Absorbent wound dressing for wrapping around jointed limbs

Abstract

A non-adhesive absorbent wound dressing (10) is suitable for application about a jointed limb. The wound dressing (10) has a first portion (20) adapted to conform to and wrap around an upper part of the limb, a second portion (30) adapted to conform to and wrap around a lower part of the limb, and a hinge portion (40) between said first portion (20) and said second portion (30), said hinge portion (40) in use lying adjacent to the joint of the limb. The wound dressing (10) also comprises a porous wound contact sheet (80) and a substantially liquid-impermeable backing sheet (90), the wound contact sheet (80) and the backing sheet (90) being bounded (50) together at their periphery and along lines that define a plurality of pockets (60) in both the first portion (20) and the second portion (30), the pockets (60) containing absorbent material (70).

Claims

1. A non-adhesive absorbent wound dressing for application about a jointed limb, the wound dressing having a first portion adapted to conform to and wrap around an upper part of the limb, a second portion adapted to conform to and wrap around a lower part of the limb, and a hinge portion between said first portion and said second portion, said hinge portion in use lying adjacent to the joint of the limb; wherein the dressing comprises a porous wound contact sheet and a substantially liquid-impermeable backing sheet, the wound contact sheet and the backing sheet being bonded together at their periphery and along lines that define a plurality of pockets in both the first portion and the second portion, the pockets (i) containing a superabsorbent material and (ii) being located across substantially the entire surface of the wound contact sheet; and wherein the hinge portion between the first and second portions comprises a bonded area which extends across the dressing, from one point on a perimeter of the dressing to another, and wherein the hinge portion is of lesser width than the first portion and the second portion.

2. An absorbent wound dressing according to claim 1, wherein the wound contact sheet comprises a woven or non-woven fabric.

3. An absorbent wound dressing according to claim 1, wherein the wound contact sheet is formed with a regular array of perforations across its full extent.

4. An absorbent wound dressing according to claim 3, wherein the perforations have a size of from 50 μm to 10 mm.

5. An absorbent wound dressing according to claim 3, wherein the perforations have a size of from 0.1 mm to 1.5 mm.

6. An absorbent wound dressing according to claim 1, wherein the backing sheet is vapour permeable.

7. An absorbent wound dressing according to claim 1, wherein the backing sheet comprises a film of plastics material, such as polyurethane or polyethylene.

8. An absorbent wound dressing according to claim 1, wherein the materials of the wound contact sheet and the backing sheet include a fusible component so that bonds can be formed by the application of heat and pressure.

9. An absorbent wound dressing according to claim 1, wherein the bonding is by adhesive or stitching.

10. An absorbent wound dressing according to claim 1, wherein the absorbent material is formed into a sheet, mat or pad.

11. An absorbent wound dressing according to claim 10, wherein the sheet, mat or pad of absorbent material is shaped and dimensioned such that it occupies substantially the whole of the pocket within which it is contained.

12. An absorbent wound dressing according to claim 1, wherein the absorbent material absorbs up to 200, 400, or 500 times or more its weight of fluid.

13. An absorbent wound dressing according to claim 1, wherein the superabsorbent material is selected from one or more polyacrylates, polyacrylamide copolymers, ethylene maleic anhydride copolymers, cross-linked carboxymethylcellulose, polyvinylalcohol copolymers, cross-linked polyethylene oxides, starch-grafted copolymers of polyacrylonitrile, and alginates.

14. An absorbent wound dressing according to claim 13, wherein the superabsorbent material is calcium alginate or sodium alginate.

15. An absorbent wound dressing according to claim 10, wherein the sheet, mat or pad is formed from a material that acts as a carrier for superabsorbent material.

16. An absorbent wound dressing according to claim 1, wherein the first and second portions each comprise at least three pockets.

17. An absorbent wound dressing according to claim 1, wherein the first and second portions each comprise no more than ten pockets.

18. An absorbent wound dressing according to claim 1, wherein the first and second portions differ in size and comprise differing numbers of pockets.

19. An absorbent wound dressing according to claim 1, wherein the areas of the first and second portions are in a ratio of less than 3:1.

20. An absorbent wound dressing according to claim 1, wherein the areas of the first and second portions are in a ratio of greater than 3:1.

21. An absorbent wound dressing according to claim 1, wherein the width of the hinge portion is up to 75% of that of the first and/or the second portion.

22. A wound dressing according to claim 1 which further comprises a carbonised deodoriser or an anti-microbial material.

23. A wound dressing according to claim 22, wherein the anti-microbial material is silver.

24. A wound dressing according to claim 1, for application about a knee joint.

25. A wound dressing according to claim 1, for application about an elbow joint.

26. A wound dressing according to claim 1, for application about a wrist joint.

Description

(1) The present invention will now be described in greater detail, by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 shows a plan view of a dressing according to the invention, and

(3) FIG. 2 shows, schematically and not to scale, a cross-sectional view on line “c-c” in FIG. 1.

(4) Referring first to FIG. 1, an embodiment of the absorbent dressing according to the invention is shown and is generally designated 10. In this particular example the dressing has a shape suitable for application to the lower leg and foot, around an ankle joint.

(5) The first portion of the dressing according to the invention is that generally designated 20. The second portion of the dressing according to the invention is that generally designated 30. A hinge portion 40 is positioned between the first and second portions 20, 30.

(6) The dressing 10 comprises a wound contact sheet 80, absorbent material 70 and a backing sheet 90, as shown in FIG. 2 which is cross-sectional view on line c-c in FIG. 1. The wound contact sheet 80 is formed of a non-woven blend of polyester and viscose, perforated across its whole extent with perforations of approximate size 1 mm. The backing sheet is a liquid-impermeable but vapour-permeable polyethylene film. The absorbent material 70 comprises a mechanically bonded cellulose pad containing particles of superabsorbent polymer.

(7) The backing sheet 90 and the wound contact sheet 80 have the same overall shape and dimensions, and are superimposed on top of one another and bonded at the perimeter of the dressing and at a number of other positions within the periphery of the dressing, as indicated by the bonds 50. The bonds 50 are created by the application of heat and pressure, and define pockets 60. Each pocket contains absorbent material 70 which substantially fills each pocket 60. As can be seen from FIG. 1, the dressing 10 is symmetrical about its centre line (vertical as depicted in FIG. 1), the sides (denoted A and B) of each of the first and second portions 20,30 being formed as a pair of wings that can be wrapped around a limb to which the dressing is applied.

(8) In the illustrated embodiment, the first portion 20 is formed with seven pockets 60, and the second portion with five pockets 60. Compartmentalisation of the first and second portions 20,30 into discrete pockets 60 is beneficial in that the absorbent material contained within each pocket 60 is less liable to slumping, which reduces the frequency with which the dressing must be changed, as well as improving its conformability and comfort for the patient.

(9) The wound contact sheet 80 is permeable to fluid and is in contact with the wound. As such, the wound contact sheet 80 is able to transport wound exudate to the absorbent 70. The absorbent 70 may absorb many times, eg several hundred times, its own weight in wound exudate. The backing sheet 90 is impermeable to fluid and permeable to vapour, so that wound exudate is retained within the dressing 10 whilst vapour is allowed to escape. The materials of the dressing 10 are flexible and therefore the dressing 10 can be adapted to conform to and wrap around a jointed limb.

(10) The embodiment of the dressing 10 depicted in the drawings is dimensioned and configured for application to a patient's lower leg and foot. In use, the dressing 10 is positioned such that the hinge portion 40 is located adjacent the patient's heel. The wings of the first portion 20 are then wrapped around the patient's lower leg (calf) and overlapped, and the wings of the second portion 30 are wrapped around the patient's foot and overlapped. The dressing 10 may then be secured by means of surgical tapes or the like. In alternative embodiments, the dressing itself may incorporate suitable fastenings, such as hook-and-loop or adhesive fasteners.

(11) Use of the Dressing According to the Invention in Clinical Practice

(12) A 44-year old man was chosen as the subject of the clinical study. He was admitted to the medical unit generally very unwell and was suffering from liver failure, cardiac myopathy, and renal failure. His lower limbs were grossly oedematous and the skin had begun to beak down in the week prior to admission. He presented with superficial ulceration to both legs which were heavily contaminated with Pseudomonas. Both limbs, from the level of the knees down, were leaking copious amounts of fluid, both from the ulcer beds and the skin pores. This leakage was causing maceration, increasing ulcer size and excruciating pain to the man.

(13) A first line treatment was employed to combat the Pseudomonas infection but this was increasingly difficult due to the deteriorating medical condition of the patient and the fact that he was unable to tolerate most dressing/topical treatments or compression due to the levels of pain experienced. The aim of the initial management therefore was to promote comfort while preventing further maceration and subsequent ulcer expansion.

(14) Initially, foam dressings were used, but these were unable to hold the copious amounts of fluid being expressed and required changing two or three times a day. At this point the patient remained in severe pain and the ulcer beds were increasing in size. The combination of pain and his bandages dripping within an hour of each dressing change had a considerable negative impact on the quality of life of the patient, and he found that mobilisation was impossible. A dressing according to the invention generally taking the form of the embodiment depicted in FIGS. 1 and 2 was applied and within two days the nurses reported a reduction in dressing change frequency to only once a day. They also reported that the dressing held all the exudate, with strike-through being seen only after 24 hours. Furthermore the dressings were very easy to use and dressing changes were mostly pain free.

(15) Within five days of commencing treatment with the dressing, there was no further evidence of maceration and the ulcer edges had stopped advancing. The patient reported a significant reduction in pain levels. As the dressing was holding all the exudate, he was able to mobilise without the embarrassment and discomfort of wet bandages.