<% vol = 15 number = 1 nextlink = 29 prevlink = 17 titolo = "ACTIVETEX® WOUND DRESSINGS IN BURN TREATMENT" volromano = "XV" data_pubblicazione = "March 2002" header titolo %>

Alekseev A.A., Krutikov M.G., Bobrovnikov A.E., Vasilyeva T.S., Grishina I.A., Paltsyn A.A.

A.V. Vishnevski Institute of Surgery, Burn Centre, Moscow, Russia


SUMMARY.An analysis was performed of the topical treatment of 40 patients suffering from various burns using Activetex® dressings. Activetex® provides a prolonged therapeutic effect due to its content of various medicines (antibacterial, anaesthetic, wound-healing) in combination with a biocompatible polymer. A control group of patients with analogous burn injuries was treated with ointments on a polyethylene glycol base with antibacterial preparations. It was shown that the efficiency of Activetex® dressings is in many cases superior to that of water-soluble ointments and in other cases is generally equal to such ointments in burn wound treatment. Activetex-ChL is effective in the treatment of limited non-infected II-IIIA burns, Activetex-ChF can be successfully used in the treatment of limited infected II-IIIA burns and to prepare IIIB burns for autografting, and Activetex-ChHap is effective in the treatment of residual non-healing burn wounds. Activetex® dressings can be successfully used as an alternative to traditional methods at all stages of topical burn treatment in clinics, out-patient departments, and emergency services.

Introduction

The ultimate goal of burn treatment is to provide the most rapid possible healing of surface burns and to speed up the surgically provided restoration of lost skin in deep burns. The local conservative treatment of burn injuries is of major importance. Treatment of patients with superficial damage is always conservative. In deep burns, conservative methods of local treatment are used to prepare wounds for surgery and to create conditions for the non-rejection of autodermotransplants and full-thickness grafts.

A wide variety of preparations and remedies of non-organic, organic, biogenic, and phytogenic origin have been devised and used in the topical treatment of burns. Surgeons have to evaluate and select the most efficient remedies and dressings in each single case. The choice must be based on knowledge of the characteristics of the dressings and an assessment of the specifics of the wound process.

Currently, the closed method of burn treatment is widely used, in which various dressings and wound bandages are employed. This method has a number of advantages over the open or dressing-free technique. In the closed method, favourable conditions are created for the topical therapy of burns.1 This method is normally be the only possibility in out-patient treatment.2 However, a universal wound dressing cannot be developed because the processes that occur within the various kinds of wounds - whether in fresh, festering, or healing tissues or in epithelializing wounds - are too variable. Yet, at every stage, a bandage should reliably protect the wound from infection and external contamination; the bandage should model the wound surface and at the same time be atraumatic during dressing procedures.3,4

Biological wound dressings have remained the gold standard as temporary skin substitutes. Growing interest has however been attributed to the research and development of synthetic burn dressings.5 The immobilization of various pharmacological preparations in synthetic dressings provides antibacterial and wound healing properties similar to those of natural biological dressings.6

Recently, widespread attention has been aroused by certain synthetic-base dressings containing a complex of polymers with various medicinal preparations aimed at ensuring a local effect on the wound, especially as regards prolongation of the therapeutic effect.7-9

Among such products are Activetex® wound healing dressings (designed and produced by Altex Plus Ltd, Russia). These incorporate a knitted fabric substrate impregnated with a special therapeutic composition of biocompatible polysaccharide polymers with various medicinal preparations possessing local anaesthetic, antibacterial, and wound-healing action. In a moist medium these dressings exert a pronounced therapeutic effect due to the water gel layer formed by the polymer. This gel dispenses medicinal substances into the wound for a prolonged period of time. Microbial burn flora is usually highly resistant to the majority of locally applied antibacterial preparations. A combination of chlorhexidine and furagin in Activetex® dressings, together with the prolonged therapeutic effect (up to several days), ensures high sensitivity to the main pathogenic agents causing burn infection. Activetex® has no direct analogues on the western market.

The application of novel modern dressings for topical burn treatment clearly requires specific indications and evaluation of their efficiency for the healing of burn wounds of various depth in the different phases of the wound process. When evaluating new wound dressings it is significantly important to take into account not only the good therapeutic outcome of treatment but also statistically measurable benefits compared with a control group of patients treated with conventional methods.10

Materials and methods

In 1999-2000 a clinical and laboratory study of Activetex® dressings of various medicinal compositions was performed by the Applied Research Centre for Thermal Lesions at the A.V. Vishnevski Institute of Surgery of the Russian Medical Sciences Academy.

Of the sixteen types of Activetex® dressings, the following were chosen:

The main group was comprised of 40 patients in whom treatment was performed with Activetex-ChL, Activetex-ChF, and Activetex-ChHap dressings. The patients were divided into four subgroups:

  1. Activetex-ChL for treatment of limited non-infected II-IIIÀ degree burns. This group consisted of 10 patients (4 women, 6 men) aged 15 to 53 yr (average, 40.14 ± 5.4 yr) with an overall burned body surface area (BSA) between 5 and 38% (average, 18.14 ± 4.31%) and a deep burn area between 0 and 15% BSA (average, 4.2 ± 2.7%). Activetex-ChL was used only for treatment of II-IIIÀ degree burns in areas of 1-5% BSA (average, 3.1 ± 1.8%). Treatment started on day 2 to 5 post-burn (average, day 2.8 ± 0.45) and continued for 7 to 13 days.
  2. Activetex-ChF for treatment of limited infected II-IIIA degree burns. This test group included 10 patients (3 women, 7 men) aged 15 to 71 yr (average, 33.0 ± 6.7 yr) with an overall burned BSA between 1.5 and 60% (average, 26.3 ± 6.3%) with deep burns in 0-15% BSA (average, 4.15 ± 2.14%). Activetex-ChF was used only for treatment of infected II-IIIÀ degree burns in injured areas of 2-5% BSA (average, 3.7 ± 1.3%). Treatment started on day 2-12 post-burn (average, day 8.5 ± 1.2) and lasted for 10 to 11 days.
  3. Activetex-ChF for treatment of limited infected IIIB degree burns. This group was made up of 10 patients (1 woman, 9 men) aged 19 to 70 yr (average, 36.4 ± 7.5 yr) with an overall burned BSA between 8 and 30% (average, 22.7 ± 2.6%), with a deep burn area between 1.5 and 23% BSA (average, 12.7 ± 3.14%). Activetex-ChF was applied to treat IIIB degree burns with in burn areas of 1.5-6% BSA (average, 4.2 ± 1.6%). Treatment started on day 8-27 post-burn (average, day 19.0 ± 3.02), going on for 5 to 14 days.
  4. Activetex-ChHap for treatment of protracted post-burn non-healing residual wounds. The test group included 10 patients (2 women, 8 men) aged 18 to 47 yr (average, 34.4 ± 3.5 yr) with overall burn lesions in 5-70% BSA (average, 37.3 ± 5.6%). The area of deep burns was 1-32% BSA (average, 14.5 ± 3.9%). Activetex-ChHap was applied to treat residual burn wounds in areas ranging from 0.5 to 2% BSA (average, 1.2 ± 0.7%). Treatment started on day 22-93 post-burn (average, day 42.9 ± 6.6) and the duration of treatment was 5 to 17 days.

Control groups included patients with similar traumas whose burn lesions were treated with traditional methods using bandages with the water-soluble ointment Laevomicol, which contains laevomycetin and methyluracil.

Activetex® wound dressing application technique

Sterile Activetex® dressings were wetted with a sterile physiological solution and then transferred onto burn wounds and fixed by several layers of bandage or plaster. The dressings, while on the wound, were constantly kept wet by moistening them with sterile physiological solution or furacilinum solution 2-3 times a day. In the event of abundant exudates, additional gauze-cotton wool bandages were put on the dressing.

Prior to surgery, dressing changes were made every other day. After autodermoplastic surgery the first dressing change was made on day 5 and thereafter every other day. Before any change Activetex® dressings were amply moistened with disinfectant solutions in order to soak them and allow painless removal.

The clinical evaluation of the outcome of treatment was made on the basis of visual observations of the development of the burn process with regard to exudate volume and content and to the progress of epithelialization.

Cytological examinations of wounds were performed using “prints” taken off the wound surface. General conclusions were made on the basis of cytogram types. The following types of cytograms were differentiated: degenerative-inflammatory, inflammatory, inflammatory-regenerative, regenerative-inflammatory, regenerative, regenerative-inflammatory with autoimmune component, erythrocytic, and erythrocytic-neutrophilic.

Microbiological investigations were carried out by determining the microflora species and counting the number of micro-organisms per square centimetre of wound surface (J. Brentano, 1967). Wound material samples from the test and comparison groups were taken before, during, and after treatment with Activetex® dressings.

Histomorphological investigations concerned the biopsy material removed from deep burn wounds.

Results

Clinical assessment


1. Wounds of all the patients prior to treatment either with Activetex-ChL or with traditional healing methods presented (after removal of detached epidermis scraps) a pink moist surface with fibrin patches and moderate serous exudate in non-infected II-IIIA degree burns(Fig. 1).

<% immagine "Fig. 1","gr0000006.jpg","Non infected II-IIIA degree burn wounds  ",230 %> <% immagine "Fig. 2","gr0000007.jpg","Non infected II-IIIA degree burn wounds on day 7 of tratment with Avtivex-ChL dressings",230 %>

As soon as day 4 day of treatment with Activetex-ChL dressings, in 80% of the cases the moist surface transformed into a thin dry crust, with complete epithelialization beneath, and in 30% of the cases the dressings applied were not removed until full epithelialization (Fig. 2). Epithelialization time averaged 12 days post-injury. In 20% of cases, despite all efforts of treatment, thin-scab suppuration was observed on days 7-8 post-burn that required further treatment with Activetex-ChF dressings. In these cases, epithelialization was complete on average by day 17.

Also in the control group epithelialization was observed in 80% of cases, occurring on average on day 13 post-burn. In 20% of the patients festering of the burn wounds occurred and epithelialization was complete in 18-21 days.

Pain reaction was assessed within 30 min after bandaging. An effect of pain relief after application of Activetex-ChL was reported by 70% of patients within 30 min of bandaging, while 30% complained of pain. In the control group, after bandaging with Laevomicol ointment, abatement of pain was reported by 50% of the patients within 30 min, while the other 50% reported continuation or even aggravation of pain.


2. Prior to treatment with Activetex-ChF dressings, contaminated II-IIIÀ degree burns appeared as surfaces covered with spots of fibrin and moderate purulent discharge; some parts presented moist and partially divested crusts. Epithelialization was either sluggish or absent. There was perifocal inflammation of adjacent healthy tissues.

Application of Activetex-ChF led to the formation in 40% of cases of a dry burn crust beneath which self-sustained wound epithelialization occurred. In 30% of the observations, after separation of the crust on day 7-10 post-burn during treatment with Activetex-ChF, active epithelialization of the wounds was also observed. On average the epithelialization period lasted for 17.6 days after the trauma. In another 30% of cases, despite treatment with Activetex-ChF, suppuration of the burn wounds continued, requiring the introduction of changes into treatment tactics with the use of dioxidine ointment, which is sensitive to micro-organism cultures derived from the wound. In these observations epithelialization was complete by day 21 post-burn.

In the control group, in 20% of cases a dry crust was observed with epithelialization of the burn wounds beneath the crust. In 80% of cases, wound suppuration was found, accompanied by separation of the moist crust followed by wound epithelialization. Epithelialization time in this group was on average 19.1 days post-burn.


3. Prior to treatment of contaminated IIIB degree burns with Activetex-ChF in patients of any group, the burn wounds had pale granulations with patches of moist crust, patches of fibrin, and moderate pus discharge. There was no epithelialization. Perifocal inflammation of adjacent healthy tissues was also observed (Fig. 3).

Even after only two Activetex-ChF dressings, in 90% of cases formations of bright fine-grained moderately bleeding granulations and significantly less exudation were observed (Fig. 4). In these patients autodermoplasty was performed at the optimal time and no after-surgery lysis of autografts was observed. After treatment with Activetex-ChF one patient (10%) showed an increase of purulent discharge which required application of dioxidine ointment sensitive to a specific micro-organism extracted from the wound during preparation for plastic surgery.

In the control group, after treatment with water-soluble ointments and xenotransplantation, purulent discharge from the burn wounds was practically absent in 40% of cases, moderate in 40%, and intense in 20%. In these patients the granulations also looked different: they were hypertrophically changed, slimy, and paler than those in the main group. After autodermoplastic surgery, lysis of the autografts was observed in 20% of cases

<% immagine "Fig. 3","gr0000008.jpg","Contaminated IIIB degree burn wounds",230 %> <% immagine "Fig. 4","gr0000009.jpg","IIIB degree burns on day 2 of treatment with Activetex-ChF dressings.",230 %>

4. Prior to treatment with Activetex-ChHap, in all patients the residual burn wounds and cells of autografts presented sluggishly granulating wounds with fibrin patches and moderate purulent discharge. Epithelialization was slack or absent. Inflammation around the wounds was not observed (Fig. 5).

During treatment in both the main and the control groups, complete epithelialization of wounds was achieved on average within the same time period, on day 10-11 after the beginning of treatment (Fig. 6).

<% immagine "Fig. 5","gr0000010.jpg","Treatment of residual burn wounds with Activetx-ChHap dressings",230 %> <% immagine "Fig. 6","gr0000011.jpg","Patient on day 4 after initiation of treatement of residual wounds with Activetex-ChHap dressings.",230 %>

Microbiological assessment

Prior to treatment with Activetex® dressings, various kinds of micro-organisms discharged from the patients’ burn wounds in a monoculture or in associations. In both main and control group patients, the wound micro-flora content was identical with the average Lg CFU 3.8. The main strains were P. aeruginosa and S. aureus, while S. epidermidis, Acinetobacter spp., etc. were rarely isolated (Table I).

After treatment with Activetex-ChL, micro-organisms were observed in only 50% of cases, with a reduction of microbial dissemination of the burn wounds from 104.3 to 101.6 Lg CFU per g of tissue. In the control group, micro-organisms in the burn wounds were observed in 60% of cases, and there was a non-significant reduction in microbial dissemination (from 103.6 to 102.3 CFU per g of tissue).

After treatment of contaminated II-IIIA degree burns with Activetex-ChF dressings, in 70% patients micro-flora could not be determined in the final stage of therapy, while the decrease in microbial dissemination was from 103.75 to 102.3 CFU per g of tissue. During treatment of contaminated IIIB degree burns with Activetex-ChF dressings, bacteriological examinations of the wounds showed in 60% of cases no growth of micro-organisms, while microbial dissemination decreased from 104.5 to 102.1 CFU per g of tissue.

In control groups in similar periods of treatment, the same micro-organisms continued to persist as before treatment, while a slightly lower microbial dissemination was observed (falling from 104.6 to 103.5 CFU per g of tissue).

During treatment with Activetex-ChHap dressings, both in the main and the control groups, there was a reduction in microbial dissemination down to 102 CFU per g of tissue. However, despite the therapy applied, three patients in each group showed a persistence of P. aeruginosa, S. aureus, and E. coli cultures.

<% createTable "Table I","Variation of microbial flora and dissemination of burn wounds after treatment with Activetex-ChHap dressings and bandages with Laevomicol ointment",";Micro-organism§1,2§Activetex dressing§1,2§ Bandage with Laevomicol ointment@; Before treatment;After treatment;Before treatment;After treatment@;S. aureus;10;3;14;8@;S. epidermidis;3;1;3;1@;Gram-positive ;    @;bacilli ;2;-;1;1@;P. aeruginosa;17;8;16;14@;E. coli;1;1;1;2@;Citrobacter spp.;1;-;1;1@;Acinetobacter spp.;4;4;3;5@;P. mirabilis;1;-;1;1@;Non-fermenting Gram-negative bacilli;-;-;-;1@;Candida spp.;1;-;-;-@;Total;40;17;40;34@;Microbial dissemination,Log CFU;3.08;2.00;3.08;2.08","",4,300,true %>

Cytological assessment

The cytological picture of burn wounds treated with Activetex-ChL was characteristic of a rapid emergence and prevalence of macrophages. Sporadic epidermocytes were also observed, which testified to the development of regeneration processes.

In cases treated with Activetex-ChF, the cytological picture showed a predominance of microphages and polyblasts, and in the treatment of IIIA degree burns single epidermocytes were found in contrast with the control group, in which neutrophils were observed more frequently and lymphocytes were predominant.

Before treatment of non-healing residual wounds, the cytological examination of wound prints in both the main and the comparison groups showed a prevalence of the inflammatory-regenerative type of cytogram (80% in each group). Against the background of active treatment, the cytological picture showed improvement in both groups, and a transition towards regenerative-inflammatory (60%) and regenerative (40%) types of cytogram was observed. The cytological picture during treatment with Activetex-ChHap, compared with that of the control group, was characteristic of microphage predominance and the appearance of fibroblasts which were not seen previously during therapy with other types of Activetex® dressings.

The cytological picture in the course of Activetex-ChHap therapy, compared with the comparison group, was characteristic of a large number of fibroblasts in wound prints.

Histomorphological studies

The histomorphological investigation of granulating IIIB degree wounds prior to treatment of patients in both the main and the control groups showed acute oedema and massive derma infiltration by neutrophils and macrophages. These were especially pronounced in the boundary between the derma and hypodermic-adipose tissue (demarcation swell) and in blood-sodden and haemorrhagic areas in subcutaneous fat. On the surface, fibrin patches were observed in the form of tissue detritus and neutrophils. After conservative treatment, at the time of surgery the morphological investigation of burn wound biopsies showed a decrease in oedematous tissue infiltration, the appearance of blood vessels at the lower boundary of the demarcation swell being a sign of the development of granulation tissue. A specific feature the histological picture of post-Activetex-ChF treatment, compared with the control group, was a pronounced reduction in tissue infiltration, with a smoother demarcation swell. No haemorrhages or fibrin patches were seen on the granulation surface.

In contrast with the control group, after treatment with Activetex-ChHap an intense reduction was observed in neutrophil infiltration as well as fibroblast emergence and a more pronounced organization of collagen fibres.

Discussion

The effectiveness of the Activetex-ChF wound dressing is not less than that of traditional methods of treatment in limited non-contaminated II-IIIA degree wounds and in a number of instances is even higher. In addition, Activetex-ChL showed 100% treatment effectiveness in limited non-infected II degree burns, to cure which in most cases just one dressing application proved to be sufficient. Activetex-ChL has anaesthetic features and can be successfully used in out-patient clinics and as a first-aid measure in patients with limited non-infected II-IIIA degree burns.

The Activetex-ChF wound dressing, when used in the treatment of limited infected II-IIIÀ degree burns, thanks to its clinical efficiency is on the same level as traditionally used polyethylene glycol-based ointments. However, thanks to the antibacterial effect provided by furagin and chlorhexidine, the effect of Activetex-ChF on burn infection pathogens is greater.

Compared with traditional therapeutic methods, the use of one or two Activetex-ChF dressings prior to autodermoplastic surgery makes it possible in an absolute majority of cases to prepare granulating wounds for plastic surgery, reduce microbial dissemination, improve the cytological picture, and reduce the number of complications.

The application of Activetex-ChHap dressings in the care of non-healing burn wounds did not show any clinically significant advantages over traditional therapy, despite the cytologically proven stimulating effect on the regeneration process.

Overall, Activetex® dressings of various types - if judged on their clinical effectiveness - are equal to traditional therapeutic methods of treating burn wounds by polyethylene glycol-based ointments and in certain cases are superior to them.

Comparing treatment with Laevomicol ointment with treatment with Activetex® wound dressings, microbial dissemination of burns was 1.5-2 times lower and some acceleration of epithelialization was observed (1-2 days). The application of Activetex-ChHap stimulated regeneration processes, as proved by cytological and morphological investigations. Owing to the presence of certain drugs in the dressings, activation of the phagocyte reaction takes place in the wounds. The therapeutic action of Activetex® dressings is best exerted in moist conditions and periodical wetting is therefore performed (2-3 times a day). When wetted, the textile substrate of Activetex® dressings provides excellent wound surface modelling. In the presence of suppuration an accumulation of exudate under the dressing was sometimes observed, but this inconvenience was reduced by using perforated the dressings.

Our investigation shows that Activetex® dressings can be widely used as an alternative to traditional methods of topical burn treatment both in clinics and in the pre-hospital stage.


RESUME. Les Auteurs ont analysé le traitement topique de 40 patients atteints de plusieurs types de brûlures avec l’emploi de pansements d’Activetex®. L’Activetex exerce un effet prolongé thérapeutique grâce aux diverses substances médicinales qu’il contient (antibactériennes, anesthétiques, promotrices de la guérison) en association avec un polymère biocompatible. Un groupe témoin de patients atteints de brûlures analogues a été traité avec des onguents sur une base polyéthylèneglycole avec des préparations antibactériennes. Ils ont démontré la supériorité, en plusieurs cas, de l’efficacité des pansements Activetex par rapport aux onguents hydrosolubles; dans les autres cas l’efficacité est généralement égale à celle des onguents hydrosolubles dans le traitement des brûlures. L’Activetex-ChL est efficace dans le traitement des brûlures limitées non-infectées de degré II et III et peut être utilisé avec succès dans le traitement des brûlures infectées limitées de degré II et IIIA et pour préparer les brûlures de degré IIIA pour l’autogreffe. L’Activetex ChHap est efficace dans le traitement des brûlures résiduaires lentes à guerir. Le pansement Activetex peut être utilisé avec succès comme méthode alternative aux méthodes traditionnelles dans toutes les phases du traitement topique des brûlures dans les cliniques, dans les services ambulatoires et dans les services d’urgence.


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<% riquadro "This paper was received on 27 September 2001.

Address correspondence to: Dr A.A. Alekseev, A.V. Vishnevski Institute of Surgery, Burn Centre, Moscow, Russia." %>


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