Comparison of cultured epidermal autograft and massive excision with serial autografting plus homograft overlay.

The chief determinant of mortality in severe burn injuries has been the size and severity of the wound. Early massive excision of the wound has increased the median lethal dose to 98% of total body surface area burn but presents the problem of wound closure. Autograft substitutes must be used for a large burn. We report our experience with early massive excision in the treatment of 47 pediatric patients with burns who had greater than 80% total body surface area burn and greater than 80% full-thickness burn. Four patients died within hours of admission. Fifteen patients died of sepsis and multiorgan failure; the primary source of bacterial contamination was the open wound. The 28 survivors received approximately 2.0 m2 2:1 homograft until autograft became available. A case report of a 10-year-old boy illustrates the use of two types of cultured epidermal autograft, one "homegrown" and one commercially produced.     

Primary excision and immediate wound closure

Surgical principles of early excision of devitalized tissue and prompt wound closure which govern the management of all traumatic injuries have been developed in the primary treatment of burns. Topical and systemic antibiotics which delay wound infection and control invasive sepsis provide an initial period of two to three weeks in which wound excision and closure is safe and effective. Full support of the central and peripheral circulation, respiratory function, nutrition, and musculoskeletal function are essential features of care until the burn wound is eliminated and closed.Following initial evaluation, wound excision is carried beyond the deepest level of injured tissue. Excision to the level of muscle fascia is used for fullthickness injury and sequential excision in or below the dermis for deep dermal injury. Techniques of skin grafting and subsequent care of the graft are described, including the use of human allografts.Primary excision has reduced mortality, morbidity and later reconstructive measures by a factor of 50% when compared to results obtained by awaiting spontaneous separation of eschar with later grafting.With massive burns the use of allografts from familial donors of close immunologic type and immunosuppression of the patient prolong the period before allograft rejection and permit repeated harvest of the patient's donor sites for permanent wound closure. Over 60% of young burn victims with greater than 70% full-thickness burn injury have survived with this method of treatment.     

The effects of biological wound dressings on the healing process

Three major biological dressings are available for the temporary closure of wounds: partial-thickness cadaveric human allograft skin, several forms of partial-thickness antibiotic-treated porcine xenograft skin, and human amnion. Generally, biological dressings reduce pain, close the wound to contamination and fluid loss, and prepare the wound bed for permanent closure, usually with autografts. The three types of biological dressings differ in their performance, with allograft skin being clearly superior in its wound maintenance and preparation characteristics, while porcine xenograft presents serious difficulties in incorporation into the wound bed and antigenic challenge to the recipient, and amnion is excessively fragile and tends to allow wound desiccation. The most serious potential liability of biological wound dressings is transmission of infection; however, the actual incidence of such transmission is extremely low. The advantages of physiological coverage provided by biological wound dressings greatly outweighs the chance for harm in the case of human allograft.     

Burn therapy 1985: Acute management

Mortality occurs from a burn injury because of infections which result from the metabolic and bacterial consequences of a large open wound, depression of the host's resistance, and both protein and total caloric malnutrition. Systemic antibiotics, topical wound therapy, and gentle wound debridement constitute traditional burn therapy. The systemic antibiotics and topical wound therapy do not solve problems presented by large open wounds and the related protein and caloric deprivation. A more rational approach uses antibiotics and topical wound therapy only as adjuncts to a program of early operative removal or excision of the devitalized, burned tissue and immediate closure of the wound. The excised wound is normally closed with available autograft, but in massive burn injuries, donor skin is insufficient. In these massive injuries, artifical skin can provide that immediate wound closure. As long as devitalized, burned tissue remains present in the setting of depressed host resistance, cross infection tends to colonize those remaining devitalized burn wounds with more virulent organisms than those that were already present. Bacterial controlled nursing units (BCNU) provide strict protection against that cross infection. Though inevitably a catabolic response occurs with massive injury, intensive nutritional support provides the calories necessary for the response to injury to avoid a prolongation of that negative nitrogen balance.     

复方磺胺嘧啶锌涂膜与磺胺嘧啶银霜治疗小儿Ⅱ度烧伤创面的比较研究

目的：观察复方磺胺嘧啶锌涂膜治疗小儿Ⅱ度烧伤创面的疗效和安全性，探讨其在小儿烧伤治疗中的应用价值。方法：133例患儿随机分为复方磺胺嘧啶锌涂膜组70例（甲组）和磺胺嘧啶银霜组63例（乙组），比较两组患儿创面愈合时间、愈合率、药物抗感染效果及不良反应。结果：甲组创面愈合时间较乙组提前（P〈0．05），细菌检出率甲组小于乙组（P〈0．05）。用药后甲组未见加深现象，乙组出现加深现象，两组均无其他不良反应。结论：复方磺胺嘧啶锌涂膜治疗小儿烧伤安全、有效，可促进创面愈合，尤其适用于小儿Ⅱ度创面的治疗。     

Increased survival after massive thermal injuries in adults: preliminary report using artificial skin

Survival of major burn injuries has improved markedly from an expected survival of 10% to 20% in both children and adults to an expected survival of 60% in children with burns greater than 70% BSA. Increased survival for adults after similar burn injuries has been less dramatic than in children because of the profound influences of advancing age and the coexistent processes of aging upon survival after a major injury. Consecutive admissions of patients with massive burn injuries (greater than or equal to 70% BSA) to the Massachusetts General Hospital Adult Burn Unit from 1974 to 1986 were analyzed statistically using univariate and multiple logistic regression analysis to identify factors associated with survival and to identify patient characteristics associated with increases in expected survival. Survival of adults with massive burn injuries has improved markedly, from 24% of adults admitted to the Adult Burn Center in 1974-75 to 48% of adults admitted in 1984-86. An increased likelihood of survival was shown to be associated with the use of artificial skin. Improved survival rates in these massive burn injuries were attributed to multiple factors including wound management of prompt eschar excision and immediate wound closure.     

The 1999 clinical research award. Cultured skin substitutes combined with Integra Artificial Skin to replace native skin autograft and allograft for the closure of excised full-thickness burns

Prompt and permanent closure of excised full-thickness burns remains a critical factor in a patient's recovery from massive burn injuries. Hypothetically, Integra Artificial Skin (Integra) may replace the need for allografts for immediate wound coverage, and cultured skin substitutes (CSS) that contain stratified epithelium may replace the need for autografts for definitive wound closure. To test this hypothesis, 3 patients with full-thickness burns of greater than 60% of their total body surface areas had their eschar excised within 14 days of admission. Integra was applied, and a skin biopsy was collected from each patient for the preparation of CSS. At 3 weeks or more after the application of the Integra and the collection of skin biopsies, the outer silastic cover of the Integra was removed and CSS were grafted. The CSS were irrigated with nutrients and antimicrobials for 6 days and then dressed with antimicrobial ointment and cotton gauze. Treated wounds were traced on days 14 and 28 after the grafting of CSS for determination of engraftment and wound closure, respectively. Cost analysis was not performed. Engraftment on postoperative day (POD) 14 was 98%+/-1% (mean +/- standard error of the mean), the ratio of closed:donor areas on POD 28 was 52.3+/-5.2, and no treated sites required regrafting. The histology of the closed wounds showed stable epithelium that covered a layer of newly formed fibrovascular tissue above the reticulated structure of the degrading Integra. The clinical outcomes of the closed wounds after POD 28 demonstrated smooth, pliable, and hypopigmented skin. Two patients who had received CSS grafts over Integra on their backs were positioned supine on air beds from POD 8 or POD 9 with minimal graft loss because of mechanical loading. One patient with a full-thickness burn of 88% of the total body surface area was covered definitively at 55 days postburn. These results demonstrate that the combination of CSS and Integra can accomplish functionally stable and cosmetically acceptable wound closure in patients with extensive full-thickness burns. This combination of alternatives to the conventional grafting of split-thickness skin permits the substitution of cadaveric allograft with Integra and the substitution of donor autograft with CSS. This approach to the closure of excised full-thickness burns is expected to reduce greatly the time to definitive closure of burn wounds and to reduce the morbidity associated with the harvesting of donor sites for split-thickness skin autografts.     

Minor burns: treatment using a new drug delivery system with silver sulfadiazine

We investigated a new product for treatment of burn wounds in outpatients. The product is a drug delivery system composed of polyethylene glycol 400, poly-2-hydroxyethyl methacrylate, and dimethyl sulfoxide into which silver sulfadiazine is incorporated for sustained release. It is applied to the wound and changed every four to five days until the wound has epithelialized. Of the 20 patients we treated by this method, none had wound infections. Most patients had partial-thickness injuries that epithelialized without difficulty. One patient with full-thickness injuries required subsequent excision and grafting. Application of the product over joint surfaces facilitated range of motion. The product was easy to apply, it diminished pain, and it produced no abnormal effects except for an occasional bad odor.     

Vacuum-assisted closure use in calciphylaxis

Calciphylaxis-induced chronic wounds are difficult to heal. The value of vacuum-assisted closure (VAC) was assessed in two patients with calciphylaxis. Two middle-aged females with type 2 diabetes were transferred to the burn unit with a clinical diagnosis of necrotizing fasciitis, although the pathologic diagnosis was calciphylaxis. With extensive debridement, antibiotics, and meticulous wound care, one patient had progressive necrosis of her skin from 18 to 48% TBSA, whereas the other progressed from 5 to 10% TBSA only. The patient with the smaller chronic wound healed well and left the hospital at 72 days after admission. Although there was some success with the use of VAC, the patient with the extensive progressive wounds developed a fungal wound infection that did not respond to treatment; she died 78 days after initiation of burn center treatment. Some disadvantages to the usefulness would be extensive contiguous wounds and the lack of an intact skin surface. The VAC system was of value in healing wounds resulting from calciphylaxis.     

早期应用辐照氟银猪皮对浅Ⅱ度烧伤创面愈合作用的临床研究

目的探讨早期应用辐照氟银猪皮对浅Ⅱ度烧伤创面的愈合作用。方法对20例大面积浅Ⅱ度烧伤患者早期应用辐照氟银猪皮治疗,观察其对创面愈合作用的影响。结果所有病例创面均顺利愈合,创面平均愈合时间为（9.2±1.2）d,且愈合后色素沉着、瘢痕少,无一例发生感染,平稳度过休克期,均无局部刺激症状和过敏反应,肝、肾功能,血常规检查指标均正常。结论早期应用辐照氟银猪皮治疗大面积浅Ⅱ度烧伤创面愈合快,最大限度地保留创面再生能力,给创面愈合提供了良好的内环境。同时患者病情平稳、疼痛轻、瘢痕少,提高了生活质量。     

Lack of long-term durability of cultured keratinocyte burn-wound coverage: a case report.

Cultured epithelial autografts have been advocated for permanent closure of skin surfaces after massive thermal injuries. A 10-year-old boy sustained a nearly 100% total body surface area burn (98% full-thickness) in an explosion accident. Cultured epithelial autograft was used to cover 70% of the total body surface area on postburn day 26. In spite of early success of coverage, 60% of cultured epithelial autograft areas blistered and sloughed over the ensuing weeks. Electron microscopic examination of a biopsy specimen of the healed cultured epithelial autograft (80 days after placement) revealed a lack of dermal attachments of the anchoring fibrils. Additionally, blister fluid that was taken from the bullae of the cultured epithelial autograft revealed levels of 18 ng/ml thromboxane and 24 ng/ml prostaglandin E2. These levels are significantly higher than those seen in acute burn blister fluid and indicate an ongoing inflammatory process. Cultured keratinocytes, although they provide early wound closure, may not provide adequate long-term coverage for patients with massive burns.     

Wound bed preparation: approaches to replacement of dermis.

Cultured epidermal autograft (CEA) can provide a valuable source of protection in patients with large amounts of skin loss as a result of thermal injury. An unanswered question is: will the long-term outcome be better if a dermis is present? We have approached the problem by attempting to retain the cryopreserved allograft dermis that is originally placed as temporary wound coverage. The retained dermis provides a substantial, uniform, well-vascularized bed that accepts the CEA. The areas that are grafted with CEA have remained durable, and cosmesis is superior to that which results from meshed grafts. We report experience with our technique in three patients with total body surface area burns of 70% to 90% who had cryopreserved meshed (1:1.5) allografts placed immediately after tangential excision of their burns. Excision and application of the allografts were complete by day 14 or 15. CEA was placed on allodermis on days 24, 28, and 35, respectively. Patients 1 and 2, who survived and returned to work, had a "take" of at least a 90% of allograft and a permanent coverage CEA take of 88% and 81%, respectively. Patient 3, who died, had an allograft take of only 20% to 30% and a CEA take of less than 10%.     

Herpes simplex infection in a minor burn wound: a case report

The etiology of herpetic lesions on burn wounds generally is believed to be a reactivation of previous infection or possible exposure to the pathogens under an immunocompromised status. However, this scenario rarely happens in a non-immunocompromised infant with low burned body surface area (<4% TBSA). We report a case of previously healthy 21-month-old boy who sustained minor scald burn injury involving only 4% TBSA that was complicated with herpes simplex type 1 viral infection. The infection presented with ulcerative burn wound and delayed wound healing. The Tzanck smear of vesicular fluid for the identification of multinucleated giant cells is helpful in making the decision for the early initiation of acyclovir. In this work, we describe a case of pediatric burn patient with herpetic infection and emphasize the need for careful and impartial examination of the child to improve the accuracy of diagnosis.     

Addendum: multicenter experience with cultured epidermal autograft for treatment of burns.

Since 1989 BioSurface Technology, Inc. (Cambridge, Mass.) has provided over 37,000 cultured epidermal autografts (CEAs) for more than 240 patients in 79 different burn centers in the United States and Europe. The average burn treated with BioSurface's CEA has been 70% total body surface area, half of that being full-thickness. Data, verified for 104 patients, indicate an average final "take" of about 60%, with half of all patients achieving a final take greater than or equal to 70% and 22% with final take greater than or equal to 90%. Sixteen percent of the patients had a take of less than 30%; many of these were associated with wound infection. Patient age, size of burn, and extent of full-thickness injury did not significantly affect take. Early excision followed by temporary coverage with homograft, which is allowed to engraft, was found to be associated with a low infection rate and a higher rate of CEA take. When engrafted homograft was only partially excised, leaving a layer of "allodermis" as the graft bed for CEA, take averaged 90% among 14 patients. Thus, our analysis of the extensive experience of many burn centers now permits more specific and helpful recommendations on standards of care to maximize efficacy of CEA.     

Lack of immediate effects of wound excision on the hyperdynamic circulation of burned patients

The high cardiac output (CO) observed during the chronic phase in burned patients has been ascribed, among other factors, to the elevated blood flow in the burn wound. The hemodynamic effects of wound excision to fascia have been studied in eight patients with second- and third-degree burns ranging from 42% to 70% total body surface area (TBSA) undergoing debridement and skin-grafting procedures. The study was performed on the 4th to the 51st postburn day when all patients were in a hyperdynamic state. Serial hemodynamic measurements, including arterial and mixed-venous blood O2 saturation and content, were made before induction of anesthesia, during surgery both before and after wound excision, and in the recovery room a few hours after surgery. During anesthesia, the elevated CO decreased probably as a consequence of decreased metabolic requirements, but no further hemodynamic change was observed following wound excision. The size of burn wound excised to fascia averaged 24% TBSA and ranged from one-third to more than one-half of the initial burn. With discontinuation of anesthesia, CO rose rapidly above preoperative values, apparently to meet a similar increase in oxygen consumption. The excision of large areas of burned tissue did not attenuate the hyperdynamic circulation in burned patients, at least during and immediately after surgery. The data suggest that the elevated blood flow in the burn wound does not play a significant role in the pathogenesis of the hyperdynamic state.     

A nonuser's questions about cultured epidermal autograft.

Clinical experience assumes major importance as the source of data on cultured epidermal autograft (CEA), since a large controlled study is probably not forthcoming. Among the general questions to be answered are: Which patients are candidates for grafting with CEA? Do selection criteria specify size of total body surface area burn or age? Is CEA more suitable for certain body areas than others? Does CEA close the wound as quickly, as well, and as safely as other available methods of coverage? Fresh or frozen allograft, the gold standard, is presumed to be safe, but the current concern about transmission of viral diseases raises doubts. Presumably, CEA would be safe. Other concerns are care of the wound and control of infection during the 3-week waiting period that is required for CEA. What is actual CEA "take" (i.e., areas that do not require regrafting)? What is the clinical experience with follow-up? Cost-effectiveness of CEA is a factor including hospital stay and hidden costs such as failure of temporary wound coverage. Whether CEA saves lives is probably unanswerable, but as a skin cover it may reduce incidence of burn wound sepsis. Perhaps in the future, a combination of cultured epidermal cells and a type of permanent dermis will produce a cover that is genuine skin. Today we have only materials that are parts of skin.     

Conservative treatment of scald burns is superior to early excision.

Early excision of deep burns has been advocated; however, it is difficult to clinically determine the depth of scald burns during the early postburn period. This prospective, randomized study was designed to determine whether early excision was superior to conservative treatment of scald injuries. Patients with scald injuries (which were not caused by grease) of clinically indeterminant depth were randomized to early (n = 12) or late (n = 12) excision; all patients with obvious superficial and full-thickness injuries were excluded. In the early excision group, all deep wounds were tangentially excised and grafted within 72 hours of admission, whereas in the late treatment group wounds were excised and grafted after 2 weeks had passed since injury. Area excised, postburn day of excision, percent graft take, operating-room time, blood replacement, incidence of infection, and length of hospital stay were compared. No patient experienced a significant wound infection or systemic sepsis. A significantly smaller area of excision was necessary for those patients who were treated with delayed surgery, and concomitant decreases in operating-room time and blood loss were observed. Notably, only one half of the patients who were randomized to the delayed excision group ultimately required surgical intervention to achieve wound closure. Graft take was comparable for both groups, as was length of hospital stay. Early clinical evaluation of scald injuries appears to be equivocal, and later evaluations reveal a less severe injury. Financial gains can be made when surgical excision of scald injuries is delayed until 2 weeks after injury because of a related reduction in hospital expenditures.     

Cost-effective use of helicopters for the transportation of patients with burn injuries

We performed a retrospective review to analyze the use of helicopters for the transportation of patients with burn injuries to determine whether a more cost-effective approach could be developed without impairing the quality or delivery of health care. Charts were reviewed for all patients with burn injuries who were transported by helicopter to our hospitals during a 2-year period. Patients with inhalation injuries, with burn injuries received more than 24 hours before admission or more than 200 miles from our burn center, with more than 30% total body surface area (TBSA) burned, or with associated trauma injuries were excluded. Control patients with burn injuries who were transported by ambulance were identified and matched to the patients with burn injuries transported by helicopter for the percentage of TBSA burned, the percentage of third-degree burns, transport mileage, and age. The outcome was evaluated by comparison of length of stay, days on ventilator, and mortality rate. Comparisons were performed with Student t test. The transportation charge was determined for the patients transported by helicopter who we believed were eligible for transport by ambulance. Forty-seven of 85 patients transported by helicopter matched the inclusion criteria and had survived. There was no statistically significant difference between the percentage of TBSA burned, the percentage of third-degree burns, length of stay, days on ventilator, age, or transport mileage. There was, however, a significant difference in the time from the injury to admission to the hospital, as well as in the charge for transportation. Patients who had less than 30% TBSA thermal cutaneous injuries without evidence of inhalation injury, and who are less than 200 miles from a burn center may be safely transported by ambulance. Ambulance transportation may take additional time; however, stricter protocols for helicopter transportation of patients with burn injuries will result in potentially substantial savings without affecting outcomes for patients.     

Effect of sequential early burn wound excision and closure on postburn oxygen consumption

OBJECTIVE: To determine the effect of early excision and closure of burns on postburn hypermetabolism, measured as oxygen consumption (VO2). METHODS: Twelve patients with deep burns of 30% to 50% of total body surface underwent sequential excisions and wound coverage, beginning 1 to 3 days after burn. The majority of the deep burn was removed by day 7, but with the addition of a donor site area of 20% to 25% of total body surface. RESULTS: No decrease in VO2 was noted in relation to the percent removal of burn tissue. In addition, a transient further increase in VO2 was noted early after excision, especially with surgical procedures performed after 5 days. This response could not be attributed to wound manipulation-induced bacteremias. CONCLUSION: We conclude that early surgical excision and closure of burns in excess of 30% to 50% of total body surface do not decrease postburn hypermetabolism in proportion to the area closed. It is possible that remaining open wounds in the form of donor sites and nonexcised burn are sufficient to perpetuate the hypermetabolic process, once established.     

Laser Doppler monitoring of microcirculatory changes in acute burn wounds

Because burns are dynamic wounds that can change in apparent depth during the first 72 hours, we asked whether measuring changes in cutaneous blood flow might help predict the ultimate fate of burns that were not obviously shallow or deep. A laser Doppler flowmeter was used to study cutaneous perfusion for at least 72 hours in partial-thickness wounds on patients with burns of less than 15% TBSA and in experimental wounds of similar size on rats. Clinical wounds that healed without grafting consistently showed elevated perfusion levels which increased further within 72 hours, whereas wounds eventually requiring grafting experienced lower perfusion levels with no obvious pattern of increase. Differences between average flow levels for healing and nonhealing burns were statistically significant throughout the study period. Perfusion levels in experimental wounds were stratified according to burn severity, with shallower wounds showing a pattern of increase similar to the clinical wounds.