Multi-Layer Dressings, Systems, And Methods For Applying Reduced Pressure At A Tissue Site

Abstract

The illustrative systems, methods, and dressings for applying reduced pressure to a tissue site are presented that involve quickly removing fluids from the tissue site to reduce or avoid maceration of the epidermis. One dressing includes a dressing material for transferring the reduced pressure to the tissue site and a drape covering at least a portion of the dressing material. The dressing material includes a hydrophobic tissue-interface layer adapted to contact the tissue site. The dressing material also includes a manifold adapted to distribute reduced pressure. The manifold may be a hydrophobic layer. The dressing material also includes one or more absorbent layers adapted to absorb liquid from the tissue site via the tissue-interface layer and the manifold. Other aspects are disclosed.

We claim: 
     
         1 . A dressing material for treating a tissue site, the dressing material comprising
 a tissue-interface layer configured to permit a passage of a liquid from the tissue site, the tissue-interface layer being formed of a hydrophobic material, and   a first absorbent layer configured to absorb the liquid from the tissue site via the tissue-interface layer, the first absorbent layer being formed of a first hydrophilic material.   
     
     
         2 . The dressing material of  claim 1  further comprising a second absorbent layer configured to absorb the liquid from the tissue site via the first absorbent layer, the second absorbent layer being formed of a second hydrophilic material. 
     
     
         3 . The dressing material of  claim 2 , wherein the first hydrophilic material is more hydrophilic than the second hydrophilic material. 
     
     
         4 . The dressing material of  claim 2 , wherein the second absorbent layer is configured to have a greater absorptive capacity than the first absorbent layer. 
     
     
         5 . The dressing material of  claim 4 , wherein a thickness of the second absorbent layer is greater than a thickness of the first absorbent layer. 
     
     
         6 . The dressing material of  claim 4 , where a surface area of the second absorbent layer is greater than a surface area of the first absorbent layer. 
     
     
         7 . The dressing material of  claim 2 , wherein the second hydrophilic material is more hydrophilic than the first hydrophilic material. 
     
     
         8 . The dressing material of  claim 2 , wherein the first absorbent layer is configured to absorb the liquid from the tissue site at a faster rate than the second absorbent layer. 
     
     
         9 . The dressing material of  claim 8 , wherein a surface area of the first absorbent layer is greater than a surface area of the second absorbent layer. 
     
     
         10 . The dressing material of  claim 9 , where the second absorbent layer is configured to have a higher fluid storage capacity than the first absorbent layer. 
     
     
         11 . The dressing material of  claim 1 , wherein the hydrophobic material of the tissue-interface layer is a non-absorbent material. 
     
     
         12 . The dressing material of  claim 1 , wherein the hydrophobic material of the tissue-interface layer is non-adherent and course on a tissue-facing side. 
     
     
         13 . The dressing material of  claim 1 , wherein the hydrophobic material of the tissue-interface layer is configured as a scaffold on a tissue-facing side to support new cell-growth. 
     
     
         14 . The dressing material of  claim 1 , wherein the hydrophobic material of the tissue-interface layer is stretchable. 
     
     
         15 . The dressing material of  claim 1 , wherein a thickness of the hydrophobic material of the tissue-interface layer is less than a thickness of the first absorbent layer. 
     
     
         16 . The dressing material of  claim 1 , further comprising a manifold adapted to be positioned between the tissue-interface layer and the first absorbent layer, the manifold being formed of a hydrophobic material. 
     
     
         17 . The dressing material of  claim 16 , wherein the manifold is adapted to distribute the liquid uniformly across the manifold. 
     
     
         18 . The dressing material of  claim 16 , wherein the manifold is adapted to separate the liquid from the tissue-interface layer. 
     
     
         19 . The dressing material of  claim 16 , wherein the manifold is adapted to migrate the liquid radially outward towards edges of the manifold. 
     
     
         20 . The dressing material of  claim 1 , wherein at least a portion of the dressing material is configured to be covered by a drape. 
     
     
         21 . The dressing material of  claim 2 , further comprising a distribution manifold adapted to be positioned adjacent a non-tissue-facing side of the second absorbent layer and configured to distribute a reduced pressure uniformly across an entire surface of the second absorbent layer. 
     
     
         22 . The dressing material of  claim 21 , further comprising a hydrophobic filter adapted to be positioned adjacent a non-tissue facing side of the distribution manifold and configured to prevent a flow of exudate from the tissue site and allow a flow of gas and liquid from the tissue site. 
     
     
         23 . A system for applying a reduced pressure at a tissue site, the system comprising
 a reduced-pressure source for supplying reduced pressure;   a reduced-pressure delivery conduit for transferring reduced pressure; and   a dressing material for delivering reduced pressure at the tissue site and receiving a liquid from the tissue site;   wherein the reduced-pressure delivery conduit fluidly couples the reduced-pressure source and the dressing material, and   wherein the dressing material comprises:
 a tissue-interface layer configured to permit a passage of the liquid from the tissue site, the tissue-interface layer being formed of a hydrophobic material, and 
 a first absorbent layer configured to absorb the liquid from the tissue site via the tissue-interface layer, the first absorbent layer being formed of a first hydrophilic material. 
   
     
     
         24 . The system of  claim 23 , wherein the dressing material further comprises a second absorbent layer configured to absorb the liquid from the tissue site via the first absorbent layer, the second absorbent layer being formed of a second hydrophilic material. 
     
     
         25 . The system of  claim 24 , wherein the first hydrophilic material is more hydrophilic than the second hydrophilic material. 
     
     
         26 . The system of  claim 24 , wherein the first absorbent layer is configured to absorb the liquid from the tissue site at a faster rate than the second absorbent layer. 
     
     
         27 . The system of  claim 24 , wherein the second hydrophilic material is more hydrophilic than the first hydrophilic material. 
     
     
         28 . The system of  claim 24 , wherein the second absorbent layer is configured to have a greater absorptive capacity than the first absorbent layer.