Abstract:
A hemostatic biocidal dressing includes pro-coagulant and biocidal agents providing a physical barrier to bleeding as well as chemical action to promote blood coagulation and thereby arrest coverage. At the same time, biocidal properties of the dressing prevent the introduction of infected agents and the establishment of infection within wounded tissue. A silverized textile provides biocidal action while a granulated hemostatic agent disposed within interstitial regions between polymer fibers provides coagulating action.

Description:
[0001]    This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/933,027, entitled “MILITARY HEMOSTATIC BIOCIDAL TRAUMA DRESSING,” filed Jun. 4, 2007, the contents of which are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to medical consumables and more particularly to wound dressings. 
       BACKGROUND 
       [0003]    When physical trauma or medical treatment results in a significant breach of the skin, blood loss and infection can pose serious risks to patient survival. It is essential to quickly control hemorrhage and to limit the entry of infective agents, such as microbes, into a wound. The exigencies of combat medicine make achieving these goals particularly important. In combat, wounds are often life-threatening and the time pressures always associated with treating hemorrhage may be amplified by ongoing hostilities. 
         [0004]    It has long been known to apply a tourniquet to a significant wound to arrest major blood loss. A major disadvantage of applying a tourniquet is that a substantial amount of undamaged issue may be deprived of circulation and necrotize, broadening corporeal damage beyond the original wound and significantly increasing the risk of gangrene. 
         [0005]    More recently, astringents, clotting factors and coagulants have been applied to wounds in an effort to accelerate blood clotting, and thereby arrest hemorrhaging. Typically, a coagulant powder is sprinkled onto a wound and absorbent dressing is applied to the wound with compression. Often initial manual compression with a dressing is followed by binding the absorbent dressing to the wound region with integral and/or separate bandages. 
         [0006]    The application of a coagulant powder is limited in its effectiveness by a tendency of rapidly flowing blood to wash the coagulant powder out of the wound, and by a tendency of the powder to blow away from the wound in the presence of rain, wind and air flows generated by the blades of evacuation helicopters. In addition to limiting the delivery of coagulant powder to a wound, thereby rendering it ineffective, wind can blow the coagulant into the eyes and/or respiratory system of a first responder, limiting that person&#39;s effectiveness in treating the patient and others, and avoiding injury to him or herself. 
       SUMMARY 
       [0007]    The present invention provides an integrated system for arresting bleeding, suppressing infection and reducing pain at a traumatic injury site. In surprising contrast to previously available treatments, a dressing according to principles of the present invention can be applied to a wound to rapidly arrest bleeding, form a physical and chemical infection barrier, and stabilize the wound area pending further treatment. In addition, according to various embodiment, the dressing provides an analgesic function, reducing pain related to the wound. 
         [0008]    According to one embodiment, the dressing includes a highly absorptive pad that includes both a biocidal component and a coagulation enhancing component. In one surprising aspect of the invention, according to one embodiment, the presence of a metallic coating on an external surface of a fiber of the pad serves both to enhance absorbency of the pad and to provide biocidal functionality. In another surprising aspect of the invention, according to one embodiment, a portion of the pad serves as a filter, whereby blood emerging from a wound under treatment is separated into component parts. Some or all platelets are retained in a first spatial region of the pad, thereby encouraging rapid coagulation, whereas some or all plasma is allowed to pass through the first region of the pad into a second region of the pad. In the second region of the pad, the plasma is brought into contact with a reactive material. According to one embodiment of the invention, the reactive material reacts with the plasma to form a substantially rigid and substantially impermeable barrier to further plasma migration. In a still further surprising aspect of the invention, and one that is remarkable to a practitioner of ordinary skill and creativity, the novel combination of a high surface area fiber, a silver coating, and a coagulant material such as, for example, Chitosin, results in hemostasis substantially faster than previously available, while providing the additional benefit of an integrated biocidal functionality. Thus, in contrast to previous approaches involving using manual or device-assisted compression, along with separately applied coagulation enhancing materials, the device of the present invention provides unexpectedly superior performance. 
         [0009]    These and other advantages and features of the invention will be more readily understood in relation to the following detailed description of the invention, which is provided in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows, in cutaway perspective view, a portion of a hemostatic biocidal dressing according to one embodiment of the invention; 
           [0011]      FIG. 2  shows a magnified surface portion of a dressing according to one embodiment of the invention; 
           [0012]      FIG. 3  shows a magnified surface portion of a dressing according to one embodiment of the invention; 
           [0013]      FIG. 4  shows a magnified surface portion of a dressing according to one embodiment of the invention; 
           [0014]      FIG. 5  shows a magnified surface portion of a dressing according to one embodiment of the invention; 
           [0015]      FIGS. 6A-6G  show various exemplary profiles of respective fiber materials according to various embodiments of the invention; 
           [0016]      FIGS. 7A-7E  show various exemplary profiles of respective fiber materials according to various embodiments of the invention; 
           [0017]      FIG. 8  shows, in perspective view, a portion of a fiber material including an interstitial particulate material according to an aspect of one embodiment of the invention; 
           [0018]      FIGS. 9A-9F  show, in graphical form, various exemplary distribution profiles of active materials within a wound dressing according to respective embodiments of the invention; 
           [0019]      FIGS. 10A-10B  show various exemplary geometrical configurations of respective wound dressings according to embodiments of the invention; 
           [0020]      FIG. 11  shows a portion of an exemplary wound dressing and method according to one aspect of the invention, the dressing and method being adapted for treatment of a substantially convex wound region; 
           [0021]      FIG. 12  shows a portion of an exemplary wound dressing and method according to one aspect of the invention, the dressing and method being adapted for treatment of a substantially concave wound region; 
           [0022]      FIG. 13  shows a portion of a wound dressing according to one embodiment of the invention; 
           [0023]      FIGS. 14A-14C  show various exemplary configurations of respective wound dressings according to embodiments of the invention; 
           [0024]      FIGS. 15A-15C  show various aspects of exemplary wound dressings according to embodiments of the invention; 
           [0025]      FIGS. 16A-16B  show respective wound dressings including tourniquet portions according to embodiments of the invention; 
           [0026]      FIGS. 17A-17C  show various aspects of exemplary wound dressings according to embodiments of the invention; 
           [0027]      FIGS. 18A-18B  show various aspects of exemplary wound dressings according to embodiments of the invention; 
           [0028]      FIG. 19  shows a portion of packaged wound dressings according to embodiments of the invention; and 
           [0029]      FIGS. 18A-18B  show various aspects of exemplary packaged wound dressings according to embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    The following description is provided to enable any person skilled in the art to make and use the disclosed inventions and sets forth the best modes presently contemplated by the inventors of carrying out their inventions. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in schematic form in order to avoid unnecessarily obscuring the present inventions. 
         [0031]      FIG. 1  shows, in cutaway perspective view, a wound dressing  100  according to one embodiment of the invention. The illustrated wound dressing  104  includes an outer layer or envelope  102  including a porous region. Disposed within the envelope  102  is a first transfer layer  104 . Disposed within the first transfer layer  104  is a second hemostatically active layer  106 . In certain embodiments, the envelope  102  includes first  108  and second  110  substantially flexible sheets coupled to one another at a peripheral bond region  112 . In various embodiments of the invention, bond region  112  includes a bonding device such as for example, stitching, an adhesive material, a thermal weld, an ultrasonic weld, a mechanical fastener such as a rivet, a snap, and a zipper, and combinations thereof. In other embodiments of the invention, the envelope  102  is formed as an integral unit. 
         [0032]    In various embodiments of the invention, and as will be discussed in additional detail below, one or more of the envelope  102  the first transfer layer  104  and the second hemostatically active layer  106  includes a respective fiber material. In various embodiments of the invention the respective fiber material includes a biocidal material. In various embodiments of the invention, the respective fiber material includes a fiber having a cross-section adapted to provide a high degree of capillary action (a high capillary cross-section). In still further embodiments of the invention, the respective fiber material includes a fiber having a metallic portion or component. In certain embodiments of the invention, a fiber batting is employed with or without hemostatically active material. In other embodiments of the invention a felt material is employed with or without hemostatically active material. 
         [0033]    According to still further embodiments of the invention, one or more of the envelope  102 , the first transfer layer  104  and the second hemostatically active layer  106  includes a non-fibrous material of appropriate characteristics. In further embodiments of the invention, as will be described below, fewer or more layers of material are present. 
         [0034]    Without intending to be bound to a theory of operation, it is noted that the combination of astringent or other hemostatically active materials with bodily fluids can result in adverse consequences to adjacent tissue and, in some circumstances, produce sufficient energy to damage adjacent tissue or structures. For example, an exothermic reaction can, under some circumstances, produce sufficient energy to damage adjacent tissue. 
         [0035]    Out of careful study, thoughtful effort and creativity, the inventors have come to understand that an intervening layer of absorbent material can transfer a fluid including water, such as, for example, blood or plasma, to a hemostatic agent material, where the hemostatic agent material is disposed comparatively distal with respect to the wound and surrounding tissue. Accordingly, the activity of the hemostatic agent as it comes into contact with the transferred fluid is non-damaging to the wound and surrounding tissue. In certain embodiments of the invention, it is believed that silverized fibers, and particularly high-surface-area silverized fibers, are exceptionally effective in transferring plasma from a wound to a distally disposed hemostatic agent material. According to certain embodiments, silverized fibers are of particular value in selectively transferring plasma while retaining blood cells in a region distal to the hemostatic agent material. 
         [0036]    Surprisingly, the application of a metallic coating to high surface area/hi capillary action material serves to strongly increase capillary action and enhance the transfer of fluid between a wound and a hemostatic material arranged in a dressing as described above. Also surprisingly, a metallic coating including metallic silver has the ability to release ions into adjacent fluids and consequently provide a biocidal and analgesic effect in relation to a wound, while simultaneously promoting capillary transfer of fluids to a hemostatic material such as a coagulant. Thus, the novel invention disclosed herewith exhibits it a surprising and remarkable synergy resulting from the combination of hemostatic material with a silverized transfer material to render a wound dressing effective to provide rapid and non-tissue-damaging hemostasis while concurrently providing beneficial biocidal and analgesic effects. 
         [0037]    More generally, it should be understood that a transfer material can be used to transfer plasma away from a wound to, for example, a hemostatic material while simultaneously transferring a pharmaceutical material toward the wound. The pharmaceutical material can include, for example, an analgesic, an antibiotic, a sedative, a vaccine, a genetic transfer vector, a nanoscale material, a nutrient, a vitamin, or any other material determined appropriate for the treatment or well-being of the patient. 
         [0038]    With the foregoing in mind, and in light of the exemplary embodiment illustrated in  FIG. 1 , one of ordinary skill in the art would understand that a wide variety of materials are properly employed as outer porous layers in respective embodiments of the invention. Thus, as shown in  FIG. 2 , one exemplary embodiment of the invention includes a wound dressing  200  with an envelope  202  including a material of woven fibers. As shown in a magnified view  204 , according to one embodiment, the woven fibers include a first plurality of warp fibers  206  and a second plurality of wove fibers  208  with the warp fibers and wove fibers arranged in substantially perpendicular relationship with respect to one another. As will be discussed in additional detail below, these fibers include, in certain embodiments, high surface area capillary fibers and fibers having a surface treatment such as a metallic coating and such as a coating including silver. In certain embodiments, the fibers include homogenous fibers or an organized or randomized mixture of inhomogenous fibers. In various embodiments, the envelope includes at least one region that is substantially porous and adapted to transfer a fluid such as, for example, plasma, from a first side to a second side thereof. 
         [0039]      FIG. 3  shows a further embodiment of a wound dressing  300  according to the invention. As shown, the wound dressing includes an envelope  302  having a substantially porous region including knitted fibers. The knitted fibers  304  are shown in magnified view  306 . As in the embodiments discussed above, in various embodiments, the knitted fibers  304  include high capillary action fibers. In certain embodiments the knitted fibers  304  include metallic material such as filler. In other embodiments, the knitted fibers  304  include a metallic coating or other metallic surface region. According to certain embodiments, the envelope  302  includes a single integral knitted tube. In other embodiments a knitted portion  308  is coupled to a non-knitted portion  310  at a boundary region  312 . In certain embodiments, the non-knitted portion  310  includes a woven portion. In other embodiments, the non-knitted portion  310  includes a sheet material such as, for example, a sheet polymer material. According to various embodiments of the invention, different surface regions of the envelope  302  have respective surface characteristics such that a particular surface region is adapted for application to a wound, or such that different surface regions are adapted for application to respective different classes or types of wound. 
         [0040]      FIG. 4  shows a still further embodiment of the invention including a wound dressing  400  having an envelope  402  including a non-woven fibrous textile material. As shown in a magnified view  404 , certain embodiments of the invention include a non-woven textile having a plurality of substantially randomly oriented fibers  406 . In other embodiments of the invention, as would be understood by one of skill in the art, fibers of the non-woven textile are distributed in various non-random orientations including, for example, periodic and a periodic perpendicular and/or radial orientations. In certain embodiments, this non-woven fibrous textile material is a felted material. In certain embodiments, the fibers include a metallic material such as, for example, a metallic silver coating. 
         [0041]    In certain embodiments of the invention, the metallic silver coating includes a substantially pure silver coating. In certain embodiments of the invention the silver coating includes a silver material having a purity of at least about 99.99% pure. In another embodiment of the invention, the silver coating includes a silver material having a purity of the least about 99.995% pure. In another embodiment of the invention, the silver coating includes a silver material having a purity of the least about 99.9995% pure. In one embodiment of the invention, the metallic silver coating has a thickness of at least about 50μ. In another embodiment of the invention, the metallic silver coating has a thickness of between about 1μ and about 50μ. 
         [0042]    According to various embodiments of the invention, an integrity of the non-woven textile is maintained by the formation of bond interfaces between various fibers of the non-woven textile material. According to various embodiments of the invention, the bond interfaces include, for example, chemical adhesive bond interfaces, thermally welded bond interfaces resulting from the application of, for example heat and/or ultrasonic energy, bond interfaces formed by metallic welds between the above-noted metallic materials by, for example the deposition of further medal in an electrochemical process or the application of heat and/or pressure and/or ultrasonic and/or electrical energy. 
         [0043]    In the various embodiments, as discussed above, the envelope includes fibrous material formed of fibers including a polymeric material. In certain embodiments, the polymeric material includes a polyamide material. In exemplary embodiments, the fibers include drawn and undrawn fibers, on grooves, grooved and deep grooved fibers, of natural and synthetic polymer material including, for example, polyaramid, polyethylene, polyester, polyethylene terephthalate, polyhexamethylene adipamide, or polypropylene, wool, cotton, flax and cellulose, and including addition polymers, condensation polymers, thermoplastics and thermoset materials, among others. 
         [0044]      FIG. 5  shows another embodiment of the invention including a wound dressing  500  having an envelope  502 . The envelope  502  includes a porous region (as shown magnified  504 ) with a plurality of holes or pores  506  therethrough. In certain embodiments, the pores are distributed substantially evenly over a surface  508  of the envelope  502 . In other embodiments, the pores are concentrated in a particular region of the envelope. In still other embodiments of the invention, the pores include pores of uniform or variegated perimeter shape, size, distribution and density. For example, in certain embodiments, the pores include pores with perimeters that are substantially circular, elliptical, oval, polygonal including triangular, rectangular, pentagonal, hexagonal heptagonal, and/or octagonal. As a creative practitioner of ordinary skill in the art would understand, other perimeter arrangements, including combinations thereof, would fall within the scope of the invention. In various embodiments, the envelope includes a material such as a reinforced or unreinforced polymer material. In certain embodiments this material is a natural polymer or a synthetic polymer. In certain embodiments, the polymer material includes one or more of a polymer and an elastomer such as, for example, polyethylene, polyethylene terephthalate (polyester) including, for example, bi-axially oriented polyethylene terephthalate (Mylar®), polyamide (Nylon®), polypropylene, polyaramid, polyurethane, neoprene, butadiene, Polyetheretherketone (PEEK), ceramic material and other appropriate materials such as are known or may become known in the art. According to various embodiments of the invention, the polymer material includes a textile material and/or fiber reinforcement material. 
         [0045]    Referring again to  FIG. 1 , certain embodiments of the invention include a transfer layer  104  and a hemostatically active layer  106  disposed within a cavity defined by an inner surface of the envelope  102 . According to certain embodiments of the invention, the transfer layer  104  includes a bat of fibrous material. According to certain embodiments of the invention, the fibrous material includes a polymer fiber material having a high capillary action fiber with a relatively large silverized surface area adapted to promote high capillary transfer of fluids from the envelope  102  to the hemostatically active material  106 . In various embodiments, the fiber material includes a homogenous fiber material. In other embodiments, the fiber material includes a mix of fiber materials including one or more of un-grooved, grooved and deep grooved fiber materials, either uniformly oriented or randomly oriented. Also in various embodiments, the fibers include one or more of heavy denier, fine denier and microfibers, alone or in accommodation. In addition, in various embodiments, the fibers include short staple, long staple and continuous filament/TOW fibers, alone or in combination. 
         [0046]    In certain embodiments of the invention, a silverized fiber material included in the wound dressing includes a silverized fiber material prepared according to the disclosure presented in one or more of U.S. Pat. No. 7,172,785 entitled Process for Deposition of a Metal on a Surface and U.S. Pat. No. 6,726,964 entitled Ultrasonic Process for Autocatalytic Deposition of a Metal on a Micro-Particulate. 
         [0047]    In other embodiments of the invention, transfer layer  104  includes another material adapted to promote a transfer of fluid between envelope  102  and the hemostatically active material  106 . Thus, in certain embodiments, transfer material  104  includes a more or less porous, more or less flexible material such as an open cell polymer foam material (including, for example, a natural or synthetic sponge material), a sintered or un-sintered particulate material, and aerogel material, a cellulosic material including, without limitation, a felt, a textile, a leather, an aerogel, a paper material or other more or less porous material as known in the art. 
         [0048]    In embodiments including a porous material the pores may be of, for example, circular shape, elliptical shape, oval shape, polygonal shape including triangular, rectangular, pentagonal, hexagonal, heptagonal, octagonal, etc. In other embodiments, the pores may be of random shape and/or size and of substantially uniform or mixed size. 
         [0049]      FIGS. 6A-6E  shows, in cross-sectional view, various exemplary profiles of fibers including high-surface area fibers used in various respective embodiments of the invention.  FIG. 6A  shows an exemplary fiber of substantially circular cross-section.  FIG. 6B  shows an exemplary fiber of generally circular fluted cross-section.  FIG. 6C  shows an exemplary fiber of generally circular deeply grooved cross-section.  FIG. 6D  shows an exemplary fiber of generally serpentine cross-section.  FIG. 6E  shows an exemplary fiber of generally stellate cross-section.  FIG. 6F  shows an exemplary fiber of generally elliptical cross section, and  FIG. 6G  shows an exemplary fiber of generally polygonal cross-section. The creative practitioner of ordinary skill in the art will appreciate a wide variety of other fiber profiles, including mixtures of profiles, are possible. Further exemplary profiles are illustrated and discussed in U.S. Pat. No. 6,610,903 entitled Materials for Fluid Management in Personal Care Products,  FIG. 3  of which is reproduced herewith as  FIGS. 7A-7E . 
         [0050]    In various embodiments, the fibers include one or more of cotton, flax, hemp, polyamide, polyethylene (including low-density linear polyethylene, high-density polyethylene, ultrahigh molecular weight polyethylene), polyethylene terephthalate (polyester), copolyester, polypropylene, poly lactic acid, poly 1, 4 cyclohexane dimethyl, terephthalate (PCT), and glycol-modified PET (PETG), among others. 
         [0051]    As discussed above in relation to  FIG. 1 , the hemostatically active layer  106  of the wound dressing  100  is disposed inwardly of transfer layer  104 . In one exemplary embodiment, this hemostatically active layer includes a substantially fibrous material and a hemostatically active particulate material disposed interstitially between the fibers of the fibrous material. In other embodiments, the hemostatically active material is disposed in a coating on the transfer material: for example as a pharmaceutical coating on a deep grooved fiber. In still another embodiment of the invention, the hemostatically active material includes a liquid. In still another embodiment of the invention, the hemostatically active material includes a gel. In yet another embodiment of the invention, the hemostatically active material includes a material encapsulated within a second material, such as a gel or powder disposed within a frangible capsule of, for example, gelatine or a polymer material. In yet another embodiment of the invention, the fibers are intrinsically hemostatic and in still another embodiment of the invention, sheets, strips, disks, spheres, or any other appropriate arrangement of hemostatically active material is employed. Accordingly,  FIG. 8  shows, in perspective cutaway view, a portion of an exemplary hemostatically active region  800  according to one aspect of the invention. As shown, the hemostatically active region  800  includes a plurality of fibers  802  and a further plurality of particles  804  of hemostatically active material disposed interstitially between the fibers. In certain embodiments, the hemostatically active material particles  804  includes substantially non-porous particles. In other embodiments, the hemostatically active material particles include substantially porous particles. In certain embodiments, the particles include faceted, smooth or corrugated surfaces respectively. 
         [0052]    According to certain embodiment of the invention, the fibers include fibers having high capillary action and high surface area fibers. Likewise, in various embodiments of the invention, the fibers include silverized fibers or otherwise metallically coated, embedded or otherwise activated fibers. In some embodiments of the invention, the fibers of the hemostatically active region are substantially identical to fibers of a transfer region. In certain embodiments of the invention, the silverized fibers include fibers having silver ironically bonded to nylon. In certain embodiments of the invention, the silver is ironically bonded within deep channels of a deep grooved nylon fiber material. 
         [0053]    In certain embodiments of the invention, a hemostatically active material is substantially uniformly distributed within a hemostatically active layer. In other embodiments of the invention, a hemostatically active material is disposed in a nonuniform distribution within the in the hemostatically active layer. For example, in certain embodiments of the invention the density distribution of hemostatically active material increases monotonically with distance from an edge of the hemostatically active region. In other embodiments of the invention, a distribution of the hemostatically active material varies cyclically and in still other embodiments the density of hemostatically active material within the hemostatically active region varies stochastically as a function of location over the region. 
         [0054]    In certain embodiments of the invention, hemostatically active material is distributed throughout the transfer region  104  within the envelope  102  of  FIG. 1 . According to certain embodiment of the invention, the distribution of the hemostatically active material varies substantially monotonically from a relatively low density distribution of hemostatically active material disposed relatively proximal to an internal surface of the envelope  102  to a relatively high density distribution of hemostatically active material disposed relatively distal to the internal surface of the envelope. 
         [0055]    Accordingly,  FIGS. 9A-9F  show, in graphical form, various exemplary distributions of hemostatically active material within and throughout respective exemplary dressings. As indicated, a spatial concentration of hemostatically active material is plotted with respect to spatial distance across the device. The graphs of  FIGS. 9A-9F  assume a spatially symmetrically configured dressing and distribution of hemostatically active material. The creative practitioner of ordinary skill in the art would appreciate, however, that a wide variety of arrangements are possible, and appropriate to various applications and general use or special use dressings, and that the illustrated distributions are merely exemplary of many alternative embodiments. 
         [0056]      FIG. 9A  shows a first distribution  900  of hemostatically active material. According to the embodiment of  FIG. 9A  the envelope  902  is substantially free of hemostatically active material, as is a first transfer layer  904 . At an interface  906  between the transfer layer and a second hemostatically active layer  908  the concentration  910  of hemostatically active material rises precipitously, and in some embodiments substantially instantaneously, from zero to a specified level  912 . In the illustrated embodiment, the concentration/distribution of hemostatically active material  910  is substantially constant across the hemostatically active layer  908  between the interface  906  and the center of the dressing  914 . Thus, in a substantially symmetrical dressing, the concentration of hemostatically active material is substantially constant throughout the hemostatically active layer  908 . 
         [0057]      FIG. 9B  shows a distribution of hemostatically active material in a wound dressing  920  according to an alternative embodiment of the invention. In dressing  920 , envelope  902  is substantially free of hemostatically active material. Within the dressing, a concentration  922  of hemostatically active material rises substantially linearly from an inner surface  924  of the envelope  902  to a center  926  of the dressing. 
         [0058]      FIG. 9C  shows a distribution of hemostatically active material in a wound dressing  930  according to another embodiment of the invention. In dressing  930 , envelope  902  is substantially free of hemostatically active material. Within the dressing, a concentration  932  of hemostatically active material rises nonlinearly and, in the illustrated embodiment, substantially monotonically from an inner surface  924  of the envelope  902  to a center  926  of the dressing. In the illustrated embodiment, the concentration  932  of hemostatically active material is a substantially parabolic function of distance taken with respect to interface  924 . 
         [0059]      FIG. 9D  shows a distribution of hemostatically active material in a wound dressing  940  according to still another embodiment of the invention. In dressing  940 , envelope  902  includes a relatively low, substantially constant concentration  942  of hemostatically active material is present throughout the envelope  902  between an external surface  944  and an internal surface  946  of the envelope. Within the dressing, a concentration  922  of hemostatically active material rises, here nonlinearly, from the inner surface  946  of the envelope  902  to the center  926  of the dressing. 
         [0060]      FIG. 9E  shows a distribution of hemostatically active material in a wound dressing  950  according to yet another embodiment of the invention. In dressing  950 , the envelope  902  is substantially free of hemostatically active material, as is a first region  952  of the dressing  950  disposed inwardly of the envelope  902 . Further inward within the dressing  950 , a concentration  954  of hemostatically active material, rises to a peak concentration  956 . The peak concentration  956  occurs at a region  958  disposed outwardly of a center  960  of the dressing  950 . In a further region of the dressing  962  disposed between region  958  and center  960 , the concentration  954  of the hemostatically active material decreases to a local minimum  962 . In certain embodiments of the invention, local minimum  962  corresponds to a concentration of substantially zero. In certain embodiments of the invention a concentration of substantially zero is achieved outwardly of the center  960  of the dressing. 
         [0061]      FIG. 9F  shows a distribution of hemostatically active material in a wound dressing  970  according to still a further embodiment of the invention. In dressing  970 , the envelope  902  is substantially free of hemostatically active material. A first concentration  972  of a first hemostatically active material rises from a relatively low-level, or zero, adjacent an inner surface  974  of envelope  902  to a peak value  976  and a region of the dressing  970  between inner surface  974  and a center of the dressing  980 . Thereafter, concentration  972  decreases to a sub-peak value  978  at a region, here shown as adjacent center  980 , of the dressing  970 . A concentration  982  of a further material is shown to increase from a further region  984  of the dressing  972  of value, here shown as a maximum value  986  in proximity to the center  980  of the dressing. According to various modes of the invention, the second concentration  982  is a concentration of a second hemostatically active material. In other embodiments of the invention, the second concentration  982  is a concentration of a material adapted to cooperate with, or otherwise enhance, an activity of the hemostatically active material of concentration  972 . In certain embodiments of the invention, the material of concentration  982  is adapted to react endothermically with a material such as, for example, blood plasma. 
         [0062]    In light of the disclosure provided above, and particularly in relation to  FIGS. 9A-9F , the creative practitioner of ordinary skill in the art would appreciate a wide variety of distributions of physical and chemical constituents, including but not limited to hemostatically active materials, are provided in various embodiment of the invention and fall within the scope of the present disclosure. 
         [0063]    In certain embodiments of the invention, the hemostatically active material includes particulate material of substantially uniform size. In other embodiments of the invention, the hemostatically active material includes particulate material including particles having respective average diameters marrying over a distribution of sizes. In certain embodiments, the particles of hemostatically active material are have a substantially smooth peripheral surface such as, for example, a substantially smooth substantially spherical surface or a substantially smooth substantially ellipsoidal surface. In other embodiments, the particles of hemostatically active material are rough, groove, pitted, or otherwise have substantially non-smooth peripheral surfaces. 
         [0064]    In light of the disclosure above, the creative practitioner of ordinary skill in the art will appreciate that a wide variety of general purpose and special-purpose dressings can be prepared according to the principles of the present invention. Thus,  FIG. 10A  shows an exemplary dressing  1000  with an external surface  1002  substantially defining a rectangular solid.  FIG. 10B  shows a further exemplary dressing  1004  with an external surface  1006  substantially defining a cylindrical solid.  FIG. 10C  shows yet another exemplary dressing  1008  having a surface  1010  including a first substantially hemispherical region  1012  and a second substantially flat region interfacing with region  1012  at a substantially circular boundary  1016 . 
         [0065]    One of skill in the art will appreciate that the various symmetries and asymmetries presented in the exemplary embodiments illustrated permit the wound dressing to be adapted to various applications. Thus, surface region  1014  of dressing  1008  is readily adapted to be disposed adjacent to a substantially flat wound such as a burn, whereas, under other circumstances, surface region  1012  can be disposed adjacent to an inner surface of a wound cavity. It should be noted that, in many embodiments, the dressing is substantially elastically compressible and thus can conform to a wound of a particular geometry. 
         [0066]    In addition to dressings of various general shapes, certain embodiments of the invention are well adapted for the treatment of particular classes of wounds or for use in particular situations. For example  FIG. 11  shows, in perspective view, an exemplary embodiment of a wound dressing  1100  adapted for application to a truncated limb  1102  according to one aspect of the invention. The truncated limb dressing  1100  includes a first enclosing portion  1104  and a second harness portion  1106  coupled to the enclosing portion. The enclosing portion  1104  is adapted to cover and protect the wound, here at a truncated end  1108  of the limb  1102 . The harness portion is adapted to be disposed about an adjacent region of a body of the patient, and to locate and support the enclosing portion in substantially fixed location with respect to the truncated end  1108 . 
         [0067]    In certain embodiments the enclosing portion  1104  includes and outer surface  1105  and a substantially concave surface region defining a cavity within the enclosing portion  1104  adapted to receive the end  1108  of the truncated limb  1102  therewithin. In various embodiments, and in light of the disclosure provided above, the enclosing portion  1104  includes a silver coated fibrous material and a hemostatically active material such as Chitosin. In certain embodiments, the harness portion  1106  includes a substantially elastic material. In other embodiments, the harness portion  1106  includes a substantially inelastic material. In various embodiments, harness portion  1106  is adapted to be disposed in tension so as to apply a force (or pressure) between a wound-contacting surface of enclosing portion  1104  and an end  1108  of the truncated limb  1102 . 
         [0068]    According to certain embodiments, the harness portion is adapted to cover and protect secondary wounds (e.g.,  1110 ,  1112 ). Thus in certain embodiment, the harness portion includes one or more of a silver coated fibrous material and a hemostatically active material such as Chitosin. In certain embodiments, harness portion  1106  includes a substantially tubular envelope formed of a substantially elastic material such as a knitted silverized high capillary action fiber material. In certain embodiments of the invention, the dressing  1100  includes a first relatively more elastic inner surface and a second relatively more robust outer surface. One of skill in the art will appreciate a wide variety of inner and outer surface materials would fall within the scope of the invention, including woven, knitted, and nonwoven textile materials, sheet polymer materials, cellulosic materials and other materials known in the art. In one embodiment of the invention, at least one layer of silverized batting  1107 , including a hemostatically active particulate material, is disposed within the harness portion  1106  of the dressing  1100 . In other embodiments of the invention, a layer of silverized felt material including a hemostatically active particular material is disposed within the harness portion. In another embodiment of the invention, a layer of silverized batting material and/or silverized felt material including a coating of hemostatically active material is included in the harness portion. 
         [0069]      FIG. 12  shows an alternative application  1200  of dressing  1100 . In the illustrated application, the dressing  1100  is used to dress a substantially concave wound such as a belly wound. As shown, the enclosing portion  1104  is disposed substantially entirely within the cavity of the wound. In the illustrated application, what was previously disposed as an outer surface  1105  is now disposed substantially in contact with the wounded tissue. The harness portion  1106  is disposed circumferentially about an abdomen  1202  of a patient. The versatility of the invention in its various embodiments utility and is thus illustrated. 
         [0070]      FIG. 13  shows, in perspective view, a further embodiment of the invention including a wound dressing  1300  incorporating various features as described above. The wound dressing  3000  includes a harness portion  1302  and an enclosing portion  1304 . In certain embodiments, the harness portion  1302  includes a silverized substantially elastic material; for example a silverized knitted deep groove nylon fiber material. In further embodiments, the harness portion  1302  includes one, two or more layers of silverized material with one, two or more layers of Chitosin impregnated batting. 
         [0071]    As illustrated, the enclosing portion includes a first wound covering portion  1306  and a second wound covering portion  1308 . In the illustrated embodiment, both wound covering portion  1306  and wound covering portion  1308  are coupled to the harness portion  1302 . Wound covering portion  1308  is adapted to be either folded over on top of wound covering portion  1306   1310  so as to provide a relatively thick configuration of enclosing portion  1304 . Alternately wound covering portion  1308  is adapted to be unfolded  1312  so as to provide a relatively thin configuration of enclosing portion  1304  but with a larger effective wound covering surface area. One of skill in the art will appreciate that the various hemostatic, biocidal and analgesic features discussed above are readily incorporated into the various embodiments of the invention represented by exemplary wound dressing  1300 . In addition, in certain embodiments, the wound dressing of the invention includes to capture mechanism such as, for example, a hook and loop fastener material adapted to hold the field dressing  1300  in one or both of a stored configuration and a deployed configuration. 
         [0072]    Of course it should be understood that the dressings exemplified by the illustrated embodiments can be prepared in a wide variety of sizes and shapes according to the demands of particular applications and circumstances. Thus for example,  FIG. 14A  shows a wound dressing  1400  including an enclosing portion  1402  coupled substantially symmetrically between first  1404  and second  1406  harness portions.  FIG. 14B  shows an enclosing portion  1408  coupled substantially symmetrically between first  1410 , second  1412 , third  1414 , and fourth  1416  harness portions.  FIG. 14C  shows an enclosing portion  1418  coupled asymmetrically at one end of a harness portion  1420 . 
         [0073]      FIG. 15A  shows, in perspective view, a wound dressing  1500  according to a further embodiment of the invention. Wound dressing  1500  includes a substantially tubular dressing having a first closed end  1502  and a second open end  1504 . As shown in  FIG. 15B  would dressing  1500  can be disposed, as for storage, in a rolled configuration. Prior to, or in the course of, application a first for us  1506  is applied at a central region of an internal surface  1508  concurrently, curling forces  1510 ,  1512  are applied at respective outer edge regions  1514 ,  1516  of the dressing. Consequently, the dressing  1500  tends to unroll and assume the configuration shown in  FIG. 15A . 
         [0074]    Referring again to  FIG. 15A , an internal surface  1520  defines a cavity within the dressing. The cavity is adapted to receive therewithin a truncated, burned, or otherwise injured limb, head, or other appropriately sized body part, for example. Because the transition from a rolled configuration as shown in  FIG. 15B  to an unrolled configuration as shown in  FIG. 15A  can be made with a wounded extremity in situ, this transition can be used to facilitate application of the dressing. Thus, according to one embodiment, the invention includes a method of applying a dressing including disposing a rolled dressing adjacent to a wounded extremity and unrolling the dressing over the extremity so as to hold, for example, a hemostatic biocidal material generally in proximity to the wound. It should also be noted that because application of the dressing involves and unrolling of the dressing rather than, for example, a helical winding of the dressing, application of the dressing is often possible significantly faster and with less risk of contamination of wound-interfacing surfaces that is possible in other dressings and methods. 
         [0075]    In various embodiments, the dressing includes a substantially elastic material such as, for example, a knitted textile material. In certain embodiments, the new textile material includes a silverized knitted nylon material. One of skill in the art will appreciate that as the dressing  1500  is unrolled over an extremity, the substantially elastic material tends to apply a compressive force  1522  radially inwardly on a corresponding external service region of a wounded extremity. This compressive force tends to hold the dressing in place adjacent to the extremity. 
         [0076]      FIG. 15C  shows, in cross-section, a further aspect of a dressing  1550  according to one embodiment of the invention. The dressing  1550  includes a substantially elastic sleeve portion  1552  having a first inner surface region  1554  and a second outer surface region  1556 . In various monitor the invention, the substantially elastic sleeve portion  1552  includes a polymeric material such as, for example, a woven or nonwoven textile, a knitted textile, a felted textile, an elastomeric polymer sheet material, an elastomeric helical spring material, high surface area high capillary action fiber material, metallized fiber material including silverized fiber material, other appropriate materials as known in the art, and combinations thereof. As illustrated, sleeve portion  1552  includes a closed end  1558  having a further substantially concave (as applied) surface region  1560 , defining a cavity  1562  and adapted to receive wounded flesh adjacent thereto. 
         [0077]    According to various embodiments of the invention, one  1564 , two  1566  or more layers of silverized high capillary action fiber batting are disposed in proximity to inner surface region  1560 . According to still further embodiments of the invention, one or more of the layers of batting include a hemostatic material such as, for example, a distributed particulate hemostatic material. In certain embodiments of the invention, a transfer layer is disposed between the inner surface  1560  and the hemostatic material so as to prevent hemostatic material from adversely affecting tissue of the wound or other tissue. 
         [0078]    In still further embodiments of the invention, silverized fibers are found throughout the dressing so as to provide beneficial biocidal and analgesic functionality to a primary wound and any proximate secondary wounds. According to one embodiment of the invention at least one layer of silverized batting  1570  including Coagulant particulate material is disposed within the substantially elastic sleeve portion  1552  of the dressing  1550 . 
         [0079]    It should be noted that the embodiments of the invention exemplified as  1500  and  1550  constitute a self-contained dressing and bandage combination. As such they offer decreased application time in a trauma setting as compared with conventional dressing devices and methods. The Coagulant impregnated batting will significantly increase clotting potential over other dressing materials including, for example, cotton. The silverized elasticized tubing provides immediate compression, antimicrobial protection and analgesic effect. According to certain embodiments, significant analgesic effect is available beginning at a time from about 5 minutes to about 20 minutes after application of the dressing. In various embodiments, the dressing of the invention is robust and readily adapted to storage in a vacuum package for significant shelf life. 
         [0080]      FIG. 16A  shows a wound dressing  1600  according to another embodiment of the invention including a substantially tubular portion  1602  and an integrated tourniquet portion  1604 . In certain embodiments of the invention, the tourniquet portion  1604  is substantially permanently coupled to the tubular portion. In other embodiments of the invention, the tourniquet portion  1604  is remotely coupled to the tubular portion  1602  by a coupling device  1606  such as, for example, a hook and loop fastener system (e.g. Velcro®). In certain embodiments, the coupling device  1606  is further adaptable for fixing the tourniquet in place to apply tourniquet pressure. 
         [0081]    According to still another embodiment  1620  of the invention, as illustrated in  FIG. 16B , a tourniquet portion includes a flexible member  1622  such as, for example, a cord or lace. In certain embodiments, the cord or lace is disposed between inner and outer fabric layers of the tubular portion  1602 . In certain embodiments of the invention, the likable member passes into and out of an outer fabric layer of the tubular portion through respective first  1624  and second  1626  eyelets. 
         [0082]      FIG. 17A  shows, in perspective view, a further embodiment of the invention including a wound dressing and tourniquet combination  1700 . In the illustrated embodiment, the combination includes a dressing portion  1702  adapted to be unrolled over a wound such as a truncated extremity wound. In the illustrated embodiment, a fastening device  1704  is coupled to an external surface  1706  of the dressing portion  1702 . In certain embodiments, the fastening device  1704  is a substantially flexible fastening device such as, for example, a hook and loop fastener device. Hook and loop fastener devices are well known in the art, for example under the trade name Velcro®. In the illustrated embodiment, the fastener device  1704  includes a hook portion  1708  and a loop portion  1710 . As shown, in one embodiment be hook  1708  and loop  1710  portions are coupled to one another at coupling region  1712 . As illustrated, the hook portion  1708  of the fastening device is coupled to external surface  1706  of the dressing portion. One of skill in the art will appreciate that an alternative arrangement, in which the loop portion  1710  of the fastening device  1704  is disposed adjacent to surface  1706 , is appropriately employed in certain embodiments. 
         [0083]    In the illustrated embodiment, a tourniquet portion  1714  is included with the dressing portion  1702 . Also included with the dressing portion  1702 , in certain embodiments, is a handle portion  1716 . In certain embodiments of the invention, the dressing portion  1702 , the tourniquet portion  1714 , and the handle portion  1716  are mutually enclosed in a common package. According to certain embodiments of the invention, the tourniquet portion  1714  is disposed within a rolled-up region of the dressing portion  1702  prior to application of the dressing portion to a wound. According to certain amount of the invention, the tourniquet portion forms a continuous loop circumferentially around the outer surface of the dressing portion  1702 . In other embodiments of the invention, the tourniquet portion  1714  includes a fastening device adapted to allow an effective circumference of the and tourniquet portion, as applied, to be adjusted. 
         [0084]      FIG. 17B  shows, in cross-section, a further view of wound dressing and tourniquet combination  1700 . In use, the tourniquet portion  1714  is disposed circumferentially around the wound dressing portion  1702 . A fastener portion  1704  holds the tourniquet portion adjustably in a particular location with respect to a close end  1720  of the dressing portion  1702 . 
         [0085]    Referring again to  FIG. 17A  one sees that once the dressing portion  1702  has been applied to, for example, a truncated limb, a loop portion  1710  of the hook and loop fastener  1704  can be withdrawn  1722  from the hook portion  1708  of the fastener  1704 . Thereafter, paternity portion  1714  can be moved laterally  1724  along a longitudinal axis of the dressing portion according to the needs and circumstances of a particular patient. Once a tourniquet portion  1714  is properly positioned, the loop portion  1710  of the hook and loop fastener  1704  can be re-coupled  1726  to the hook portion  1708  of the fastener, thereby securing the tourniquet portion  1714  in place. Thereafter, according to one embodiment of the invention, handle  1716  can be used to twist, and thereby tighten the tourniquet portion  1714 . 
         [0086]    In certain embodiments of the invention, as shown in  FIG. 17C , the tourniquet portion  1714  includes a loop portion  1728 . The loop portion  1728  defines a cavity  1730  adapted to receive the handle  1716  therethrough, so as to facilitate twisting of the tourniquet. 
         [0087]    Referring again to  FIG. 17A  one sees that rotation of the handle  1716  results in a twisted portion  1732  of the tourniquet portion  1714 . According to certain embodiments, the invention includes a method of disposing a region of the twisted portion  1732  and/or a portion of the handle  1716  between the hook portion  1708  and the loop portion  1710  of the fastener  1704  so as to retain the tourniquet portion  1714  in a constricted configuration about a wounded limb of a patient. It should be appreciated that in various methods according to the invention, it is possible to subsequently release the loop portion  1710  of the fastener  1704  from the hook portion  1708  of the fastener to allow further adjustment of a circumferential tension and/or longitudinal position of the tourniquet portion  1714 . 
         [0088]    In another embodiment of the invention, the tourniquet portion includes a detent device adapted to readily include one way constrictive motion of the tourniquet strap. A first end of the tourniquet strap is coupled to be detent device and a second end of the tourniquet strap is passed through the detent device. Pulling on the second end of the strap tightens the tourniquet about, for example, a limb. In one embodiment, a release device on the detent device allows the tourniquet strap to be subsequently loosened. 
         [0089]      FIG. 18A  shows an exemplary wound dressing  1800  according to a further embodiment of the invention. In the illustrated embodiment, the wound dressing includes a first portion  1802  adapted to be disposed adjacent to a wound. The illustrated first portion  1802  is generally comparable to the truncated limb dressing  1700  of  FIG. 17 . When a skill in the art will appreciate, however, that the first portion  1802  could just as well be a dressing of the style presented as dressing  100  in  FIG. 1 , or any of a wide variety of other appropriate dressing configurations. Coupled to the first portion  1802  is a wrapping portion  1804 . In the illustrated embodiment, the wrapping portion  1804  includes a substantially elastic textile material including, for example, a plurality of silverized deep groove nylon fibers. In various embodiments, the wrapping portion  1804  also includes a fiber batting material including a one or more of analgesic and hemostatic materials. 
         [0090]    In the illustrated embodiment, the wrapping portion  1804  includes a plurality of capture devices  1806 .  FIG. 18B  shows an exemplary capture device  1806  in additional detail. The capture device  1806  includes a grommet portion  1808  and a hook portion  1810 . Grommet portion  1808  includes first  1812  and second  1814  flange portions and a tubular portion  1816  disposed between the first  1812  and second  1814  flange portions. The grommet portion  1808  is adapted to be coupled to the wrapping portion  1804  in a matter typically employed, and well understood in the art of grommets and riveting. Grommet portion  1808  includes an inner surface  1809  defining a bore therethrough. In various embodiments, the capture device  1806  includes a brass material, stainless steel material, an aluminum material another metallic material, a polymer material including, for example polyamide, polyamide, polyethylene (including, for example, ultrahigh molecular weight polyethylene) or any other appropriate material available and known in the art at the time of manufacture. 
         [0091]    The dressing  1800  is applied by positioning first portion  1802  adjacent to wounded flesh. Thereafter, the wrapping portion  1804  is disposed about an additional portion of a patient&#39;s body, either in a helical wrapping arrangement or otherwise, as appropriate to particular clinical circumstances. When an appropriate degree of wrapping has been completed, a hook portion  1810  of one capture device  1806  is disposed within a bore of another capture device to secure the wrapping in place. Thereafter, any excess portion of the wrapping can be severed from the dressing and employed elsewhere in treatment of the same or another patient. One of skill in the art will appreciate that alternative fastening means, including, for example, a hook and loop (Velcro®) fastener is included in alternative embodiments of the invention. 
         [0092]      FIG. 19  shows, in cutaway perspective view, a wound dressing package  1900  according to one embodiment of the invention. The wound dressing package  1900  includes a wound dressing  1901  and a substantially gas and liquid impermeable envelope  1902 . In certain embodiments, the package is adapted to sustain a substantial vacuum or an atmosphere of substantially nonreactive liquid or gas, therewithin. In various embodiments, the envelope includes a synthetic polymer material such as, for example, (Mylar), polyamide, polyaramid, polyethylene or other polymer material such as would be known to the creative practitioner of ordinary skill in the art. In a further embodiment of the invention, the envelope includes a reinforcing material such as, for example, reinforcing fibers. Depending on the particular application, the reinforcing fibers may include polymer fibers, glass fibers, carbon fibers, or other fibers or reinforcing devices appropriate for reinforcing a polymer material, as would be known to the creative practitioner of ordinary skill in the art. 
         [0093]    As will be described below in additional detail, the envelope  1902  is adapted to be robust against inadvertent opening, but readily openable when required. Thus, for example, in the embodiment illustrated in  FIG. 19 , the envelope  1902  includes a pull-tab  1904 . The pull-tab  1904  is coupled to, or integrally formed with, a pull-strip portion of the envelope  1906  disposed adjacent to a region of the envelope  1908  that is adapted to tear, or otherwise separate, when an appropriate force is applied between the pull-tab  1904  and the balance of the envelope  1902 . 
         [0094]    In the illustrated embodiment, the envelope contains a single item wound dressing  1901 . According to one embodiment, the wound dressing  1901  is substantially as shown and described in relation to  FIG. 1 . 
         [0095]      FIG. 20A  shows a portion of a further embodiment of the invention including a wound dressing package  2000  having a notch  2001  at an edge thereof. The notch  2001  is adapted to facilitate opening of the wound dressing package  2000  by tearing. 
         [0096]      FIG. 20B  shows a portion of another embodiment of the invention including a wound dressing package  2010 . In the illustrated embodiment, the wound dressing package  2010  includes a zipper device  2012  having a coupling portion  2014  and a tab portion  2016 . The tab portion is drawn along a longitudinal axis of the coupling portion to release a wound dressing disposed within the package  2010 . In another embodiment, the zipper device is replaced by a ripcord device. 
         [0097]    In certain embodiments, the invention includes applying a dressing as described above in combination with modulated pulse wave ultrasonics. In other embodiments, a wound surface is pre-saturated with sterile water. In still other embodiments, vacuum pulse or hyperbaric conditions are applied in conjunction with a dressing as described above. In still further embodiment of the invention, an electric field is applied in conjunction with a dressing as described above. 
         [0098]    While the exemplary embodiments described above have been chosen primarily from the field of emergency trauma wound dressings, one of skill in the art will appreciate that the principles of the invention are equally well applied, and that the benefits of the present invention are equally well realized in a wide variety of other dressing systems including, for example, postsurgical dressing systems. Further, while the invention has been described in detail in connection with the presently preferred embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.