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Introduction Blast overpressure health hazard assessment is required prior to fielding of weapon systems that produce blast overpressures that pose risk of auditory and nonauditory blast lung injuries. The anthropomorphic blast test device (ABTD) offers a single device solution for collection of both auditory and nonauditory data from a single blast at anthropometrically correct locations for injury risk assessment. It also allows for better replication of personnel positioning during weapons firings. The ABTD is an update of the blast test device (BTD), the current Army standard for collection of thoracic blast loading data. Validation testing of the ABTD is required to ensure that lung injury model validated using BTD collected test data and sheep subjects is still applicable when the ABTD is used. Methods Open field validation blast tests were conducted with BTD and ABTD placed at matching locations. Tests at seven blast strength levels were completed spanning the range of overpressures for occupational testing. Results The two devices produced very similar values for lung injury dose over all blast levels and orientations. Conclusion The ABTD was validated successfully for open field tests. For occupational blast injury assessments, ABTD can be used in place of the BTD and provide enhanced capabilities.

Purpose To describe and explain the blast injuries and imaging findings in the Ankara terrorist explosion that took place on October 10, 2015. Material and methods A total of 77 patients who underwent radiologic imaging were classified as primary, secondary, tertiary, and quaternary, according to the injury type. The patients were evaluated based on body regions, such as head and neck, thorax, abdomen, lower extremity, and upper extremity. Results Blast lung injury was identified in one patient and tympanic membrane perforation in seven patients, as the primary injury. Sixty-two of 77 patients had secondary blast injuries caused by shrapnel. The blast injuries were observed in the head and neck (16/77, 20.7%), thorax (11/77, 14.2%), abdomen (16/77, 20.7%), lower extremity (48/77, 62.3%), and upper extremity (5/77, 6.4%). Vascular injuries were seen in eight cases, of which seven were in the lower extremities. Conclusions The most common blast injury pattern was of a secondary type in the current study. Lower extremities were the significantly more affected body region, probably due to the bomb exploding at ground level. In mass casualty events, radiologic imaging is located at the centre of patient management.

Blast lung injury (BLI) caused by both military and civilian explosions has become the main cause of death for blast injury patients. By building three-dimensional (3D) models of rat explosion regions, we simulated the surface pressure of the skin and lung. The pressure distributions were performed at 5 distances from the detonation center to the center of the rat. When the distances were 40 cm, 50 cm, 60 cm, 70 cm and 80 cm, the maximum pressure of the body surface were 634.77kPa, 362.46kPa, 248.11kPa, 182.13kPa and 109.29kPa and the surfaces lung pressure ranges were 928–2916 Pa, 733–2254 Pa, 488–1236 Pa, 357–1189 Pa and 314–992 Pa. After setting 6 virtual points placed on the surface of each lung lobe model, simulated pressure measurement and corresponding pathological autopsies were then conducted to validate the accuracy of the modeling. For the both sides of the lung, when the distance were 40 cm, 50 cm and 60 cm, the Pearson’s values showed strong correlations. When the distances were 70 cm and 80 cm, the Pearson’s values showed weak linear correlations. This computational simulation provided dynamic anatomy as well as functional and biomechanical information.

War and asymmetrical conflicts are becoming increasingly prevalent in the modern world. Due to improvements in conflict medicine, survivable injuries are now more severe than they once were. Therefore, it is now more important than ever that there exist scientific and engineering methods for replicating wartime injuries in the context of the laboratory. We have developed one such method: a shock tube platform for testing ex vivo samples of the porcine respiratory system. Using this platform, we can, to some extent, simulate the pathophysiological consequences of blast lung. This is a condition commonly present in victims of explosive blasts, both those due to typical armaments and Improvised Explosive Devices (IEDs). Presented here are the results of experiments conducted using porcine bronchiole tissue as ex vivo organ cultures. Data presented show epithelial damage, consistent with known trauma-induced cell injury that can lead to acute respiratory distress syndrome (ARDS).

Blast lung injury (BLI) caused by both military and civilian explosions has become the main cause of death for blast injury patients. By building three-dimensional (3D) models of rat explosion regions, we simulated the surface pressure of the skin and lung. The pressure distributions were performed at 5 distances from the detonation center to the center of the rat. When the distances were 40 cm, 50 cm, 60 cm, 70 cm and 80 cm, the maximum pressure of the body surface were 634.77kPa, 362.46kPa, 248.11kPa, 182.13kPa and 109.29kPa and the surfaces lung pressure ranges were 928-2916 Pa, 733-2254 Pa, 488-1236 Pa, 357-1189 Pa and 314-992 Pa. After setting 6 virtual points placed on the surface of each lung lobe model, simulated pressure measurement and corresponding pathological autopsies were then conducted to validate the accuracy of the modeling. For the both sides of the lung, when the distance were 40 cm, 50 cm and 60 cm, the Pearson's values showed strong correlations. When the distances were 70 cm and 80 cm, the Pearson's values showed weak linear correlations. This computational simulation provided dynamic anatomy as well as functional and biomechanical information.

Background Primary blast lung injury (PBLI) presents as a syndrome of respiratory distress and haemoptysis resulting from explosive shock wave exposure and is a frequent cause of mortality and morbidity in both military conflicts and terrorist attacks. The optimal mode of mechanical ventilation for managing PBLI is not currently known, and clinical trials in humans are impossible due to the sporadic and violent nature of the disease. Methods A high-fidelity multi-organ computational simulator of PBLI pathophysiology was configured to replicate data from 14 PBLI casualties from the conflict in Afghanistan. Adaptive and responsive ventilatory protocols implementing low tidal volume (LTV) ventilation and airway pressure release ventilation (APRV) were applied to each simulated patient for 24 h, allowing direct quantitative comparison of their effects on gas exchange, ventilatory parameters, haemodynamics, extravascular lung water and indices of ventilator-induced lung injury. Results The simulated patients responded well to both ventilation strategies. Post 24-h investigation period, the APRV arm had similar PF ratios (137 mmHg vs 157 mmHg), lower sub-injury threshold levels of mechanical power (11.9 J/min vs 20.7 J/min) and lower levels of extravascular lung water (501 ml vs 600 ml) compared to conventional LTV. Driving pressure was higher in the APRV group (11.9 cmH2O vs 8.6 cmH2O), but still significantly less than levels associated with increased mortality. Conclusions Appropriate use of APRV may offer casualties with PBLI important mortality-related benefits and should be considered for management of this challenging patient group.

Background Regarding blast injuries, fatal damage leading to immediate death is considered due to shock-lung, respiratory arrest, or circulatory failure induced by a neurological reflex, such as the severe vagal nerve reflex. It has not yet been determined whether a bulletproof vest protects against or aggravates shock-lung or the neurological reflexes considered to be fatal in the super-acute phase after an explosion. Purpose The purpose of this study was to clarify whether a bulletproof vest would protect the body in a pig blast model using a blast tube built at National Defense Medical College, which is the first such blast tube in Japan. Methods Seventeen pigs were divided into two groups: the body armor group (n = 6) and the non-body armor group (n = 11). Pigs underwent tracheal intubation with IV and A lines were secured to measure vital signs were checked and collect blood samples. Then, under intravenous anesthesia, the pigs were tightly fixed in the left lateral position on a table and exposed from the back neck to the upper lumbar back to the blast wave and wind with or without body armor, with the driving pressure of the blast tube set to 3.0 MPa. We checked the vital signs, collected blood samples, and observed the pigs for 3 hours after injury. Results When the surviving and dead pigs were compared, blood gas analyses revealed significant differences in PaO2, PaCO2, and pH in the super-early phase. In addition, all pigs injured by the blast wave and wind had lung hemorrhage, and 14 of 17 pigs had intra-abdominal hemorrhage with splenic injury. All 6 animals in the body armor group and 6 of the 11 animals in the control group survived for 3 hours after injury. Respiratory arrest immediately after exposure to the blast wave and wind was considered to influence the outcome in our pig model. Conclusions Respiratory arrest within several minutes after injury influenced the mortality of pigs. Body armor may have the beneficial effect in protecting against respiratory arrest immediately after an explosion.

Primary blast lung injury is the most important component of a multisystem syndrome of injury that results from exposure to an explosive shockwave. The majority of such casualties require ventilation in an intensive care unit. We describe the use of a novel primary blast lung injury simulator to evaluate the potential efficacy of continuous positive airway pressure in 6 in silico casualties over 24 hours after injury. Our results suggest that primary blast lung injury is a form of acute lung injury that can be effectively managed with continuous positive airway pressure. In austere environments or in circumstances where medical resources are overwhelmed, continuous positive airway pressure using ambient air may be of benefit.

In explosive accidents (military conflicts, terror assaults, and production and living associated explosions), the lungs are the most easily injured organs owing to the exposure of blast wave. The primary pulmonary blast injury (PBLI) constitutes the key aspect in the diagnosis and therapy of explosive blast injury. Presently, some new findings in the epidemiology, injury mechanism, diagnosis, and therapeutics have been given. Especially, the categories, patterns, equivalent weight, physico-chemical properties of explosive substances and more complicated spatial distribution of explosive sites, the state of PBLI, measures of its diagnosis and therapy, and prognostic outcome showed the characters of complexity and nonlinearity. Hence, the overall plan of this chapter firstly reviews the definition and connotation, epidemiology, and pathological changes of PBI. The injury mechanism and clinical outcome of PBLI were then elucidated from the biological mechanical points as well as neuroendocrine immune network. The common clinical manifestation, diagnosis, and therapeutic criteria of PBI were further introduced regarding the precision diagnosis and individualizing treatment. Finally, based on the idea that any efficient prevention is superior to excellent remedy, the preventive measures of PBLI were extensively discussed. As described elsewhere in this volume, based on the 4P (preventive, predictive, personalized and participatory) medicine models of burn and trauma, it is of great necessity to discriminate the regularity of happening and transformation of PBI from the view of translational medicine and investigate the probability of precision treatment of PBLI given its previous theoretical results. It may propel the transformation of patterns of its diagnosis and therapy from routine experienced qualitative to personalized quantitative treatment. The aim of the chapter tries to supply a new paradigm for the understanding of PBI.

Blast injuries are particularly complex, because blast effects are multimodal, with injury-causing overpressure, dynamic pressure, debris, and fragmentation. The organs most vulnerable to blast injury are those which are gas-containing, such as the ears and lungs. Improvements to personal protective gear have improved the likelihood of surviving a blast event, but at the cost of sustaining significant, multisystem injuries. This chapter reviews the state of the science in terms of our understanding of the effects of blast on major physiological systems: auditory, respiratory, digesting, vascular, and neurological. A significant emphasis is placed upon the effects of blast on the neurological system, where the most significant advances have been made over the last 15–18 years and where the most significant advances are still needed.

Introduction Primary blast lung injury occurs when an explosive shock wave passes through the thorax and transits through tissues of varying densities. It requires close proximity to an explosion and presents quick with respiratory distress in survivors. Materials and Methods The Joint Theatre Trauma Registry and the Defence Statistics (Health) Database were interrogated for casualties injured as a result of an explosion during the conflict in Afghanistan. The case notes and imaging of casualties meeting the criteria for diagnosis were reviewed. Demographic and clinical data on casualties with primary blast lung injury were analyzed. Results 848 blast-exposed casualties survived to discharge from intensive care, and 238 blast-exposed casualties were killed in action. Following exclusions, 111 case notes and all postmortem reports were reviewed in detail. About, 25 casualties had isolated primary blast lung injury (2.9% of casualties surviving to discharge from intensive care) and 31 nonsurvivors (13% of nonsurvivors) had the disease documented at postmortem. Severe cases of primary blast lung injury required an estimated average of 4.5 days of conventional mechanical ventilation. Conclusions 8.1% of blast exposed casualties suffered primary blast lung injury. It was a less severe disease than other nontraumatic forms of acute lung injury and did not cause deaths once a casualty had reached a combat support hospital. It was well managed with a relatively brief period of conventional mechanical ventilation.

Traumatic brain injury sustained after blast exposure (blast-induced TBI) has recently been documented as a growing issue for military personnel. Incidence of injury to organs such as the lungs has decreased, though current epidemiology still causes a great public health burden. In addition, unprotected civilians sustain primary blast lung injury (PBLI) at alarming rates. Often, mild-to-moderate cases of PBLI are survivable with medical intervention, which creates a growing population of survivors of blast-induced polytrauma (BPT) with symptoms from blast-induced mild TBI (mTBI). Currently, there is a lack of preclinical models simulating BPT, which is crucial to identifying unique injury mechanisms of BPT and its management. To meet this need, our group characterized a rodent model of BPT and compared results to a blast-induced mTBI model. Open field (OF) performance trials were performed on rodents at 7 days after injury. Immunohistochemistry was performed to evaluate cellular outcome at day seven following BPT. Levels of reactive astrocytes (GFAP), apoptosis (cleaved caspase-3 expression), and vascular damage (SMI-71) were significantly elevated in BPT compared to blast-induced mTBI. Downstream markers of hypoxia (HIF-1α and VEGF) were higher only after BPT. This study highlights the need for unique therapeutics and prehospital management when handling BPT.

BACKGROUND A great number of children suffer from blast lung injury (BLI) worldwide, but there is a little basic study on the topic. METHODS Infant (4-week-old) and adult New Zealand rabbits were selected. Comparison of BLI characteristics: 16 infant rabbits were randomly divided into a 4.0 MPa group (n = 8, "IRG4.0MPa") and a 4.5 MPa group (n = 8, "IRG4.5MPa") and exposed to shock waves of those magnitudes. Eight adult rabbits were exposed to 4.0 MPa ("ARG4.0MPa"). The severity of BLI was compared among these three groups. Comparison of impact characteristics between infant and adult rabbits at the same scale of BLI: infant and adult rabbits were randomly divided into a control group (n = 8 per age group) and a blast injury group (n = 40 infants, "IRG4.0MPa"; n = 40 adults, "ARG4.5MPa"). The vital signs, physiological indicators, gross anatomy, and light microscope pathology were observed. RESULTS The differences in lung injury severity and in abbreviated injury scale (AIS) scores between IRG4.5MPa (87.5%, AIS 4.13 ± 0.64) and ARG4.0MPa (75.5%, AIS 4.18 ± 0.75) were not statistically significant (P > .05); IRG4.0MPa (12.5%, AIS 3.38 ± 0.52) showed a lower proportion of lung injury and lower AIS scores than the others (P

Blast injuries seen in various accidents involving pressurized containers like gas cylinders, tires, et cetera, and acts of terrorism. The associated factors can vary from poor handling of equipment to inadequate safety precautions. These injuries include a variety of injuries, such as, injuries due to shock wave, burns, fractures, et cetera, involving multi-organ systems, especially lungs and hollow organs, due to the high-pressurized shock wave. The presented case is of the death of a 24-years-old male as a result of a blast of the compressor present in the AC outdoor unit during the filling of the gas. Here, the body showed injuries due to shock wave, secondary impact, tertiary impact because of fall on the ground, and quaternary injuries due to burns. The cause of death was Blast lung associated with Subarachnoid hemorrhage.

IntroductionPrimary blast lung injury causes intrapulmonary haemorrhage. A number of case reports have suggested the efficacy of recombinant activated factor VII (rFVIIa) in the treatment of diffuse alveolar haemorrhage from a range of medical causes, but its efficacy in blast lung is unknown. The aim of this study was to investigate whether nebulised rFVIIa attenuates the haemorrhagic effects of blast lung injury in an animal model.MethodsTerminally anaesthetised rabbits subjected to blast lung injury were randomised to receive either rFVIIa or placebo via a nebuliser. The primary outcome was the level of blood iron–transferrin complex, a marker of the extent of blast lung injury, analysed using low temperature electron paramagnetic resonance spectroscopy.ResultsBlast exposure led to a significant fall in iron-bound transferrin in both groups of animals (pConclusionA single dose of nebulised rFVIIa did not attenuate pulmonary haemorrhage in a rabbit model of blast lung injury. As there was some evidence of systemic absorption, the inhaled route does not avoid the concern about potential thromboembolic complications from administration of rFVIIa.

Mathematical modelling and computational simulation are becoming increasingly important tools in many fields of medicine where in vivo studies are expensive, difficult or impractical. This is particularly the case with primary blast lung injury, and in this paper, we give a brief overview of mathematical models before describing how we generated our blast lung injury simulator and describe some early results of its use.

Pulmonary injuries are a major source of morbidity and mortality associated with trauma. Trauma includes injuries associated with accidents and falls as well as blast injuries caused by explosives. The prevalence and mortality of these injuries has made research of pulmonary injury a major priority. Lungs have a complex structure, with multiple types of tissues necessary to allow successful respiration. The soft, porous parenchyma is the component of the lung which contains the alveoli responsible for gas exchange. Parenchyma is also the portion which is most susceptible to traumatic injury. Finite element simulations are an important tool for studying traumatic injury to the human body. These simulations rely on material properties to accurately recreate real world mechanical behaviors. Previous studies have explored the mechanical properties of lung tissues, specifically parenchyma. These studies have assumed material isotropy but, to our knowledge, no study has thoroughly tested and quantified this assumption. This study presents a novel methodology for assessing isotropy in a tissue, and applies these methods to porcine lung parenchyma. Briefly, lung parenchyma samples were dissected so as to be aligned with one of the three anatomical planes, sagittal, frontal, and transverse, and then subjected to compressive mechanical testing. Stress-strain curves from these tests were statistically compared by a novel method for differences in stresses and strains at percentages of the curve. Histological samples aligned with the anatomical planes were also examined by qualitative and quantitative methods to determine any differences in the microstructural morphology. Our study showed significant evidence to support the hypothesis that lung parenchyma behaves isotropically.

Purpose To study the relationship between serum neutrophil gelatinase-associated lipocalin (NGAL) and military blast and gunshot wound (GSW) to establish whether potential exists for NGAL as a biomarker for blast lung injury (BLI). Method Patients from the intensive care unit (ICU) of the Role 3 Medical Treatment Facility at Camp Bastion, Helmand Province, Afghanistan were studied over a five month period commencing in 2012. Age, mechanism, trauma injury severity score (TRISS) and serum NGAL were recorded on ICU admission (NGAL1). Serum NGAL (NGAL2) and PaO 2 /FiO 2 ratio (P/F ratio2) were recorded at 24 h. Results 33 patients were injured by blast and 23 by GSW. NGAL1 inversely correlated with TRISS ( p = 0.020), pH ( p = 0.002) and P/F ratio 2 ( p = 0.009) overall. When data was stratified into blast and GSW, NGAL1 also inversely correlated with P/F ratio 2 in the blast injured group ( p = 0.008) but not GSW group ( p = 0.27). Conclusion Raised NGAL correlated with increased severity of injury (worse survival probability i.e. TRISS and low pH) in both patient groups. There was an inverse correlation between admission NGAL and a marker of blast lung injury (low P/F ratio) at 24 h in blast injured group but not GSW group that warrants further investigation.

Introduction Venovenous extracorporeal membrane oxygenation (VV-ECMO) has been gaining use to bridge the recovery from acute respiratory distress syndrome (ARDS) refractory to conventional treatment. However, these interventions are often limited to higher echelons of military care. We present a case of lung salvage from severe ARDS in an Afghani soldier with VV-ECMO at a Role-2 (R2) facility in an austere military environment in Afghanistan. Case A 25-year-old Afghani soldier presented to an R2 facility with blast lung injury and multiple penetrating injuries following an explosion. The patient underwent immediate damage control laparotomy. The abdomen was left open for subsequent washouts and ongoing resuscitation. Due to his ineligibility for evacuation and worsening ARDS, despite 5 d of conventional ventilation strategies, he was started on VV-ECMO. The patient had immediate improvements in oxygenation, which continued for 10 d. Moreover, he underwent three transportations to the operating room without accidental decannulation or disruption of the VV-ECMO device. Despite significant improvements, the patient expired on postoperative day 15, due to an overwhelming intra-abdominal sepsis. Conclusion As future advancements are sought, VV-ECMO may become a consideration for casualties with severe ARDS at the point of injury and at lower echelons of military care.

Primary blast lung injury frequently complicates military conflict and terrorist attacks on civilian populations. The fact that it occurs in areas of conflict or unpredictable mass casualty events makes clinical study in human casualties implausible. Research in this field is therefore reliant on the use of some form of biological or non-biological surrogate model. This article briefly reviews the modelling work undertaken in this field until now and describes the rationale behind the generation of an in silico physiological model.

Blasts injuries are responsible for about two-thirds of the conventional combat injuries during any military operation and account for a sizeable number during terrorist activities. The pathophysiology, clinical presentation and urgency of management vary significantly in primary blast injuries. These can lead to a wide range of overt and covert injuries, making diagnosis and management difficult. The clinical picture varies from acute respiratory distress to deafness with absence of any external injuries. Such patients are best identified and dealt with by a team of health care professionals well acquainted with battle field injuries.

Multiple casualties and the complex set of injuries in survivors of a terrorist bomb blast poses a real challenge to health care providers. We are presenting three such cases, first case suffered a fracture of both bone lower limb bilaterally along with head injury (foreign bodies were impacted in the scalp and brain parenchyma). Following primary resuscitation, patient shifted to operation theatre after a quick computerized tomography scan and external fixator applied in general anesthesia using the rapid sequence induction. No active neurosurgical intervention was done. As this patient had acute post-traumatic stress response, he was subjected to low pressure hyperbaric oxygen therapy (pressure of 1.5 ATA for 60 min a day for 10 days) and group counseling. He had good recovery except one lost a limb because of extensive neurovascular damage due to blast. Second case had much more extensive damage involving multiple organ systems. He had blast lung, big cerebrovascular hemorrhage along with gut perforation. Despite best possible surgical and intensive care interventions, patent developed multiple organ failure and unfortunately we lost our patient. Third case was of a right sided globe rupture resulted from blast induced flying foreign bodies. After primary survey and initial resuscitation evisceration done for the damaged eye and patient later on discharged with necessary instruction (including warning signs) for follow-up.

Blast injuries are rare, but life-threatening medical emergencies. We report the clinical presentation and management of four bomb blast victims admitted in Intensive Care Unit of Trauma center of our hospital in 2011. Three of them had lung injury; hemothorax (2) and pneumothorax (1). Traumatic brain injury was present in only one. Long bone fractures were present in all the victims. Presence of multiple shrapnels was a universal finding. Two blast victims died (day 7 and day 9); cause of death was multi-organ failure and septic shock. Issues relating to complexity of injuries, complications, management, and outcome are discussed.

About the prediction of the biological damage effects on the lung of human under explosion wave, there are three different criterions, including excessive pressure-impulse criterion, kinematic velocity criterion and specific energy criterion. In the paper, based on the established three criterions and the practical anatomical structure of lung , a new theoretical model on blast lung injury from an explosion is developed. In the present model, the problem of blast lung injury is simplified as the one-dimensional propagation of stress wave in metal foam. Results show that the failure stress of the lung is 0.036~0.072 MPa, and the three criterions can convert to each other.

Blast lung injury is a well documented barotrauma pulmonary pressure insult, often seen in victims and survivors of high pressure extrinsic explosions, such as those caused by extrinsic explosive devices or gas leaks. In this case we present a case of blast lung injury secondary to internal barotrauma, namely suicide by intra-oral shotgun use, and provide correlative post-mortem CT and autopsy images.

Primary blast lung injury (PBLI) is an acknowledged cause of death in explosive blast casualties. In contrast to vehicle occupants following an in-vehicle explosion, the injury profile, including PBLI incidence, for mounted personnel following an external explosion has yet to be as well defined.This retrospective study identified 146 cases of UK military personnel killed by improvised explosive devices (IEDs) between November 2007 and July 2010. With the permission of Her Majesty's Coroners, relevant postmortem computed tomography imaging was analyzed. PBLI was diagnosed by postmortem computed tomography. Injury, demographic, and relevant incident data were collected via the UK Joint Theatre Trauma Registry.Autopsy results were not available for 1 of 146 cases. Of the remaining 145 IED fatalities, 24 had catastrophic injuries (disruptions), making further study impossible, leaving 121 cases; 79 were dismounted (DM), and 42 were mounted (M). PBLI was noted in 58 cases, 33 (79%) of 42 M fatalities and 25 (32%) of 79 DM fatalities (p0.0001). Rates of associated thoracic trauma were also significantly greater in the M group (p0.006 for all). Fatal head (53% vs. 23%) and thoracic trauma (23% vs. 8%) were both more common in the M group, while fatal lower extremity trauma (7% vs. 48%) was more commonly seen in DM casualties (p0.0001 for all).Following IED strikes, mounted fatalities are primarily caused by head and chest injuries. Lower extremity trauma is the leading cause of death in dismounted fatalities. Mounted fatalities have a high incidence of PBLI, suggesting significant exposure to primary blast. This has not been reported previously. Further work is required to determine the incidence and clinical significance of this severe lung injury in explosive blast survivors. In addition, specific characteristics of the vehicles should be considered.

The potential of blast-induced traumatic brain injury from the mechanism of localized cavitation of the cerebrospinal fluid (CSF) is investigated. While the mechanism and criteria for non-impact blast-induced traumatic brain injury is still unknown, this study demonstrates that local cavitation in the CSF layer of the cranial volume could contribute to these injuries. The cranial contents of three post-mortem human subject (PMHS) heads were replaced with both a normal saline solution and a ballistic gel mixture with a simulated CSF layer. Each were instrumented with multiple pressure transducers and placed inside identical shock tubes at two different research facilities. Sensor data indicates that cavitation may have occurred in the PMHS models at pressure levels below those for a 50% risk of blast lung injury. This study points to skull flexion, the result of the shock wave on the front of the skull leading to a negative pressure in the contrecoup, as a possible mechanism that contributes to the onset of cavitation. Based on observation of intracranial pressure transducer data from the PMHS model, cavitation onset is thought to occur from approximately a 140 kPa head-on incident blast.

Fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes can accumulate via dodecapeptide HHLGGAKQAGDV interactions at bleeding sites where they release adenosine 5'-diphosphate that is rapidly metabolized to adenosine, which has tissue-protective effects. We investigated the efficacy of fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes to treat blast lung injury, with a focus on adenosine signaling.Controlled animal study.University research laboratory.Adult male C57BL/6 mice.Mice were pretreated with fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes, dodecapeptide HHLGGAKQAGDV-(phosphate-buffered saline)-liposomes, adenosine 5' diphosphateliposomes, or phosphate-buffered saline-liposomes. Five minutes after treatment the mice received a single laser-induced shock wave (1.8 J/cm) that caused lethal blast lung injury, and their survival times and lung injuries were then assessed. We also evaluated the therapeutic effect of posttreatment with fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes or H12-(phosphate-buffered saline)-liposomes 1 minute after laser-induced shock wave exposure. To examine the effect of adenosine signaling, adenosine A2A receptor (ZM241385) or adenosine A2B receptor (PSB 1115) antagonists were administered to the mice 1 hour before the pretreatment with fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes that was followed by laser-induced shock wave exposure.Pre- and posttreatment with fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes significantly increased mouse survival [fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes: 58% survival vs H12-(phosphate-buffered saline)-liposomes: 8%; p0.05 (posttreatment)] and mitigated pulmonary tissue damage/hemorrhage and neutrophil accumulation after laser-induced shock wave exposure. fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes accumulated at pulmonary vessel injury sites after laser-induced shock wave exposure with both pre- and posttreatment. Furthermore, pretreatment with fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes reduced albumin and macrophage inflammatory protein-2 levels in bronchoalveolar lavage fluid. Although fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV)-coated adenosine 5'-diphosphate-encapsulated liposomes pretreatment did not affect blood coagulation activity in the injured mice, its beneficial effect on blast lung injury was significantly abrogated by A2A or A2B adenosine receptor antagonists (A2A antagonist: 17% survival; A2B antagonist: 33% vs dimethyl sulfoxide control: 80%; p0.05, respectively).Fibrinogen γ-chain (dodecapeptide HHLGGAKQA GDV)-coated adenosine 5'-diphosphate-encapsulated liposomes may be effective against blast lung injury by promoting tissue-protective adenosine signaling and could represent a novel controlled-release drug delivery system.

Blast related injuries are common in military conflict and can also result from action by terrorist groups against civilian targets. The pattern of injury depends on the type of explosive, with high explosives capable of causing unique effects through the action of the blast wave. The environment is critically important in determining the effects of blast injury, with blast in enclosed spaces or underwater magnifying the effect of blast wave force transmission. Blasts can also cause ballistic injury by energising projectiles, blunt trauma from structural collapse, and thermal and toxic injuries. “Blast Lung” is imprecisely defined but results from damage at the alveolar capillary interface with the predominant feature being pulmonary haemorrhage. Death is most commonly caused by severe cardiovascular impairment resulting from arterial gas embolism. The incidence of severe respiratory failure in survivors of blast injury is probably quite low. Management is essential supportive and similar to that applied to other forms of lung injury in critically injured patients. Attention should be paid to lung protective ventilation and a conservative fluid management strategy. Specific novel therapies such as pro or anti- coagulants and steroids remain unproven.