Advances in the treatment of burn patients

Advances in Skin Tissue Bioengineering and the Challenges of Clinical Translation

Skin tissue bioengineering is an emerging field that brings together interdisciplinary teams to promote successful translation to clinical care. Extensive deep tissue injuries, such as large burns and other major skin loss conditions, are medical indications where bioengineered skin substitutes (that restore both dermal and epidermal tissues) are being studied as alternatives. These may not only reduce mortality but also lessen morbidity to improve quality of life and functional outcome compared with the current standards of care. A common objective of dermal-epidermal therapies is to reduce the time required to accomplish stable closure of wounds with minimal scar in patients with insufficient donor sites for autologous split-thickness skin grafts. However, no commercially-available product has yet fully satisfied this objective. Tissue engineered skin may include cells, biopolymer scaffolds and drugs, and requires regulatory review to demonstrate safety and efficacy. They must be scalable for manufacturing and distribution. The advancement of technology and the introduction of bioreactors and bio-printing for skin tissue engineering may facilitate clinical products' availability. This mini-review elucidates the reasons for the few available commercial skin substitutes. In addition, it provides insights into the challenges faced by surgeons and scientists to develop new therapies and deliver the results of translational research to improve patient care.

A Single Institution Experience with Standardized Objective and Subjective Scar Evaluation While Undergoing Fractional Ablative Carbon Dioxide Laser Treatment

Laser treatment of burn scar has increased in recent years. Standard components of scar evaluation during laser scar revision have yet to be established. Patients who began laser scar revision from January 2018-2020, underwent at least three treatments, and completed evaluations for each treatment were included. Patients underwent fractional ablative carbon dioxide laser scar revision and pre- and post-procedure scar evaluations by a burn rehabilitation therapist, including Patient and Observer Scar Assessment Scale, Vancouver Scar Scale, our institutional scar comparison scale, durometry, and active range of motion measurements. Twenty-nine patients began laser scar revision and underwent at least three treatments with evaluations before and after each intervention. All patients improved in at least one scar assessment metric after a single laser treatment. After second and third treatments, all patients improved in at least three scar assessment metrics. Range of motion was the most frequently improved. Durometry significantly improved after a third treatment. Patients and observers showed some agreement in their assessment of scar, but observers rated overall scar scores better than patients. Patients acknowledged substantial scar improvement on our institutional scar comparison scale. Burn scar improves with fractional ablative laser therapy in a range of scar ages and skin types, as early as the first session. Improvements continue as additional sessions are performed. This work suggests baseline evaluation components for patients undergoing laser, and a timeline for expected clinical improvements which may inform conversations between patients and providers when considering laser for symptomatic hypertrophic scar.

Clinical features and mortality-related factors of extensive burns among young adults: the Kunshan disaster experience

Background

The aim of the study was to identify the clinical features and the factors associated with burn induced mortality among young adults after exposure to indoor explosion and fire.

Methods

This is an observational study which included burn patients who were admitted to eighteen ICUs after a fire disaster. Epidemiologic and clinical characteristics, as well as therapy were recorded. The primary outcome was 90-day mortality. The mortality-related factors were also analyzed.

Results

There were 167 burn patients enrolled in the study, the median age was 38 years, 62 (37.1%) patients died within 90 days. Seventy-one percent of patients had a burn size ≥90% TBSA, and 73.7% of patients had a full-thickness burn area above 50% TBSA. The survivors had lower Baux scores, and received earlier escharectomy and autologous skin grafts. The 50% mortality rates (LA50s) for burn size and full-thickness burn area were 95.8% and 88.6% TBSA, respectively. The multivariate analysis showed that full-thickness burn area over 50% TBSA and residual burned surface area (RBSA)/TBSA at 28 days were strong predictors of mortality among burn patients (odds ratio 2.55; 95% CI, 1.01 to 6.44, P=0.047; odds ratio 1.07; 95% CI, 1.04 to 1.09, P<0.001). The ROC curve-based cut-off values of RBSA/TBSA at 28 days for predicting 90-day mortality were 62.5%.

Conclusions

Burn size and full-thickness burn area were the main risk factors for poor outcome in patients with extensive burns. Earlier escharectomy and autologous skin grafts may improve outcomes.

Tissue Engineered Skin Substitutes

The fundamental skin role is to supply a supportive barrier to protect body against harmful agents and injuries. Three layers of skin including epidermis, dermis and hypodermis form a sophisticated tissue composed of extracellular matrix (ECM) mainly made of collagens and glycosaminoglycans (GAGs) as a scaffold, different cell types such as keratinocytes, fibroblasts and functional cells embedded in the ECM. When the skin is injured, depends on its severity, the majority of mentioned components are recruited to wound regeneration. Additionally, different growth factors like fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) are needed to orchestrated wound healing process. In case of large surface area wounds, natural wound repair seems inefficient. Inspired by nature, scientists in tissue engineering field attempt to engineered constructs mimicking natural healing process to promote skin restoration in untreatable injuries. There are three main types of commercially available engineered skin substitutes including epidermal, dermal, and dermoepidermal. Each of them could be composed of scaffold, desired cell types or growth factors. These substitutes could have autologous, allogeneic, or xenogeneic origin. Moreover, they may be cellular or acellular. They are used to accelerate wound healing and recover normal skin functions with pain relief. Although there are a wide variety of commercially available skin substitutes, almost none of them considered as an ideal equivalents required for proper wound healing.

Monitoring End Points of Burn Resuscitation

This article discusses commonly used methods of monitoring and determining the end points of resuscitation. Each end point of resuscitation is examined as it relates to use in critically ill burn patients. Published medical literature, clinical trials, consensus trials, and expert opinion regarding end points of resuscitation were gathered and reviewed. Specific goals were a detailed examination of each method in the critical care population and how this methodology can be used in the burn patient. Although burn resuscitation is monitored and administered using the methodology as seen in medical/surgical intensive care settings, special consideration for excessive edema formation, metabolic derangements, and frequent operative interventions must be considered.

Skin and skin substitutes in burn management

Early burn excision has reduced the mortality from major burns. This practice presents the problem of wound coverage after excision, since the availability of autologous donor sites is limited in very large burns. This article reviews the methods available for covering burn wounds. Methods of expanding autologous skin are discussed as well as techniques using allogeneic tissue and xenograft. Newer synthetic skin substitutes have become an important advance and are also described. Cultured skin replacements are also discussed along with their shortfalls. The treatment of a patient with major burns may require the use of many different skin substitutes, as none is entirely satisfactory on its own.

Fluid resuscitation management in patients with burns: update

Since 1968, when Baxter and Shires developed the Parkland formula, little progress has been made in the field of fluid therapy for burn resuscitation, despite advances in haemodynamic monitoring, establishment of the 'goal-directed therapy' concept, and the development of new colloid and crystalloid solutions. Burn patients receive a larger amount of fluids in the first hours than any other trauma patients. Initial resuscitation is based on crystalloids because of the increased capillary permeability occurring during the first 24 h. After that time, some colloids, but not all, are accepted. Since the emergence of the Pharmacovigilance Risk Assessment Committee alert from the European Medicines Agency concerning hydroxyethyl starches, solutions containing this component are not recommended for burns. But the question is: what do we really know about fluid resuscitation in burns? To provide an answer, we carried out a non-systematic review to clarify how to quantify the amount of fluids needed, what the current evidence says about the available solutions, and which solution is the most appropriate for burn patients based on the available knowledge.

Measuring burn injury outcomes

Burn injury affects all facets of life. Burn care has improved over time. Improved survival after burn injury has resulted in a shift in outcome measurement from inpatient morbidity and mortality to long-term functional and health-related quality-of-life measures. Integration of professionals from different disciplines has enabled burn centers to develop collaborative methods of assessing the quality of care delivered to patients with burns based on their ability to reintegrate into their normal physical, social, psychological, and functional activities. Burn outcomes will continue to develop on the foundation that has been built and will generate evidence-based best practices in the future.

Tunable engineered skin mechanics via coaxial electrospun fiber core diameter

Autologous engineered skin (ES) offers promise as a treatment for massive full thickness burns. Unfortunately, ES is orders of magnitude weaker than normal human skin causing it to be difficult to apply surgically and subject to damage by mechanical shear in the early phases of engraftment. In addition, no manufacturing strategy has been developed to tune ES biomechanics to approximate the native biomechanics at different anatomic locations. To enhance and tune ES biomechanics, a coaxial (CoA) electrospun scaffold platform was developed from polycaprolactone (PCL, core) and gelatin (shell). The ability of the coaxial fiber core diameter to control both scaffold and tissue mechanics was investigated along with the ability of the gelatin shell to facilitate cell adhesion and skin development compared to pure gelatin, pure PCL, and a gelatin-PCL blended fiber scaffold. CoA ES exhibited increased cellular adhesion and metabolism versus PCL alone or gelatin-PCL blend and promoted the development of well stratified skin with a dense dermal layer and a differentiated epidermal layer. Biomechanics of the scaffold and ES scaled linearly with core diameter suggesting that this scaffold platform could be utilized to tailor ES mechanics for their intended grafting site and reduce graft damage in vitro and in vivo.

Strategies to increase flap survival in nasal reconstruction in patients with deep panfacial burns

Total nasal reconstruction requires the management of skin, cartilage, and nasal mucosa. This three-dimensional surgical approach is especially restricted in patients with severe deformities after deep panfacial burns. In this regard, the development of tissue fibrosis reduces the quality and reliability of surrounded donor sites, limiting the surgical options and flap survival outcomes. This report discusses the benefit of tissue protection procedures, such as flap delay and leech therapy, in the total nasal reconstruction of a patient with split-thickness skin grafts on donor sites for forehead and nasolabial flaps.

XBP-1s is linked to suppressed gluconeogenesis in the Ebb phase of burn injury

The first 24 h following burn injury is known as the ebb phase and is characterized by a depressed metabolic rate. While the postburn ebb phase has been well described, the molecular mechanisms underlying this response are poorly understood. The endoplasmic reticulum (ER) regulates metabolic rate by maintaining glucose homeostasis through the hepatic ER stress response. We have shown that burn injury leads to ER stress in the liver during the first 24 h following thermal injury. However, whether ER stress is linked to the metabolic responses during the ebb phase of burn injury is poorly understood. Here, we show in an animal model that burn induces activation of activating transcription factor 6 (ATF6) and inositol requiring enzyme-1 (IRE-1) and this leads to increased expression of spliced X-box binding protein-1 (XBP-1s) messenger ribonucleic acid (mRNA) during the ebb phase. This is associated with increased expression of XBP-1 target genes and downregulation of the key gluconeogenic enzyme glucose-6-phosphatase (G6Pase). We conclude that upregulation of the ER stress response after burn injury is linked to attenuated gluconeogenesis and sustained glucose tolerance in the postburn ebb phase.

Incidence and treatment of burns: a twenty-year experience from a single center in Germany

OBJECTIVE

To analyze trends in incidence and treatment of thermal injuries over the last two decades.

METHODS

We retrospectively reviewed our local single center database of patients with thermal injuries admitted to the burn intensive care unit (BICU) of the Cologne-Merheim Medical Center (University Hospital of Witten/Herdecke). The cohort was divided into two groups according to the decade of admission and the epidemiology and clinical course of the patient sample admitted during the period 1991-2000 (n=911) was compared to that of 2001-2010 (n=695).

RESULTS

The following variables were significantly different in the bivariate analysis: mean age (39.8 years vs. 44.0 years), burn size of total body surface area (23.2% vs. 18.0%) and size of 3rd degree burns (9.6% vs. 14.9%). The incidence of inhalation injury was significantly lower in the last decade (33.3% vs. 13.7%) and was associated with a shorter duration of mechanical ventilation (10.8 days vs. 8.5 days). The ABSI-score as an indicator of burn severity declined in the second period (6.3 vs. 6.0) contributing partially to the decline of BICU length of stay (19.1 days vs. 18.8 days) and to the mortality rate decrease (18.6% vs. 15.0%).

CONCLUSION

The severity of burn injuries during the last two decades declined, probably reflecting the success of prevention campaigns. Concerning mortality, the chance of dying for a given severity of injury has decreased.

Skin tissue engineering--in vivo and in vitro applications

Significant progress has been made over the years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin or for the establishment of human-based in vitro skin models. This review summarizes these advances in in vivo and in vitro applications of tissue-engineered skin. We further highlight novel efforts in the design of complex disease-in-a-dish models for studies ranging from disease etiology to drug development and screening.

Use of a nanocrystalline silver dressing and vacuum-assisted closure in a severely burned dog

OBJECTIVE

To describe the first veterinary use of a nanocrystalline silver dressing (NSD) and use of vacuum-assisted closure (VAC) to treat a severely burned dog.

CASE OR SERIES SUMMARY

A 1-year-old female intact American Staffordshire Terrier with 50% total body surface area burned was referred for definitive care approximately 18-24 hours post injury. The dog was treated with crystalloid fluids, hydroxyethyl starch, and antimicrobials based on culture and sensitivity results of wound cultures, fresh frozen plasma, human serum albumin, and packed red cells. Wound care initially consisted of daily debridement under anesthesia with silver sulfadiazine application and bandaging. Because of the extent and the location of the wounds and morbid state of the patient, early wound grafting was not an option. Because of its reported improvement in granulation tissue formation and decreased tissue edema, VAC was used once the majority of burned tissue was manually debrided. Because of the pain caused by VAC and traditional bandaging techniques with this extent of injury, an NSD was utilized. This strategy was chosen due to the antimicrobial properties of NSD and the reduced necessity for daily bandage changes, which was reduced to only every 3 days. This protocol reduced the need for daily sedation or anesthesia.

NEW OR UNIQUE INFORMATION PROVIDED

VAC and NSD were used successfully for the treatment of a severe burn injury in a dog. The use of NSD decreased the cost of therapy by reducing the need for daily bandage changes, thereby reducing the anesthetic and analgesic costs and allowing the patient to be managed on an outpatient basis.

Skin tissue engineering--in vivo and in vitro applications

Significant progress has been made over the years in the development of in vitro-engineered substitutes that mimic human skin, either to be used as grafts for the replacement of lost skin or for the establishment of human-based in vitro skin models. This review summarizes these advances in in vivo and in vitro applications of tissue-engineered skin. We further highlight novel efforts in the design of complex disease-in-a-dish models for studies ranging from disease etiology to drug development and screening.

[Estimation of substitution volume after burn trauma. Systematic review of published formulae]

BACKGROUND

Fluid resuscitation after severe burns remains a challenging task particularly in the preclinical and early clinical phases. To facilitate volume substitution after burn trauma several formulae have been published and evaluated, nevertheless, the optimal formula has not yet been identified.

METHODS

A systematic PubMed search was performed to identify published formulae for fluid resuscitation after severe burns. The search terms "burn", "thermal", "treatment", "therapy" or "resuscitation", "fluid", "formula" and "adult", "pediatric" or "paediatric" were used in various combinations. Analysis was limited to the period from 01.01.1950 to 30.06.2010 and database entries in PubMed (http://www.pubmed.com). Additionally, references cited in the papers were analyzed and relevant publications were also included. Publications and formulae were assessed and classified by two independent investigators.

RESULTS

Within the specified time frame eight publications (five original contributions and three book chapters) were identified of which three formulae recommended colloid solutions, four recommended electrolyte solutions and one suggested hypertonic solutions within the first 24 h for fluid resuscitation. Only one formula specifically dealt with fluid resuscitation in infants.

CONCLUSION

The identified formulae led to sometimes strikingly diverse calculations of resuscitation fluid volumes. Therefore their use should be monitored closely and clinical values included. Urine output is a well established individual parameter. Use of colloid and hypertonic solutions leads to a reduced total fluid volume but is still controversially discussed.

Critical care of the burn patient: the first 48 hours

OBJECTIVE

The goal of this concise review is to provide an overview of some of the most important resuscitation and monitoring issues and approaches that are unique to burn patients compared with the general intensive care unit population.

STUDY SELECTION

Consensus conference findings, clinical trials, and expert medical opinion regarding care of the critically burned patient were gathered and reviewed. Studies focusing on burn shock, resuscitation goals, monitoring tools, and current recommendations for initial burn care were examined.

CONCLUSIONS

The critically burned patient differs from other critically ill patients in many ways, the most important being the necessity of a team approach to patient care. The burn patient is best cared for in a dedicated burn center where resuscitation and monitoring concentrate on the pathophysiology of burns, inhalation injury, and edema formation. Early operative intervention and wound closure, metabolic interventions, early enteral nutrition, and intensive glucose control have led to continued improvements in outcome. Prevention of complications such as hypothermia and compartment syndromes is part of burn critical care. The myriad areas where standards and guidelines are currently determined only by expert opinion will become driven by level 1 data only by continued research into the critical care of the burn patient.

Enteral glutamine supplementation reducing infectious morbidity in burns patients: a randomised controlled trial

PURPOSE

Enteral glutamine supplements have been shown to reduce infectious morbidity in trauma patients, but their effect on patients with burns is not completely studied. The objective of this study was to measure the impact of enteral glutamine supplementation on infectious morbidity and in turn, the hospital-stay in patients with burns.

METHODS

Thirty patients with burns were randomly divided into two groups with 15 patients in each, the study (glutamine supplemented) and control group. Patients were randomised to receive either isonitrogenous mixture without glutamine or isonitrogenous mixture with glutamine until complete healing of the burn wound occurred. Incidence of positive blood culture, wound culture, total leucocyte count, hospital-stay and mortality was recorded.

RESULTS

The results showed that the incidence of positive blood culture was considerably reduced in the study group (0.20±0.41) vs. control (0.73±0.96; p = 0.065). The incidence of positive wound culture was significantly reduced in the study group (1.00 ± 1.25) vs. control (3.53 ± 2.47; p = 0.001). In addition, the wound healing was better and hospital-stay days were reduced in the study group (22.73 ± 9.13 days) vs. (39.73 ± 18.27 days; p = 0.003).

CONCLUSIONS

These results indicate that enteral glutamine supplementation in adult burn patients could abate the degree of infectious morbidity and reduce hospital-stay.

Modern trends in fluid therapy for burns

The majority of burn centres use the crystalloid-based Parkland formula to guide fluid therapy, but patients actually receive far more fluid than the formula predicts. Resuscitation with large volumes of crystalloid has numerous adverse consequences, including worsening of burn oedema, conversion of superficial into deep burns, and compartment syndromes. Resuscitation fluids influence the inflammatory response to burns in different ways and it may be possible, therefore to affect this response using the appropriate fluid, at the appropriate time. Starches are effective volume expanders and early use of newer formulations may limit resuscitation requirements and burn oedema by reducing inflammation and capillary leak. Advanced endpoint monitoring may guide clinicians in when to 'turn off' aggressive fluid therapy and therefore avoid the problems of over-resuscitation.

Progress and opportunities for tissue-engineered skin

Tissue-engineered skin is now a reality. For patients with extensive full-thickness burns, laboratory expansion of skin cells to achieve barrier function can make the difference between life and death, and it was this acute need that drove the initiation of tissue engineering in the 1980s. A much larger group of patients have ulcers resistant to conventional healing, and treatments using cultured skin cells have been devised to restart the wound-healing process. In the laboratory, the use of tissue-engineered skin provides insight into the behaviour of skin cells in healthy skin and in diseases such as vitiligo, melanoma, psoriasis and blistering disorders.

Epidemiological and clinical profile of burn victims

OBJECTIVES

To describe the clinical and epidemiological profile of the patients in the Burn Unit of the Hospital Universitario San Vicente de Paúl (HUSVP) de Medellín, Colombia, from 1994-2004.

METHODS

Retrospective descriptive study of all pediatric and adult burn patients. The following were recorded: age, gender, cause, extent and severity of the burns, time in the hospital, operations, complications and death rate. Statistica 6.0 (Stafsoft Inc.) was used.

RESULTS

Two thousand three hundred and nineteen patients were admitted, 66.8% were males and 62.9% were less than 15 years old. Burns caused by scalding were the most frequent (45.9%) followed by flames (38.5%) The average burn area was 26.9%. Average hospital stay was 26.9 days. In 2004, 40.4% of the patients required surgery; 13.4% of the patients had complications. 7.4% of the patients died, with an average burn area of 62%; burns caused by flames accounted for 63% of the deaths.

CONCLUSIONS

There is a continuing improvement in hospital stay, survives burn sizes, with figures comparable to others without access to a tissue bank or skin cultivation.

Engineered skin substitutes: practices and potentials

Wound healing can be problematic in several clinical settings because of massive tissue injury (burns), wound healing deficiencies (chronic wounds), or congenital conditions and diseases. Engineered skin substitutes have been developed to address the medical need for wound coverage and tissue repair. Currently, no engineered skin substitute can replace all of the functions of intact human skin. A variety of biologic dressings and skin substitutes have however contributed to improved outcomes for patients suffering from acute and chronic wounds. These include acellular biomaterials and composite cultured skin analogs containing allogeneic or autologous cultured skin cells.

A three decade analysis of factors affecting burn mortality in the elderly

This study's objective was to identify variables that affect the mortality of elderly burn patients and to assess their changes over time. A retrospective review was conducted on all patients 75 or older (n=201) admitted to a university-based burn center between 1972 and 2000. Variables examined were age, sex, TBSA, ABSI, inhalation injury, timing from burn to operative intervention, the number of surgical procedures, the number of pre-morbid conditions, and mortality. There were 95 fatalities. TBSA strongly correlated with mortality (p<0.0001). Adjusting for TBSA and inhalation injury, mortality significantly decreased (p=0.04, odds ratio=0.58). Mortality significantly increased with inhalation injury (p<0.01). Fatality risk increased by 400% with inhalation injury. Absence of inhalation injury was not significant with respect to mortality in the 1970s, however there was a significant decrease (p=0.02) in mortality without an inhalation injury in the 1980s and 1990s. ABSI was strongly predictive of mortality (p<0.0001). On average there was a 200% increase in mortality per unit increase of ABSI. The elderly are 58% less likely to die from burns now as compared to the 1970s. Although mortality rose with increasing TBSA equally in each decade, the absolute risk of mortality decreased over time. This data suggests major strides have been made in burn care, however similar success has not been achieved with inhalation injuries.

[Current status of tissue engineering in urology. Review of the literature]

In the eighties a new field of the medicine appears wich applies the principles of cellular cultivation to synthetic biodegradable polymers scaffolds with the purpose of creating autologous biological substitutes that could improve, maintain or restore the function of organs or damaged tissues. The Tissue Engineering constitutes a new discipline in full phase of development especially in USA, with multiple potential applications in several medical specialities. Our speciality can't remain indifferent to interest and encouraging future originated by this new science. In this work we have made a wide bibliographical revision in the Medline to know the antecedents, current state and the possible future applications of Tissue Engineering in Urology.

Role of artificial neural networks in prediction of survival of burn patients-a new approach

A burn patient may require the most complicated treatment regimes encountered among trauma victims. Predicting the outcome of such treatment depends on several factors which have non-linear relationships. Traditional methods in prediction are "logistic regression" and "maximum likelihood". In this study, an artificial neural network (ANN) is used for computing survival among burn patients admitted to the "Motahary Burn Center", during a 1 year period (1996-1997). Fifteen different observations, such as total body surface area (TBSA), rescue time, admission period, surgery, inhalation injuries, etc. were obtained, retrospectively. A normal feed forward ANN was developed by Thinkspro software. It has 15 input-units, two hidden layers, and one output-unit. Survival was higher in males, those in whom early fluid resuscitation had been initiated and in patients in the middle of the age spectrum (P<0.0001). Strong correlations with these factors were noted. In the training phase, the ANNs accuracy reached 90%. In this study, the ANN has been applied for the first time to predict burn victim survival. This study can enable a different view point to help burn center physicians in the prediction of survival of their patients.

Protective effect of topical iodine preparations upon heat-induced and hydrofluoric acid-induced skin lesions

In this study, the protective prophylactic and post-exposure effects of novel topical iodine preparations were demonstrated upon heat- and hydrofluoric acid-induced skin lesions in the haired guinea pig. Prophylactic treatment of thermal bums with a liquid iodine preparation resulted in statistically significant reductions of 39% and 30%, respectively, in acute inflammation and hemorrhage-microscopic dermal parameters indicative of acute tissue damage. A clear trend of iodine-induced reduction in dermal necrosis occurred, and the epidermal healing markers, acanthosis and hyperkeratosis, were increased. Postexposure treatment of thermal burns with an iodine ointment preparation immediately after occurrence also conferred significant therapeutic reduction in parameters of tissue damage such as epidermal ulceration (87%), acute inflammation (58%), and hemorrhage (30%). Gross pathological evaluation showed that prophylactic and postexposure treatments with the liquid iodine preparation significantly reduced the heat-induced ulceration area by 97% and 65%, respectively. In addition, immediate treatment with an ointment iodine formulation significantly decreased the ulceration area by 98%; its tetraglycol vehicle also had a beneficial effect. Postexposure treatment with the iodine ointment proved efficacious upon hydrofluoric acid-induced skin burns. We observed statistically significant reductions of 76% and 68% in ulceration areas at intervals of 5 and 10 minutes between exposure and treatment, whereas a weaker effect was observed at a longer time interval of 15 minutes. Our findings suggest the therapeutic usage of these newly developed iodine preparations for thermally induced and hydrofluoric acid-induced skin burns.

Glutamine administration reduces Gram-negative bacteremia in severely burned patients: a prospective, randomized, double-blind trial versus isonitrogenous control

OBJECTIVE

To determine the effect of intravenous glutamine supplementation vs. an isonitrogenous control on infectious morbidity in severely burned patients. Previous clinical studies in seriously ill patients suggest a beneficial effect of glutamine on infectious morbidity, but no trials have examined possible clinical benefits in severely burned patients.

DESIGN

Prospective, double-blind, randomized trial.

SETTING

Burn intensive care unit of a university hospital.

PATIENTS

Twenty-six severe burn patients with total burn surface area of 25% to 90% and presence of full-thickness burns. Patients were evaluated for occurrence of bacteremia and antibiotic use during the first 30 days of their burn unit admission. Nutritional status and overall inflammation were also measured.

INTERVENTION

Either intravenous glutamine or an isonitrogenous control amino acid solution was administered as a continuous infusion during burn intensive care unit stay.

MEASUREMENTS AND MAIN RESULTS

The incidence of Gram-negative bacteremia was significantly reduced in the glutamine-supplemented group (8%) vs. control (43%; p <.04). No difference was seen in the incidence of Gram-positive bacteremia or fungemia. Average number of positive blood cultures, antibiotic usage, and mortality rates also were reduced but did not reach statistical significance. Significant improvements in serum transferrin and prealbumin were observed in glutamine-supplemented patients at 14 days after burn injury (p <.01 and.04, respectively). C-reactive protein was also significantly reduced at 14 days after burn injury in the glutamine group (p <.01).

CONCLUSIONS

Significantly fewer bacteremic episodes with Gram-negative organisms occurred in the glutamine-supplemented patients. Glutamine supplementation improved measures of nutrition and decreased measures of overall inflammation. In addition, a trend toward lower mortality rate, decreased overall bacteremia incidence, and antibiotic usage in the glutamine group was observed. Glutamine's beneficial effects may be a result of improved gut integrity or immune function, but the precise mechanism of glutamine's protection is unknown.

Burn resuscitation with two doses of 4 mL/kg hypertonic saline dextran provides sustained fluid sparing: a 48-hour prospective study in conscious sheep

BACKGROUND

The large fluid volumes usually required for burn resuscitation can be suppressed for 8 to 12 hours by intravenous infusion of 4 mL x kg(-1) hypertonic saline dextran (HSD) 1 hour after burn. We hypothesized that a double (8 mL x kg(-1)) dose of HSD or two repeated doses of 4 mL x kg(-1) could enhance or prolong the volume sparing.

METHODS

We produced a full-thickness flame burn covering 40% of the body surface on 18 anesthetized sheep. One hour after the burn, the animals were awake and resuscitated with either (1) lactated Ringer's solution (LR) only, (2) 8 mL x kg(-1) HSD followed by LR, or (3) 4 mL x kg(-1) HSD followed by LR, with a second dose of 4 mL x kg(-1) HSD administered when net fluid accumulation increased to 20 mL x kg(-1). For all regimens, infusion rates were adjusted to produce a urine output of 1 to 2 mL x kg(-1) x h(-1).

RESULTS

Animals resuscitated with only LR required fluid volumes identical to that predicted by the Parkland formula for the first 12 hours. Infusion of 8 mL x kg(-1) HSD initially created a net fluid loss (urine output > infused volume), followed by a rebound fluid requirement eventually equaling that of animals treated with LR only. Animals treated with two separate doses of 4 mL x kg(-1) HSD generally did not experience a net fluid loss or a rebound fluid requirement. Also in the HSD x 2 group, peak and net fluid accumulation was less than that of the other two groups from 18 hours through 48 hours, although the difference was not significant.

CONCLUSION

An initial 4 mL x kg(-1) dose of HSD reduces fluid requirements early after burn, and a second dose administered after an appropriate interval may prolong volume sparing through 48 hours. An 8 mL x kg(-1) continuously infused initial dose was without prolonged fluid sparing effect. The volume-sparing effect of HSD is thus dependent on all of the following: dose, dosing interval, and infusion rate.

The experience in the treatment of patients with extensive full-thickness burns

The aim of the present study is to analyze the changes of cure rate and the main causes of death in the last 40 years, and to summarize our experience in the treatment of extensive full-thickness burn patients. The clinical characteristics, cure rate and main causes of death of 73 cases with total burned area more than 90% TBSA and full-thickness burn area more than 70% TBSA were analyzed retrospectively. Among them, 21 cases (28.8%) were cured and 52 cases (71.2%) died. The cure rate increased significantly in the recent years, and the main causes of death changed from shock and sepsis in the time period 1959-1978 to sepsis and MODS in the past two decades. Due to the improvement of early comprehensive management of burn shock, aggressive surgical approach to full-thickness burn wound and potent systemic supporting measures, the survival rate increased significantly.

Expression of the soxR gene of Pseudomonas aeruginosa is inducible during infection of burn wounds in mice and is required to cause efficient bacteremia

Burn wounds are prone to infection by Pseudomonas aeruginosa, which is an opportunistic pathogen causing various human diseases. During infection, the bacterium senses environmental changes and regulates the expression of genes appropriate for survival. A purine-auxotrophic mutant of P. aeruginosa was unable to replicate efficiently on burn wounds, suggesting that burn wounds are purine-deficient environments. An in vivo expression technology based on purEK gene expression was applied to the burned mouse infection model to isolate P. aeruginosa genes that are specifically induced during infection. Four such in vivo-inducible (ivi) genetic loci were identified, including the gene for a superoxide response regulator (soxR), the gene for a malate synthase G homologue (glcG), an antisense transcript of a putative regulator responding to copper (copR), and an uncharacterized genetic locus. SoxR of Escherichia coli is known to regulate genes involved in protecting the bacterium against oxidative stress. The expression of soxR was proven to be highly inducible during the infection of burned mice and also inducible by treatment with paraquat, which is a redox-cycling reagent generating intracellular superoxide. The SoxR protein functions as an autorepressor in the absence of paraquat, whereas in the presence of paraquat, this autorepression is diminished. Furthermore, a soxR null mutant was shown to be much more sensitive than wild-type P. aeruginosa to macrophage-mediated killing. In support of this observation, a soxR null mutant exhibited a significant delay in causing systemic infections in the burned mice. Since most mortality in burn patients is caused by systemic infection, the defect in the ability to cause efficient bacteremia in burned mice suggests an important role of the soxR gene in the infection of burn wounds.

Mortality according to age and burned body surface in the Virgen del Rocio University Hospital

The application of updated clinical protocols for the treatment of burned patients is showing very good results. The mortality curves according to age and the percentage of burned body surface could be of great use for the comparison of clinical results between different burns units. The probability of survival in 1000 consecutive patients admitted to the Burns Unit of the Virgen del Rocio University Hospital between July, 1993 and August, 1997, is compared, by graphic analysis, with the mortality curves of other centers, obtaining similar results. We conclude that the results of medical attendance in our unit are in line with those considered as a reference.