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.     

Cultured epidermal autograft and the treatment of the massive burn injury.

As a rule, adult and pediatric patients with thermal injuries that involve more than 90% total body surface area (TBSA) burn have poor prognoses. Even for patients who are 5 to 34 years old with a 70% TBSA burn, the mortality rate is 80%. Lack of autologous donor skin, which is essential for permanent wound closure, is the major problem. Recent advances in growth of cultured epidermal autograft (CEA) have allowed closure of full- and partial-thickness burns; in approximately 3 weeks, a 2 cm2 biopsy specimen will produce enough CEA to cover a pediatric patient. Since 1989, we have used this product on nine patients; the average age was 39, and the average TBSA burn was 70% (range, 44% to 93%). We report our approach to use of CEA in six of these patients, including topical applications of 1% silver sulfadiazine and excision of full- and deep partial-thickness wounds within 2 weeks of injury. Temporary closure was achieved with cadaver allograft. "Take" of the allograft forecasted take of CEA. The total operative time of CEA placement was decreased by a two-step technique that obviates repeating debridement: the technique consists of debriding and grafting with allograft, then removing it at the time of CEA placement. CEA take is best on early granulation tissue or freshly excised wounds. Early excision of burn eschar, temporary wound closure with cadaveric allograft and Biobrane (Winthrop Pharmaceuticals, Wound Care Div., Fountain Valley, Calif.), and permanent closure with CEA may improve survival rates among patients with massive burn wounds. CEA is a tremendous asset to the management of massive burn injuries.     

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.     

Efficacy of topically delivered moxifloxacin against wound infection by Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus

Wound infection is a common risk for patients with chronic nonhealing wounds, causing high morbidity and mortality. Currently, systemic antibiotic treatment is the therapy of choice, despite often leading to several side effects and the risk of an insufficient tissue penetration due to impaired blood supply. If systemically delivered, moxifloxacin penetrates well into inflammatory blister fluid, muscle, and subcutaneous adipose tissues and might therefore be a possible option for the topical treatment of skin and infected skin wounds. In this study, topical application of moxifloxacin was investigated in comparison to mupirocin, linezolid, and gentamicin using a porcine wound infection and a rat burn infection model. Both animal models were performed either by an inoculation with methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. Wound fluid, tissue, and blood samples were taken, and bacterial counts as well as the moxifloxacin concentration were determined for a 14-day follow-up. A histological comparison of the rat burn wound tissues was performed. Both strains were susceptible to moxifloxacin and gentamicin, whereas mupirocin and linezolid were effective only against MRSA. All antibiotics showed efficient reduction of bacterial counts, and except with MRSA, infected burn wounds reached bacterial counts below 10(5) CFU/g tissue. Additionally, moxifloxacin was observed to promote wound healing as determined by histologic analysis, while no induction of bacterial resistance was observed during the treatment period. The use of topical antibiotics for the treatment of infected wounds confers many benefits. Moxifloxacin is therefore an ideal candidate, due to its broad antibacterial spectrum, its high efficiency, and its potential to promote wound healing.     

Immunosuppression of the burned patient

The burn patient is highly susceptible to infection due to the loss of the skin as a barrier to microorganisms. Immune defenses are activated in response to the burn injury; however, some of these defenses are altered. Neutrophil chemotaxis is compromised by decreased perfusion caused by hypovolemia and the formation of microthrombi. Chemotaxis and phagocytosis are dependent on complement components that are reduced in a large burn wound. Neutrophil intracellular killing power is reduced as oxygen delivery to the wound is decreased. Humoral immunity is altered with the drop in IgG levels. Cell-mediated immunity is depressed and T cell lymphocyte counts are deceased. Suppressor T cells are generated. Specific sources of infection for the burn patient include the patient's own bacterial flora; hospital personnel; respiratory equipment; and catheters, both urinary and intravascular. The best control for burn wound infection is the closure of the wound by early excision and grafting. When lack of donor sites prohibits this surgical therapy, control centers on the environment and wound care techniques. The selection of wound topical antibiotics on the basis of visual inspection and surface culturing assists in the prevention of burn wound sepsis. When wound sepsis does occur, systemic antibiotics are instituted. Although burn wound sepsis is an obvious cause of death for the burn patient, it is not the primary cause. Increasing sophistication in fluid resuscitation and in intensive care therapy has resulted in patients living beyond the initial insult and the following few days. Burn patient mortality is now associated with a syndrome presenting clinically as sepsis but without any identifiable septic source.(ABSTRACT TRUNCATED AT 250 WORDS)     

Therapeutic efficacy of timentin and augmentin versus silvadene in burn wound infections

Successful closure of thermal injuries, by either skin graft or delayed wound closure, largely depends on the ability to control the number of bacteria in the wound. The purpose of this study was to investigate the efficacy of two new antimicrobial agents, ticarcillin and clavulanate (Timentin) and amoxicillin and clavulanate (Augmentin), in the infected thermal injury. The therapeutic results were compared with the model treated with the standard topical silver sulfadiazine (Silvadene). Seventy-six Sprague-Dawley rats received a 20% full-thickness thermal injury and were then divided into six treatment groups. Three of the groups were inoculated topically with 10(8) Pseudomonas aeruginosa/ml, and three of the groups received topical inoculation of 10(8) Staphylococcus aureus/ml. The groups inoculated with P. aeruginosa received either intraperitoneal Timentin, topical Silvadene, or placebo treatment. The groups inoculated with S. aureus were treated with either enteral Augmentin, topical Silvadene, or placebo. The animals received 10 days of therapy and underwent tissue biopsies on alternate days. Statistical analysis showed that the level of bacteria in the wounds compared with the control group was significantly (p less than 0.05) decreased for both antibiotics tested as measured by quantitative wound biopsies. These studies demonstrate the efficacy of systemic Timentin and Augmentin in the infected thermal injury.     

Evaluating and managing open skin wounds: colonization versus infection

Open skin wounds are colonized with bacteria, and optimal wound care is required to prevent progression to infection. Intact skin normally provides protection from external environmental assaults. Disruption of the skin or tissue creating an open skin wound can result in infection, dehydration, hypothermia, scarring, compromised immunity, and changes in body image. Biofilms and bacterial genomics are areas of intense scientific investigation in the face of the emerging threat of bacterial resistance. Optimal wound care to prevent progression from colonization to infection remains the foundation of good clinical practice. On the basis of wound conditions, cleansing, debridement, measures to increase oxygenation and perfusion, adequate nutrition, and appropriate use of topical agents and antibiotics, when indicated, are the keys to managing open skin wounds. This article provides a targeted review of normal skin flora, wound healing, prevention of skin infection, colonization versus infection, biofilms, genomics and infectious disease, and management of open skin wounds.     

Skin lipopolysaccharide-binding protein and IL-1beta production after thermal injury

In response to a burn injury, skin can have an inflammatory response characterized by the production of inflammatory cytokines, recruitment of immune cells, containment of invading organisms, and clearance of noxious substances from the wound. Lipopolysaccharide-binding protein (LBP) is a molecule that is capable of coordinating all 4 functions; we previously found evidence that suggested that LBP is produced within surgical wounds. Because of the central role of LBP in the response to bacterial infection, as well as in the high rate of infection after burn injuries, we sought to determine whether a thermal injury could affect wound LBP production and thereby affect host responses against bacterial infection. Rats were given either a burn or a sham burn and were killed 24, 48, and 72 hours after the injuries. Wound specimens were assayed for bacterial counts and for the presence of LBP, messenger (m)RNA, and interleukin (IL)-1beta mRNA. Wound LBP mRNA was significantly upregulated at 24 hours in the group with burn injuries (P < .05; burn vs sham burn); this was followed by decreases at 48 and 72 hours. Immunohistochemistry showed LBP protein in the epidermis of animals with burns. Bacterial counts increased in the group with burn injuries (P < .05; burn vs sham burn) and continued to rise for 72 hours. IL-1beta mRNA levels were elevated at all time points in the group with burn injuries (P < .05). These results suggest an inverse correlation between burn wound LBP expression and bacterial wound counts. This failure to maintain local LBP production after severe thermal injury despite localized inflammation shown by high IL-1beta levels may predispose local wounds to bacterial invasion.     

The burned hemophiliac

Reports of the care of burned hemophiliac patients requiring cutaneous autografting are rare. A 28-year-old white male with classic hemophilia A sustained a 30.5% total body surface area burn. The patient received standard topical antimicrobial therapy and the majority of his burn wound healed. While undergoing therapy, multiple tooth extractions were recommended. On postburn day 25 the patient underwent multiple tooth extractions plus excision and grafting of his unhealed burn after preoperative infusion of cryoprecipitate. Despite a maximum factor VIII concentration of only 23%, no remarkable bleeding occurred from the excision sites, the skin graft donor site, or the tooth extraction wounds. Preoperative infusion of cryoprecipitate does not appear to be required for split-thickness skin graft harvest or excision of burns within the dermis.     

Comparative evaluation of zinc sulfadiazine and silver sulfadiazine in burn wound infection

One percent silver sulfadiazine has been commonly used as a topical antimicrobial agent after a burn injury. Incidence of burn wound colonization by Staphylococcus aureus in patients treated with silver sulfadiazine has spurred research for other agents. A topical preparation that contains zinc and sulfadiazine (Zad-G) was evaluated for in vitro antibacterial spectrum and in vivo efficacy. Muscle biopsy specimens of rats treated with Zad-G appear to have fewer colonies of S. aureus than groups treated with silver sulfadiazine. Topical therapy with Zad-G for patients with burns was comfortable, reduced wound infection, and was comparable to therapy with silver sulfadiazine. A topical Zad-G preparation that contains zinc sulfadiazine appears to be an effective alternative to silver sulfadiazine in the treatment of burn wounds.     

Management of lacerations in the emergency department

The goals of wound management are simple: avoid infection and achieve a functional and aesthetically pleasing scar. This is achieved by reducing tissue contamination, debriding devitalized tissue, and restoring perfusion in poorly perfused wounds, in conjunction with a well-approximated skin closure.     

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.     

USE OF ANTIBIOTICS AFTER COMPLEX OPEN HAND INJURY

SUMMARY A prospective study undertaken to examine bacterial contamination at presentation, frequency and type of antibiotic prescribed, and outcome, in 50 patients presenting with hand injuries of varying severity, is reported. Results of a national survey of trends in antibiotic prescribing for similar wounds in plastic surgery units are also recorded. Preoperative swabs cultured normal flora or no growth. Forty-eight patients received antibiotics with little consistency in the agent used, route of administration, or length of treatment. Clinical wound infection occurred in three crush injuries. No significant difference in the numbers of surgeons using antibiotics for clean and crushed injuries of all types was demonstrated. The state of the wound, rather than the tissue damaged, seemed to dictate antibiotic use. In dirty wounds, however, damage to deep structures appeared to be an indication for antibiotics — significantly fewer respondents treated dirty injuries of the skin alone. The authors believe that antibiotic use in open hand injury is of no proven benefit, and that this aspect of hand surgery requires further investigation.     

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.     

Topical matrix-based siRNA silences local gene expression in a murine wound model

The ability to affect gene expression via topical therapy has profound therapeutic implications for conditions characterized by open wounds including cutaneous neoplasms, thermal injury, skin disorders and dysfunctional wound healing. Specifically targeting local gene expression avoids systemic toxicity and simplifies treatment. We have developed a new method of topical matrix-based short interfering RNA application to precisely and effectively silence local gene expression in nondelimited wounds.     

Prospective Evaluation of Topical Antibiotics for Preventing Infections in Uncomplicated Soft-tissue Wounds Repaired in the ED

Objective: To determine differences in infection rates among uncomplicated, repaired wounds managed with: topical bacitracin zinc (BAC); neomycin sulfate, bacitracin zinc, and polymyxin B sulfate combination (NEO); silver sulfadiazine (SIL); and petrolatum (PTR). Methods: This was a prospective, randomized, double-blind, placebo-controlled study conducted at a military community hospital with an emergency medicine residency program. Patients were enrolled if they: presented to the ED within 12 hours of injury and did not have puncture wounds, allergies to the agents used, or a history of immunocompromise; were not receiving antibiotics, chemotherapy, or steroids at the time of presentation; had not taken antibiotics within the preceding seven days; did not have an underlying fracture; and were not pregnant as determined by history. Local anesthetics without epinephrine and high-pressure irrigation with normal saline were used for all the patients. Wound scrubbing, debridement, and polyglactin subcutaneous (SQ) suture placement were carried out when necessary. Interrupted simple sutures using a monofilament, nonabsorbable material were used for skin closure. Numbered, randomized vials were given to all patients, with standardized instructions to inspect, clean, and redress their wounds three times a day. The wounds were evaluated for clinical infection at the time of follow-up. Results: Among the groups, there was no difference in patient ages; gender; wound location, type, length, or depth; time elapsed from injury to ED treatment; number of wounds scrubbed or necessitating debridement; number of SQ and cutaneous sutures used; and rate of compliance with returning the used vial of dispensed topical agent. The wound infection rates for the treatment groups were: BAC, six of 109 (5.5%); NEO, five of 110 (4.5%); SIL, 12 of 99 (12.1%); and PTR, 19 of 108 (17.6%) (p = 0.0034). Conclusion: The use of topical antibiotics resulted in significantly lower infection rates than did the use of a petrolatum control. BAC and NEO had the lowest wound infection rates.     

The use of honey as a topical dressing to treat a large, devitalized wound in a stumptail macaque (Macaca arctoides).

There are many reasons wounds are managed as open wounds rather than by primary closure. Indications include gross contamination, infection, and skin loss leading to insufficient adjacent tissue for wound closure. The most common method of managing an open wound is with wet-to-dry dressings. Wet-to-dry dressings provide mechanical debridement and promote the movement of viscous exudates away from the wound. Wet-to-dry bandages ideally are changed every 12 to 24 h. For nonhuman primates, it is desirable to develop wound management techniques that limit animal handling for bandage changes and thus the frequency of sedation. Anecdotal reports on the use of honey to treat wounds date back to 2000 B.C. Recently, scientific inquiries have found merit to these reports. Honey accelerates healing because of its direct effects on tissue and antibacterial properties. In addition, dressings with honey can be changed relatively infrequently. Honey decreases inflammatory edema, hastens sloughing of devitalized tissue, attracts macrophages which cleanse the wound, provides a local cellular energy source, and protectively covers the wound. A high osmolarity, acidity, and hydrogen peroxide content confer honey with antibacterial properties. Here we describe the use of honey to manage a bite wound in a stumptail macaque (Macaca arctoides). The wound healed rapidly: after 2 weeks of treatment, there was markedly less exudate and no necrotic tissue. This report describes how honey may be helpful in the management of open wounds in nonhuman primates by minimizing the need for sedation for bandage changes.     

Burns caused by medical therapy

A burn injury may occur as an unexpected consequence of medical treatment. We examined the burn prevention implications of injuries received in a medical treatment facility or as a direct result of medical care. The records of 4510 consecutive admissions to 1 burn center between January 1978 and July 1997 were retrospectively reviewed. A cohort of 54 patients burned as a result of medical therapy was identified and stratified by location (home vs medical facility) and by mechanism of injury. Twenty-two patients were burned in a medical treatment facility, including 12 patients who were burned as a result of careless or unsupervised use of tobacco products. Thirty-two patients were burned as a result of home medical therapy, including 9 patients who had scald injuries from vaporizers, 8 patients who were burned by simultaneous use of cigarettes and home nasal oxygen therapy, and 11 patients who were burned by therapeutic application of heat. In contrast to previous studies, no patient was burned by the use of medical laser devices. To further decrease burn risk from medical therapy we advocate the prohibition of cigarette smoking in any medical facility. Continued tobacco use may represent a contraindication to home oxygen therapy. Given the lack of proof of efficacy combined with the potential for burn injury, the use of vaporizers to treat upper respiratory symptoms should be discouraged. Patients with diminished sensation or altered mental status are at increased risk of burn injury from bathing or topical heat application and merit closer monitoring during these activities.     

Efficacy of mupirocin in methicillin-resistant Staphylococcus aureus burn wound infection.

Methicillin-resistant Staphylococcus aureus strains (MRSA) have become increasingly prevalent as nosocomial pathogens, especially in burn wounds. MRSA constituted 38% of all S. aureus isolates in our 25-bed burns unit despite the utilization of a combination of 1% silver sulfadiazine and 0.2% chlorhexidine as topical therapy. Mupirocin, a new antibiotic, has proved in vitro and in vivo to be highly effective in the treatment of MRSA infections. A prospective clinical trial with mupirocin ointment in MRSA burn wound infection was untertaken. Forty-five children with 59 discrete burn wounds and from whom MRSA were isolated were treated with 2% mupirocin ointment under occlusive dressings, applied twice daily for 5 days. The average burned area treated was 8% (range, 2 to 20%) of the total body surface area. The burn wounds were assessed clinically and bacteriologically daily. Mupirocin eliminated MRSA in all 59 wounds treated, with the maximum therapeutic response seen within 4 days. In three wounds, gram-negative organisms persisted after 5 days of topical therapy. Treatment was well tolerated by all children. We recommend that mupirocin in its present polyethylene glycol base should be used only on a selective basis, when current prophylactic topical therapy has failed to control MRSA infection in burns of less than 20% of the total body surface area, and that it should be applied only for a limited period of 5 days. The safety and the efficacy of mupirocin in burns exceeding 20% of the total body surface area need to be established.     

Temporary skin transplantation for the treatment of extensive burns

Survival of the extensively burned patient depends upon rapid excision of necrotic tissue, and skin grafting to obtain wound closure. When a sufficient supply of autogenous skin is not available to provide wound coverage, allograft skin has been successfully substituted. Although burn patients have been noted to be immunologically hyporesponsive, their immune response to skin allografts has necessitated the administration of immunosuppressive therapy, to assure the retention of the allografts until sufficient autogenous skin can be utilized. The temporary transplantation of skin allografts has proved successful in the treatment of extensively burned children.