WO2006040743A2

WO2006040743A2 - Device for treating an opening in the skin

Info

Publication number: WO2006040743A2
Application number: PCT/IB2005/053380
Authority: WO
Inventors: Jacobus Adriaan Albertus Kotzé; Ernst Richard Eiselen
Original assignee: Kotze Jacobus Adriaan Albertus; Ernst Richard Eiselen
Priority date: 2004-10-15
Filing date: 2005-10-14
Publication date: 2006-04-20
Also published as: WO2006040743A3

Abstract

This invention relates to a device for treating the interface between a wound (8.1) in the skin (8) of a patient and an intra- or transdermally extending elongate member in the form of a needle (12) of an indwelling central line intravenous catheter. The device (10) comprises a body (14) of separate porous inert ceramic particles (16) contained in a permeable container (18). The container (18) comprises a tea bag - like envelope of a suitable medically acceptable permeable fabric and defines an elongate slit (18.1) extending into the container (18) for receiving the needle (12), in use. The body (14) is thus generally U-shaped with the base (14.1) and arms (14.2) of the U providing formations for surrounding the wound (8.1) and the needle (12) when the latter is received in the slit (18.1), in use.

Description

DEVICE FOR TREATING AN OPENING IN THE SKIN

INTRODUCTION

This invention relates to a method and device for treating the interface between an opening in the skin of a patient and an intra - or transdermally extending elongate member.

BACKGROUND TO THE INVENTION

The use of central line intravenous catheters is common practice in intensive care settings. Colonisation by pathogenic bacteria of indwelling catheters is a common problem occurring in up to 40 % of the cases in this setting. The catheters are generally left in situ for a period of 7 days provided that the devices function properly during that time.

In some cases, colonisation may take place as quickly as within 24 h, leading to infection in the patient with serious and costly consequences. Various strategies have been employed in the past without much success to reduce the rate of colonisation. Among these are impregnation of the catheters with silver compounds and various anti-biotic substances in an effort to curb this problem. In the case of indwelling intra-venous catheters the bacterial "flash point" is at the interface between the needle and the outer periphery of the wound. At this interface pathogenic bacteria tend to contaminate or infect the wound and the surface of the needle. Contamination or/and infection of this nature has serious implications for patients requiring prolonged intravenous canulisation for fluid replacement, hyper-alimentation, medication and measuring of central venous pressures.

Bacterial resistance to antibiotics is on the increase, especially in hospitals and more so in intensive care units as a result of the nature of these institutions. Such resistance makes the treatment of infected wounds relatively more difficult.

It is known to cover the wound with gauze, but this known method is not effective in preventing or minimising infection of the wound.

USA patent number 6,833,486 discloses a wound treatment device for treating relatively large wounds.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a method and device for treating the interface between an opening in the skin of a patient and an intra- or transdermal^ extending elongate member with which the aforesaid problems and disadvantages can be overcome or at least minimised. It is another object of the invention to provide improvements to and modifications of the wound treatment device disclosed in US patent 6,833,486.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a device for treating the interface between an opening in the skin of a patient and an intra- or transdermal^ extending elongate member, the device comprising a body of separate porous ceramic particles contained in a permeable container, the body defining at least one formation for at least partially surrounding the said opening.

The container may comprise a tea bag - like envelope and the body may define a formation in the form of an elongate slit extending into the envelope for receiving the intra- or transdermally extending elongate member. The body of separate ceramic particles may be generally U-shaped with the j base and arms of the U adapted to surround the opening, as well as the intra- or transdermal^ extending elongate member on at least three sides when the latter is received in the slit, in use.

Alternatively, the body or separate ceramic particles may be elongate with opposite end portions of the body defining the formations for surrounding the opening by being wound about the elongate member flush with the skin.

Preferably the container is made from a medically acceptable permeable fabric. The ceramic particles may be inert.

The ceramic particles may have a porosity of between 25% and 85%, preferably 75%.

The pores of the particles may have diameters in the range of between 0.3 to 30 micrometers.

The pores may be cellular in nature.

The pores may be interconnected by blow-holes. The arrangement may be such that, in use, the pores of the ceramic particles apply a capillary suction force to the wound area, thus continuously draining fluid from the area.

The particles may be manufactured by pulverising an inert microporous ceramic body and removing fine powder from the particles.

The particles may have a diameter range of between 45 and 300 micrometers.

The intra- or transdermal^ extending elongate member may be selected from the group consisting of intravenous needles, indwelling central line intravenous catheters, and drainage tubes.

According to a second aspect of the invention there is provided a method for treating the interface between an opening in the skin of a patient and an intra- or transdermal^ extending elongate member, the method including the steps of at least partially surrounding the opening as well as the elongate member with a device according to the first aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described further by way of a non-limiting example with reference to the accompanying drawings wherein:

figure 1 is a perspective view of a device according to a preferred embodiment of the invention for treating the interface between an opening in the skin of a patient and an intra- or transdermal^ extending elongate member;

figure 2 is a cross-sectional front end view along lines A-A¹ in figure 1 ;

figure 3 is a perspective view from above of the device of figure 1 , in use; and

figure 4 is a cross-sectional view along lines B-B¹ in figure 3.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Referring to figures 1 to 4, a device according to a preferred embodiment of the invention for treating the interface between an opening or wound 8.1 in the skin 8 (figure 4) of a patient and an intra- or transdermal^ extending tubular elongate member, is generally designated by reference numeral 10. The intra- or transdermal^ extending tubular elongate member is typically in the form of a needle 12 of an indwelling central line intravenous catheter or alternatively in the form of a drainage tube (not shown).

The device 10 comprises a body 14 of separate porous inert ceramic particles or micro-porous ceramic spheres 16 contained in a permeable container 18. The container 18 comprises a tea bag - like envelope of Vilene™ material or any other suitable medically acceptable permeable fabric material and defines an elongate slit 18.1 extending into the container for receiving the needle 12, in use. The body 14 is thus generally U-shaped with the base 14.1 and arms 14.2 of the U defining a formation for surrounding the wound 8.1 and the needle 12 when the latter is received in the slit 18.1 , in use. In the drawing, for the sake of clarity, the base 14.1 and arms 14.2 are shown slightly spaced from the opening 8.1 and needle 12, but, in use, the base 14.1 and arms 14.2 would be pressed into close contact with the opening 8.1 and needle 12.

The ceramic particles 16 have a diameter range of between 45 and 300 micrometers; a porosity of between 25% and 85%, preferably 75%; and the pores (not shown) of the particles 16 have diameters in the range of between 0.3 to 30 micrometers. The pores are cellular in nature and are interconnected by blow-holes. The particles 16 possess high capillary suction power and a high storage capacity for absorbed liquid, when contained in the permeable container 18, to create such conditions as are required for the in vivo restoration of injured tissue and mechanical removal of microorganisms.

The particles 16 are prepared by a method including the steps of: milling inert ceramic precursor, for example alumina (AI₂O3), into powder

(particle diameter 1 micrometer or less); adding a combustible substance to the powder; - mixing the powder with water to form a paste or slurry; drying out the paste to form a ceramic aggregate; firing the ceramic aggregate to a temperature of 1200⁰C to form an inert microporous solid ceramic body having pore sizes of between 0.3 to 30 micrometers; - pulverising the ceramic body into particles 16 having a diameter of between 45 and 300 micrometers; removing fine powder and ceramic dust from the particles 16; disposing the body 14 of the particles 16 in the container 18; and sealing the container 18 along the edges of the body 14.

Instead of drying out the slurry to form an aggregate paste, the slurry could alternatively be directly converted into the particles 16 that are spherical by means of a variety of techniques like spraying onto a heated surface, sol-gel processing or spray-drying to form spherical particles 16 of suitable sizes, which are then sintered. After the sintering and preparation procedure, the particles 16 are to be kept dry and the device 10 is additionally sterilised using ethylene oxide in accordance with international standards.

In use, after insertion of the needle 12 into the skin 8 of a patient thus forming an opening 8.1 in the skin 8, the device 10 is applied to the area surrounding the opening or wound 8.1 in the skin 8 flush with the skin and pressed against the interface between the opening 8.1 and the needle 12. The arrangement is such that, when applying the device, the needle 12 is slid relative to the device 10 along the slit 18.1 , until the needle 12 abuts the base 14.1 of the U, with the two arms 14.2 of the U extending past the needle 12. The two arms 14.2 are then overlapped (not shown) and the device 10 secured to the skin 8 with a suitable adhesive tape (not shown), so that the wound 8.1 and needle 12 are entirely surrounded by the body 14 and the device 10 abuts the skin 8 closely at the wound 8.1 , unlike what is shown in figure 4.

The device 10 according to the present invention offers a means of mechanical wound disinfection. The device 10 physically removes microorganisms (mostly bacteria) from an interface between the intravenous needle 12 and the opening 8.1 in the skin 8, via the wound exudate, and then "incarcerates" or captures the microorganisms in the cellular structure or pores of the device 10 by its extreme capillary suction power, owing inter alia to its porosity and the blow holes connecting the pores. For all intents and purposes a microbiological "vacuum jail" is created by the device 10.

The majority of sepsis problems in hospitals and in particular relating to the use of intravenous catheters are caused by pathogenic bacteria, many of which have become resistant to a large variety of potent antibiotics and antiseptics. The device 10 represents a logical and very inexpensive preventative treatment method for this common and dangerous problem that often lead to enormous extra expense and discomfort for patients and hospitals alike.

The particles of 16 have large surface areas allowing the particles to absorb and/or adsorb excess fluids, microorganisms and odours from open wounds. The particles 16 have a total porosity of 75 %, pores with an average diameter of 3 micrometers, are cellular in texture and have relatively thin sidewalls. The pores are interconnected by means of small blowholes, which measure approximately 0,3 micrometers in diameter. Maximum adsorption surface area, maximum absorption volume, and maximum capillary suction are assured by the high porosity and high permeability of the particles 16 and the ceramic from which they are manufactured.

A head on head, randomised pilot study was conducted to evaluate the efficacy in reducing the incidence of colonisation by pathogenic bacteria on indwelling central intra-venous catheters in a critical care setting using the device 10 of the invention on the skin entry site (wound 8.1) in comparison with the currently recommended international standard of sterile gauze and non-occlusive dressings. The study illustrated the efficacy of the devices 10 to prevent colonisation of indwelling central line intra-venous catheters in comparison to the current recommended practice internationally of placing a non-occlusive dressing with only a piece of sterile gauze on the wound. More specifically the study illustrated that:

- the devices 10 are safe to use;

- the devices caused virtually no discomfort to the patient and added no time to the patients' stay;

- the use of the devices 10 does not contravene in any way the contemporary best practice for treating catheter entry wounds; and

- the risk of applying the devices 10 to entry wounds in this manner is less than that of placing sterile woven gauze in the same location, because of the physical removal of microorganisms from the said interface.

The ceramic used in the device 10 is completely stable, inert and is devoid of any chemical reaction when in contact with wound exudate.

Example A multi-centre, head-on head study in 80 patients was conducted. Patients were treated in a simple sequential alternative selection, one group receiving the devices 10 and the other group a conventional sterile gauze dressing.

In the group treated with the devices 10, the intravenous catheters were inserted in accordance with standard aseptic practises. The devices 10 were applied immediately afterwards, as hereinbefore described. The devices 10 were covered and fixed in place using a strip of 48mm width hypoallergenic medical adhesive tape. No occlusive dressing was applied. The devices 10 were changed every 48 hours. After 7 days, the intravenous catheters were removed the catheter tips were tested for routine culture following standard protocol.

In the group of patients treated with sterile gauze, the intravenous catheters were inserted aseptically in accordance with standard practise. The sterile gauze was applied directly on the entry wounds on the skin immediately after inserting the catheters.

The sterile gauze was covered and fixed in place using a strip of 48mm width hypoallergenic medical adhesive tape. No occlusive dressings were applied and the gauze was replaced every 48 hours. After 7 days, the intravenous catheters were removed the catheter tips were tested for routine culture following standard protocol. It was surprisingly found that the devices 10 are highly effective in treating wounds of the type described herein in that no infection could be detected in the group who used the devices 10 and the wounds 8.1 healed after removal of the catheter tips, without the formation of scar tissue. This was not the case with the patients treated with gauze.

It will be appreciated that variations in detail are possible with a method and device for treating the interface between an opening in the skin of a patient and an intra - or transdermal^ extending elongate member, according to the invention, without departing from the scope of the appended claims. For example, the device could be any suitable shape such as annular, with the annulus being cut through, so that the ends could overlap. Further for example, the device could be relatively narrow and elongate, with opposite end portions of the body defining the formations for surrounding the said opening for being wound about the elongate member flush with the skin surrounding the opening.

Claims

1. A device for treating the interface between an opening in the skin of a patient and an intra- or transdermally extending elongate member, the device comprising a body of separate porous ceramic particles contained in a permeable container, the body defining at least one formation for at least partially surrounding the said opening.

2. A device according to claim 1 wherein the container comprises a tea bag - like envelope with the body defining a formation in the form of an elongate slit extending into the envelope for receiving the elongate member.

3. A device according to claim 2 wherein the body of separate ceramic particles is generally U-shaped with the base and arms of the U defining the formations for surrounding the opening or wound as well as the elongate member on at least three sides when the latter is received in the slit, in use.

4. A device according to claim 1 wherein the body of separate ceramic particles is elongate, with opposite end portions of the body defining the formations for surrounding the said opening for being wound about the elongate member flush with the skin surrounding the opening.

5. A device according to any one of the preceding claims wherein the container is made from a medically acceptable permeable fabric.

6. A device according to any one of the preceding claims wherein the ceramic particles are inert.

7. A device according to any one of the preceding claims wherein the ceramic particles have a porosity of between 25% and 85.

8. A device according to claim 7 wherein the ceramic particles have a porosity of 75%.

9. A device according to claim 7 or 8 wherein the pores of the particles have diameters in the range of between 0.3 to 30 micrometers.

10. A device according to any one of claims 7 to 9 wherein the pores are cellular in nature.

11. A device according to any one of claims 7 to 10 wherein the pores are interconnected by blow-holes.

12. A device according to any one of the preceding claims wherein the particles are manufactured by pulverising an inert microporous ceramic body and removing fine powder from the particles.

13. A device according to claim 12 wherein the particles have a diameter range of between 45 and 300 micrometers.

14. A device according to any one of the preceding claims wherein the intra- or transdermally extending elongate member is selected from the group consisting of intravenous needles, indwelling central line intravenous catheters, and drainage tubes.

15. A method for treating the interface between an opening in the skin of a patient and an intra- or transdermally extending elongate member, the method including the steps of at least partially surrounding the opening, as well as the elongate member, with a device according any one of claims 1 to 14.

16. Use of a device according to any one of claims 1 to 14 in the treatment of an interface between an opening in the skin of a patient and an intra- or transdermally extending elongate member.

17. A device for treating the interface between an opening in the skin of a patient and an intra- or transdermally extending elongate member, substantially as herein described with reference to the accompanying drawings.