Burns: military options and tactical solutions

A Potential Resuscitation Route on Battlefield: Immediate Intraperitoneal Fluid Administration Post-burn Shows Satisfactory Fluid Absorption and Anti-shock Effects

INTRODUCTION

Timely fluid resuscitation remains the key to the early treatment of severe burns. Intraperitoneal (IP) fluid administration is a simple, rapid resuscitation strategy via a puncture in the abdominal wall. This study aimed to evaluate the fluid absorption and anti-shock effects of IP delivery in the early stage after severe burns.

MATERIALS AND METHODS

A 30% total body surface area full-thickness burn model was established using male C57BL/6 mice. A total of 126 mice were randomly assigned into six groups (n = 21): the sham injury group (SHAM), the burn group without fluid resuscitation (NR), and the four IP resuscitation groups (IP-A/B/C/D, each being intraperitoneally administered with 60, 80, 100, and 120 mL/kg of sodium lactate Ringer's solution post-injury). Three-hour post-burn, six mice in each group were randomly selected and sacrificed for blood and tissue sampling to detect the IP fluid absorption rate and evaluate organ damage because of low perfusion. The remaining 15 mice in each group were observed for the vital signs within 48-h post-injury, and their survival rate was calculated.

RESULTS

The 48-h survival rate increased in the IP-A (40.0%), IP-B (66.7%), IP-C (60.0%), and IP-D (13.3%) groups, compared with the NR group (0%). The mean arterial pressure, body temperature, and heart rate of mice were significantly stabilized in the IP groups. For the first 3-h post-injury, the absorption rates of groups IP-A (74.3% ± 9.5%) and IP-B (73.3% ± 6.9%) were significantly higher than those of groups IP-C (59.7% ± 7.1%) and IP-D (48.7% ± 5.7%). The levels of arterial blood pH, partial pressure of oxygen, partial pressure of carbon dioxide, lactate, and hematocrit were better maintained in the IP groups. Intraperitoneal resuscitation remarkably reduced the injury scores in burn-induced histopathology of the liver, kidneys, lungs, and intestines, accompanied by decreased alanine transaminase, creatinine, interleukin-1, and tumor necrosis factor-α in plasma, and augmented superoxide dismutase 2 and inhibited malondialdehyde in tissues. Group IP-B has the best performance for these indices.

CONCLUSIONS

Intraperitoneal administration of isotonic saline post-burn can be adequately and rapidly absorbed, thereby boosting circulation and perfusion, precluding shock, alleviating organ damage caused by ischemia and hypoxia, and significantly increasing the survival rate. This technique, with a potential to be a supplement to existing resuscitation methods on the battlefield, is worth further investigation.

Developing a third-degree burn model of rats using the Delphi method

Animal experiments play an essential role in advances in the research and treatment of burns. Currently, researchers often rely on personal experience or the literature to complete the construction of animal disease models, which may lead to a lack of scientific rigor and a wide range of animal disease models with reference value. The purposes of this study were to establish a third-degree burn model of rats using the Delphi method to provide a reference. Two rounds of a Delphi expert consultation survey were conducted on experts (n = 13) in this study, and then the boundary value method was used to screen, modify and supplement the indicators. Next, the indicator weight was determined by dividing the boundary value, and finally, the index system of the rat model of third-degree burns was established. The statistical analysis results show that the positive coefficients of the two rounds of expert consultation are 100% and 88.67% respectively. The expert authority coefficient values were 0.73 and 0.67, respectively, and the expert coordination coefficient test was P < 0.001. According to the experts' suggestion, the third-degree burn model of rats with 8 first-degree indexes, 14 second-degree indexes and 46 third-degree indexes was finally established. According to the characteristics and quality requirements of animal models, this study constructs a rat model of third degree burns, which is expected to expressively improve the overall proficiency of burn research quality.

Development and Optimization of Acriflavine-Loaded Polycaprolactone Nanoparticles Using Box-Behnken Design for Burn Wound Healing Applications

Nanoparticles are used increasingly for the treatment of different disorders, including burn wounds of the skin, due to their important role in wound healing. In this study, acriflavine-loaded poly (ε-caprolactone) nanoparticles (ACR-PCL-NPs) were prepared using a double-emulsion solvent evaporation method. All the formulations were prepared and optimized by using a Box-Behnken design. Formulations were evaluated for the effect of independent variables, i.e., poly (ε-caprolactone) (PCL) amount (X1), stirring speed of external phase (X2), and polyvinyl alcohol (PVA) concentration (X3), on the formulation-dependent variables (particle size, polydispersity index (PDI), and encapsulation efficiency) of ACR-PCL-NPs. The zeta potential, PDI, particle size, and encapsulation efficiency of optimized ACR-PCL-NPs were found to be -3.98 ± 1.58 mV, 0.270 ± 0.19, 469.2 ± 5.6 nm, and 71.9 ± 5.32%, respectively. The independent variables were found to be in excellent correlation with the dependent variables. The release of acriflavine from optimized ACR-PCL-NPs was in biphasic style with the initial burst release, followed by a slow release for up to 24 h of the in vitro study. Morphological studies of optimized ACR-PCL-NPs revealed the smooth surfaces and spherical shapes of the particles. Thermal and FTIR analyses revealed the drug-polymer compatibility of ACR-PCL-NPs. The drug-treated group showed significant re-epithelialization, as compared to the controlled group.

3D Bioprinting: The Roller Coaster Ride to Commercialization

Three-dimensional (3D) bioprinting as a technology is being researched and applied since 2003. It is actually several technologies (inkjet, extrusion, laser, magnetic bioprinting, etc.) under an umbrella term "3D bioprinting." The versatility of this technology allows widespread applications in several; however, after almost 20 years of research, there is still a limited number of cases of commercialized applications. This article discusses the potential for 3D bioprinting in regenerative medicine, drug discovery, and food industry, as well as the existing cases of companies that create commercialized products and services in the aforementioned areas and even in fashion, including their go-to-market route and financing received. We also address the main barriers to creating practical applications of 3D bioprinting within each sphere the technology that is being studied for.

Early visualization of skin burn severity using a topically applied dye-loaded liquid bandage

Skin burns are a significant source of injury in both military and civilian sectors. They are especially problematic in low resource environments where non-fatal injuries can lead to high morbidity rates, prolonged hospitalization, and disability. These multifaceted wounds can be highly complex and must be quickly diagnosed and treated to achieve optimal outcomes. When the appropriate resources are available, the current gold standard for assessing skin burns is through tissue punch biopsies followed by histological analysis. Apart from being invasive, costly, and time-consuming, this method can suffer from heterogeneous sampling errors when interrogating large burn areas. Here we present a practical method for the early visualization of skin burn severity using a topically applied fluorescein-loaded liquid bandage and an unmodified commercial digital camera. Quantitative linear mixed effects models of color images from a four day porcine burn study demonstrate that colorimetric changes within the HSB colorspace can be used to estimate burn depth severity immediately after burning. The finding was verified using fluorescence imaging, tissue cross-sectioning, and histopathology. This low-cost, rapid, and non-invasive color analysis approach demonstrates the potential of dye-loaded liquid bandages as a method for skin burn assessment in settings such as emergency medicine triage and low resource environments.

In Situ Bioprinting of Autologous Skin Cells Accelerates Wound Healing of Extensive Excisional Full-Thickness Wounds

The early treatment and rapid closure of acute or chronic wounds is essential for normal healing and prevention of hypertrophic scarring. The use of split thickness autografts is often limited by the availability of a suitable area of healthy donor skin to harvest. Cellular and non-cellular biological skin-equivalents are commonly used as an alternative treatment option for these patients, however these treatments usually involve multiple surgical procedures and associated with high costs of production and repeated wound treatment. Here we describe a novel design and a proof-of-concept validation of a mobile skin bioprinting system that provides rapid on-site management of extensive wounds. Integrated imaging technology facilitated the precise delivery of either autologous or allogeneic dermal fibroblasts and epidermal keratinocytes directly into an injured area, replicating the layered skin structure. Excisional wounds bioprinted with layered autologous dermal fibroblasts and epidermal keratinocytes in a hydrogel carrier showed rapid wound closure, reduced contraction and accelerated re-epithelialization. These regenerated tissues had a dermal structure and composition similar to healthy skin, with extensive collagen deposition arranged in large, organized fibers, extensive mature vascular formation and proliferating keratinocytes.

Postdischarge Cause-of-Death Analysis of Combat-Related Burn Patients

Combat operations in Iraq and Afghanistan have resulted in up to 8.8% of combat-related casualties suffering burns. From World War I through Desert Storm, burns have been associated with approximately 4% of the combat-related deaths. Experiencing a blast injury and exposure to killing and death while deployed has been shown to increase suicide risk. Although several studies of military populations have investigated risk factors for death among burn patients during the acute phase, no studies have reported mortality rates, cause-of-death, or the prevalence of suicide after hospital discharge. This study examined the case fatality rate, causes of death, and the prevalence of suicide among 830 combat burn patients discharged from the sole burn center in the U.S. Department of Defense, between March 7, 2003 and March 6, 2013. Cause-of-death was determined through the Armed Forces Medical Examiner's Office and the Office of the Secretary of Defense's National Death Index. A total of 11 deaths occurred among the 830 burn survivors, for an overall case fatality rate of 1.3%. Of the 11 who died, five deaths were related to accidental poisoning by exposure to drugs; three were related to operations of war (two after returning to the war zone), and the remaining three died from other accidental causes (one explosion and two vehicle crashes). There was no indication of suicide or suspicion of suicide as a cause-of-death for the former patients included in this study, suggesting that combat burn injury did not appear to increase the risk of death by suicide in our study population. Further research is needed to understand the factors that contribute to the apparent resilience of combat burn survivors.

Xuebijing Injection () increases early survival rate by alleviating pulmonary vasopermeability in rats subjected to severe burns

OBJECTIVE

To investigate the effects of Xuebijing Injection (, XBJ) on survival rate and pulmonary vasopermeability in a rat model of severe scald injury.

METHODS

Rats were divided into two experiments: experiment 1 was monitored for 12 h post-injury for survival analysis after severe burns; in experiment 2, rats were killed for determination of pulmonary vascular permeability and pro-inflflammatory mediators. In both experiments, rats were subject to third-degree 50% total body surface area (TBSA) burns or sham injury followed by XBJ or normal saline (NS) treatment. In addition, rat pulmonary microvascular endothelium cells (PMECs) were pretreated with either XBJ or phosphate buffer saline (PBS), and then subjected to sham serum or scald serum stimulation for 2 or 6 h, followed by transwell examination for the permeability of PMECs. Meanwhile, pro-inflflammatory mediators in PMECs culture supernatant were also investigated.

RESULTS

The average survival time in the scald+XBJ group was 582.1±21.2 min, which was signifificantly longer than that in the scald + NS group (345.8±25.4 min, P<0.01). Plasma levels of tumor necrosis factor-alpha (TNF-α), E-selectin, interleukin-6 (IL-6), vascular permeability and water content of lung tissues were signifificantly increased in animals after severe burns (P<0.01). However, administration of XBJ signifificantly decreased these levels in plasma and lung tissue. In in vitro cell experiments, XBJ markedly attenuated permeability in PMECs monolayer and reduced the levels of TNF-α, IL-6 and soluble E-selectin after stimulation with scald serum (P<0.01).

CONCLUSIONS

XBJ increases early survival rate by alleviating pulmonary vasopermeability and inhibiting pro-inflflammatory mediators in rats subjected to lethal scald injury. XBJ may be a potent drug in treatment of severe burns.

Xuebijing injection treatment inhibits vasopermeability and reduces fluid requirements in a canine burn model

OBJECTIVE

High vasopermeability and excessive inflammation following severe burns may result in tissue edema, organ dysfunction and the loss of circulatory plasma volume, which can influence the doctor to do the prognosis to the patients. The study aims to examine whether Xuebijing injection (XBJ), an extracts of a traditional Chinese medicine used to treat sepsis in clinic, can reduces fluid requirements by inhibiting vasopermeability and tissue edema in a canine model after burn injury.

METHODS

Twenty-four beagle dogs were subjected to 50% TBSA burns, and then were randomly allocated to the following three groups: lactated Ringer's resuscitation (LR) group (n = 8), immediate LR containing Xuebijing injection (LR/XBJ) group (n = 8), and operation control group (n = 8). Hemodynamic variables and net fluid accumulation were measured. Blood samples were collected for measurement of hematocrit and circulatory plasma volume (PV). At 24 h after burn injury, heart, lung, small intestine and kidney were harvested for evaluation of the activities of myeloperoxidase (MPO) and neutrophil elastase (NE), vasopermeability, tissue water content and the amount of neutrophil infiltration.

RESULTS

XBJ treatment significantly reduced net fluid accumulation, and pulmonary vascular permeability index (PVPI), extravascular lung water index (ELWI), and water content of heart, small intestine, kidney and lung compared with LR group. Furthermore, XBJ infusion significantly reduced tissue activities of MPO and NE compared with LR group. The amount of neutrophil infiltration in LR/XBJ group was lower than that in LR group.

CONCLUSIONS

These results indicate that XBJ injection can reduce fluid requirements by inhibition of neutrophil protease-induced high vasopermeability and tissue edema.

Cellular Therapies in Trauma and Critical Care Medicine: Forging New Frontiers

Trauma is a leading cause of death in both military and civilian populations worldwide. Although medical advances have improved the overall morbidity and mortality often associated with trauma, additional research and innovative advancements in therapeutic interventions are needed to optimize patient outcomes. Cell-based therapies present a novel opportunity to improve trauma and critical care at both the acute and chronic phases that often follow injury. Although this field is still in its infancy, animal and human studies suggest that stem cells may hold great promise for the treatment of brain and spinal cord injuries, organ injuries, and extremity injuries such as those caused by orthopedic trauma, burns, and critical limb ischemia. However, barriers in the translation of cell therapies that include regulatory obstacles, challenges in manufacturing and clinical trial design, and a lack of funding are critical areas in need of development. In 2015, the Department of Defense Combat Casualty Care Research Program held a joint military–civilian meeting as part of its effort to inform the research community about this field and allow for effective planning and programmatic decisions regarding research and development. The objective of this article is to provide a “state of the science” review regarding cellular therapies in trauma and critical care, and to provide a foundation from which the potential of this emerging field can be harnessed to mitigate outcomes in critically ill trauma patients.

Burn wound healing and treatment: review and advancements

Burns are a prevalent and burdensome critical care problem. The priorities of specialized facilities focus on stabilizing the patient, preventing infection, and optimizing functional recovery. Research on burns has generated sustained interest over the past few decades, and several important advancements have resulted in more effective patient stabilization and decreased mortality, especially among young patients and those with burns of intermediate extent. However, for the intensivist, challenges often exist that complicate patient support and stabilization. Furthermore, burn wounds are complex and can present unique difficulties that require late intervention or life-long rehabilitation. In addition to improvements in patient stabilization and care, research in burn wound care has yielded advancements that will continue to improve functional recovery. This article reviews recent advancements in the care of burn patients with a focus on the pathophysiology and treatment of burn wounds.

Carbachol promotes gastrointestinal function during oral resuscitation of burn shock

AIM

To investigate the effect of carbachol on gastrointestinal function in a dog model of oral resuscitation for burn shock.

METHODS

Twenty Beagle dogs with intubation of the carotid artery, jugular vein and jejunum for 24 h were subjected to 35% total body surface area full-thickness burns, and were divided into three groups: no fluid resuscitation (NR, n = 10), in which animals did not receive fluid by any means in the first 24 h post-burn; oral fluid resuscitation (OR, n = 8), in which dogs were gavaged with glucose-electrolyte solution (GES) with volume and rate consistent with the Parkland formula; and oral fluid with carbachol group (OR/CAR, n = 8), in which dogs were gavaged with GES containing carbachol (20 μg/kg), with the same volume and rate as the OR group. Twenty-four hours after burns, all animals were given intravenous fluid replacement, and 72 h after injury, they received nutritional support. Hemodynamic and gastrointestinal parameters were measured serially with animals in conscious and cooperative state.

RESULTS

The mean arterial pressure, cardiac output and plasma volume dropped markedly, and gastrointestinal tissue perfusion was reduced obviously after the burn injury in all the three groups. Hemodynamic parameters and gastrointestinal tissue perfusion in the OR and OR/CAR groups were promoted to pre-injury level at 48 and 72 h, respectively, while hemodynamic parameters in the NR group did not return to pre-injury level till 72 h, and gastrointestinal tissue perfusion remained lower than pre-injury level until 120 h post-burn. CO(2) of the gastric mucosa and intestinal mucosa blood flow of OR/CAR groups were 56.4 ± 4.7 mmHg and 157.7 ± 17.7 blood perfusion units (BPU) at 24 h post-burn, respectively, which were significantly superior to those in the OR group (65.8 ± 5.8 mmHg and 127.7 ± 11.9 BPU, respectively, all P < 0.05). Gastric emptying and intestinal absorption rates of GES were significantly reduced to the lowest level (52.8% and 23.7% of pre-injury levels) in the OR group at about 2 and 4 h post-burn, and did not return to 80% of pre-injury level until 24 h. In the first 24 h post-burn, the rate of gastric emptying and intestinal water absorption were elevated by a mean 15.7% and 11.5%, respectively, in the OR/CAR group compared with the OR group. At 5 days, the mortality in the NR group was 30% (3/10), 12.5% in the OR group (1/8), and none in the OR/CAR group.

CONCLUSION

Carbachol had a beneficial effect on oral resuscitation of burn shock by promoting gastric emptying and intestinal absorption in our canine model.

[Circulation therapy for severe burn injuries]

Patients with burn injuries to more than 10% of the body surface area (BSA) are in potential danger of traumatic hypovolemic shock and from 20% BSA a generalized burn edema can occur. In the preclinical setting an increased infusion therapy is generally unnecessary. Clinical circulation therapy is goal-directed taking hemoglobin concentration, hematocrit, MAP, diuresis, CVP and central venous sO(2 )into consideration. For initial volume replacement, balanced crystalloids with the addition of acetate and possibly malate are infused. Colloids should be given with great caution. Additional gelatine solution is only to be used in patients with impending hypotension and catecholamines should also be avoided if possible. If necessary, dobutamine is used to increase cardiac inotropy and cardiac output. Norepinephrine is only indicated in patients with significantly reduced SVR. Extended hemodynamic monitoring is necessary in all patients with prolonged catecholamine therapy.

Effects of hypertonic (7%) saline on brain injury in experimental Escherichia coli meningitis

We sought to know whether hypertonic (7%) saline (HTS) attenuates brain injury by improving cerebral perfusion pressure (CPP) and down-modulating acute inflammatory responses in experimental bacterial meningitis in the newborn piglet. Twenty-five newborn piglets were assorted into three groups: 6 in the control group (C), 10 in the meningitis group (M), and 9 in the meningitis with HTS infusion group (H). Meningitis was induced by intracisternal injection of 10(8) colony forming units of Escherichia coli in 100 microL of saline. 10 mL/kg of HTS was given intravenously as a bolus 6 hr after induction of meningitis, thereafter the infusion rate was adjusted to maintain the serum sodium level between 150 and 160 mEq/L. HTS significantly attenuated meningitis-induced brain cell membrane disintegration and dysfunction, as indicated by increased lipid peroxidation products and decreased Na+, K+-ATPase activity in the cerebral cortex in M. HTS significantly attenuated acute inflammatory markers such as increased intracranial pressure, elevated lactate level and pleocytosis in the cerebrospinal fluid observed in M. Reduced CPP observed in M was also significantly improved with HTS infusion. These findings implicate some attenuation of the meningitis-induced alterations in cerebral cortical cell membrane structure and function with HTS, possibly by improving CPP and attenuating acute inflammatory responses.