Organ donation from burn-injured patients--a national perspective.

BACKGROUND: There is a discrepancy between publically available data from the United Network for Organ Sharing (UNOS) database and perception of the incidence of mortally burn-injured patients serving as organ donors. In the last 5 y, a single burn center referred several patients who went on to successfully donate multiple organs. However, UNOS data indicate very few referrals of patients with burn injuries nationwide. This discrepancy in UNOS-reported occurrences versus institutional experience prompted this work. METHODS: UNOS data from 1988-2012 was examined for causes of death related to thermal injury, electrical injury, inhalation injury, or carbon monoxide poisoning. The National Burn Repository was examined for burn center death rates and patient characteristics of those with reported nonsurvivable burn injuries. Finally, a national survey queried the clinical experiences and educated opinions of burn center directors, transplant surgeons, and organ procurement organization (OPO) representatives regarding organ donation in the burn-injured population. RESULTS: Between 42% and 52% of those surveyed responded. Survey data indicate that at least 61 patients with burn-related injuries have served as organ donors in the past 5 y alone, versus 23 identified in 24 y of UNOS data. Survey data also indicate that inhalation injuries were the most common burn-related injuries seen before successful organ procurement. Kidneys were the most commonly donated organs, but all major organs and tissues were represented in the experiences of surgeon and organ procurement organization respondents. Up to 10% surgeon respondents believe that patients with burn injuries should not be referred for possible organ donation. CONCLUSIONS: There are more organs donated by patients with mortal burn injuries than currently available UNOS data would suggest. Survey data suggest that these patients should be able to contribute successfully to the supply of organs needed by those on transplant waiting lists, but remain inconsistently recognized as such a resource. Knowledge about long-term organ and tissue viability from burn-injured patients is lacking, and should be the focus of future research.

Early serum (1→3)-ß-D-glucan levels in patients with burn injury.

Serum (1→3)-ß-D-glucan (BG) is increasingly used as diagnostic marker for invasive fungal infections. Exposure to gauze may lead to false-positive BG assays. The role of BG is unclear in thermally injured patients who frequently require extensive gauze coverage; therefore, we prospectively evaluated BG levels in burn-injured patients. Serum BG levels were measured in 18 burn patients immediately before application of the first dressing and 12 h after. Patients were stratified by extent of total body surface area (TBSA) requiring gauze coverage: <20%, 20-39%, 40-60% and >60%. BG levels were obtained from patients with non-burn trauma as controls. BG results were positive (>80 pg ml⁻¹) in 9/18 (50%) patients at baseline and in 8/18 (44%) 12 h after application of the first dressing. BG levels were positive in 1/5 (20%) of patients with <20% TBSA requiring gauze and in 10/13 (77%) with ≥ 20% (P < 0.05). None of the control patients had positive BG at any time point and none of the patients had candidemia at baseline. Mean serum BG levels decreased (19.44 pg ml⁻¹) after gauze placement. False-positive serum BG elevations are common in this patient population. Positivity correlates with extent of TBSA injured, but is not impacted by the gauze itself.

Incidence of methemoglobinemia in patients receiving cerium nitrate and silver sulfadiazine for the treatment of burn wounds: a burn center's experience.

In 1976, the combination of cerium nitrate and silver sulfadiazine was introduced as a topical therapy for burn wounds. Experience with a locally prepared combination agent has shown physical change of the eschar and delayed subeschar bacterial colonization. A potential systemic complication of this treatment is the development of methemoglobinemia (Met-Hba) due to the oxidizing nature of Ce(NO(3))(3). Met-Hba has a spectrum of clinical consequences, ranging from headache and cyanosis to cardiac ischemia, hypotension, and even death. Given the frequent use of this combination agent at our burn center, a retrospective review was conducted to evaluate the incidence of Met-Hba. A query of pharmacy records revealed 170 patients from January 2005 to October 2009 that had received this treatment. Eighteen patients (∼10%) developed Met-Hba as noted on arterial blood gas (methemoglobin>3%) and only three patients (∼2%) had methemoglobin levels >10%. In the majority of cases, there were no clinical symptoms of Met-Hba. Most patients' relative hypoxia resolved with cessation of treatment; however, five patients required treatment with methylene blue. The presence of Met-Hba associated with this topical therapy can be diagnosed early by vigilant monitoring, thereby reducing morbidity and mortality. In our experience, cerium combined with silver sulfadiazine is a valuable and safe treatment for deep partial and full-thickness burn wounds.

Contemplating a Career in Burn Surgery: Data From the 2016 Burn Physician Survey.

There is a paucity of information in the peer-reviewed literature characterizing the current burn surgeon workforce and compensation potential, and, in a parallel topic, training opportunities and recruitment methods. What does exist documents minimal exposure to the field and surgeon shortages. A comprehensive survey was created to address 1) the demographics of current burn surgeons in practice, and 2) the structure of burn centers training models. Finally, three questions were asked regarding job satisfaction. With a response rate of 23%, demographics reflect representative involvement across the age spectrum. The majority of respondents (73.9%) had training in general surgery, with subsequent postgraduate training primarily in surgical critical care or burn fellowships. Two-thirds of respondents have active practices, cover multiple specialties, and take multispecialty call throughout the month. A variety of models are used to calculate compensation. The vast majority of burn centers train residents: general surgery residents (89%), plastic surgery residents (63%), and emergency medicine residents (32%), most of whom are in their first 3 years of training. The majority of respondents would become a burn surgeon again if they had to do it over and would recommend it to young surgeons as a career. A representative sample of burn surgeons from across North America sustains practices in similar ways. Access to the next generation of surgeons is at an early period in training (PGY1-3) which may prove valuable as surgical education evolves. Overall, burn surgeons express good job satisfaction, a significant point of interest as attention turns towards succession planning.

A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.

Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCell® Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P < .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ≤ .05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG.

Reducing Wound Tension with Undermining or Imbrication-Do They Work?

BACKGROUND: For the noncolonized wound, achieving tension-free, primary wound closure is ideal. Some surgeons advocate imbrication of deeper tissues rather than undermining, posing that imbrication preserves more dermal perfusion while still reducing tension at the wound edge. We sought to determine which technique most reliably reduced wound tension while preserving dermal wound perfusion. METHODS: A total of 5 standardized, symmetrical pairs of full thickness wounds were created on Duroc swine. Wound tension was measured with a Tyrolean tensiometer before and after either method of closure, whereas a speckle contrast imager was used to assess dermal edge perfusion. Skin tension and dermal perfusion were evaluated for statistical significance via paired t tests and a multivariate analysis of variance. RESULTS: There was a significant reduction in wound tension with undermining and imbrication relative to the raw wound tension (5 and 5.9 vs 7.1 N; P < 0.05) yet no significant difference between methods of closure (P > 0.05). There was a significant reduction in dermal perfusion between unwounded skin and the imbricated wound (222 perfusion units [PU] vs 48 PU; P < 0.05) and between the unwounded skin and the undermined wound (205 vs 63 PU; P < 0.05). CONCLUSIONS: We found no significant difference in wound tension between wound undermining or imbrication and a significant decrease in dermal perfusion after imbrication and undermining although the relative decrease in perfusion was greater with imbrication. Wound undermining reduces skin tension with greater relative dermal perfusion to the skin and should be selected over wound imbrication in standard primary wound closure.

The Pentagon attack of September 11, 2001: a burn center's experience.

On September 11, 2001, an airplane flown by terrorists crashed into the Pentagon, causing a mass casualty incident with 189 deaths and 106 persons treated for injuries in local hospitals. Nine burn victims and one victim with an inhalation injury only were transported to the burn center hospital. The Burn Center at Washington Hospital Center admitted and treated the acute burn patients while continuing its mission as the regional burn center for the Washington DC region. Eight of the nine burn patients survived. Lessons learned include 1) A large-volume burn center hospital can absorb nine acute burns and maintain burn center and hospital operations, but the decision to keep or transfer burn patients must be tempered with the reality that several large burns can double or triple the work load for 2 to 3 months. 2) Transfer decisions should have high priority and be timely to ensure optimum care for the patients without need for movement of medical personnel from one burn center to another. 3) The reserve capacity of burn beds in the United States is limited, and the burn centers and the American Burn Association must continue to seek recognition and support from Congress and the federal agencies for optimal preparedness.

Tracking the daily availability of burn beds for national emergencies.

Medical planning for Operation Iraqi Freedom included predictive models of expected number of burn casualties. In all but the best-case scenario, casualty estimates exceeded the capacity of the only Department of Defense burn center. Examination of existing federal-civilian disaster plans for military hospital augmentation revealed that bed availability data were neither timely nor accurate. Recognizing the need for accurate knowledge of burn bed availability, the Department of Defense requested assistance from the American Burn Association (ABA). Directors of burn centers in the United States were queried for interest in participation in a mass casualty plan to provide overflow burn bed capacity. A list of 70 participating burn centers was devised based upon proximity to planned military embarkation points. A computer tracking program was developed. Daily automated e-mail messages requesting bed status were sent to burn center directors at 6 am Central time with responses requested before 11 am. The collated list of national overflow burn bed capacity was e-mailed each day to the ABA Central Office and to federal and military agencies involved with burn patient triage and transportation. Once automated, this task required only 1-2 hours a day. Available burn-bed lists were generated daily between March 17 and May 2, 2003 and then every other day until May 9, 2003. A total of 2151 responses were received (mean, 43 burn centers per day). A system to track daily nationwide burn bed availability was successfully implemented. Although intended for military conflict, this system is equally applicable to civilian mass casualty situations. We advocate adoption of this or a similar bed tracking system by the ABA for use during burn mass casualty incidents.

Factors impacting the likelihood of death in patients with small TBSA burns.

Survival rates of burn patients have increased greatly over the past several decades. There are, however, still patients with relatively small burns who do not survive their hospitalizations. This work aimed to elucidate factors common to this select subset of patients. The NBR Main dataset was queried for record numbers associated with TBSA between 0.1 and 10 and a discharge status indicating death. Using SAS statistical software, the patients were matched for age, sex, and TBSA. Chi-square analyses of independence on categorical variables and unpaired, two-tailed Students' t-tests with unequal variance on continuous variables were used to identify fields of further interest. SAS was then used to build multivariate logistic regression models examining variables affecting discharge status. The NBR complications child dataset was queried and categorized for the types of complications for analysis. Multivariate logistic regression for discharge status, comorbidities, and complications showed that the presence of a complication significantly impacted discharge status. The presence of an identified complication (other than death) increased the odds ratio of a discharge status of death by a factor of 3.023 (95% confidence interval [2.306, 3.964], P < .0001). Pulmonary and infection-related complications were the most frequently seen across all the records analyzed, but infection-related complications did not reach statistical significance in relation to discharge status. Multivariate logistic regression of complications in a model for discharge status identified four categories as statistically significant: neurologic, cardiovascular, pulmonary, and renal. In patients with small TBSA burns, the presence of complications significantly increases the odds ratio of death as judged by the NBR data. The complications which appear to be of particular interest are cardiovascular, neurologic, renal, and pulmonary, and those patients who are likely most susceptible to these complications are those with inhalation injury in addition to their cutaneous burns.

A multimodal assessment of melanin and melanocyte activity in abnormally pigmented hypertrophic scar.

Using a validated swine model of human scar formation, hyperpigmented and hypopigmented scar samples were examined for their histological and optical properties to help elucidate the mechanisms and characteristics of dyspigmentation. Full-thickness wounds were created on the flanks of red Duroc pigs and allowed to heal. Biopsies from areas of hyperpigmentation, hypopigmentation, and uninjured tissue were fixed and embedded for histological examination using Azure B and primary antibodies to S100B, HMB45, and α-melanocyte-stimulating hormone (α-MSH). Spatial frequency domain imaging (SFDI) was then used to examine the optical properties of scars. Hyperpigmentation was first noticeable in healing wounds around weeks 2 to 3, gradually becoming darker. There was no significant difference in S100B staining for the presence of melanocytes between hyperpigmented and hypopigmented scar samples. Azure B staining of melanin was significantly greater in histological sections from hyperpigmented areas than in sections from both uninjured skin and hypopigmented scar (P < .0001). There was significantly greater staining for α-MSH in hyperpigmented samples compared with hypopigmented samples (P = .0121), and HMB45 staining was positive for melanocytes in hyperpigmented scar. SFDI at a wavelength of 632 nm resulted in an absorption coefficient map correlating with visibly hyperpigmented areas of scars. In a red Duroc model of hypertrophic scar formation, melanocyte number is similar in hyperpigmented and hypopigmented tissues. Hyperpigmented tissues, however, show a greater amount of melanin and α-MSH, along with immunohistochemical evidence of stimulated melanocytes. These observations encourage further investigation of melanocyte stimulation and the inflammatory environment within a wound that may influence melanocyte activity. Additionally, SFDI can be used to identify areas of melanin content in mature, pigmented scars, which may lead to its usefulness in wounds at earlier time points before markedly apparent pigmentation abnormalities.

Biphasic presence of fibrocytes in a porcine hypertrophic scar model.

The duroc pig has been described as a promising animal model for use in the study of human wound healing and scar formation. However, little is known about the presence and chronology of the fibrocyte cell population in the healing process of these animals. Wounds known to form scar were created on red duroc swine (3" x 3") with a dermatome to a total depth of either 0.06 inches or 0.09 inches. These wounds were allowed to heal completely and biopsies were done at scheduled time points during the healing process. Biopsies were formalin fixed and paraffin embedded for immunohistochemical analysis. Porcine reactive antibodies to CD-45 and procollagen-1 and a human reactive antibody to LSP-1 were used to detect the presence of fibrocytes in immunohistochemistry, an immunocytochemistry. Initial immunohistochemical studies showed evidence of a biphasic presence of fibrocytes. Pigs with 0.06 inches deep wounds showed positive staining for CD-45 and LSP-1 within highly cellular areas at days 2 and 4 after wounding. Additional animals with 0.09 inches deep wounds showed positive staining within similar areas at days 56, 70, and 113 after wounding. There was no immunohistochemical evidence of fibrocytes in skin biopsies taken at days 14, 28, or 42. Procollagen-1 staining was diffused in all samples. Cultured cells were stained for CD-45, LSP-1, and procollagen-1 by immunocytochemistry. These data confirm that fibrocytes are indeed present in this porcine model. We conclude that these cells are present after initial wounding and later during scar formation and remodeling. We believe that this is an evidence of a biphasic presence of fibrocytes, first as an acute response to skin wounding followed by later involvement in the remodeling process, prompted by continued inflammation in a deep partial thickness wound.

Results of a pilot multicenter genotype-based randomized placebo-controlled trial of propranolol to reduce pain after major thermal burn injury.

BACKGROUND: Results of previous studies suggest that ß-adrenoreceptor activation may augment pain, and that ß-adrenoreceptor antagonists may be effective in reducing pain, particularly in individuals not homozygous for the catechol-O-methyltransferase (COMT) high-activity haplotype. MATERIALS AND METHODS: Consenting patients admitted for thermal burn injury at participating burn centers were genotyped; those who were not high-activity COMT homozygotes were randomized to propranolol 240 mg/d or placebo. Primary outcomes were study feasibility (consent rate, protocol completion rate) and pain scores on study days 5 to 19. Secondary outcomes assessed pain and posttraumatic stress disorder symptoms 6 weeks postinjury. RESULTS: Seventy-seven percent (61/79) of eligible patients were consented and genotyped, and 77% (47/61) were genotype eligible and randomized. Ninety-one percent (43/47) tolerated study drug and completed primary outcome assessments. In intention-to-treat and per-protocol analyses, patients randomized to propranolol had worse pain scores on study days 5 to 19. CONCLUSIONS: Genotype-specific pain medication interventions are feasible in hospitalized burn patients. Propranolol is unlikely to be a useful analgesic during the first few weeks after burn injury.

Serum lactate, not base deficit, rapidly predicts survival after major burns.

BACKGROUND: Clinical studies document correlation of serum lactate and base deficit with mortality in trauma and sepsis. No study of the prognostic value of these two serum markers has been reported in burn injury. METHODS: Resuscitation data from 49 patients admitted to the adult Burn ICU were analyzed. Lactate and base deficit were analyzed upon admission and every 2h during the initial 48 h after admission. Resuscitation was managed per standard routine, blinded to these data, guided by the Parkland formula. Initial statistical analysis with Cox's regression model was used to determine the relationship between survival, resuscitation parameters, and demographics. Then, a logistic regression was used to determine if any of these variables were quickly predictive (initial values) of the risk of death. RESULTS: Two variables were predictive of mortality by the Cox regression model: (1) serum lactate value and (2) patient age. Furthermore, analysis by logistic regression revealed that the initial serum lactate value was separately predictive of mortality. CONCLUSION: In this study, serum lactate but not base deficit, was a predictor of mortality following major burns. Moreover, initial serum lactate values were also predictive of mortality separately.

Multicenter postapproval clinical trial of Integra dermal regeneration template for burn treatment.

The safety and effectiveness of Integra Dermal Regeneration Template was evaluated in a postapproval study involving 216 burn injury patients who were treated at 13 burn care facilities in the United States. The mean total body surface area burned was 36.5% (range, 1-95%). Integra was applied to fresh, clean, surgically excised burn wounds. Within 2 to 3 weeks, the dermal layer regenerated, and a thin epidermal autograft was placed. The incidence of invasive infection at Integra-treated sites was 3.1% (95% confidence interval, 2.0-4.5%) and that of superficial infection 13.2% (95% confidence interval, 11.0-15.7%). Mean take rate of Integra was 76.2%; the median take rate was 95%. The mean take rate of epidermal autograft was 87.7%; the median take rate was 98%. This postapproval study further supports the conclusion that Integra is a safe and effective treatment modality in the hands of properly trained clinicians under conditions of routine clinical use at burn centers.

Commercially available topical platelet-derived growth factor as a novel agent to accelerate burn-related wound healing.

The authors investigated whether the application of platelet-derived growth factor (PDGF) to donor site wounds would speed healing in a porcine model. In a red duroc pig model, three wounds that were 3 inches × 3 inches were created with a dermatome (0.06-inch depth) on one side of two different animals. These wounds were digitally and laser Doppler (LDI) imaged and biopsied immediately pre- and postwound creation and every 2 days for 2 weeks. A set of identical wounds were subsequently created on the opposite side of the same animals and treated with topical PDGF (becaplermin gel 0.01%, 4 g/wound) immediately on wounding. PDGF-treated wounds were imaged and biopsied as above. Digital images of wounds were assessed for epithelialization by clinicians using an ordinal scale. Perfusion units (PU) were evaluated by LDI. Wound healing was evaluated by hematoxylin and eosin histological visualization of an epithelium and intact basement membrane. First evidence of partial epithelialization was seen in control and PDGF-treated wounds within 7.7 ± 1.4 and 6.4 ± 1.1 days postwounding, respectively (P=.03). Completely epithelialized biopsies were seen in control and PDGF-treated wounds at 11.7 ± 2.6 and 9.6 ± 1.5 days, respectively (P=.02). Clinician evaluation of digital images showed that on day 9, control wounds were, on average, 48.3 ± 18.5% epithelialized vs 57.2 ± 20.2% epithelialized for PDGF-treated wounds. At day 16, control wounds showed an average of 72.9 ± 14.6% epithelialization and PDGF-treated wounds showed an average of 90 ± 11.8%epithelialization. Overall, PDGF-treated wounds had statistically significantly higher scores across all timepoints (P=.02). Average perfusion units as measured by LDI were similar for control and PDGF-treated wounds at time of excision (225 ± 81and 257 ± 100, respectively). On day 2 postwounding, average PU for control wounds were 803 and were 764 for PDGF-treated wounds. Control wounds maintained higher PU values compared with PDGF-treated wounds at all time points and returned to excision PU values by day 12.2 ± 1.1 postwounding. PDGF-treated wounds reached the same values by day 9.7 ± 2.3 (P=.03). The authors conclude that topical PDGF speeds time to epithelialization of partial-thickness wounds in a porcine model as evidenced by histology, clinical appearance, and time to return to prewounding vascularity.

Novel application of a spatial frequency domain imaging system to determine signature spectral differences between infected and noninfected burn wounds.

Complications of infection can increase burn-related morbidity and mortality. Early detection of burn wound infection could lead to more precise and effective treatment, reducing systemic complications and the need for long-term, broad-spectrum intravenous antibiotics. Quantitative cultures from biopsies are the accepted standard to determine infection. However, this methodology can take days to yield results and is invasive. This investigation focuses on the use of noninvasive imaging to determine the infection status of burn wounds in a controlled in vivo model. Full-thickness burn wounds were created on the dorsum of adult male rats (n = 6). Twenty-four hours after burn wound creation, wounds in the "Infected" group were inoculated with a vehicle containing 1 × 10(8) colony forming unit Staphylococcus aureus. "Control" group animals received vehicle alone. Subsequently, the wounds were imaged daily for a total of 10 days and the differences of skin optical properties were assessed using spatial frequency domain imaging at 16 different wavelengths from 500 to 700 nm. Regions of interest on the resulting images were selected and averaged at each time point. Statistically significant differences in average absorption and reduced scattering coefficients (µ(a) and µ(s)') at 620 and 700 nm were observed between the two groups (P < .05). Differential optical properties were most evident by day 4 and persisted throughout the time course. Differential signature changes in optical properties are evident in infected burn wounds. This novel application of spatial frequency domain imaging may prove to be a valuable adjunct to burn wound assessment. Further work will be aimed at determining dose-response relationships and prokaryotic species differences.

Localization of superantigen virulence factors in kidney tissue of animals with Staphylococcus aureus-infected burn wounds.

Gram-positive organisms are often found in association with burn wounds. A paucity of information exists regarding the accumulation and fate of virulence factors from these bacteria. The superantigenic exotoxins produced by Staphylococcus aureus are potent immunomodulating proteins and have also been described to localize in the kidney. The aim of this work was to demonstrate renal accumulation of toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin B (SEB) in a methicillin-resistant S. aureus burn wound infection. Twelve Sprague Dawley rats were subjected to partial-thickness burns (2 × 2 cm) using an aluminum billet. On postburn day 1, the wounds were inoculated with a toxin-producing strain of methicillin-resistant Skin biopsies and serum were obtained on postburn days 3, 6, and 10 along with necropsies for three animals each day. An enzyme-linked immunosorbent assay was used to quantify amounts of TSST-1 and SEB. Immunohistochemistry was used to localize SEB, TSST-1, and cleaved caspase-3 in renal tissue, and quantitative real-time polymerase chain reaction was used to assess erythropoietin and endothelin-1 messenger RNA (mRNA) in renal tissue. Baseline skin and plasma levels of TSST-1 and SEB were not detectable. Skin biopsy TSST-1 levels were detected on all postburn days and peaked at a mean value of 39.35 ng/ml on day 6; SEB was found in the skin and kidney only on postburn days 6 and 10. An enzyme-linked immunosorbent assay of renal tissue for TSST-1 and SEB demonstrated significantly higher (P < .05) mean toxin concentrations on postburn day 10: 10.87 ng/ml for TSST-1 and 0.67 ng/ml for SEB. Immunohistochemistry of renal tissue demonstrated increased stain intensity for SEB, TSST-1, and cleaved caspase-3 over time. Quantitative real-time polymerase chain reaction demonstrated decreased expression erythropoietin mRNA and increased expression of endothelin-1 mRNA relative to negative controls (P < .01). In a burn wound infection model that is nonlethal and lacks bacteremia, TSST-1 and SEB traverse cutaneous wounds and localize to the kidney. These potent virulence factors may contribute to the induction of apoptosis, and may alter homeostasis via renal pathophysiology.

Treatment with an oxazolidinone antibiotic inhibits toxic shock syndrome toxin-1 production in MRSA-infected burn wounds.

Mortality rates in burn patients increase if they experience complications of infection. Frequently, the organisms associated with such infections are Staphylococci, including antibiotic-resistant species such as methicillin-resistant Staphylococcus aureus. Virulence factor production can further complicate treatment as a localized toxin presence may derail the healing process and allow a more invasive infection, while a toxin that becomes systemic can induce shock and cause host immune disruption. Male rats were anesthetized and subjected to full-thickness burn wounds. One day postinjury, wounds were inoculated with Toxic Shock Syndrome Toxin-1-producing methicillin-resistant S. aureus. Animals were then divided into three treatment groups: vancomycin, linezolid, or positive control. For nine additional days, animals received twice-daily antibiotics and wound assessments, blood draws, and wound biopsies were performed. All animals had wound quantitative cultures that exceeded 1 × 10 colony forming units (CFU) per gram 1 day after inoculation. Linezolid treatment significantly reduced the bacterial counts in the wounds. Positive controls and vancomycin-treated animals had toxins in their wounds by day 5 and this remained throughout the study (ranging from 20-80 ng/ml). Linezolid-treated animals had significant decrease in toxin production (< 5 ng/ml), and in most cases toxins were undetectable. No animals became systemically infected with bacteria at any point during the study. Superantigen production in burn wounds has morbid consequences in terms of long-term wound healing. A S. aureus burn wound infection model was created that allowed the study of the effect of two standard-use antibiotics on local burn wound pathophysiology. Most noteworthy is that low-dose linezolid arrested toxin production in the wound.

Donor site healing dynamics: molecular, histological, and noninvasive imaging assessment in a porcine model.

Understanding the physiology of donor site healing will lead to advances in how these wounds are treated and may ultimately allow faster healing, more frequent autografting, and more effective care of the burn-injured patient. Unfortunately, a paucity of data exists regarding perfusion metrics over the course of donor site healing. Furthermore, there are no studies that interrelate indices of perfusion with the molecular and cellular processes of donor site healing. Male Duroc pigs were anesthetized and donor site wounds were created using a Zimmer dermatome at a depth of 0.060 inch (1.52 mm). Digital photographs, laser Doppler images, and punch biopsies were obtained before and after excision and on days 2, 4, 7, 9, 11, 14, and 16 until wounds were healed. RNA isolation was performed and quantitative polymerase chain reaction was used to examine differential gene expression over the time course. Formalin-fixed biopsies were embedded in paraffin, sectioned, stained, and examined. Wound surfaces were 83% re-epithelialized by day 16. Perfusion peaked on day 2 then declined, but it remained significantly elevated compared to before excision (P < .05). From day 9 onward, mean perfusion units were not significantly different from baseline (P < .05). Twenty-two representative genes were selected for examination. RNA expression of collagen, tenascin-cytoactin, inflammatory cytokines, remodeling enzymes, growth factors, and Wnt was increased. Inflammatory cells and cytokines were demonstrated histologically. Nuclei per high powered field peaked at day 7 and neodermal thickness increased daily to day 14. A novel porcine model for donor site wound healing that interrelates re-epithelilaizationand perfusion with molecular and cellular indices has been demonstrated.

When a hero becomes a patient: firefighter burn injuries in the National Burn Repository.

Firefighters receive significant training and are outfitted with state-of-the-art protective equipment. However, given the unpredictable nature of their work environment, injuries still occur. The National Burn Repository (NBR) was viewed as a resource for defining the epidemiology of these injuries on a national level and to identify predictive factors for outcomes in this population. The NBR was queried for the occupation of "firefighter" for the years 1990-2008. Records were screened for completeness, and 597 patients were identified for analysis. Data examined included demographics, %TBSA burn, length of stay (LOS), injury circumstance, and disposition. Multiple linear regression models were created to determine factors related to outcome measures. The majority of patients were white (84%) and male (96%). The mean age was 35 years. Most injuries were caused by fire/flame (73%). Only six deaths (1%) were reported. Most injuries were work-related (86%), and most patients were discharged home (92%). Inhalation injury was documented in 9% of patients. The mean LOS was 6.5 ± 11.3 days (median 2 days), and few patients had critical care requirements. The average %TBSA was 6 ± 11.7%. Patients with larger injuries had increased LOS. The presence of inhalation injury, elevated carboxyhemoglobin levels, and advancing age were significantly associated with larger burns. From the NBR data, most firefighter burn injuries were small, and few firefighter burn patients required critical care resources or had significant disability. Firefighters comprise a small number of burn center admissions each year, yet they are an important population to consider for burn prevention efforts.