% vol = 15 number = 2 prevlink = 70 nextlink = 79 titolo = "TOPICAL TREATMENT OF TOXIC EPIDERMAL NECROLYSIS USING OMIDERM® AND GLYCEROL-PRESERVED HUMAN CADAVER SKIN*" volromano = "XV" data_pubblicazione = "June 2002" header titolo %>
SUMMARY. The extensive epidermal slough seen in toxic epidermal necrolysis resembles that of partial-thickness burns. Temporary coverage of denuded skin with biological or synthetic dressing materials minimizes heat and fluid loss from the wound, prevents wound infection, reduces pain, and promotes re-epithelialization. A 36-year-old female with epidermal sloughing in 90% total body surface area was successfully treated in this way. All detached epidermis was removed and the denuded skin was temporarily covered with Omiderm® and glycerol-preserved human cadaver allografts. We observed that these synthetic and biological materials were equally effective as regards healing time and quality.
Toxic epidermal necrolysis (TEN) or Lyell’s syndrome is an idiosyncratic severe systemic disease characterized by extensive full-thickness epidermal sloughing (30-100% total body surface area) associated with mucous membrane and corneal involvement, fever, and severe pain. TEN is most often related to adverse drug reaction and has a significant morbidity and high mortality (mean, 30%) with an average incidence in Western countries of about 1 per million.1
The acute epidermal exfoliation seen in TEN resembles a partial-thickness burn, and a significant amount of heat and fluid can be lost from the denuded skin. If viable dermis can be protected from toxic detergents, desiccation, mechanical trauma, and wound infection, spontaneous epithelialization in 1-3 weeks without scarring is the rule.1,2 The aims of local treatment methods used for TEN are: to minimize heat and fluid loss from the wound, prevent wound infection, reduce pain, and provide a moist, clean wound environment in order to promote re-epithelialization.
Biological and synthetic temporary wound coverage materials - such as amniotic membrane, porcine xenograft, fresh-frozen or cryopreserved cadaver allograft, cryopreserved cultured epidermal allograft, alginates, and Biobrane® - have been used effectively in clean wounds.2-9
Omiderm® (Omikron Scientific Limited, Rehovot, Israel) is a hydrophilic co-polymer membrane made of polyurethane that is permeable to water and oxygen. It has been used as a dressing material in the treatment of partial-thickness burns, skin graft donor sites, CO2 laser dermabraded surfaces, and exposed areas in epidermolysis bullosa.10-13 Glycerol-preserved human cadaver allografts have been used for the temporary coverage of burn wounds like cryopreserved allografts.14
To our knowledge, the present study reports the first successful use of Omiderm® and glycerol-preserved human cadaver allograft in the local treatment of TEN.
A 36-year-old female was admitted to our burns unit with a tentative diagnosis of TEN necrolysis due to intravenous treatment of ampicillin + sulbactam (1 g q.i.d.) for pyoderma. On the day of admission the skin had the appearance of having suffered a recent scald, which covered 90 per cent of the total body surface area. There was bilateral conjunctivitis, while the oro-nasal mucosa was intact. The patient’s oral temperature was 37.8 oC. Laboratory values obtained on the day of admission showed mild leukocytosis and elevated liver enzymes. The skin biopsy confirmed the diagnosis of TEN.<% immagine "Fig. 1","gr0000010.jpg","A 36-year-old female patient suffering from TEN. Patient after removal of all detached epidermis under i.v. ketamine anaesthesia without intubation.",230 %>
The sloughed epidermis was totally removed under i.v. ketamine anaesthesia without intubation (Fig. 1). Omiderm® was applied to the right upper extremity and anterior trunk and secured with sterile tapes. The denuded skin of the left upper extremity and both lower extremities were covered with 1:2 meshed glycerol-preserved human cadaver allografts (Euro Skin Bank, Beverwijk, Netherlands), which were secured with a skin stapler. The allograft-treated areas, the back, and the gluteal regions of the patient were closed with a 0.5% chlorhexidine-acetate-impregnated dressing material (Bactigras®, Smith and Nephew, England) and absorbent gauze. Omiderm®-applied areas were also closed with an absorbent gauze dressing to prevent shear forces. Mupirocin ointment was applied to the face and left open. The patient was placed on an airbed in a single room to prevent nosocomial infection. All the extremities were immobilized for three days. We then opened the external dressings and observed that both the Omiderm® and the allografts adhered well to the dermal bed and that there was no sign of wound infection (Fig. 2-5). We left the Omiderm®-applied areas open and continued to close the allografts for two weeks.
|<% immagine "Fig. 2","gr0000011.jpg","Omiderm® applied to right upper extremity.",230 %>||<% immagine "Fig. 3","gr0000012.jpg","Omiderm® applied to trunk.",230 %>|
|<% immagine "Fig. 4","gr0000013.jpg","Glycerol-preserved human cadaver allograft applied to left upper extremity.",230 %>||<% immagine "Fig. 5","gr0000014.jpg","Glycerol-preserved human cadaver allograft applied to lower extremities.",230 %>|
Four days after admission to the burns unit, the patient developed respiratory distress and required intubation and mechanical ventilation for seven days. Central catheter cultures revealed Staphylococcus aureus; the patient was started on broad-spectrum antibiotic coverage including amikacin (i.v. 500 mg b.i.d.) and vancomycin (i.v. 500 mg q.i.d.) for 10 days. Chest physiotherapy, frequent tracheal aspiration, oxygen, and humidified air were given. On day 12 after admission to the burns unit, the patient’s general condition stabilized and no further mechanical ventilator assistance was required.
On day 14, all the denuded skin regenerated except some parts of the back and the gluteal region. Omiderm® and allografts were easily removed, with epithelial regeneration progressing beneath. There was no difference between Omiderm®- and allograft-treated areas as regards healing time and quality. Aggressive physical therapy was maintained during the course of hospitalization. After complete re-epithelialization, including that of the back and the gluteal region, the patient was discharged on day 28. She was advised to protect her skin from sunlight, use skin moisturizers, and wear compressive garments for the lower extremities while standing. During the two-month period after discharge from the burns unit, no late complication was observed except for pigmentary changes and nail dystrophy (Fig. 6).<% immagine "Fig. 6","gr0000015.jpg","Patient two months after discharge from burns unit.",230 %>
It is often recommended that burn wounds should be treated conservatively, leaving the detached epidermis in position as a biological dressing and covering only the denuded skin with a dressing. Debridement is advised only for sloughed skin that can no longer serve as a biological barrier or when infection is suspected in the area.1, 15 We did not try to preserve the detached epidermis but removed it entirely, after which we applied biological and synthetic dressings. Our reasons were as follows: it was not practical to apply dressings in a patchy fashion and modify them each successive day; the decision as to when sloughed skin could no longer serve as a biological barrier was subjective; and, most importantly, there was a risk of wound infection under detached skin, with a possibility of missing the chance of applying skin substitutes.16
We covered most of the denuded areas with Omiderm® and glycerol-preserved cadaver allografts before any wound infection developed. These adhered well to the dermal bed and a temporary barrier was created between dermis and environment. Heat and fluid loss from the wound surface was thus minimized, microbial contamination from the surroundings was prevented, and a moist environment was achieved, promoting re-epithelialization. Successive dressing changes were more comfortable and less painful for the patient.
We used Omiderm® in the local treatment of partial-thickness burns. This was however the first time we had used it in cases of TEN. We observed that all the Omiderm®- or cadaver-allograft-covered sites healed in similar fashion. There was no difference, as regards healing time or quality, between right and left upper extremities, as also between the trunk and the lower extremities covered with different materials. Since there is no air-fluidized (Clinitron) bed in our burns unit, we could not apply the above-mentioned dressing materials to the back and gluteal region; these areas were under relatively greater pressures, resulting in delayed spontaneous epithelialization.
Cadaver allografts (fresh-frozen, cryopreserved, or glycerol-preserved) are the most commonly used temporary biological wound closure materials. However, the potential risk of viral transmission by allografts (due to hepatitis and HIV) and their cost constitute important drawbacks in the use of cadaver skin.
On the other hand, Omiderm® folds easily and it is difficult to cover irregular surfaces. Great care and strict immobilization are necessary for it to adhere to the wound bed. Excessive serous fluid collection under Omiderm® is a potential problem for exudative wounds, but this problem can be solved with the use of meshed Omiderm®. Omiderm® thus has some drawbacks, but it is easy to store, has a long shelf life, does not carry the risk of viral transmission, and is cheaper than allografts.
We used Omiderm® and glycerol-preserved human cadaver allografts successfully in the topical treatment of TEN and observed no significant difference between the two skin substitutes with regard to the time or quality of healing. However, no conclusions can be drawn from a single patient, and our observations have encouraged us to use Omiderm® in selected cases of TEN.
RESUME. L’escarre épidermique étendue observée dans les patients atteints de nécrolyse épidermique toxique ressemble à celle des brûlures d’épaisseur partielle. La couverture provisoire de la peau dénudée moyennant des pansements biologiques ou synthétiques minimise les pertes caloriques et liquides de part des lésions, prévient leurs infections et favorise la ré-épithélialisation. Une patiente âgée de 36 ans atteinte d’escarres épidermiques dans 90% de la surface corporelle totale a été traitée en cette manière avec de bons résultats. Tout l’épiderme détaché a été éliminé et la peau dénudée a été couverte moyennant Omiderm® et des allogreffes de cadavre humain préservées en glycérol. Les Auteurs ont noté que ces matériaux synthétiques et biologiques avaient la même efficacité pour ce qui concerne le temps et la qualité de la guérison.