GB2092006A

GB2092006A - Germicidal dressing

Info

Publication number: GB2092006A
Application number: GB8202416A
Authority: GB
Original assignee: Landstingens Inkopscentral LIC
Current assignee: Landstingens Inkopscentral LIC
Priority date: 1981-02-04
Filing date: 1982-01-28
Publication date: 1982-08-11
Also published as: DE3203225A1; DK45782A; NL8200404A; NO820324L

Abstract

A germicidal wound or burn dressing comprises an absorbent pad (2) within a thin permeable jacket (1, 4). On the side of the dressing which, in use, is placed against the wound or burn, the jacket is formed of a non-absorbent liquid-permeable sheet (1) which is coated with metallic copper or a copper compound. The coating of metallic copper or of a copper compound protects the wound or burn against the bodies own bacteria and against airborne bacteria without tending to cause the creation of resistant strains of bacteria as tends to happen with some other germicidal agents. <IMAGE>

Description

SPECIFICATION Germidical dressing The present invention relates to germicidal dressings which comprise an absorbent pad and a thin permeable jacket surrounding the pad.

One of the greatest problems in medical care is protecting a wound or surgical incision against infection by the body's own bacteria or airborne bacteria to allow rapid healing without complications. To overcome this problem, germicidal agents are used. Germicidal wound preparations, however, generally have the disadvantage that after a relatively short period of use, they give rise to resistant strains of bacteria.

The purpose of the present invention is to provide a dressing which is able to protect a wound or incision against the body's own bacteria and against bacteria penetrating through the dressing, but which does not give rise to the creation of resistant strains of bacteria.

To this end, according to this invention we provide a germicidal dresssing comprising an absorbent pad and a thin liquid and/or vapour-permeable jacket surrounding the pad, wherein the jacket, on the side of the dressing which, in use, is placed against the wound, consists of a non-absorbent liquid-permeable sheet coated with copper, silver, or gold in the form of metal or a compound.

The reaction of any of these metals destroys both the bacteria themselves and their building blocks in the form of riboses. This makes the creation of DNA and RNA, required for bacterial mitosis, impossible.

Preferably metallicopper is used. The copper-coated sheet may consist of a conventional woven or non-woven fabric of polyester, polyamide, polyurethane, polyethylene, polypropylene or cellulose triacetate, or of a perforated film of polyester, polyamide, polyurethane, polyethylene, polypropylene or cellulose acetate butyrate.

Thus the dressing has a thin, copper-coated layer of material which is permeable to wound secretion, so that the secretion can be absorbed in the absorbent material, e.g. fluffed cellulose, cotton or rayon wadding, lying behind it. This provides exceptional germicidal protection. The tendency of the dressing to stick to the wound is reduced appreciably if the copper-coated sheet is itself non-absorbent, consisting of a synthetic material. The material must not of course contain toxic, allergenic or pyrogenic substances.

The invention will now be described in more detail by the following example and with reference to the accompanying drawing, which shows a cross section through an exam ple of a dressing in accordance with the invention.

Example.

Tests were performed with small metallic copper-coated beads in the proportion of 1 ml of glass beads to 1 ml of soya bouillon, which was inoculated with 1010 organisms of Staph.

aureaus per ml of bouillon. After 24 hours the bacteria were entirely dead. This is of great significance, since it is these very staphylococci which cause the formation of pus in the wounds.

Other in-vitro tests with copper acetate in cultures of coli, pseudomonas, proteus and klebsiella in a concentration of 106 to 107 organisms per ml of bouillon were performed.

They showed that total killing of the bacteria was obtained within 24 hours with a copper concentration of 150-250 micrograms per ml of inoculated soya bouillon. The required amount of copper is dependent on the type and strain of bacteria and the number of microorganisms per ml.

The example of the dressing in accordance with the invention as shown in the drawing comprises a thin permeable sheet 1 of socalled spun-bonded polyamide fibres, e.g.

Monsanto's "Cerex" with a surface weight of 11 g/m2, coated with 300 to 500 micrograms of copper per cm2, the sheet 1 being on the side of the dressing which is to face a wound. On this copper-coated sheet there is an absorbent pad 2, which consists of a powerfully absorbent material, e.g. fluffed cellulose fibre, or cotton or rayon wadding, or several layers of cellulose wadding or tissue paper. Since dressings are often used on heavily secreting wounds, it is desirable to place a liquid-impermeable but vapour-permeable blocking layer 3 above the absorbent pad 2 to prevent wound secretion from penetrating through the top side of the dressing, but allowing moisture to evaporate unimpeded.

The blocking layer can consist of a wet-strong tissue with a surface weight of about 30 g/m2, which has been impregnated with a liquid-resisting agent. Outside the blocking layer, a strong, water vapour-permeable backing sheet 4 is placed, e.g. a non-woven layer, which forms the back of the dressing. The side edges of the copper-coated sheet 1 and of the backing sheet of the dressing are joined by means of an adhesive, by fusing, or by some other known method to form of jacket.

The width of the two sheets 1 and 4 is made 20-25 mm greater than the width of the absorbent pad 2. If all of the materials included in the dressing are used in the form of continuous webs, dressings of suitable lengths can be formed by directly cutting a length from the webs which have been bonded together. The ends of the jacket of the dressing are then open. If the absorbent pad 2 and the blocking layer 3 are instead placed between the webs 1 and 4 in the form of fitted pieces with spaces between the separate pieces, suitably 20-25 mm, cross sealing of the webs 1 and 4 can be effected in the same manner as along the sides of the webs thus producing dressings having jackets sealed on all sides.

In bad burn wounds inter alia, partially burned bits of tissue are aften present and, if these are not removed, can give rise to toxic substances. This can delay healing. With a dressing in accordance with the invention, it is possible to provide the copper-coated surface with a thin layer of the protein-decomposing enzyme Trypsin, which rapidly converts the bits of tissue into harmless amino acids.

Both such a burn dressing and a dressing for heavily secreting wounds such as leg wounds can provide increased healing effect by coating the wound-adjacent surface of the dressing with a tissue astringent, which reduces wound secretion. Suitable astringents are organic aluminium salts such as basic aluminium acetate, aluminium oleate or an addition product of such an aluminium salt and tannin.

Claims

1. A germicidal dressing comprising an absorbent pad and a thin liquid and/or vapour-permeable jacket surrounding the pad, wherein the jacket, on the side of the dressing which, in use, is placed against the wound, consists of a non-absorbent liquid-permeable sheet coated with metallic copper or a copper compound.

2. A dressing according to Claim 1, in which the copper-coated sheet consists of a conventional woven or non-woven fabric of polyester, polyamide, polyurethane, polyethylene, polypropylene or cellulose triacetate.

3. A dressing according to Claim 1, in which the copper-coated sheet consists of a perforated film of polyester, polyamide, polyurethane, polyethylene, polypropylene or cellulose acetate butyrate.

4. A dressing according to any one of Claims 1 to 3, in which the surface of the dressing, which, in use, is placed against the wound, is provided with a protein-decomposing enzyme.

5. A dressing according to Claim 4, in which the enzyme is trypsin.

6. A dressing according to any one of Claims 1 to 5, in which the surface of the dressing which, in use, is placed against the wound, is provided with a tissue astringent consisting of an organic aluminium salt.

7. A dressing according to Claim 6, in which the tissue astringent is basic aluminium acetate, aluminium oleate or an addition product of an aluminium salt and tannin.

8. A dressing according to Claim 1, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.