WO2005067837A1

WO2005067837A1 - Dressing pad

Info

Publication number: WO2005067837A1
Application number: PCT/GB2005/000089
Authority: WO
Inventors: Graham Cheslyn-Curtis
Original assignee: Graham Cheslyn-Curtis
Priority date: 2004-01-14
Filing date: 2005-01-14
Publication date: 2005-07-28
Also published as: GB0400772D0

Abstract

A dressing pad for use as a 'dry' dressing or as poultice when wet. The dressing pad has front and rear major surfaces whereof the front surface in a skin contacting surface when the dressing pad is applied, the dressing pad comprises (i) an inner absorbent cushioning pad having a poulticing action when wet, (ii) an outer fabric envelope completely enclosing the cushioning pad, and (iii) a thermally insulating membrane of a liquid impermeable material provided between the rear side of the pad and the envelope. The dressing pad may be used in combination with a bag capable of holding liquid (e.g. of plastics material) marked with at least one graduation line which indicates the level to which the bag should be flled with liquid for 'wetting' the dressing pad. This ensures that the required amount of liquid has been retained within the 'wet' dressing. The aforementioned bag may also be used in combination with any form of poultice to ensure the required level of liquid retention.

Description

DRESSING PAD

The present invention relates to a dressing pad for application to the skin for the treatment of injuries either to the skin or underlying tissue. The invention relates more particularly (but not exclusively) to such a dressing pad that is intended for veterinary use, e.g. for application to the limbs of horses or other large mammals, either as a "dry" dressing or wetted to provide a poultice.

According to a first aspect of the present invention there is provided a dressing pad having front and rear major surfaces whereof the front surface is a skin contacting surface when the dressing pad is applied, the dressing pad comprising (i) an inner absorbent cushioning pad having a poulticing action when wet, (ii) an outer fabric envelope completely enclosing the cushioning pad, and (iii) a thermally insulating membrane of a liquid impermeable material provided between the rear side of the cushioning pad and the envelope.

The dressing pad of the present invention may be used dry as a wound dressing, e.g. applied to a cut or other lesion in the skin of an animal, whereby wound exudate becomes absorbed into the dressing and retained therein by the absorbent pad. Alternatively the dressing pad may be used wet as a poultice where a drawing action is required, e.g. for absorbing and holding away pus or infected secretions.

The all-enclosing envelope assists in eliminating entry of contamination and retaining fluids within the pad. Most preferably the all-enclosing envelope is of a non-woven fabric, most preferably one having low adherent properties so as to prevent damage to wounds on removal of the dressing pad and protecting sensitive skin conditions. A non-woven material allows the passage of moisture and exudates from the exterior to interior of the dressing pad . Typically the outer envelope will have a basis weight of 15 to 80 gsm. A particular suitable material is Grade HX 20 Polyester (20g gsm, colour natural, thickness 0.233 (E)) or Grade HDN40 Polyester (40gsm, colour natural, thicknessθ.399 (E)) manufactured by BFF NonWoven, Bridgewater, Somerset.

The inner cushioning pad, which will generally have a basis weight of 100- 600 gsm (preferably about 400 gsm), acts as a cushioning protective layer and may for example be of cotton wool or other absorbent fibres e.g. formed in several layers. BP grade pure cotton wool is particularly suitable. The pad may be of, or incorporate, a super-absorbent material, e.g. sodium carboxymethyl cellulose in fine granular form. Such a super-absorbent material is particularly effective for "poulticing" applications since when wet it helps draw out abscesses, pus and dirt. Additionally the super-absorbent material forms a gel within the cushioning pad when hydrated and this enhances the dressing pad's thermal retention properties. The super-absorbent material also has advantages when the dressing pad is used dry as a wound dressing since it enhances retention of wound exudates.

The dressing may incorporate 50 to 100 grams of super-absorbent material (e.g. sodium carboxymethyl cellulose) per square metre of pad area, preferably 70-80 grams and more preferably about 75 grams on the same basis.

The cushioning pad may incorporate salt which when dissolved in water (e.g. in a "poulticing" application of the pad) forms a saline solution which enhances the poulticing properties as well as providing cleansing, healing and tissue stimulating properties. The amount of salt (sodium chloride) may for example be 30 to 70 grams per square metre of pad area, more preferably 40-60 and most preferably about 50 grams on the same basis.

The cushioned pad may also incorporate boric acid, preferably in an amount to 5 to 20 grams per square metre of pad area, more preferably 10 to 15 and most preferably about 12.5 grams on the same basis.

Preferably the cushioning pad incorporates all of the super-absorbent material (e.g. sodium carboxymethyl cellulose), salt and boric acid. Alternatively or additionally the super-absorbent material may incorporate an encapsulated liquid that can be released by applying external pressure to the dressing pad to burst the membrane retaining the liquid. Such an encapsulated liquid may, for example, be a medicament. Alternatively or additionally, the cushioning pad may incorporate pharmaceutical agents for delivery to the treatment site.

The thermally insulating layer prevents leakage through the dressing pad of blood or exudates and assists in reducing evaporation so as to improve heat or cold retention. The membrane preferably has a thickness of 1-10 mm (e.g. about 1.5 mm). The membrane may be of a foamed plastics material and may for example be a layer of polyethylene foam. Such a foam material is particularly suitable because it allows the dressing pad to be heated in a microwave oven before application to the skin of an animal patient to be treated. It is however also possible for the liquid impermeable, thermally insulating layer to be comprised of a thin plastics metal foil reflective laminate, e.g. silver or gold "space blanket" type materials that thermally insulate by reflection. Such a foil may be metallic and, whilst providing the necessary thermal insulting properties, will not allow the dressing pad to be heated in a microwave oven. A further possibility is for the thermally insulating membrane to comprise a layer of foamed plastics material (e.g. polyethylene foam) laminated to a plastics metal foil reflective laminate.

Preferably the dressing pad in accordance with the invention additionally comprises a layer of a piled fabric located between the front side of the cushioning pad and the envelope preferably with the pile of the fabric being in contact with the cushioning pad.

The fabric layer with the piled surface may be one having a random (e.g. "fluffy") pile or "nap" and may be lint or a lint-like material (BP Codex 1973 states that lint consists of a cotton cloth of plain weave, on one side of which the nap has been raised from the warp yarns). White absorbent surgical Lint BP is particularly preferred. The layer with the piled surface provides strength and ease of handling when used wet as well as absorbing and holding away pus or infection secretions. Typically this fabric layer will have a basis weight of 150-250 gsm (preferably about 185 gsm).

The outer fabric envelope may be sealed along the reverse phase of the dressing and at the side edges thereof. In this case, the dressing pad has three seals. A further possibility would be for the outer envelope to be formed with four seals, i.e. one along each edge of the dressing.

As indicated above, the dressing pad may be used "dry" as a wound dressing, in which case the dressing pad is applied to the afflicted area and located in position, e.g. with a bandage.

Alternatively the dressing pad may be used "wet" as a poultice. For this purpose, the dressing pad may be immersed in a container of liquid (e.g. water or aqueous solution) at the desired temperature and then squeezed to remove excess liquid. This procedure does however have the disadvantage that it is difficult to ensure that the correct amount of liquid has been retained within the "wet" dressing. In order to overcome this disadvantage, and in an advantageous embodiment of the present invention, the dressing pad is supplied together with a bag capable of holding liquid (e.g. of plastics material) marked with at least one graduation line which indicates the level to which the bag should be filled with liquid for "wetting" the dressing pad.

This is an important feature of the present invention in its own right and leads to a second aspect of the invention according to which there is provided the combination of a dressing pad capable of being treated with liquid (e.g. water or an aqueous solution) to provide a poultice and a bag capable of holding liquid marked with at least one graduation line indicating a level to which the bag is to filled with liquid for "wetting" the dressing pad.

Most preferably the bag is transparent and is most preferably of a plastics material. Preferably also the bag is provided at or adjacent to its mouth with a closure (e.g. providing a seal). The closure may be of the type formed (on one interior surface of the bag) with a rib and, on the other interior surface with a channel into which the rib removably locates to seal the bag. Alternatively there may be more than one rib and channel. A further possibility is a bag incorporating a plastics "zipper" closure.

The bag may have a single graduation line. Alternatively, the bag may be one produced for supply with dressing pads of different sizes, in which case the bag may have a plurality of graduation lines, each for a different size of dressing pad (since such different size will require a different amount of liquid). hi use, the bag is filled with liquid (e.g. water or aqueous solution) to the (appropriate) graduation line. The dressing pad is then put into the bag (which may now be sealed) and the assembly squeezed as necessary to "work" the liquid into the dressing pad to provide for even hydration throughout.

The dressing pad employed in the second aspect of the invention may be in accordance with the first aspect of the invention. However the second aspect of the invention is applicable to any other dressing pad that is intended to be hydrated to form a poultice.

The invention will be further described by way of example only with reference to the accompanying drawings, in which:

Fig 1 is a cut-away perspective view of one embodiment of dressing pad in accordance with the invention as viewed from the rear surface thereof;

Fig 2 is a fragmentary sectional view on the line A-A in Fig 1 ; and

Fig 3 illustrates a bag for use in impregnating the dressing of Fig 1 with a predetermined quantity of water.

Referring to Fig 1, the illustrated dressing pad 1 is rectangular and is shown with its front surface (i.e. the skin-contacting surface in use) lowermost and the rear surface uppermost. The dressing pad 1 comprises an outer envelope 2 of a low adherent non- woven fabric completely enclosing a cushioning pad 3, a layer of Lint 4 and a thermally insulting polyethylene foam layer 5. All of layers 3-5 are rectangular and are of substantially the same length and width.

Cushioning pad 3 is formed of layers of cotton wool incorporating fine granular sodium carboxymethyl cellulose (a natural plant derived poulticing and gelling agent) which provides the pad 3 with super-absorbent properties.

Provided between the cushioning pad 3 and the front of the dressing pad is the layer of white surgical Lint BP 4 having its side on which the nap has been raised from the warp yarns in contact with the cushioning pad 3.

Thermally insulating polyethylene foam layer 5 is liquid impermeable and is provided between the cushioning pad 3 and the rear of the dressing pad.

To construct the dressing pad 1, the low adherent non- woven fabric that forms envelope 2 is cut as a rectangle. This rectangle is of a length so as to be capable of being folded around the assembled layers 3-5. Additionally the rectangle of the low adherent non-woven fabric has a width which is slightly greater than the lengths of layers 3-5. The low adherent non-woven fabric is folded around layers 3-5 so that the widthwise edges of the fabric meet centrally of the rear face of the dressing and extend longitudinally thereof. The non-woven fabric material projects beyond each widthwise edge of the assembly of layers 3-5.

The non-woven fabric is sealed to itself at all of its mating edges (i.e. both longitudinally of the rear face of the dressing and along the widthwise edges thereof). Additionally a coloured line 6 is provided along those sealed edges of the non- woven fabric envelope that extend longitudinally along the rear face of the dressing pad. This coloured line 6 serves to identify the rear face of the dressing.

The envelope 2 and layers 3-5 provide properties for the dressing pad as discussed more fully above. The illustrated dressing pad may be used "dry" as a wound-dressing or "wet" as a poultice.

For dry use, the front surface of the (dry) dressing pad is applied to the affected area and retained in position by any suitable means, e.g. by means of a bandage.

For use as a poultice, the dressing pad is firstly impregnated with water or solution. This may be achieved simply by immersing the poultice in a bucket of water and squeezing out excess water, i.e. the technique conventionally used for hydrating poultices. However using this technique it is difficult to ensure that the poultice does not include either too much or too little water. For this purpose, the poultice is advantageously treated with water in a bag of the type illustrated in Fig 3.

Referring now to Fig 3, there is illustrated a clear plastics bag 10 having adjacent the mouth thereof a seal 11 of the type formed (on one interior surface of the bag) with a rib and, on the other interior surface, with a channel into which the rib removably locates to seal the bag. In an alternative embodiment, there may be more than one rib and channel. In a further alternative, the rib/channel seal may be replaced by a plastics "zipper" closure.

The bag is marked towards its top left hand corner with the words "Hold Here" and towards its bottom right hand corner is marked with a number of graduation lines designated as A-D.

Each such graduation line represents a level to which the bag is to be filled with water or solution for hydrating a dressing pad of a particular size.

It will be appreciated at this point that the dressing pad 1 and the bag 10 will be supplied as a packaged unit (i.e. both items included within an outer wrapping) with instructions indicating the level to which the bag is to be filled for hydrating a dressing pad of that size.

To hydrate the dressing pad, the bag is held (e.g. between the thumb and forefinger of one hand) at the location designated "Hold Here". With the bag held in this way, the lines designated A-D are generally horizontal. Water is now introduced into the bag 10 to the level of the appropriate line A-D. The dressing pad 10 is then put into the bag and the seal 11 closed. The bag and dressing pad may now be squeezed and manipulated to ensure that the dressing pad becomes uniformly hydrated with the water.

The dressing pad may now be removed from the bag although it should be appreciated that the dressing pad could be retained in the bag for later use.

It will also be appreciated that the water introduced into the bag will be at an appropriate temperature, e.g. cold or hot as required. Alternatively it may be reheated or cooled inside the bag within twelve hours of activation, e.g. as detailed on instructions provided with the bag.

Reference has been made above to supplying the dressing pad 1 and the bag 10 within an outer wrapping. It will be appreciated that it is also possible to supply a multi-pack product in which a plurality of the dressing pads 1 and a single bag 10 are provided within an outer wrapping since obviously the bag 10 is reusable.

Claims

1. A dressing pad having front and rear major surfaces whereof the front surface in a skin contacting surface when the dressing pad is applied, the dressing pad comprising (i) an inner absorbent cushioning pad having a poulticing action when wet, (ii) an outer fabric envelope completely enclosing the cushioning pad, and (iii) a thermally insulating membrane of a liquid impermeable material provided between the rear side of the pad and the envelope.

2. A dressing pad as claimed in claim 1 wherein the outer fabric envelope comprises a non-woven fabric.

3. A dressing pad as claimed in claim 2 wherein the non- woven fabric is one having low adherent properties.

4. A dressing pad as claimed in any one of claims 1 to 2 wherein the inner absorbent cushioning pad comprises cotton wool or other absorbent fibres.

5. A dressing pad as claimed in any one of claims 1 to 4 wherein the cushioning pad incorporates a super-absorbent material, e.g. sodium carboxymethyl cellulose.

6. A dressing pad as claimed in any one of claims 1 to 5 wherein the cushioning pad incorporates salt.

7. A dressing pad as claimed in any one of claims 1 to 6 wherein the cushioning pad incorporates boric acid.

8. A dressing pad as claimed in any one of claims 1 to 7 wherein the thermally insulating membrane is of a plastics foam.

9. A dressing pad as claimed in claim 8 wherein the plastics foam is polyethylene foam.

10. A dressing pad as claimed in any one of claims 1 to 9 additionally comprising a layer of a piled fabric located between the front side of the cushioning pad and the envelope with the pile of the fabric being in contact with the cushioning pad.

11. A dressing pad as claimed in claim 10 wherein the piled fabric is lint.

12. A dressing pad as claimed in any one of claims 1 to 9 wherein the outer fabric envelope is sealed along the reverse face of the dressing and at the side edges thereof.

13. A combination of a dressing pad as claimed in any one of claims 1 to 12 and a bag capable of holding liquid marked with at least one graduation line indicating a level to which the bag is to be filled with liquid for hydrating the dressing pad.

14. The combination of a dressing pad capable of being treated with liquid to provide a poultice and a bag capable of holding liquid marked with at least one graduation line indicating a level to which the bag is to be filled with liquid for hydrating the dressing pad.

15. The combination as claimed in claim 13 or 14 wherein the bag is transparent.

16. The combination as claimed in any of claims 13 to 15 wherein the bag is of plastics material.

17. The combination as claimed in any one of claims 13 to 16 wherein the bag is provided at or adjacent its mouth with a closure arrangement.

18. The combination as claimed in claim 17 wherein the seal is of the type formed with a rib on one interior surface of the bag and a channel into which the rib removably locates to seal the bag located on the other inner surface of the bag.