IE55196B1 - Multilayer,tubular burn dressing - Google Patents

Abstract

A tubular multilayer dressing (10) comprising an inner layer of an absorbent material (12), optionally a middle vapor barrier layer of plastic film (13), and an outer layer of an elastic supporting material (14), said layers being sewn together into a tubular shape by a seam (15) running the length of the dressing, said seam being sewn with a temporary thread stitch which is releasable by pulling the thread, said temporary stitch permitting the removal of the dressing from a patient by pulling the thread and releasing the stitch, thereby opening the seam and permitting the previously tubular dressing to be laid open and removed from the patient. [FR2543823A1]

Description

BACKGROUND OF THE! INVENTION The present invention is directed to a tubular dressing for use on various bodily injuries, particularly • injuries to the extremities such as burns which affect 5 relatively large surface areas. With respect to burn injuries and the like, it is often necessary or desirable · to cover the injury with an absorbent bandage or dressing for a variety of important purposes. Thus with serious burns the prevention of infection is a primary concern 10 and antibiotic ointments of silver sulfadiazine cream' must be repeatedly applied to the injured area. The dressing serves to maintain the ointment or cream in contact with the injured area. Toward this same end, the dressing serves to prevent bacteria from the environ-15 ment from further contaminating the wound.

A severe burn will also typically exude fluids and an absorbent dressing is required to absorb this exudate 5 519 6 ί t On the other hand, it is normally desired that the wound be kept from drying out in that moisture may promote healing and minimize pain (particularly during physical therapy or when the wound is cleaned). Therefore, fluid loss, either from the ointment or cream or from the wound itself, is preferably controlled by the use of an appropriate dressing.

In carrying out one or more of these functions, moreover, it is desirable that the dressing not be overly tight (e.g. so as to minimize discomfort and to accommodate swelling), that it permit joint motion, (particularly during physical therapy), that it be easily and quickly applied (preferably in a single step), and that it be easily removable with a minimum of patient discomfort.

With the above considerations in mind, burns were heretofore dressed by first applying a medicated ointment to the burn (e.g. with a sterile gloved hand). Alternatively, a gauze soaked in a medicament is wrapped around the wound followed by a wrapping of dry sterile gauze (e.g. Intersorb® type) in multiple layers. An open weave tubular stretch garment is then applied to keep the underlying layers in place and against the skin.

These prior procedures are time consuming and may cause considerable pain to the severely injured patient. Just as important, the dressing is typically changed frequently, thereby necessitating removal of the dressing either by unwinding or cutting the many layers. Here again valuable time is not only wasted but the patient may be subjected to severe trauma during the delicate removal procedure. -2- 55iy 6 l Also, while it is apparent that the dressing be wound sufficiently tight to maintain continued contact with the injured area, it is all too easy, particularly when many successive wrappings are applied, to obtain a 5 dressing which is overly tight or restrictive. This problem may become especially serious if swelling of the injured area occurs after the dressing is applied or if it is desired to flex the injured limb (e.g. as during physical thereapy).

SUMMARY OF THE INVENTION In accordance with the invention, there is provided a multilayer tubular dressing for use on the limbs or torso of the body. The dressing includes one or more absorbent layers next to the skin with an elastic or sup-15 porting layer for applying a gentle, yielding pressure situated thereover. There may also be provided a vapor ' barrier layer between the absorbent and supporting layers' for controlling moisture loss from the wound, particularly from medication which has been applied to the wound.

The multilayered dressing is formed into a tubular shape and sewn along a single seam. The resulting tubular dressing may then be pre-rolled into a toroidal shape such that it may be applied to the limb or torso simply by unrolling (i.e. much as a nylon stocking may be unrolled 25 up the leg).

In order to facilitate removal of the dressing, the seam of the dressing is sewn with a temporary stitch similar to that used on a potato sack— i.e. a stitch that releases as one end of the thread comprising the stitch is -3- ί 5 519 6 Γ . ν - t ' ι pulled along the seam. Once the seam is released, the previously tubular dressing may be laid open and quickly, easily and gently removed from the burn.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of the invention, reference may be made to the following description of an exemplary embodiment taken in conjunction with the figure of the accompanying drawing, in which: Figure 1 is a perspective view of a dressing according to the invention.

DESCRIPTION OF THE PREFERREND EMBODIMENT Looking to Fig, 1 of the drawing, there is shown a tubular dressing 10 which is depicted as being only partially unrolled from a pre-rolled toroidal shape 11.

The dressing can be pre-cut to any desired length, e.g. so as to cover a portion of or the entire length of an arm or leg, and preferably thereafter rolled so as to form a toroid. This toroid can then be merely slipped over the patient's hand or foot and, as it is unrolled, made to form a tubular dressing covering the entire limb.

The multilayer dressing comprises an inner (i.e. next to the skin) layer 12 which is preferably an absorbent knitted fabric or the like. Suitable in this regard is a cotton or cotton and polyester "stockinette" knit fabric.

For example, according to the invention there may be used a knit ribbed stocking fabric knitted to have 8-12 ribs/inch width running the machine direction, with 35 yarns/inch length running in the cross direction, with a fabric weight of 0.125 gins + 0.08 gms/sq.ir.. in the relaxed state. This L fabric preferably should have the following stretch characteristics: Maximum stretch in width direction = 3.7 + 0.3 x original, width.

Maximum stretch in machine direction = 1.17 ± 0.02 . x original length.

The stretch force in the width direction for one layer of fabric originally 5 inches in length and 6.5 inches in width should be as follows: Distance stretched Force 2.0 in. 0.1 lbs. 6.5 in. 0.2 lbs. .0 in. 0.3 lbs. 12.5 in. · 0.5 lbs.

Over the absorbent layer there is preferably a vapor barrier layer 13 which assists in keeping the skin or wound surface soft and moist. Healing is thereby promoted and cleaning of the wound between dressing applications is rendered easier and less painful.

The vapor barrier layer may be moisture impermeable or semipermiable, the important feature being that the layer at least control the passage of moisture therethrough. A variety of materials are suitable for forming the vapor barrier, e.g. 2.0 mil polyurethane film.

In order to hold the absorbent layer, and the vapor barrier layer if present, against the wound, there is provided an outer elastic or supporting layer 14. This layer is typically a thin, knitted fabric of natural or synthetic fiber, e.g. nylon, rayon or.silk. The elastic r 55196 knit is preferably the type used in white stocking, panti-hose or certain tee shirt materials. One such fabric is a ribbed stocking fabric knitted to have 40 to 55 ribs/inch width running in the machine direction, with 40-55 yarns/inch length running in the cross direction with a fabric weight of 0.034 ± 0.003 gms/sq.in. in the relaxed state. This fabric preferably should have the following stretch characteristics : Maximum stretch in width direction = 3.5 ± 0.3 x original width.

Maximum stretch in machine direction = 1.17 ± 0.02 x original length.

The stretch force in the width direction for one layer of fabric originally 10 inches in length and 4 inches in width in the relaxed state should be as follows: Distance stretched in width direction Force 1 in. 0.1 lbs. 2 in. 0.15 lbs. 3 in. 0.25 lbs. 4 in. 0.35 lbs. 5 in. 0.4 lbs. 6 in. 0.5 lbs. 7 in. 0.6 lbs. 8 in. 0.7 lbs. An important feature of the supporting layer is that it provides the needed support for the absorbent layer but at the same time is sufficiently yielding so as to permit movement of the injured limb. This gentle controlled -6- 5 5 1 y 6 g t· pressure is also useful in controlling edema in the injured area.

It will be apparent to one skilled in the art that the degree of pressure exerted by the dressing will 5 depend not only upon the stretch characteristics of the · fabric comprising the dressing, but also upon the circumference of the dressing relative to the circumference of the limb to be covered. In this regard, since the support is provided primarily by the supporting layer, it is pre-10 ferably sized somewhat smaller than the underlying absorbent layer. A typical dressing for use on the arm or lower leg . of an adult will have an absorbent layer circumference of ten to twelve inches and a Supporting layer circumference of eight to ten inches. Using these dimensions the 15 absorbent layer may be slightly stretched when applied while the supporting layer may be stretched up to about 60% beyond of its original or relaxed width..

As noted above, the vapor barrier layer 13. is preferable. According to one embodiment of the invention, however, 20 this layer may be omitted with the result that the dressing is comprised only of an .absorbent layer and a supporting layer.

While the dressing is easily applied simply by unrolling it up the patient's limb, a different means of removal is provided. In this regard, the dressing is formed into a 25 tubular shape by means of a sewn seam 15 running the entire length of the dressing. This seam is comprised of a temporary or removable stitch which may be pulled from one end of the seam so as to release the seam. Once the seam is released, the dressing may be gently laid open and removed from the injured limb. -7- i 5519 In order to facilitate the opening of the temporary seam, the seam thread is left free at least at one end and the thread end is attached to a plastic ring 16 or the like. Similarly, the thread end may be taped to the dressing fabric 5 with a strip of masking tape which, when pulled away from the fabric, pulls the thread out of the seam.

Temporary seams made as follows are exemplary of the invention: EXAMPLE I A single thread chain stitch was made at setting #4 on a Juki Sewing Machine, Model M0804 using a cotton polyester thread (Polyester core cotton tex 40(60/30) from Coats and Clark). This stitch was sewn through all the layers of the dressing for the entire length with the fabrics 15 stretched to the desired width and length. At the end of the stitch, the thread was cut, and the end of the thread was removed from the last loop. The loop and the thread end were then taped to the fabric with a strip of masking tape. To remove this temporary seam this tape is pulled 20 away from the fabric, taking the thread out.

EXAMPLE II A double thread basting stitch was made with a Singer Sewing Machine, Model 776, set at width #3 and the needle position in the center with 8 to 10 stitches per 25 inch using Clark's Phantom Nylon Monofilament Thread M-25 Cat. No. 6244. This stitch was sewn through all the layers of the dressing for the entire length with the fabric stretched to the desired width and length. The seam was started and finished so that approximately 2 inches of thread remained -8- ΰ 5 1 a 6 f t. 1. free at each end of the seam. These ends of nylon monofilament were then tied to small plastic rings to keep the stitch in place until it is to be released.

This temporary seam is removed by cutting both 5 monofilaments from the ring at one end and one from the ring at the other end. The ring with the attached monofilament is then pulled gently to remove the thread from the seam.

Clinical tests of the dressings according to the 10 invention have been carried out with the following results: EXAMPLE III (Multilayer dressings with barrier film) These dressings containing the film were tested on inoculated scald injuries in animals using silver sul-15 . fadiazine emulsion as the topical antibacterial agent.

Quantitative bacteriology of the burn wound showed that those injuries treated with dressings containing the barrier film were less contaminated than those treated with dressings without this film. In addition, the 20 dressings acted to keep the wound and the standard topical medications from drying out. In particular, the blood oozing from the debrided burn did not dry out and form a hard crust that is difficult to clean.

These observations were confirmed by patients who 25 said dressings containing the barrier film were more comfortable to wear, more comfortable for physical therapy, and less painful to remove. Wound cleaning was also less painful than dressings without the barrier film. 9- 5 5 10 6 EXAMPLE IV (Multilayer dressing without barrier film) A series of dressings according to the invention were applied to hospitalized patients recovering from 5 serious burns. The nurse noted that these dressings were easier to apply than their standard dressing procedure which involved wrapping injured arms with rolls of gauze.

The patients noted that these dressings were more comfortable than standard dressings, especially when their injured limbs 10 were subjected to physical therapy.

It will be understood by those skilled in the art that the above description is directed to preferred embodiments only and that various changes and modifications can be made thereto without departing from the spirit or scope 15 of the invention.

Claims (6)

1. 7. A tubular multilayer dressing according to claim 3 wherein the supporting layer is comprised of a ribbed stocking fabric having a maximum stretch in the width direction of approximately 315 + 0.3 x original width and a maximum stretch in the machine direction of approximately 1.17 ± 0.02 x original length.

2. 18. A tubular multilayer dressing according to claim 4 wherein the supporting layer is comprised of a ribbed stocking fabric having a maximum stretch in the width direction of approximately 3.5 i 0.3 x original width and a maximum stretch in the machine direction of approximately 1.17 ± 0.02 x original length.

3. 19. A tubular multilayer dressing according to claim 3 wherein the stretch characteristics of the fabric comprising the supporting layer are such that a 10 inch length of a single layer of said fabric requires a force in the width direction of approximately 0.35 pounds for a stretch of approximately 100% of the original width.

4. 20. A tubular multilayer dressing according to claim 4 wherein the stretch characteristics of the fabric comprising the supporting layer are such that a 10'inch length of a single layer of said fabric requires a force in the width direction of' approximately 0.35 pounds for a stretch of approximately 100% of the original width.

5. 21. A tubular multilayer dressing as claimed in any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing. 5Siae Dated this the 4th day of April, 1984. F. R. BY: EXECUTIVE

6. 27 Clyde Road, Ballsbridge, Dublin 4. AGENTS FOR THE APPLICANTS.