged catheter alignment feature 35 as the placement guide to the caregiver. Specifically, the edges of the reinforcement material are designed to match the proximal edges 104 of the catheter adapter (rather than the distal edges 103, as depicted in Figs. 3A-C and 4A-c). Further, the stiffening frame 40 is
formed as an open loop, with a gap positioned in alignment with the notch 21 in the dressing sheet 20. Consequently, no distinct notch needs to be formed in the stiffening frame.
[00036] Referring to Figs. 6A-C, in accord with another aspect of the invention, a design 200 is provided to guide the caregiver in aligning the dressing 1 on the catheter hub
100. As shown, the design may be a silhouette or outline of the catheter hub. Other designs could also be employed. Specifically, an outline of the wings alone, or the proximal and/or distal edges of the wing, could be provided and still practice aspects of the invention. Further, shading or other visual indicia may be employed to serve as a guide. A dashed centerline may also be provided for guidance. As shown in Figs. 6A-C, no reinforcement sheet is provided. However, it will be appreciated that a reinforcement sheet may be provided to provide additional tactile guidance to the caregiver. Further, an extra strength adhesive may be applied at the periphery of the dressing sheet. This additional adhesion force reduces curling of the edges of the dressing once placed on the patient.
[00037] Referring to Figs. 7A-C, another aspect of the invention relates to a dressing 1 in which the dressing sheet 20 has a substantially square cross section with rounded corners. It will be appreciated that the release liner 10 and the reinforcement material may also include rounded corners. A writing surface 37 is provided for the caregiver to write the name, date, time, and the like on the dressing. The writing area may be provided on the reinforcement material. Alternatively, a distinct material may be applied to the surface of the dressing that is adapted to be written on.
[00038] As shown in Fig. 7B, the notch may be designed as a slit 121. The slit may be provided with a hole 122 through which the tube is positioned. Such a hole reduces the deformation of the dressing caused by the tube and the strain on the dressing. As shown in Fig. 7C, the stiffening frame 40 may be provided with a handle 141 extending beyond the dressing sheet, which permits easy manipulation of the dressing into position by the caregiver.
[00039] As shown in the drawings, the stiffening frame is preferably disposed near the periphery of the dressing sheet such that the portion of the dressing sheet that will lie on the hub is not covered by the stiffening frame. This permits the inherent flexibility of the dressing sheet to accommodate the shape of the hub without interference from the frame. It will be appreciated that the stiffening frame could be extended inwardly, thereby positioning the inward edge of the stiffening frame to serve as a guide for placement by the caregiver.
[00040] As discussed above, the lower surface of the dressing sheet is covered with adhesive to secure the dressing to the patient's skin. It will be appreciated that, in certain applications, the adhesive may be selectively applied to the bottom surface and provide adequate securing force. Specifically, adhesive may be applied at the periphery of the dressing sheet, leaving the center of the dressing sheet free to slide over the catheter hub while being positioned by the caregiver.
[00041] Although this invention is described herein in connection with an IV catheter including a sideport, it is to be understood that this invention is applicable to other catheters and other devices to be secured to a patient. In addition, while this invention is satisfied by embodiments in many different forms, there are shown in the drawings and herein described in detail, preferred embodiments of the invention with the scope of the invention measured by the appended claims.