FR2543823A1 - MULTILAYER TUBULAR DRESSING, ESPECIALLY FOR BURNS - 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.

Description

MULTI-LAYERED TUBULAR DRESSING, ESPECIALLY FOR
BURNS.

 The present invention relates to a tubular bandage intended for use on various bodily injuries, in particular on certain injuries of the extremities, such as burns affecting relatively large surfaces. In the case of burn injuries and the like, it is often necessary or desirable to cover the wound with an absorbent bandage or dressing, for various important reasons. Thus, for serious burns, the prevention of infection is a main object, and antibiotic ointments in the form of silver sulfadiazine cream must be repeatedly applied in the area of the wound. The dressing is used to keep the ointment or cream in contact with the area of the wound. Similarly, the dressing is used to prevent bacteria from the environment from further contaminating the wound.

 A serious burn will also commonly result in oozing fluids, and an absorbent dressing is required to absorb this exudate. On the other hand, it is normally desirable for the wound to be prevented from drying out, since moisture can promote healing and minimize pain (especially during physical therapy or when the wound is cleaned).

Thus, fluid losses, either from the ointment or cream, or from the wound itself, are preferably controlled by the use of an appropriate dressing.

When implementing one or more of these functions, it is also desirable that the dressing is not excessively tight (for example to minimize discomfort and to accept swelling), that it allows movement joints (especially during physical therapy),
that it can be easily and quickly applied, (preferably in a single step), and that it can be easily removed, with minimal discomfort for the patient.

 Keeping in mind the above considerations, burns have so far been healed by first applying a medicated ointment to the burn (for example by a sterile gloved hand). Alternatively, a gauze impregnated with a medicament is wrapped around the wound, after which a dry sterile gauze (for example of Intersob type - registered trademark) is wrapped on several layers. A stretchy tubular garment with an airy texture is then applied to hold the underlying layers in place and against the skin.

 These prior art methods are time consuming and can cause considerable pain in a seriously injured patient. Equally importantly, it is common for the dressing to be changed frequently, thus requiring the dressing to be removed, either by unrolling it or by cutting the many layers. Here again, not only is precious time wasted, but the patient can be subjected to serious trauma during this delicate removal procedure.

 In addition, although it is clear that the dressing can be wound tightly enough to ensure permanent contact with the injured region, it is quite easy, especially when many successive wraps are applied, to obtain a dressing that is too tight or restrictive. This problem can become particularly serious if swelling of the injured area occurs after application of the dressing, or if it is desirable to bend the injured limb (for example during physical therapy).

 Thus, the present invention relates to a multi-layer tubular dressing intended to be used on the limbs or on the body torso. The dressing comprises one or more absorbent layers adjacent to the skin, and an elastic or support layer intended to apply a slight elastic pressure, situated on top. A vapor barrier layer may also be provided between the absorbent and support layers, for controlling moisture loss from the wound, particularly from a drug which has been applied to the wound.

 The multi-layer dressing is, shaped into a tubular shape and is sewn along a single seam. The. tubular dressing obtained can then be ## pre-wound in a toroidal shape, so that it can be applied to the limb or torso by simply unrolling it (that is to say in the same way as a sock , for example in synthetic material, can be unrolled to go up along the leg).

 In order to facilitate the removal of the dressing, the seam of the dressing can be sewn using a temporary stitch similar to that used on the potato sacks, i.e. a stitch which becomes free when one end of the thread from which the stitch is made is pulled along the seam. Once the seam is released, the previously tubular dressing can be opened and removed quickly, easily and gently from the burn.

 The invention will be better understood on reading the following description of an embodiment given by way of examples, made with reference to the appended drawing, in which the single figure is a perspective view of a dressing according to invention.

 Referring to the figure of the drawing is shown a tubular dressing 10 which is illustrated in a position only partially unwound from a pre-wound toroidal shape 11. The dressing can be pre-cut to any desired length, for example so as to cover a portion lengthwise, or the entire length of an arm or a leg, and preferably subsequently wound so as to form a torus. This torus can then simply be slipped onto the patient's hand or foot and, when it is unrolled, led to form a tubular dressing covering the entire limb.

The multi-layer dressing includes an inner layer 12 (i.e., adjacent to the skin) which is preferably made of an absorbent mesh or the like. In this respect, a mesh fabric called "Stockinette" in cotton or cotton and polyester is suitable. For example, according to the invention, a fabric for knitted stockings can be used, knitted so as to have 3 to 5 stitches / cm. in width, extending in the direction of the machine, with 14 threads / cm in length extending in the transverse direction, with a fabric weight of 0.020 t: i
g./cm2 '0.012 g./cm2 in the relaxed state. This fabric will preferably have the following stretch characteristics
Maximum extension in the width direction = 3.7 i 0.3 times the original width.

 Maximum extension in the machine direction = 1.17 + 0.02 times the original length.

The extension force in the width direction for a fabric layer with a length of 12.5 cm and a width of 16.5 cm at the origin should be as follows
force extension distance
5.08 cm 45 g
16.5 cm 90 g
25.4 cm 136 g
31.75 cm 226.5 g
Above the absorbent layer is preferably provided a layer 13 forming a vapor barrier, which helps to keep the injured skin or surface soft and moist. Scarring is thus favored and cleaning of the wound between bandage applications is made easier and less painful.

 The vapor barrier layer may be impermeable or semi-permeable to moisture, the important feature being that the layer at least controls the passage of moisture through it. Various materials are suitable for forming the vapor barrier, for example a 0.05 mm polyurethane film.

In order to maintain the absorbent layer and, if present, the vapor barrier layer, against the wound, an elastic or supportive outer layer 14 is provided. This layer is conventionally a thin mesh fabric of natural or synthetic fibers, for example of Nylon (registered trademark), Rayon (registered trademark) or silk. The elastic mesh is preferably of the type used in white stockings, tights, or in certain shirt material. Such a fabric is a ribbed stocking fabric knitted so as to have 16 to 22 cts / cm in width extending in the direction of the machine, with 16 to 22 threads / cm in length extending in the transverse direction the fabric having a weight of 0.0054 + 0.00048 g / cm2 in the relaxed state. This fabric will preferably have the following stretch characteristics
Maximum extension in the width direction = 3.5 + 0.3 times the original width.

 Maximum extension in the machine direction = 1.17 4 0.02 times the original length.

The stretching force in the width direction for a layer of fabric originally having a length of 25.4 cm and a width of 10.2 cm in the relaxed state should be as follows
force extension distance
in the sense of
tearfulness
2.54 cm 45.3 g
5.08 cm 68.0 g
7.62 cm 113.2 g
10.16 cm 158.5 g
12.70 cm 181.2 g
15.24 cm 226.5 g
17.78 cm 271.8 g
20.32 cm 31: 7.1 g
An important feature of the support layer is that it provides the necessary support for the absorbent layer while being sufficiently elastic to allow movement of the injured limb. This gentle, controlled pressure is also helpful in controlling edema in the injured area.

 Those skilled in the art will note that the degree of pressure exerted by the dressing will depend not only on the extensibility characteristics of the tissue constituting the dressing, but also on the circumference of the dressing relative to the circumference of the member to be covered. In this regard, since the support action is mainly provided by the support layer, the latter is preferably dimensioned so as to be slightly smaller than the underlying absorbent layer. A typical dressing intended for use on the arm or lower leg of an adult will have an absorbent layer with a circumference between 25.4 and 30.5 cm and a support layer with a circumference between 20, 3 and 25.4 cm. With these dimensions, the absorbent layer can be slightly extended during its application, while the support layer can be extended by approximately 60% beyond its original or relaxed width.

 As previously noted, the use of a layer 13 forming a vapor barrier is preferable. However, according to an embodiment of the invention, this layer can be omitted, with consequently a dressing which consists only of an absorbent layer and a support layer.

 Although the dressing can be applied easily by simply unrolling it on the patient's limb, different removal means are provided. In this regard, the dressing is formed into a tubular shape, by means of a sewn seam extending over the entire length of the dressing. This seam consists of a temporary or removable stitching which can be pulled from one end of the seam so as to release it. Once the seam is released, the dressing can be gently opened and removed from the injured limb.

 In order to facilitate the opening of the temporary seam, the seam thread is left free at least at one end, and the end of the thread is fixed to a plastic ring 16 or the like. Similarly, the end of the thread can be fixed with adhesive tape to the dressing fabric using a piece of masking tape -which, when torn from the fabric, removes the thread sewing.

 Temporary seams made as below are examples of the invention.

EXAMPLE 1
A single thread chain stitching was carried out with setting No. 4 on a Juki sewing machine, model
M0804 using cotton and polyester yarn (cotton with polyester core tex 40 (60/30) from Coats and Clark).

This stitching was sewn through all the layers of the dressing and over its entire length, the fabric being extended to the desired length and width. At the end of the stitching, the wire was cut and the end of the wire was removed from the last loop. The loop and the end of the wire were attached to the fabric with a piece of masking tape.

To remove this temporary seam, this ribbon is pulled from the fabric to take out the thread.

EXAMPLE II
A stitching of two-threaded bati was carried out with a Singer sewing machine model 776, adjusted to width no.3, the position of the needle being in the center, with 3 or 4 stitches per cm using a nylon thread ( trademark) with phantom monofilament from Clark, model M-25 cat. 6244. This stitching was sewn through all the layers of the dressing and over its entire length, the fabric being extended to the desired width and length. The seam has been # started and finished so that about 5 cm of thread remain free at each end of the seam. These ends of the nylon monofilament (registered trademark) were then attached to small plastic rings to hold the point in place until it had to be released.

 This provisional seam is removed by cutting the two monofilaments of the ring at one end, and only one at the other end. The ring on which the monofilament is attached is then gently pulled to remove the thread from the seam.

Clinical trials of the dressings according to the invention were carried out, with the following results
EXAMPLE III
(multi-layer barrier film dressings)
These film-containing dressings have been tested on scald wounds inoculated into animals, using a silver sulfadiazine emulsion as a local anti-bacterial agent. Quantitative bacteriology of the burn has shown that these wounds treated with dressings containing the barrier film were less contaminated than those treated with dressings devoid of this film. In addition, the dressings worked to prevent conventional local medicines from drying out. In particular, the blood oozing from the unrestrained burn did not dry out and did not form a hard crust which was difficult to clean.

 These observations have been confirmed by patients who have stated that the dressings containing the barrier film are more comfortable to wear, more comfortable for physical therapy and less painful to remove. Cleaning the wound was also less painful than with dressings without the barrier film.

EXAMPLE IV
(multi-layer dressings without barrier film)
A series of dressings according to the invention have been applied to patients hospitalized in recovery from serious burns. The nurses observed that these dressings were easier to apply than their conventional dressing process, which consisted of wrapping rolls of gauze over injured arms. Patients observed that these dressings were more comfortable than conventional dressings, especially when their injured limbs were undergoing physical therapy.

 It will be obvious to those skilled in the art that the above description relates only to preferred embodiments, and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (12)

 1. Multi-layer tubular dressing, characterized in that it comprises an inner layer (12) of absorbent material and an outer layer (14) of an elastic support material, said layers being sewn together to take a tubular shape by a seam (15) extending over the length of the dressing, the seam being sewn using a temporary thread stitch which can be released by pulling the thread, said temporary stitch making it possible to remove the dressing from a patient by pulling the thread and releasing the stitching, thereby opening the seam and allowing the previously tubular dressing to be opened and removed from the patient.  2. A dressing according to claim 1, characterized in that it further comprises a layer (13) forming a vapor barrier between the absorbent layer and the support layer.  3. Dressing according to claim 1 or 2, characterized in that the absorbent layer (12) consists of a fabric of natural or synthetic fibers, and in that the support layer (14) consists of a mesh fabric elastic, the elastic mesh fabric being made of a synthetic or natural fiber and being chosen and sized so as to maintain the absorbent layer against the wound with a slight pressure allowing movement.  4. A dressing according to claim 3, characterized in that the layer (13) forming a vapor barrier consists of a thin plastic film.  5. Dressing according to claim 4, characterized in that the layer forming (13) vapor barrier consists of a polyurethane film.  6. Dressing according to claim 3 or 4, characterized in that the temporary puncture (15) comprises gripping means at at least one end of the thread of the puncture, the gripping means allowing the thread to be pulled so as to release the bite.  7. A dressing according to claim 6, characterized in that the temporary puncture (15) is a single puncture stitched through all the layers of the dressing so as to form a seam extending over the entire length of the tubular dressing, said seam maintaining the layers in tubular form, the wire being cut at the end of the seam and the end of the wire being removed from the last loop of the seam, said end of the wire being attached to the gripping means to facilitate the pulling of the end of the wire and the release of the bite.  8. Dressing according to claim 6, characterized in that the provisional stitching (15) is a double thread frame stitching sewn through all the layers of the dressing so as to form a seam extending over the entire length of the dressing, said seam being started and terminated so that lengths of thread are free at each end of the seam, said lengths of thread being attached to the gripping means at each end of the seam so as to hold the stitching in place until 'ceqn'elle must be released, the bite can be released by cutting gripping means all ends of the son except one and pulling the gripping means on which is attached said wire  9 dressing according to claim 3, characterized in that the absorbent layer (l2) consists of a tissue. knitted dimensions having a maximum extension in the width direction of approximately 3.7 i 0; 3 times its original width and a maximum extension in the direction of the machine of approximately 1.17 + 0.02 times its original length.  10. Dressing according to claim 3, characterized in that the extensibility characteristics of the fabric constituting the absorbent layer (12) are such that a length of 12.7 cm of a single layer of this fabric requires in the direction of the width a force of approximately 90 grams for an extension of approximately 100% of the original width.  11. Dressing according to claim 3, characterized in that the support layer (14) consists of a fabric for ribbing having a maximum extension in the width direction of about 3.5 + 0.3 times its original width and a maximum extension in the machine direction of approximately 1.17 to 0.02 times its original length.  12. A dressing according to claim 3, characterized in that the extensibility characteristics of the fabric constituting the support layer (14) are such that a length of 25.4 cm of a single layer of this fabric requires in the direction of the width a force of approximately 158 grams for an extension of approximately 100% of its original width.