Dressings and methods for treating a tissue site on a patient

• US 8,604,265 B2
• Filed: 04/12/2011
• Issued: 12/10/2013
• Est. Priority Date: 04/16/2010
• Status: Active Grant

• Current Assignee: Solventum Intellectual Properties Company (Solventum Corp.)
• Original Assignee: KCI Licensing Incorporated (3M Company)
• Inventors: Locke, Christopher Brian, Robinson, Timothy Mark, Tout, Aidan Marcus
• Primary Examiner(s): Brown, Michael A.
• Application Number:
  US13/084,813
• Publication Number:
  US 20110257572A1
• Time in Patent Office: 973 Days
• Field of Search: 602 41- 54
• US Class Current: 602/41
• CPC Class Codes: A61F 13/00063 comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00
• CPC Class Codes: A61F 13/02 Adhesive bandages or dressings
• CPC Class Codes: A61F 13/0206 with absorbent fibrous layers, e.g. woven or non-woven absorbent pads or island dressings
• CPC Class Codes: A61F 13/0223 characterized by parametric properties of the fluid retention layer, e.g. absorbency, wicking capacity, liquid distribution
• CPC Class Codes: A61F 13/0226 characterised by the support layer
• CPC Class Codes: A61F 13/0266 especially adapted for wound covering/occlusive dressings
• CPC Class Codes: A61F 13/05 specially adapted for use with sub-pressure or over-pressure therapy, wound drainage or wound irrigation, e.g. for use with negative-pressure wound therapy [NPWT]
• CPC Class Codes: A61F 2013/00119 elastic
• CPC Class Codes: A61F 2013/00246 in a special way pervious to air or vapours
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61F 2013/0074 containing foams
• CPC Class Codes: A61M 1/60 Containers for suction drainage, adapted to be used with an external suction source containers not adapted for subjection to vacuum A61M1/69
• CPC Class Codes: A61M 1/64 Containers with integrated suction means containers not adapted for subjection to vacuum A61M1/69
• CPC Class Codes: A61M 1/71 Suction drainage systems containers therefor A61M1/60, A61M1/64; negative pressure wound therapy systems A61M1/90
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 1/784 by filtering, sterilising or disinfecting the exhaust air, e.g. swellable filter valves
• CPC Class Codes: A61M 1/80 Suction pumps A61M1/64, A61M1/71, A61M60/00 take precedence
• CPC Class Codes: A61M 1/85 with gas or fluid supply means, e.g. for supplying rinsing fluids or anticoagulants for negative pressure wound therapy A61M1/92, A61M1/94; combined with tracheal tubes A61M16/0463; dental instruments with combined rinsing and aspirating A61C17/0208
• CPC Class Codes: A61M 1/884 Draining devices provided with means for filtering out the harmless water content before discarding the drainage container
• CPC Class Codes: A61M 1/94 : with gas supply means
• CPC Class Codes: A61M 1/962 : having pumping means on the suction site, e.g. miniature pump on dressing or dressing capable of exerting suction
• CPC Class Codes: A61M 1/964 : having venting means on or near the dressing
• CPC Class Codes: A61M 1/98 : Containers specifically adapted for negative pressure wound therapy
• CPC Class Codes: A61M 1/985 : the dressing itself forming the collection container
• CPC Class Codes: A61M 2205/7527 : liquophilic, hydrophilic
• CPC Class Codes: A61M 2205/7536 : allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes

Abstract

Dressings, systems, and methods for treating a tissue site on a patient involve allowing liquids from the tissue site or a priming fluid to evaporate and exit the dressing through a liquid-impermeable, vapor-permeable membrane. The dressing is able to process more liquids than would otherwise be possible without evaporation and potentially to create reduced pressure. Other dressings, systems, and methods are disclosed.

Claims

1. A dressing for treating a tissue site on a patient, the dressing comprising:

a wound interface member for placing proximate to the tissue site;

a covering, wherein at least a portion of the covering comprises an evaporative window having a liquid-impermeable, vapor-permeable membrane;

a removable release layer that is releasably attached at least over the evaporative window, wherein the removable release layer comprises a fluid barrier;

wherein the covering is operable to form a sealed space over the tissue site; and

wherein the liquid-impermeable, vapor-permeable membrane allows liquids in the sealed space that have evaporated to egress the sealed space.

2. The dressing of claim 1, wherein the dressing is not in fluid communication with an external source of reduced pressure.

3. The dressing of claim 1, further comprising a one-way valve coupled to the covering that allows fluid in the sealed space to egress when the covering is moved toward the tissue site.

4. The dressing of claim 1, further comprising a pressure-regulating valve coupled to the covering for allowing ambient air into the sealed space to keep the pressure in the sealed space from exceeding a maximum value.

5. The dressing of claim 1, further comprising an absorbent layer for receiving and storing liquids from the tissue site, the absorbent layer disposed between the wound interface member and the covering.

6. The dressing of claim 5, further comprising a priming fluid in the absorbent layer.

7. The dressing of claim 1, further comprising a container storing priming fluid.

8. The dressing of claim 1, wherein the evaporative window comprises a plurality of apertures in the covering that are covered by the liquid-impermeable, vapor-permeable membrane.

9. The dressing of claim 1, wherein the wound interface member comprises a foam member.

10. The dressing of claim 1, wherein the wound interface comprises a foam member and further comprising a biasing member disposed around the foam member.

11. The dressing of claim 10, wherein the biasing member comprises bellows around the foam member.

12. The dressing of claim 1, wherein the evaporative window is defined by an area of the covering that is free of adhesive.

13. The dressing of claim 1, wherein the covering comprises a drape material having an adhesive on a portion thereof and the liquid-impermeable, vapor-permeable membrane comprises the area of the drape material substantially free of adhesive.

14. The dressing of claim 1, further comprising a forced-air device associated with the covering that forces air across the liquid-impermeable, vapor-permeable membrane.

15. The dressing of claim 14, wherein the forced-air device comprises a piezoelectric pump and further comprising flexible baffling adapted to direct air to or from the piezoelectric pump across the liquid-impermeable, vapor-permeable membrane.

16. A method for treating a tissue site with a reduced pressure, the method comprising:

deploying a foam member proximate to the tissue site;

covering the foam member with a covering having an evaporative window, wherein the evaporative window comprises a liquid-impermeable, vapor-permeable membrane, the covering forming a sealed space over the foam member;

removing a removable release layer that is releasably attached at least over the evaporative window, wherein the removable release layer comprises a fluid barrier; and

allowing liquids from the tissue site to evaporate and to egress the sealed space through the liquid-impermeable, vapor-permeable membrane.

17. The method of claim 16, wherein the step of allowing liquids from the tissue site to evaporate and to egress further comprises creating a reduced pressure in the sealed space by the evaporation.

18. The method of claim 16, wherein the covering comprises a drape material having an adhesive and the liquid-impermeable, vapor-permeable membrane comprises the drape material without adhesive.

19. The method of claim 16, wherein no external reduced pressure is applied to the sealed space and wherein a reduced pressure is created in the sealed space.

20. The method of claim 16, wherein:

the step of deploying the foam comprises deploying a foam containing a priming fluid; and

the step of allowing the liquids from the tissue site to evaporate comprises allowing the liquids from the tissue site and priming fluid to evaporate.

21. The method of claim 16, wherein a one-way valve is associated with the covering and further comprising the step the depressing the foam member to remove air through the one-way valve from the sealed space.

22. The method of claim 16, further comprising fluidly coupling a pressure-regulating valve to the covering and wherein the pressure-regulating valve is operable to open at a maximum value of reduced pressure.

23. The method of claim 16, wherein the liquid-impermeable, vapor-permeable membrane is covered by a removable release liner and further comprising the step of removing the removable release liner.

24. The method of claim 16, further comprising:

disposing a container storing a priming fluid between the covering and the foam member and pressing on the container to rupture the container to allow the priming fluid to be released in the sealed space.

25. The method of claim 16, further comprising forcing air across the liquid-impermeable, vapor-permeable membrane with a forced-air device.