State of the Art in Burn Treatment

Contribution of bacterial and viral infections to attributable mortality in patients with severe burns: an autopsy series

Bacterial infections are a common cause of mortality in burn patients and viral infections, notably herpes simplex virus (HSV) and cytomegalovirus (CMV) have also been associated with mortality. This study is a retrospective review of all autopsy reports from patients with severe thermal burns treated at the US Army Institute of Research (USAISR) burn unit over 12 years. The review focused on those patients with death attributed to a bacterial or viral cause by autopsy report. Of 3751 admissions, 228 patients died with 97 undergoing autopsy. Death was attributed to bacteria for 27 patients and to virus for 5 patients. Bacterial pathogens associated with mortality included Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. This association with mortality was independent of % total body surface area burn, % full-thickness burn, inhalation injury, and day of death post-burn. Bloodstream infection was the most common cause of bacteria related death (50%), followed by pneumonia (44%) and wound infection (6%). Time to death following burn was < or =7 days in 30%, < or =14 days in 59% and < or =21 days in 67%. All of the viral infections associated with mortality involved the lower respiratory tract, HSV for 4 and CMV for 1. Four of these 5 patients had evidence of inhalation injury by bronchoscopy, all had facial and neck burns, and 2 had concomitant Staphylococcus pneumonia. Time to death following burn ranged from 14 to 42 days for the 5 patients. Despite advances in care, gram negative bacterial infections and infection with S. aureus remain the most common cause of bacteria related mortality early in the hospital course. Viral infections are also associated with mortality and numbers have remained stable when compared to data from prior years.

Synthesis of highly antibacterial nanocrystalline trivalent silver polydiguanide

Highly monodispersed nanoparticles of a trivalent silver polydiguanide complex are synthesized by oxidation of the monovalent silver, followed by stabilization of the oxidized higher-valent metal through complexation with a polydiguanide ligand in a reverse microemulsion at room temperature. The synthesized nanoparticles have excellent photostability and displayed superior antibacterial activity toward Gram-positive and Gram-negative prokaryotes of clinical interest in vitro compared to silver sulfadiazine. These nanoparticles may serve as a new generation antibacterial metallopharmaceutical in wound care.

Scar and contracture: biological principles

Dysregulated wound healing and pathologic fibrosis cause abnormal scarring, leading to poor functional and aesthetic results in hand burns. Understanding the underlying biologic mechanisms involved allows the hand surgeon to better address these issues, and suggests new avenues of research to improve patient outcomes. In this article, the authors review the biology of scar and contracture by focusing on potential causes of abnormal wound healing, including depth of injury, cytokines, cells, the immune system, and extracellular matrix, and explore therapeutic measures designed to target the various biologic causes of poor scar.

Accelerated adhesion of grafted skin by laser-induced stress wave-based gene transfer of hepatocyte growth factor

Gene therapy using wound healing-associated growth factor gene has received much attention as a new strategy for improving the outcome of tissue transplantation. We delivered plasmid DNA coding for human hepatocyte growth factor (hHGF) to rat free skin grafts by the use of laser-induced stress waves (LISWs); autografting was performed with the grafts. Systematic analysis was conducted to evaluate the adhesion properties of the grafted tissue; angiogenesis, cell proliferation, and reepithelialization were assessed by immunohistochemistry, and reperfusion was measured by laser Doppler imaging as a function of time after grafting. Both the level of angiogenesis on day 3 after grafting and the increased ratio of blood flow on day 4 to that on day 3 were significantly higher than those in five control groups: grafting with hHGF gene injection alone, grafting with control plasmid vector injection alone, grafting with LISW application alone, grafting with LISW application after control plasmid vector injection, and normal grafting. Reepithelialization was almost completed on day 7 even at the center of the graft with LISW application after hHGF gene injection, while it was not for the grafts of the five control groups. These findings demonstrate the validity of our LISW-based HGF gene transfection to accelerate the adhesion of grafted skins.

Inhalation injury in southwest China--the evolution of care

AIM

This study aims to review the changes in management of inhalation injury and the associated reduction in mortality over the past 2 decades.

METHODS

The records of burn patients with inhalation injury hospitalised in our institute from 1986 to 2005 were retrospectively analysed. The incidence of inhalation injury and the associated mortality were analysed. Meanwhile, the relationship of inhalation injury with age, total burn area, tracheostomy intubation and mechanical ventilation were studied.

RESULTS

The incidence of inhalation injury was 8.01% in the total 10 608 hospitalised burn patients during the 20 years surveyed. Inhalation injury was always associated with large-sized burn and was more common in adults. The incidence of tracheostomy and mechanical ventilation increased from 39.46 and 30.28% in the period from 1986 to 1995 to 70.12 and 39.74% from 1996 to 2005, respectively. The overall mortality of inhalation-injured burn patients was 15.88% compared with 0.82% of the non-inhalation group. The mortality of the burn patients with inhalation injury dropped from 25.29% during the first 10 years to 11.71% during the second decade (p<0.01). Mortality secondary to inhalation injury as the lead cause decreased from 14.56 to 6.29% (p<0.01).

CONCLUSION

The care of inhalation injury has made significant progress over the past 2 decades. The early diagnosis of inhalation injury, early airway control and pulmonary function assistance with mechanical ventilation contribute to the reduction of mortality.

Severe burn injuries: acute and long-term treatment

BACKGROUND

The physician that initially sees a patient with an extensive and deep dermal burn injury must be able to provide initial acute treatment and to make a well-founded decision whether to have the patient transported to a burn care center (BCC). Physicians from a variety of specialities will be involved in the management of long-term sequelae.

METHODS

This article provides an overview of the treatment of severe burns and their commonest complications. Special attention is paid to initial emergency treatment (first aid) and to late complications, because physicians from multiple specialties are often involved in these phases of treatment. The data and guidelines that are summarized here were obtained through a selective Medline search and supplemented by the authors' experience in their own burn care center.

RESULTS

Analgesia, careful fluid balance, and early intubation are important elements of the initial emergency treatment. Long-term complications of burns, such as disfiguring scars on exposed areas of skin and functionally significant contractures, often require surgical treatment. Early measures for scar care may improve the outcome.

CONCLUSIONS

The effective treatment of severe burns is interdisciplinary, involving general practitioners and emergency physicians as well as plastic surgeons and physicians of other specialties. Knowledge of the basic principles of treatment enables physicians to care for patients with burns appropriately both in the acute setting and in the long term.

Burn rehabilitation and research: proceedings of a consensus summit

Burn rehabilitation is an essential component of successful patient care. In May 2008, a group of burn rehabilitation clinicians met to discuss the status and future needs of burn rehabilitation. Fifteen topic areas pertinent to clinical burn rehabilitation were addressed. Consensus positions and suggested future research directions regarding the physical aspects of burn rehabilitation are shared.

Primary human dermal fibroblast interactions with open weave three-dimensional scaffolds prepared from synthetic human elastin

We present an elastic, fibrous human protein-based and cell-interactive dermal substitute scaffold based on synthetic human elastin. Recombinant human tropoelastin promoted primary human dermal fibroblast attachment, spreading and proliferation. Tropoelastin was cross-linked to form a synthetic elastin (SE) hydrogel matrix and electrospun into fibrous SE scaffolds. Fibroblasts attached to and proliferated across SE hydrogel scaffold surfaces for at least 14 days and deposited the extracellular matrix proteins fibronectin and collagen type I. To allow for the benefit of greater cell infiltration, SE was electrospun into open weave, fibrous scaffolds that closely mimic the fibrous nature of the skin dermis. 3D SE scaffolds were robust and consisted of flat, ribbon-like fibers with widths that are similar to native dermal elastic fibers. The scaffolds displayed elasticity close to that of natural elastin. 3D SE retained the ability to interact with primary human dermal fibroblasts, which consistently attached and proliferated to form monolayers spanning the entire scaffold surface. The open weave design, with larger spaces between individual fibers and greater fiber diameters beneficially allowed for substantial cell infiltration throughout the scaffolds.

Fluid resuscitation for major burn patients with the TMMU protocol

BACKGROUND

Fluid resuscitation is one of the critical treatments for the major burn patient in the early phases after injury. We evaluated the practice of fluid resuscitation for severely burned patients with the Third Military Medical University (TMMU) protocol, which is most widely used in many regions of China.

METHODS

Patients with major burns (>30% total body surface area (TBSA)) presenting to Southwest Hospital, Third Military Medical University, between January 2005 and October 2007, were included in this study. Fluid resuscitation was initiated by the TMMU protocol.

RESULTS

A total of 71 patients were (46 adults and 25 children) included in this study. All patients survived the first 48 h after injury smoothly and none developed abdominal compartment syndrome or other recognised complications associated with fluid resuscitation. The average quantity of fluid infused was 3.3-61.33% more than that calculated based on the TMMU protocol in both adult and paediatric groups. The average urine output during the first 24h after injury was about 1.2 ml per kg body weight per hour in the two groups, but reached 1.2 ml and 1.7 ml during the second 24h in adult and pediatric groups, respectively.

CONCLUSION

This study indicates that the TMMU protocol for fluid resuscitation is a feasible option for burn patients. Individualised resuscitation - guided by the physiological response to fluid administration - is still important as in other protocols.

Antibacterial effect of dressings containing multivalent silver ion carried by zirconium phosphate on experimental rat burn wounds

To evaluate the antibacterial effect of multivalent silver ion carried by zirconium phosphate (ZP-Ag) both in vitro and in an experimental rat burn wound compared with that of sulfadiazine silver (SD-Ag). Firstly, the minimal inhibition concentration and the minimal bactericidal concentration of ZP-Ag to three different strains of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli) were compared with those of SD-Ag in vitro. Following this dressings containing the same mass of ZP-Ag or SD-Ag were applied to wounds in a rat burn model and their antimicrobial activity assayed. The inflammatory response of the wounds managed with the two kinds of dressings was compared. Both the minimal inhibition concentration and minimal bactericidal concentration of ZP-Ag to S. aureus, P. aeruginosa, and E. coli were two to four times lower than those of SD-Ag. In vivo ZP-Ag had a more effective antibacterial action inhibiting the growth of the above three bacterial strains under burn scar, compared with dressings made from the same mass of SD-Ag. Moreover, the antibacterial effect was unchanged after the ZP-Ag dressings were washed 20 times, while it dramatically decreased after the dressings with SD-Ag were washed 20 times. When covered by either regular or washed ZP-Ag dressings, the wounds showed integrity with no visible inflammatory reaction. However, various extents of inflammatory reactions on or around the wounds covered with regular SD-Ag dressing were observed. This study showed that dressings with ZP-Ag had a prominent and relative long-term antibacterial effect. ZP-Ag dressings could be an effective, low-cost management option for burn wounds.

Metabolic implications of severe burn injuries and their management: a systematic review of the literature

BACKGROUND

Severe burn patients are some of the most challenging critically ill patients, with an extreme state of physiologic stress and an overwhelming systemic metabolic response. A major component of severe burn injury is a hypermetabolic state associated with protein losses and a significant reduction of lean body mass. The second prominent component is hyperglycemia. Reversal of the hypermetabolic response by manipulating the patient's physiologic and biochemical environment through the administration of specific nutrients, growth factors, or other agents, often in pharmacologic doses, is emerging as an essential component of the state of the art in severe burn management. The present review aims at summarizing the new treatment modalities established to reduce the catabolic burden of severe burn injuries, for which there is some evidence-based support.

METHODS

A systematic review of the literature was conducted. Search tools included Elsevier ScienceDirect, EMBASE.com, Medline (OVID), MedlinePlus, and PubMed. Topics searched were Nutrition and Burns, Metabolic Response and Burns, Hypermetabolism and Burns, Hyperglycemia and Burns, and several more specific topics when indicated. With a focus on the most recently published articles, abstracts were reviewed and, when found relevant, were included as references. Full text articles, whenever available, were retrieved.

RESULTS

Many issues remain unanswered. Unfortunately, the present state of our knowledge does not allow the formulation of clear-cut guidelines. Only general trends can be outlined, and these will certainly have some practical applications but above all will dictate future research in the field.

Photoacoustic monitoring of burn healing process in rats

We performed multiwavelength photoacoustic (PA) measurement for extensive deep dermal burns in rats to monitor the healing process of the wounds. The PA signal peak at 532 nm, an isosbestic point for oxyhemoglobin (HbO(2)) and deoxyhemoglobin (HHb), was found to shift to a shallower region of the injured skin tissue with the elapse of time. The results of histological analysis showed that the shift of the PA signal reflected angiogenesis in the wounds. Until 24 h postburn, PA signal amplitude generally increased at all wavelengths. We speculate that this increase in amplitude is associated with dilation of blood vessels within healthy tissue under the injured tissue layer and increased hematocrit value due to development of edema. From 24 to 48 h postburn, the PA signal showed wavelength-dependent behaviors; signal amplitudes at 532, 556, and 576 nm continued to increase, while amplitude at 600 nm, an HHb absorption-dominant wavelength, decreased. This seems to reflect change from shock phase to hyperdynamic state in the rat; in the hyperdynamic state, cardiac output and oxygen consumption increased considerably. These findings show that multiwavelength PA measurement would be useful for monitoring recovery of perfusion and change in local hemodynamics in the healing process of burns.

Burn prevention mechanisms and outcomes: pitfalls, failures and successes

Burns are responsible for significant mortality and morbidity worldwide and are among the most devastating of all injuries, with outcomes spanning the spectrum from physical impairments and disabilities to emotional and mental consequences. Management of burns and their sequelae even in well-equipped, modern burn units of advanced affluent societies remains demanding and extremely costly. Undoubtedly, in most low and middle income countries (LMICs) with limited resources and inaccessibility to sophisticated skills and technologies, the same standard of care is obviously not possible. Unfortunately, over 90% of fatal fire-related burns occur in developing or LMICs with South-East Asia alone accounting for over half of these fire-related deaths. If burn prevention is an essential part of any integrated burn management protocol anywhere, focusing on burn prevention in LMICs rather than treatment cannot be over-emphasized where it remains the major and probably the only available way of reducing the current state of morbidity and mortality. Like other injury mechanisms, the prevention of burns requires adequate knowledge of the epidemiological characteristics and associated risk factors, it is hence important to define clearly, the social, cultural and economic factors, which contribute to burn causation. While much has been accomplished in the areas of primary and secondary prevention of fires and burns in many developed or high-income countries (HICs) such as the United States due to sustained research on the epidemiology and risk factors, the same cannot be said for many LMICs. Many health authorities, agencies, corporations and even medical personnel in LMICs consider injury prevention to have a much lower priority than disease prevention for understandable reasons. Consequently, burns prevention programmes fail to receive the government funding that they deserve. Prevention programmes need to be executed with patience, persistence, and precision, targeting high-risk groups. Depending on the population of the country, burns prevention could be a national programme. This can ensure sufficient funds are available and lead to proper coordination of district, regional, and tertiary care centres. It could also provide for compulsory reporting of all burn admissions to a central registry, and these data could be used to evaluate strategies and prevention programmes that should be directed at behavioural and environmental changes which can be easily adopted into lifestyle. Particularly in LMICs, the emphasis in burn prevention should be by advocating change from harmful cultural practices. This needs to be done with care and sensitivity. The present review is a summary of what has already been accomplished in terms of burn prevention highlighting some of the successes but above all the numerous pitfalls and failures. Recognizing these failures is the first step towards development of more effective burn prevention strategies particularly in LMICs in which burn injury remains endemic and associated with a high mortality rate. Burn prevention is not easy, but easy or not, we have no options; burns must be prevented.

Skin tissue engineering for tissue repair and regeneration

Tissue-engineered skin is a significant advance in the field of wound healing. It has mainly been developed because of limitations associated with the use of autografts and allografts where the donor site suffers from pain, infection, and scarring. Recently, tissue-engineered skin replacements have been finding widespread application, especially in the case of burns, where the major limiting factor is the availability of autologous skin. The development of a bioartificial skin facilitates the treatment of patients with deep burns and various skin-related disorders. The present review gives a comprehensive overview of the developments and future prospects of scaffolds as skin substitutes for tissue repair and regeneration.

Assessment of burn depth and burn wound healing potential

The depth of a burn wound and/or its healing potential are the most important determinants of the therapeutic management and of the residual morbidity or scarring. Traditionally, burn surgeons divide burns into superficial which heal by rapid re-epithelialization with minimal scarring and deep burns requiring surgical therapy. Clinical assessment remains the most frequent technique to measure the depth of a burn wound although this has been shown to be accurate in only 60-75% of the cases, even when carried out by an experienced burn surgeon. In this article we review all current modalities useful to provide an objective assessment of the burn wound depth, from simple clinical evaluation to biopsy and histology and to various perfusion measurement techniques such as thermography, vital dyes, video angiography, video microscopy, and laser Doppler techniques. The different needs according to the different diagnostic situations are considered. It is concluded that for the initial emergency assessment, the use of telemetry and simple burn photographs are the best option, that for research purposes a wide range of different techniques can be used but that, most importantly, for the actual treatment decisions, laser Doppler imaging is the only technique that has been shown to accurately predict wound outcome with a large weight of evidence. Moreover this technique has been approved for burn depth assessment by regulatory bodies including the FDA.

Suprathel, a new skin substitute, in the management of partial-thickness burn wounds: results of a clinical study

OBJECTIVE

A prospective, randomized, bicentric, nonblinded, clinical study was conducted to evaluate the impact on wound healing of Suprathel in partial-thickness burn injuries. Suprathel represents an absorbable, synthetic wound dressing with properties of natural epithelium.

METHODS

Thirty patients suffering from second-degree burn injuries were included in the study, with a mean of age 40.4 years old. Burn injuries were randomly selected, partly treated with Omiderm and partly treated with Suprathel. The first gauze change was applied the fifth day postoperatively, followed by regular wound inspection until complete reepithelization. The study focused on patient pain score, healing time, analysis of wound bed, ease of care, and treatment costs.

RESULTS

There was no significant difference between the 2 materials tested regarding healing time and reepithelization. There was a significant lower pain score for patients treated with Suprathel (P = 0.0072). Suprathel becomes transparent when applied, thus allowing close monitoring of wound healing. In contrast to Omiderm, Suprathel shows better attachment and adherence to wounds. During the course of healing, it detaches smoothly, without damaging the reepithelized wound surface. Moreover, it reduces the frequency of dressing changes required. Ease of care of Suprathel has been rated outstanding by patients and healthcare professionals. When interviewed, patients reported Suprathel as their treatment preference. As dressing material, Omiderm is more cost-effective than Suprathel.

CONCLUSION

Suprathel represents a reliable epidermal skin substitute, with a good impact on wound healing and pain reduction in partial-thickness burn injuries. Although it is less cost-effective than Omiderm, the significant increase of patient comfort makes this material represent a reliable and solid treatment alternative when dealing with partial-thickness burn injuries. Further studies with this synthetic dressing on other types of wounds are warranted.

Blockade of thrombospondin-1-CD47 interactions prevents necrosis of full thickness skin grafts

BACKGROUND

Skin graft survival and healing requires rapid restoration of blood flow to the avascular graft. Failure or delay in the process of graft vascularization is a significant source of morbidity and mortality. One of the primary regulators of blood flow and vessel growth is nitric oxide (NO). The secreted protein thrombospondin-1 (TSP1) limits NO-stimulated blood flow and growth and composite tissue survival to ischemia. We herein demonstrate a role for TSP1 in regulating full thickness skin graft (FTSG) survival.

METHODS AND RESULTS

FTSG consistently fail in wild type C57BL/6 mice but survive in mice lacking TSP1 or its receptor CD47. Ablation of the TSP1 receptor CD36, however, did not improve FTSG survival. Remarkably, wild type FTSG survived on TSP1 null or CD47 null mice, indicating that TSP1 expression in the wound bed is the primary determinant of graft survival. FTSG survival in wild type mice could be moderately improved by increasing NO flux, but graft survival was increased significantly through antibody blocking of TSP1 binding to CD47 or antisense morpholino oligonucleotide suppression of CD47.

CONCLUSIONS

TSP1 through CD47 limits skin graft survival. Blocking TSP1 binding or suppressing CD47 expression drastically increases graft survival. The therapeutic applications of this approach could include burn patients and the broader group of people requiring grafts or tissue flaps for closure and reconstruction of complex wounds of diverse etiologies.

Wound-healing factors secreted by epidermal keratinocytes and dermal fibroblasts in skin substitutes

Full-skin substitutes, epidermal substitutes, and dermal substitutes are currently being used to heal deep burns and chronic ulcers. In this study, we investigated which wound-healing mediators are released from these constructs and whether keratinocyte-fibroblast interactions are involved. Autologous skin substitutes were constructed from human keratinocytes, fibroblasts, and acellular donor dermis. Full-thickness skin was used to represent an autograft. Secretion of wound-healing mediators was investigated by means of protein array, enzyme-linked immunosorbent assay, neutralizing antibodies, and conditioned culture supernatants. Full-skin substitutes and autografts produce high amounts of inflammatory/angiogenic mediators (IL-6, CCL2, CXCL1, CXCL8, and sST2). Epidermal and dermal substitutes produced less of these proteins. Epidermal-derived proinflammatory cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) were found to mediate synergistically the secretion of these wound-healing mediators (with the exception of sST2) from fibroblasts in dermal substitutes. The secretion of proinflammatory cytokines (IL-1alpha, TNF-alpha), chemokine/mitogen (CCL5) and angiogenic factor (vascular endothelial growth factor) by epidermal substitutes and tissue remodeling factors (tissue inhibitor of metalloproteinase-2, hepatocyte growth factor) by dermal substitutes was not influenced by keratinocyte-fibroblast interactions. The full-skin substitute has a greater potential to stimulate wound healing than epidermal or dermal substitutes. Both epidermal-derived IL-1alpha and TNF-alpha are required to trigger the release of dermal-derived inflammatory/angiogenic mediators from skin substitutes.

Infection in patients with severe burns: causes and prevention thereof

The better understanding of burn pathophysiology has resulted in effective fluid resuscitation in the acute stage, but the morbidity and mortality of burn patients are mostly linked to the burn wound consequences. Once the initial acute phase is over, the burn wound becomes the source of virtually all ill effects, local and systemic. The dysfunction of the immune system, a large cutaneous bacterial load, the possibility of gastrointestinal bacterial translocation, prolonged hospitalization, and invasive diagnostic and therapeutic procedures all contribute to infectious complications. Wound infection may lead to septicemia that may not only consume additional resources but is associated with significant morbidity and mortality despite the advances in burn care.

Bone marrow-derived stem cells in wound healing: a review

Optimum healing of a cutaneous wound requires a well-orchestrated integration of the complex biological and molecular events of cell migration and proliferation, and of extracellular matrix deposition and remodeling. Several studies in recent years suggest that bone marrow derived stem cells such as mesenchymal stem cells, progenitor cells such as endothelial progenitor cells and fibrocytes may be involved in these processes, contributing to skin cells or releasing regulatory cytokines. Stem/progenitor cells may be mobilized to leave the bone marrow, home to injured tissues and participate in the repair and regeneration. Direct injection of bone marrow derived mesenchymal stem cells or endothelial progenitor cells into injured tissues shows improved repair through mechanisms of differentiation and/or release of paracrine factors. Enhanced understanding of these cells may help develop novel therapies for difficult cutaneous conditions such as non-healing chronic wounds and hypertrophic scarring as well as engineering cutaneous substitutes.

Rehabilitation methods for the burn injured individual

Physiatrists play a critical role in managing the medical and functional consequences of serious burn injuries. Goals of rehabilitation include wound healing, scar prevention, hypertrophic scarring suppression, full range of motion, strengthening, and independent mobility and activities of daily living. This article is an overview of burn rehabilitation principles and patient management. The ultimate rehabilitation goal is independence in all spheres of an individual's life. Achievement of independence depends on the commitment of the injured individual and the entire health care team.

Curcumin reduces burn progression in rats

OBJECTIVES

Cutaneous burns are dynamic injuries with a central zone of necrosis surrounded by a zone of ischemia. Conversion of this ischemic zone to full necrosis over the days following injury is due in part to highly reactive oxygen radicals. Curcumin is a component of the Oriental spice turmeric that has been shown to have antioxidant and antiapoptotic properties. The authors hypothesized that treatment of burns with curcumin would reduce the conversion of the ischemic zone to full necrosis.

METHODS

This was a randomized controlled experiment. Twenty Sprague-Dawley rats were used. Two burns were created on each animal's dorsum using a brass comb with four rectangular prongs preheated in boiling water and applied for 30 seconds, resulting in four rectangular 10 x 20-mm full-thickness burns separated by three 5 x 20-mm unburned interspaces (zone of ischemia). Animals were randomized to curcumin or vehicle by oral gavage 30 minutes before injury and at 24, 48, and 72 hours after injury. Wounds were observed at one, two, and three days after injury for visual evidence of necrosis in the unburned interspaces. Full-thickness biopsy specimens from the interspaces were evaluated with hematoxylin and eosin staining seven days after injury for evidence of necrosis. The percentage of interspaces that progressed to necrosis was compared with chi-square tests.

RESULTS

Forty comb burns with 120 unburned interspaces were created, evenly distributed between curcumin and vehicle alone. The percentage of interspaces that progressed to full-thickness necrosis at one, two, three, and seven days after injury in the curcumin and vehicle groups were 30% versus 63% (p = 0.003), 30% versus 70% (p < 0.001), 63% versus 95% (p = 0.02), and 63% versus 95% (p = 0.02), respectively.

CONCLUSIONS

Pretreatment of rats with oral curcumin followed by once-daily oral treatment for three days reduced the percentage of unburned skin interspaces that progressed to full necrosis.

Pharmacological modulation of wound healing in experimental burns

Factors involved in wound healing and their interdependence are not yet fully understood; nevertheless, new prospects for therapy to favor speedy and optimal healing are emerging. Reports about wound healing modulation by local application of simple and natural agents abound even in the recent literature, however, most are anecdotal and lack solid scientific evidence. We describe the effect of silver sulfadiazine and moist exposed burn ointment (MEBO), a recently described burn ointment of herbal origin, on mast cells and several wound healing cytokines (bFGF, IL-1, TGF-beta, and NGF) in the rabbit experimental burn model. The results demonstrate that various inflammatory cells, growth factors and cytokines present in the wound bed may be modulated by application of local agents with drastic effects on their expression dynamics with characteristic temporal and spatial regulation and changes in the expression pattern. Such data are likely to be important for the development of novel strategies for wound healing since they shed some light on the potential formulations of temporally and combinatory optimized therapeutic regimens.

Suprathel®, a new skin substitute, in the management of donor sites of split-thickness skin grafts: Results of a clinical study

OBJECTIVE

A prospective, randomized, two center clinical study was conducted to evaluate the impact on wound healing of Suprathel in donor sites of split-thickness skin grafts. Suprathel represents an absorbable, synthetic wound dressing with properties of natural epithelium.

METHODS

22 burn patients who were treated with split-thickness skin grafts, and with a mean age of 39.6 years were included in the study. Donor sites of skin grafts were randomly selected; partly treated with Jelonet and partly treated with Suprathel. First gauze change was carried out the fifth day postoperatively followed by regular wound inspection until complete re-epithelization. The study focused on patient pain score, healing time, analysis of wound bed, ease of care, and treatment costs.

RESULTS

There was no significant difference between the two materials tested regarding healing time and re-epithelization. There was a significantly lower pain score for patients treated with Suprathel (p=0.0002). Suprathel became transparent when applied and allowed close monitoring of wound healing. In contrast to Jelonet, Suprathel showed excellent plasticity with better attachment and adherence to wound surfaces. Throughout the healing process it detached from wounds without damaging the new epithelial surface. In addition, wound areas treated with Suprathel required less frequent dressing changes. It also demonstrated excellent ease of care. This, altogether with the significant pain reduction, presented a positive feedback by patients and healthcare professionals who both rated Suprathel as their treatment preference. Though Jelonet is more cost effective as dressing material, the study revealed an overall reduction in total treatment costs achieved with Suprathel.

CONCLUSION

Suprathel represents a solid, reliable epidermal skin substitute with impact on wound healing, patient comfort and ease of care. The material effectiveness contributes to the reduction of overall treatment costs.

Uniplanar external fixation for care of circumferential extremity burn wounds in adults

The optimal management of circumferential extremity burns remains a challenge. Elevation of the extremity to decrease wound swelling and avoid pressure at the point of contact on new skin grafts is a standard objective but can be frequently difficult to accomplish. Although various forms of elevation have been proposed, our purpose was to evaluate the safety and efficacy of the uniplanar external fixation (UEF) device in providing extremity elevation and stabilization while optimizing skin grafting. Intraoperative application of either upper or lower extremity UEF was performed at the time of eschar excision and application of split-thickness autografts. Inclusion criterion was that patients should be over 16 years of age with third-degree circumferential extremity burns that were planned for autologous skin grafting within 48 hours after their injury. Patient consent was obtained in every case. Eight patients aged 17 to 62 with circumferential extremity burns were reviewed. No pin-tract infections were observed, nor were any of the skin grafts lost due to shearing. Peripheral nerve and arterial injuries were not encountered. Only one patient with an oversized arm secondary to morbid obesity had a pin pull-out. No other patient developed adverse sequelae from the surgery or from the placement of the UEF device. The UEF device provides a safe and effective means for elevation of extremites in patients with circumferential extremity burns undergoing skin grafting. This allows for optimal access for skin grafting, dressing changes, and postoperative positioning. Shear injury and pressure necrosis of the fresh grafts is minimized. Increasing the number of pins in obese patients should be considered to avoid the complications of pin pull-out.

“Shift to right flypaper technique” a refined method for postage stamp autografting preparation

"Lack of donor skin" is a challenge condition for autografting in the treatment of extensive burns. The modified Meek technique seems to be a practical solution for this problem. However, the equipment and consumed materials for the modified Meek technique are expensive which limits routine use. Designing a less expensive, efficient and easy to apply expansion method may improve burn care quality and shorten hospital stay period. Our previous study reported the "flypaper technique" for preparation of postage stamp autografting. The time for confluence of the burned wound depends on the size of the skin islands and expansion ratio. In clinical practice, 5mm skin squares is the preferred size of the skin islands; however, the positioning procedure can be modified to improve the wound healing process. According to the chessboard diagram, the "shift to right" positioning technique shortens the 10% biggest distance in six times expansion diagrams and 20% biggest distance in nine times expansion diagrams. By using a quick cutting plate, chessboard tray and petrolatum gauze, the skin islands can be uniformly located and correctly oriented on the gauze. This method allows a true expansion ratio up to nine times. In comparison with the modified Meek technique, this method also offers rapid wound reepithilization but with lower cost. However, the burn scar needs further rehabilitation and compression therapy to improve the functional and cosmetic result. This "shift to right flypaper technique" is worthy of consideration in dealing with extensive burns.

Topical negative pressure (TNP) for partial thickness burns

BACKGROUND

A burn wound is a complex and evolving injury, with both local and systemic consequences. Treatment includes using variety of dressings, but newer strategies such as topical negative pressure therapy have been developed to try and promote the wound healing process and minimize burn wound progression to involve deeper tissue in the acute phase. Topical negative pressure uses a suction force to drain excess fluids.

OBJECTIVES

To assess the effectiveness of TNP for those people with partial thickness burns.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (searched April 2007), the Cochrane Central Register of Controlled Trials (CENTRAL)(The Cochrane Library Issue 2, 2007), Ovid MEDLINE (1950 to April Week 4 2007), Ovid EMBASE (1980 to Week 18 2007) and Ovid CINAHL (1982 to April Week 4 2007).

SELECTION CRITERIA

All randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated the safety and effectiveness of TNP for partial thickness burns.

DATA COLLECTION AND ANALYSIS

Two authors using standardised forms extracted the data independently. Each trial was assessed for internal validity with differences resolved by discussion. A narrative synthesis of results was undertaken as the absence of missing data, poor reporting, or both precluded the authors to undertake any formal statistical analysis.

MAIN RESULTS

One RCT satisfied the inclusion criteria. The methodological quality of the trial was poor.

AUTHORS' CONCLUSIONS

There is a paucity of high quality RCTs on TNP for partial thickness burn injury with insufficient sample size and adequate power to detect differences, if there are any, between TNP and conventional burn wound therapy dressings.

Management of local burn wounds in the ED

Each year there are over 500,000 burns that present to the emergency department (ED). Most burns are minor, and their care focuses on local wound management. The current article will present a typical case and then review the epidemiology, pathophysiology, diagnosis, and management of minor burns in the ED.

The Pathogenesis of Burn Wound Conversion

OBJECTIVE

Burn wound progression is a poorly understood process by which certain superficial partial-thickness burns spontaneously advance into deep partial-thickness or full-thickness wounds. Progression of an injury into deeper tissue is an important phenomenon in the treatment of thermal injury due to the fact that burn wound depth may be a significant determinant of morbidity and treatment. This article reviews current knowledge of the pathogenesis, molecular and cellular mechanisms, local and systemic factors, and treatment modalities related to wound conversion.

DATA SOURCES AND STUDY SELECTION

All peer-reviewed, original, and review articles published in English-language literature relevant to the topic of burn wound conversion on animals and human subjects were selected for this review.

DATA EXTRACTION AND SYNTHESIS

After assessing data relevance, independent extraction by a sole reviewer was performed. Data were tabulated according to the following categories: pathogenesis, mechanisms, local and systemic factors, and treatment.

CONCLUSIONS

Burn wound progression is complex and caused by additive effects of inadequate tissue perfusion, free radical damage, and systemic alterations in the cytokine milieu of burn patients, leading to protein denaturation and necrosis. Even though insufficient evidence exists for causal inferences, infection, tissue desiccation, edema, circumferential eschar, impaired wound perfusion, metabolic derangements, advanced age, and poor general health play important roles. Although consensus-building research is ongoing, current mainstays of treatment include adequate fluid resuscitation, nutritional support, and local wound care, with an emphasis on topical antimicrobial agents and biosynthetic dressings. Identifying early indicators by elucidating possible interacting or synergistic mechanisms and by developing preventative strategies will enhance prevention and treatment.

Enhanced angiogenesis in grafted skins by laser-induced stress wave-assisted gene transfer of hepatocyte growth factor

Treatment to increase secretion of growth factors related to angiogenesis by gene transfection is a promising therapeutic solution for improving the outcome of tissue transplantation. We attempted to deliver a therapeutic vector construct carrying the human hepatocyte growth factor (hHGF) gene to skin grafts of rats using laser-induced stress waves (LISWs), with the objective of enhancing their adhesion. First we delivered the hHGF gene to rat native skin in vivo to determine the optimum gene transfer conditions. We then transferred the hHGF gene to excised rat skins, with which autografting was performed. We found that the density and uniformity of neovascularities were significantly enhanced in the grafted skins that were transfected using LISWs. These results suggest the efficacy of this method to improve the outcome of skin grafting. To our knowledge, this is the first experimental demonstration of a therapeutic efficacy based on LISW-mediated gene transfection. Since the present method can be applied not only to various types of tissues but also to bioengineered tissues, this technique has the potential to contribute to progress in transplantation medicine and future regenerative medicine.

Burn injury pain: the continuing challenge

The development of more effective methods of relieving pain associated with burn injury is a major unmet medical need. Not only is acute burn injury pain a source of immense suffering, but it has been linked to debilitating chronic pain and stress-related disorders. Although pain management guidelines and protocols have been developed and implemented, unrelieved moderate-to-severe pain continues to be reported after burn injury. One reason for this is that the intensity of pain associated with wound care and rehabilitation therapy, the major source of severe pain in this patient population, varies widely over the 3 phases of burn recovery, making it difficult to estimate analgesic requirements. The effects of opioids, the most commonly administered analgesics for burn injury procedural pain, are difficult to gauge over the course of burn recovery because the need for an opioid may change rapidly, resulting in the overmedication or undermedication of burn-injured patients. Understanding the mechanisms that contribute to the intensity and variability of burn injury pain over time is crucial to its proper management. We provide an overview of the types of pain associated with a burn injury, describe how these different types of pain interfere with the phases of burn recovery, and summarize pharmacologic pain management strategies across the continuum of burn care. We conclude with a discussion and suggestions for improvement. Rational management, based on the underlying mechanisms that contribute to the intensity and variability of burn injury pain, is in its infancy. The paucity of information highlights the need for research that explores and advances the identification of mechanisms of acute and chronic burn injury pain.

PERSPECTIVE

Researchers continue to report that burn pain is undertreated. This review examines burn injury pain management across the phases of burn recovery, emphasizing 3 types of pain that require separate assessment and management. It provides insights and suggestions for future research directions to address this significant clinical problem.

Thermal and electrical injuries

Through progress in wound management, resuscitation, intensive care treatment, and a coordinated rehabilitation process, modern burn care has been able to deliver substantial increases in survival and improvement in functional outcomes for burn victims. The development of regionalized burn centers has contributed greatly to this progress. As the field of burns matures, burn centers are preparing to meet future challenges through collaborative efforts in disaster management and outcomes research.

Effect of silver on burn wound infection control and healing: review of the literature

Silver compounds have been exploited for their medicinal properties for centuries. At present, silver is reemerging as a viable treatment option for infections encountered in burns, open wounds, and chronic ulcers. The gold standard in topical burn treatment is silver sulfadiazine (Ag-SD), a useful antibacterial agent for burn wound treatment. Recent findings, however, indicate that the compound delays the wound-healing process and that silver may have serious cytotoxic activity on various host cells. The present review aims at examining all available evidence about effects, often contradictory, of silver on wound infection control and on wound healing trying to determine the practical therapeutic balance between antimicrobial activity and cellular toxicity. The ultimate goal remains the choice of a product with a superior profile of infection control over host cell cytotoxicity.

Burn wound depth assessment--is laser Doppler imaging the best measurement tool available?

Accurate early assessment of burn wound depth is increasingly important in clinical decision-making. Clinimetric principles are absolutely mandatory while developing a new test or tool for use in the clinical setting. This article critically evaluates the clinimetrics of a powerful tool for assessment of burn depth and whether Laser Doppler Imaging can meet those criteria by virtue of differentiation between superficial and deep burns.

Noninvasive assessment of cutaneous wound healing using ultrahigh-resolution optical coherence tomography

Ultrahigh-resolution optical coherence tomography (OCT) was used for noninvasive in vivo evaluation of the wound healing process. Cutaneous wounds were induced by 2.5-mm diameter full-thickness punch biopsies on the dorsal surface of seven mice. OCT imaging was performed to assess the structural characteristics associated with the healing process. The OCT results were compared to corresponding histology. Two automated quantitative analysis routines were implemented to identify the dermal-epidermal junction and segment the OCT images. Hallmarks of cutaneous wound healing such as wound size, epidermal migration, dermal-epidermal junction formation, and differences in wound composition were readily identified on the OCT images. Blister formation was also observed. Preliminary findings suggest OCT is a viable tool to noninvasively monitor wound healing in vivo.

Combining cell therapy and nanotechnology

Cell transplantation to treat diseases characterised by tissue and cell dysfunction, ranging from diabetes to spinal cord injury, has made great strides preclinically and towards clinical efficacy. In order to enhance clinical outcomes, research needs to continue in areas including the development of a universal cell source that can be differentiated into specific cellular phenotypes, methods to protect the transplanted allogeneic or xenogeneic cells from rejection by the host immune system, techniques to enhance cellular integration of the transplant within the host tissue, strategies for in vivo detection and monitoring of the cellular implants, and new techniques to deliver genes to cells without eliciting a host immune response. Overcoming these obstacles will be of considerable benefit, as it allows understanding, visualising and controlling cellular interactions at a submicron level. Nanotechnology is a multidisciplinary field that allows us to manipulate materials, tissues, cells and DNA at the level of and within the individual cell. As such, nanotechnology may be well suited to optimise the generally encouraging results already achieved in cell transplantation. This review presents some of the ways that nanotechnology can directly contribute to cell transplantation.

Imaging acute thermal burns by photoacoustic microscopy

The clinical significance of a burn depends on the percentage of total body involved and the depth of the burn. Hence a noninvasive method that is able to evaluate burn depth would be of great help in clinical evaluation. To this end, photoacoustic microscopy is used to determine the depth of acute thermal burns by imaging the total hemoglobin concentration in the blood that accumulates along the boundaries of injuries as a result of thermal damage to the vasculature. We induce acute thermal burns in vivo on pig skin with cautery. Photoacoustic images of the burns are acquired after skin excision. In a burn treated at 175 degrees C for 20 s, the maximum imaged burn depth is 1.73+/-0.07 mm. In burns treated at 150 degrees C for 5, 10, 20, and 30 s, respectively, the trend of increasing maximum burn depth with longer thermal exposure is demonstrated.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.

Burn wound infections

Burns are one of the most common and devastating forms of trauma. Patients with serious thermal injury require immediate specialized care in order to minimize morbidity and mortality. Significant thermal injuries induce a state of immunosuppression that predisposes burn patients to infectious complications. A current summary of the classifications of burn wound infections, including their diagnosis, treatment, and prevention, is given. Early excision of the eschar has substantially decreased the incidence of invasive burn wound infection and secondary sepsis, but most deaths in severely burn-injured patients are still due to burn wound sepsis or complications due to inhalation injury. Burn patients are also at risk for developing sepsis secondary to pneumonia, catheter-related infections, and suppurative thrombophlebitis. The introduction of silver-impregnated devices (e.g., central lines and Foley urinary catheters) may reduce the incidence of nosocomial infections due to prolonged placement of these devices. Improved outcomes for severely burned patients have been attributed to medical advances in fluid resuscitation, nutritional support, pulmonary and burn wound care, and infection control practices.