Large Burns Research Articles

64 Community Level Disadvantage Negatively Impacts Return to Work After Burn Injury

IntroductionThe loss of income from injury, additional health care expenses, and inability to return work can lead to unsatisfactory outcomes. Community level disadvantage (e.g., low high school completion, low home ownership, low income) are more common among minority groups. We hypothesized community level disadvantage would negatively impact the ability to return to work after burn injury. This could serve to identify patients who need focused social, vocational, and financial support during rehabilitation.MethodsData from adult participants in a large multicenter database from 1998-2021 were linked by zip-code to three multi-domain community level-indices: i) Distressed Communities Index, ii) Social Vulnerabilities Index (SVI), iii) Social Deprivation Index (SDI). Cohort characteristics, the distribution of each index within cohort, and days to return to work were described. Fit and strength of association between the indices and return to work was assessed with multi-level logistic regression models. A non-responder analysis examining demographic and clinical differences between was performed using Chi-square tests and Wilcoxon rank sum tests to understand potential bias in the findings.ResultsA total of 1960 participants provided both zip code and employment data 6 months after injury. 75% of participants were male. Mean age was 39. Race/Ethnicity Data: 81.4% identified as White, 11% Black, and 7% as “other” race; 84% of the participants as non-Hispanic or Latino. Median burn size was 20% TBSA (IQR 0.1-95.0), and length of hospitalization was 30 days (IQR 0-379). Of the community indices tested, both DCI and SVI were associated with return to work with DCI having the strongest association with return to work after injury, irrespective of indices. However, when DCI and SVI were included in the model to represent community disadvantage, the impact of race on return to work was less. Participants who did not provide employment information were younger, sustained larger burn sizes, and had longer LOS compared to those who did.ConclusionsDCI and SVI are associated with return to work after burn injury and can be used to focus limited social, vocational, and financial services. Minoritized participants were less likely to return to work but they live in communities with greater disadvantage (e.g. fewer employment opportunities), which highlights the public health impacts of structural racism.

109 The Impact of Distance to Treatment Center on Long-term Outcomes of Burn Patients

IntroductionGeospatial access to American Burn Association (ABA)-verified burn centers or self-designated burn care facilities varies across the country. It is often necessary to transport patients hundreds of miles to provide definitive burn care and rehabilitation services. This study evaluates the impact of distance to treatment center on long-term outcomes of burn patients.MethodsData from the National Institute on Disability, Independent Living, and Rehabilitation Research Burn Model System (BMS) National Database, collected from 2015 to 2019, were analyzed to investigate the impact of distance to BMS center on long-term, patient-reported outcomes. Distance was calculated as driving distance between home zip code centroid and BMS center. Demographic and clinical data were compared between groups by distance from BMS center (< 20, 20-49.9, >50 miles). The following patient-reported outcome measures, collected 12 months after injury, were examined: Veterans Rand 12 Physical Component Summary Score (VR-12 PCS), Veterans Rand 12 Mental Component Summary Score (VR-12 MCS), Satisfaction with Life (SWL), employment status, and days to return to work. Mixed regression model analyses were used to examine the associations between distance to BMS center and each outcome measure, controlling for demographic and clinical variables.ResultsOf the 726 participants included in this study, 191 (26.3%) and 204 (28.1%) were < 20 and between 20-49.9 miles from a BMS center, respectively; 331 (46.6%) were >50 miles from a BMS center. Greater distance to BMS center was associated with white race/ethnicity (p< 0.001) and employment at time of injury (p=0.001). Greater distance to BMS center was also associated with flame injury (p< 0.001) and larger burn size (p< 0.001). There were no significant differences in length of stay or number of operations between groups. Regression analyses did not identify significant associations between distance to BMS center and VR-12 PCS, VR-12 MCS, SWL, employment at 12 months, or days to return to work.ConclusionsAfter burn injury, patient-reported outcome measures of physical and psychosocial function, as well as employment, do not differ based on distance to BMS center.

Biomechanical modeling of novel high expansion auxetic skin grafts.

Over 20 million burn injuries are reported every year, with severe cases requiring skin grafting. Traditionally, split thickness skin grafts are prepared by excising a small portion of healthy skin and its incision patterning using a suitable meshing device, which allows the graft to be expanded beyond its capacity. To date, the maximum expansion achieved through skin grafting has been reported to be less than three times, which is not sufficient for covering large burn sites with limited donor site skin. In this work, we have attempted to study skin graft expansion potential with novel auxetic patterns, which are known to exhibit negative Poisson's effect. Two-layer skin graft models were developed using eight different auxetic incision patterns, and subjected to uniaxial and biaxial tensile strains. The Poisson's ratio, meshing ratio, and induced stresses were characterized for all graft models. The numerical results indicated expansion potentials greater than that of traditional skin grafts across all loads. Extremely high expansions (i.e., >30 times) were estimated for the I-Shaped Re-entrant and Rotating Triangles shaped auxetic models without rupture. Such pioneering findings are anticipated to initiate ground-breaking advances towards skin graft research and improved outcomes in burn surgeries.

Expansion potential of skin grafts with alternating slit based auxetic incisions

Due to a dearth of skin substitutes, severe burn injuries result in millions of deaths every year. Split thickness skin grafting, which involves the projection of a parallel incision pattern on a small section of excised healthy skin, is commonly used to improve the expansion and cover a large burn site. The true expansion capacity of such grafts is currently limited to less than three times, which is insufficient for treating severe burn damage. In this work, we investigated the expansion potential of skin grafts using alternating slit based auxetic incision designs, with the hypothesis that this would lead to greater expansion than standard graft models. Nine two-layer skin graft models were developed with varying slit lengths and spacing, and the Poisson's ratio, meshing ratios, and induced stresses were estimated under uniaxial and biaxial load tests. For up to 100% applied strains, the Poisson's ratio increased with increase in the unit cell spacing. For the biaxial tests, equal lengths of the slits of the pattern, with a high unit cell spacing, was found to lead to a greater skin cover and lower stress localization in the graft models. However, when the graft models were tested up to the ultimate tensile strength of skin, a low unit cell spacing was found to be more desirable. Maximum uniaxial and biaxial meshing ratios, approximately 13 and 5 times higher than that of traditional grafts respectively, were quantified. Such expansion potentials and stress estimations with skin grafts have not been reported previously and would be indispensable for ground breaking advances in burn surgery research.

The energy sector and environmental pollution

The report examines the historical and forecasting aspects of global warming, the structure and dynamics of greenhouse gas emissions and emissions of hazardous gases in Ukraine. The main provisions of the Strategy for Environmental Safety and Adaptation to Climate Change until 2030, as well as the National Plan for Reducing Emissions from Large Combustion Plants until 2033 are analyzed. Data on the dynamics of primary and final energy use, on the amount of global investments in energy efficiency, as well as data on energy efficiency of primary energy resources and the degree of carbon content of renewable and alternative energy sources are given.

The use of Lactic-Acid-Based Copolymer (LABC) as a dressing on split thickness skin grafts in partial and full thickness burn

Split-thickness skin grafting (STSG) is one of the most frequently used approaches to wound coverage in large size deep partial thickness and full thickness burns. The technique, however, is often degraded by partial, and at times complete, failure of graft to take. Though often multifactorial; operative technique, quality of wound bed and the type of dressing used are key factors in the ability of the STSG to heal. Various dressing methods have been described in the literature with varying benefits and degree of success but no consensus on a gold standard has been reached. This study describes the use of intra-operatively placed Lactic-Acid-Based Copolymer (LABC) as a dressing for meshed STSG and its impact on skin graft survival.A retrospective chart review of patients who received LABC dressing over their STSG was performed. A total of 22 patients, 16 male (73%) and 6 female (27%), with a mean age of 36.5 years, were included. Burn injuries were due to fire (10), grease (8), scald (2) and electrical (2), with a median treated area of 375 cm2 and follow up ranging from 21 to 232 days. Complete wound healing with no graft loss was documented in 17 of 22 (77%) patients; with the remaining 5 patients being lost to follow up.Intraoperative LABC dressing application after split-thickness skin grafting in burn patients was shown to be an effective strategy in protecting the STSG site and allowing graft take.

Autologous skin micro-grafts and allogenic skin allograft for mitten hand deformity treatment in epidermolysis bullosa

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; In the genetic skin blistering disorder dystrophic epidermolysis bullosa recurrent blisters and erosions on mechanically stressed areas, as the hands, result in subsequent scarring and development of pseudosyndactylies and contractures. In its most severe form, all fingers are constrained into a fist of scarred (“mitten-hand”-deformity). No causative therapy exists and only a surgical release of the fingers is possible. Hereby, the development of large skin defects is inevitable; the lack of healthy autologous skin for grafting remains a difficult challenge.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods:&lt;/strong&gt; We propose a new technique: It adopts a treatment strategy from the therapy of large extent burns and consists of a combination of autogenic and allogenic skin grafting.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; We present a beneficial outcome in 18 mitten hand deformities treated with this technique. In all patients, the initial functional outcome was improved. Nearly all patients got a considerably widened grip span and durable skin conditions post-operatively. Mean follow-up was 3 years. Typically, recurrence of the scarring occurred from 6 months to 2 years after operation.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; This is the first report on the use of the combination of autogenous pinch skin grafts with allogenic (parental) skin overlay for skin defects in EB. It provides undisturbed wound healing under a “biological dressing”, furthermore, a temporary take of the parental skin was visible. Defects were permanently covered with skin of increased mechanical stability, hand function improved remarkably. However, long term follow-up showed beginning recurrence in most of the patients comparable to recurrence rates described in the literature.&lt;/p&gt;

Short and long term mortality following massive burn injury (>50% TBSA) in a UK burns centre

IntroductionDespite advances in burn care, large burn injuries carry significant mortality risk. Although studies examining immediate mortality are available, little data is available regarding risk after discharge from hospital. This study aimed to determine short and long term mortality rate at a UK burns centre for patients with massive burn injuries. We were particularly interested to determine whether mortality rate for self inflicted injuries was present and whether this was by suicide. MethodsThe International Burn Injury Database (iBID) was interrogated to identify patients admitted with> 50% TBSA (total body surface area) injuries from January 2009- September 2019. Documented cause of death on death certificates were viewed for patients who died. General Practitioners were contacted to determine if discharged patients were alive. Descriptive statistics were generated. Results96 patients were identified. Mean age was 45.6 years (range 16.4–93.7) with male to female ratio of 2:1. Mean TBSA was 71.8% (range 50–99). Mortality was 71.9% and was higher in females (75.7% vs 69.8%). Overall mean revised Baux score was 130 (range 68–184). Nearly half were self-inflicted (49.0%) with higher TBSA (74.4%). Of 69 patients who died only 1 was after discharge. Coroner inquiry determined that this was caused by acute alcohol intoxication. Most of those who died did so within 60 days (91.3%), usually within 48 h (71.0%). Burn futility accounted for most deaths (71.0%) followed by multi-organ failure (14.5%). ConclusionsLarge burns carry significant mortality risk. Self-inflicted large burns carry a higher mortality which may be attributed to larger TBSA. In patients surviving to discharge long term prognosis is good. Patients with self-inflicted burns seem to not make a subsequent successful suicide attempt after discharge from hospital.

Does patient load affect clinical outcome of burn patients in specialized centers? An analysis of the German Burn Registry

Hospital volume has been identified as an independent outcome parameter for a number of medical fields and surgical procedures, and there is a tendency to increase required patient numbers for center verification. However, the existing literature does not support a clear correlation between patient load and clinical outcome in adult burn care and recent data from Germany does not exist. We therefore evaluated the effect of patient volume in German burn centers on clinical outcome. Patient data was extracted from the German Burn Registry from 2015 to 2018. For better inter-center comparability, solely burn patients with a TBSA ≥ 10% were included. Mortality, number of surgeries and length of stay (LOS) were evaluated with respect to burn center patient volume. Burn center volume was divided into two and three groups. A total of 2718 patients with a TBSA ≥ 10% were admitted to the participating 17 burn centers. Independent from the division of patient data into either 2 or 3 groups, the TBSA and ABSI score-related severity of burn injuries were comparable between groups. There was no significant difference in mortality due to center size. Nevertheless, patients treated in large volume burn centers showed a significantly increased LOS (+4.5 days, [1.9–7.2] CI, p = 0.001) and required significantly more surgeries (+0.5 surgeries [0.2–0.8] CI, p = 0.002) when compared to the small volume centers. A similar phenomenon regarding mortality and LOS (p 0.001) was observed after dividing the centers into two groups. Interestingly a division into three groups showed significant differences with the best outcome for patients in medium-volume centers. Nevertheless, mortality did not differ significantly. Therefore, our data demonstrates that in contrast to many other medical fields, outcome and mortality are not automatically improved in burn care by simply increasing the patient load, at least in centers treating 20–100 BICU patients/year.

Effects of continuous goal-directed analgesia on fluid resuscitation of massive burn patients during shock

Effects of continuous goal-directed analgesia on fluid resuscitation of massive burn patients during shock

Possibilities of using innovative technologies for treating a victim with thermal injury (case report)

BACKGROUND: Victims with severe burn injuries require specialized and high-tech care. The treatment results of such patients, as a rule, depend on the timing of the transfer and the volume of surgical treatment aimed at removing necrotic tissues and restoring the skin in conditions of a shortage of donor resources. In this regard, the development and implementation into clinical practice of innovative techniques for the temporary closure of burn wounds with synthetic coatings and the creation of optimal conditions in the wound for engraftment of skin grafts with a high perforation index.&#x0D; СLINICAL CASE: This paper demonstrates a clinical case of successfully treating a child with a critical area of deep burn injury by flame (carriage trauma) using early surgical treatment, innovative wound dressings, and cellular technologies.&#x0D; DISCUSSION: We consider the transfer to a specialized department of a multidisciplinary hospital essential in successfully treating a patient with a large burn area. Under burn center conditions, surgical treatment was performed to remove the necrotic tissues in the largest part of the deep lesion before inflammatory reactions developed. Subsequently, active surgical techniques were used to prepare the wounds for delayed plastic closure. The use of wound dressings and the introduction of cell technologies into clinical practice ensured successful patient treatment due to the early adaptation of skin autografts and risk minimization of their regression, and acceleration of epithelialization in the cells.&#x0D; CONCLUSIONS: The early transfer of a severely burned child to a specialized burn center, active surgical techniques, the use of innovative wound dressings and cellular technologies in the treatment of a patient with a critical area of deep burn lesions made it possible to save a life, successfully restore damaged skin, and create optimal conditions for starting early rehabilitation measures.

A proof-of-concept study on mortality prediction with machine learning algorithms using burn intensive care data.

IntroductionBurn injuries are a common traumatic injury. Large burns have high mortality requiring intensive care and accurate mortality predictions. To assess if machine learning (ML) could improve predictions, ML algorithms were tested and compared with the original and revised Baux score.MethodsAdmission data and mortality outcomes were collected from patients at Uppsala University Hospital Burn Centre from 2002 to 2019. Prognostic variables were selected, ML algorithms trained and predictions assessed by analysis of the area under the receiver operating characteristic curve (AUC). Comparison was made with Baux scores using DeLong testResultsA total of 17 prognostic variables were selected from 92 patients. AUCs in leave-one-out cross-validation for a decision tree model, an extreme boosting model, a random forest model, a support-vector machine (SVM) model and a generalised linear regression model (GLM) were 0.83 (95% confidence interval [CI] = 0.72–0.94), 0.92 (95% CI = 0.84–1), 0.92 (95% CI = 0.84–1), 0.92 (95% CI = 0.84–1) and 0.84 (95% CI = 0.74–0.94), respectively. AUCs for the Baux score and revised Baux score were 0.85 (95% CI = 0.75–0.95) and 0.84 (95% CI = 0.74–0.94). No significant differences were observed when comparing ML algorithms with Baux score and revised Baux score. Secondary variable selection was made to analyse model performance.ConclusionThis proof-of-concept study showed initial credibility in using ML algorithms to predict mortality in burn patients. The sample size was small and future studies are needed with larger sample sizes, further variable selections and prospective testing of the algorithms.Lay SummaryBurn injuries are one of the most common traumatic injuries especially in countries with limited prevention and healthcare resources. To treat a patient with large burns who has been admitted to an intensive care unit, it is often necessary to assess the risk of a fatal outcome. Physicians traditionally use simplified scores to calculate risks. One commonly used score, the Baux score, uses age of the patient and the size of the burn to predict the risk of death. Adding the factor of inhalation injury, the score is then called the revised Baux score. However, there are a number of additional causes that can influence the risk of fatal outcomes that Baux scores do not take into account. Machine learning is a method of data modelling where the system learns to predict outcomes based on previous cases and is a branch of artificial intelligence. In this study we evaluated several machine learning methods for outcome prediction in patients admitted for burn injury. We gathered data on 93 patients at admission to the intensive care unit and our experiments show that machine learning methods can reach an accuracy comparable with Baux scores in calculating the risk of fatal outcomes. This study represents a proof of principle and future studies on larger patient series are required to verify our results as well as to evaluate the methods on patients in real-life situations.

Residual forest structure influences behaviour of Pacific marten (

Wildfires are broad-scale disturbances in North American forests, with impacts that persist for many decades. Further disturbance from post-fire salvage logging is extensively modifying burned landscapes. The removal of habitat structure by fire and salvage logging may affect the persistence of forest-specialist wildlife such as Pacific marten (Martes caurina). However, it is unclear which resources are important to marten on burned landscapes. We used snow tracking and habitat surveys to examine marten habitat selection after three large fires in north-central Washington, USA (10–13 years post-fire), and central British Columbia, Canada (1–2 and 6–9 years post-fire). We developed site-scale habitat models to explain marten foraging and scent-marking post-fire, and assessed further structural changes from salvage logging. Foraging marten chose sites with lower burn severity, greater canopy closure, more vertical structures (trees, snags, saplings, and shrubs), and greater moss/lichen cover than what was generally available. When scent-marking, marten selected structurally-complex sites with abundant deadfall or saplings. Marten moved more quickly when canopy cover was sparse, and rarely used salvage-logged areas. Our results suggest that marten rely on residual habitat structure within large burns, and that secondary disturbance from salvage logging is substantially more harmful to marten than the original fire.

Evolution of a concept with enzymatic debridement and autologous in situ cell and platelet-rich fibrin therapy (BroKerF).

BackgroundDeep partial-thickness burns are traditionally treated by tangential excision and split thickness skin graft (STSG) coverage. STSGs create donor site morbidity and increase the wound surface in burn patients. Herein, we present a novel concept consisting of enzymatic debridement of deep partial-thickness burns followed by co-delivery of autologous keratinocyte suspension and plated-rich fibrin (PRF) or fibrin glue.Material and methodsIn a retrospective case study, patients with deep partial-thickness burns treated with enzymatic debridement and autologous cell therapy combined with PRF or fibrin glue (BroKerF) between 2017 and 2018 were analysed. BroKerF was applied to up to 15% total body surface area (TBSA); larger injuries were combined with surgical excision and skin grafting. Exclusion criteria were age <18 or >70 years, I°, IIa°-only, III° burns and loss of follow-up.ResultsA total of 20 patients with burn injuries of 16.8% ± 10.3% TBSA and mean Abbreviated Burn Severity Score 5.45 ± 1.8 were identified. Of the patients, 65% (n = 13) were treated with PRF, while 35% (n = 7) were treated with fibrin glue. The mean area treated with BroKerF was 7.5% ± 0.05% TBSA, mean time to full epithelialization was 21.06 ± 9.2 days and mean hospitalization time was 24.7 ± 14.4 days. Of the patients, 35% (n = 7) needed additional STSG, 43% (n = 3) of whom had biopsy-proven wound infections.ConclusionBroKerF is an innovative treatment strategy, which, in our opinion, will show its efficacy when higher standardization is achieved. The combination of selective debridement and autologous skin cells in a fibrin matrix combines regenerative measures for burn treatment.Lay SummaryPatients suffering from large burn wounds often require the use of large skin grafts to bring burned areas to heal. Before the application of skin grafts, the burned skin must be removed either by surgery or using enzymatic agents. In this article, we describe a method where small areas of skin are taken and skin cells are extracted and sprayed on wound areas that were treated with an enzymatic agent. The cells are held in place by a substance extracted from patients’ blood (PRF) that is sprayed on the wound together with the skin cells. We believe this technique can be helpful to reduce the need of skin grafts in burned patients and improve the healing process.

Research on emissions from large combustion plants (LCP). Case Study

According to Directive 2010/75 / EU and Law 278/2013 on industrial emissions, operators of large combustion plants (IMA) must carry out continuous self-monitoring of pollutant emissions and are required to perform parallel measurements with accredited laboratories, to certify results. Thus, INCD INSEMEX Petroșani, through the Testing Laboratories Group, accredited by RENAR, offers these type services to various economic agents. The curent paper presents measurements performed at two IMA exhaust chimneys, in two different stages, to quantify pollutants released into the atmosphere and to establish the impact they generate on health of population in the area of the study. Analysis of results showed that the maximum allowed value for the SO2 was exceeded, so that, at the end of this paper, some recommendations were reviewed, according to BAT (Best Available Techniques), to support the economic agent and inhabitants of the area in haveing a cleaner environment.

Post-fire early successional vegetation buffers surface microclimate and increases survival of planted conifer seedlings in the southwestern United States

Climate change and fire exclusion have increased the flammability of western United States forests, leading to forest cover loss when wildfires occur under severe weather conditions. Increasingly large high-severity burn patches limit natural regeneration because of dispersal distance, increasing the chance of conversion to non-forest. Post-fire planting can overcome dispersal limitations, yet warmer and drier post-fire conditions can still reduce survival. We examined how two shrub species with different structures affect below-shrub microclimate and survival rates of planted tree seedlings (Pinus ponderosa Lawson &amp; C. Lawson, Pinus edulis Engelm., Pinus strobiformis Engelm., Pseudotsuga menziesii (Mirb.) Franco) following a high-severity fire in northern New Mexico. We expected that Gambel oak (Querus gambelii Nutt.), with its denser canopy, would buffer below-shrub climate causing higher survival rates of planted seedlings more than the lower canopy density New Mexico locust (Robinia neomexicana A. Gray). Seedlings planted under Gambel oak had survival rates 10% to 35% greater than those planted under New Mexico locust. Higher light availability beneath New Mexico locust corresponded to higher temperatures, lower humidity, and higher vapor pressure deficit, impacting the mortality of planted tree seedlings. These results indicate that by waiting for post-fire shrub establishment, selective use of shrubs can buffer microclimate and increase post-fire planting success in the southwestern United States.

Silver sulfadiazine loaded core-shell airbrushed nanofibers for burn wound healing application

Ideal dressing materials for complex and large asymmetric burns should have the dual properties of anti-bacterial and regenerative with advanced applicability of direct deposit on the wound at the patient bedside. In this study, core-shell nanofibers (polycaprolactone; PCL and polyethylene oxide; PEO) with different percent of silver sulfadiazine (SSD) loading (2–10%) were prepared by the airbrushing method using a custom build device. Results indicate a sustained release profile of silver sulfadiazine (SSD) up to 28 days and concentration-dependent anti-bacterial activity. The morphology and proliferation of human dermal fibroblast (HDF) cells and human dental follicle stem cells (HDFSC) on the silver sulfadiazine loaded nanofibers confirm the biocompatibility of airbrushed nanofibers. Moreover, upregulation of extracellular matrix (ECM) proteins (Col I, Col III, and elastin) support the differentiation and regenerative properties of silver sulfadiazine nanofiber mats. This was further confirmed by the complete recovery of rabbit burn wound models within 7 days of silver sulfadiazine loaded nanofiber dressing. Histopathology data show silver sulfadiazine loaded core-shell nanofibers' anti-inflammatory and proliferative activity without any adverse response on the tissue. Overall data display that the airbrushed silver sulfadiazine-loaded core-shell nanofibers are effective dressing material with the possibility of direct fiber deposition on the wound to cover, heal, and regenerate large asymmetric burn wounds.

Comparison of stationary and dynamic fractional CO2 laser modalities of large burns treatment: Experimental laboratory model

ObjectivesTo experimentally compare two fractional ablative CO2 laser handpieces intended for the treatment of large area burn scars. Each handpiece coverage rate, depth of penetration and application time were measured and compared in a simulation model of large area burns scars using a dynamic/roller handpiece (small footprint) and a stationary/stamping handpiece (large footprint). MethodsA 30 W fractional ablative CO2 laser was applied using 2 different handpieces and footprints on a A4 size paper stack. The handpieces were a stationary (stamping) handpiece with 7 × 7 (49 pixels/square shape) and dynamic (roller) handpiece with 7 × 1 (7 pixels/single row shape). For both handpieces the laser settings were fixed at "High" power (30 W), providing an energy level of 100 mJ/pixel. Both handpieces were applied perpendicular to the surface, with the process repeated for the dynamic handpiece with an angled operation. The depth of laser penetration was assessed by the number of pages of paper having visible holes and burn area coverage time measured under each handpiece/condition. ResultsThe application time was faster and the penetration deeper for the dynamic handpiece compared to the stationary handpiece in both the perpendicular and angled conditions. This study has practical implications for lasers operators to improve time efficacy in large area scars with improved clinical endpoints. ConclusionThe fractional ablative dynamic handpiece demonstrated superior application efficiency compared to the stationary handpiece in the simulated treatment of large surface area burn scars, reducing treatment time with improved depth of penetration.

Hybrid rocket propulsion technology for space transportation revisited - propellant solutions and challenges

This paper presents the status of developments worldwide regarding use of hybrid rocket motors for space transportation. Historical roots are presented and reasons for revisiting hybrid technology after a few decades of limited interest are examined. Modern developments in sounding rockets, reusable suborbital systems and launch vehicles are discussed with particular focus on propellant technology. Various propellant combinations include use of liquid oxygen, hydrogen peroxide, nitrous oxide and nitrous oxide-oxygen mixtures as oxidizers. Different fuels are considered, taking into account performance, as well as inter alia obtainable regression rates. Results of preliminary calculations for vehicles using different propellant combinations are presented and analysed. This is compared with proposed configurations of hybrid rockets worldwide. Unresolved problems and several unknowns are pointed out, including hybrid rocket motor scalability issues, large motor combustion instabilities, combustion efficiency of metalized fuels, propellant volumetric performance and mass of fuel residuals in case of wagon wheel grain geometry. It is discussed whether new-space hybrid launch vehicles, while typically with limited stage reusability, may be cost-competitive in regard to other chemical rocket propulsion system developments. The paper is summarized with a list of potential future advances and technical opportunities. The main purpose of the conducted research is to provide a comparison between different hybrid propulsion technologies available, or currently under development, worldwide.

Early non-excisional debridement of paediatric burns under general anaesthesia reduces time to re-epithelialisation and risk of skin graft

Reported advantages of early excision for larger burn injuries include reduced morbidity, mortality, and hospital length of stay for adult burn patients. However, a paucity of evidence supports the best option for paediatric burns and the advantages of non-excisional (mechanical) debridement. Procedural sedation and analgesia in the emergency department is a popular alternative to debridement in operating theatres under general anaesthesia. This study aims to evaluate the association between early (< 24 h post-injury) non-excisional debridement under general anaesthesia with burn wound re-epithelialisation time and skin graft requirements. Cohort study of children younger than 17 years who presented with burns of five percent total body surface area or greater. Data from January 2013 to December 2019 were extracted from a prospectively collected state-wide paediatric burns’ registry. Time to re-epithelialisation was tested using survival analysis, and binary logistic regression for odds of skin graft requirementto analyse effects of early non-excisional debridement in the operating theatre. Overall, 292 children met eligibility (males 55.5%). Early non-excisional debridement under general anaesthesia in the operating theatre, significantly reduced the time to re-epithelialisation (14 days versus 21 days, p = 0.029)) and the odds of requiring a skin graft in comparison to paediatric patients debrided in the emergency department under Ketamine sedation (OR: 6.97 (2.14–22.67), p < 0.001. This study is the first to demonstrate that early non-excisional debridement under general anaesthesia in the operating theatre significantly reduces wound re-epithelialisation time and subsequent need for a skin graft in paediatric burn patients. Analysis suggests that ketamine procedural sedation and analgesia in the emergency department used for burn wound debridement is not an effective substitute for debridement in the operating theatre.