Primary blast injuries--an updated concise review

Implications for future humanitarian aid missions: Lessons from point-of injury and hospital care for Syrian refugees

BACKGROUND

Warzone humanitarian medical aid missions are infrequent and applying lessons from these missions is vital to ensuring preparedness for future crises. Between 2013-2018, the Israel Defense Forces Medical Corps (IDF-MC) provided humanitarian medical aid to individuals injured in the Syrian Civil War who chose to seek medical assistance at the Israeli-Syrian border. Patients requiring care surgical or advanced care were transferred to civilian medical centers within Israel. This study aims to describe the injury characteristics and management of hospitalized Syrian Civil War trauma patients over a five-year period.

METHODS

Retrospective cohort analysis cross-referencing data from the IDF trauma registry, documenting prehospital care, and the Israel National Trauma Registry, documenting in-hospital care, between 2013 and 2018. Syrian trauma patients hospitalized in Israeli hospitals were cross-referenced between the two registries. Multivariable logistic regression was applied to identify independent factors associated with in-hospital mortality.

RESULTS

Overall, 856 hospitalized trauma patients were included following definitive cross-matching. The median age was 23 years, and 93.3% were males. Blast (n = 532; 62.1%) and gunshot (n = 241; 28.2%) were the most common injury mechanisms. Injury Severity Score was ≥25 for 28.8% of patients and most common body regions with severe injury (Abbreviated Injury Scale≥3) were the head (30.7%) and thorax (25.0%). Intensive care unit admission was required for 40.1% of patients, and the median hospital stay was 13 days. In-hospital mortality was recorded for 73 (8.5%). Signs of shock upon emergency department admission and severe head injury were significantly associated with mortality in the adjusted model whereas age of <18 years was associated with decreased odds for in-hospital mortality.

CONCLUSIONS

Trauma patients hospitalized in Israel following injuries sustained in the Syrian Civil War were characterized by a high prevalence of blast injuries with concomitant involvement of several body regions. Future missions should ensure preparedness for complex multi-trauma, often involving the head, and ensure high intensive care and surgical capacities.

High risk and low prevalence diseases: Blast injuries

INTRODUCTION

Blast injury is a unique condition that carries a high rate of morbidity and mortality, often with mixed penetrating and blunt injuries.

OBJECTIVE

This review highlights the pearls and pitfalls of blast injuries, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Explosions may impact multiple organ systems through several mechanisms. Patients with suspected blast injury and multisystem trauma require a systematic evaluation and resuscitation, as well as investigation for injuries specific to blast injuries. Blast injuries most commonly affect air-filled organs but can also result in severe cardiac and brain injury. Understanding blast injury patterns and presentations is essential to avoid misdiagnosis and balance treatment of competing interests of patients with polytrauma. Management of blast victims can also be further complicated by burns, crush injury, resource limitation, and wound infection. Given the significant morbidity and mortality associated with blast injury, identification of various injury patterns and appropriate management are essential.

CONCLUSIONS

An understanding of blast injuries can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Secondary blast injury: radiological characteristics of shrapnel injuries in children

PURPOSE

The aim of this study is to examine the radiological images of child victims suffering from secondary blast injuries, to reveal organ-based injury patterns and their interrelationships, and to record mortality rates that may develop due to injured systems.

METHODS

A total of 65 patients with secondary blast injury due to bomb explosion were included in the study. Injury findings due to shrapnel in radiologic images of the patients were examined. Injured systems and types of injuries were recorded.

RESULTS

The most common injuries were intra-abdominal injuries (63%) and fractures (58.5%). Lung injury was observed in 4 (9.8%) of 41 patients with intra-abdominal injury, while 37 (90.2%) did not, and this was statistically significant (p = 0.003). The most common intra-abdominal organ injury was a small bowel injury in 23 (35.4%) patients. The coexistence of small bowel injury and large bowel injury was present in 8 patients (34.8%), and it was statistically significant (p = 0.019). A total of 14 (21.5%) of the patients died. There was no significant relationship between mortality and gender (p = 319). Brain damage was present in 10 (71.4%) of the 14 (21.5%) patients who died, which was statistically significant (p < 0.001).

CONCLUSION

Our results showed that the most common injuries were intra-abdominal injuries, damage to different organs could occur at the same time, and deaths were especially associated with brain injuries. For this reason, it should not be forgotten that CT scans will have an important place in the triage of the patient, especially in victims with shrapnel at the abdominal and cranial levels in radiography examinations.

Beirut massive blast explosion: A unique injury pattern of the wounded population

INTRODUCTION

On August 4, 2020, a massive explosion of a warehouse holding 2,700 metric tons of ammonium nitrate took place in the port of Beirut, Lebanon. This incident, which is considered as one of the largest industrial disasters lead to the death of at least 220 people and more than 6000 injuries. Hospitals near the blast were damaged significantly which made it difficult to treat injured patients. The objective of this study is to report the epidemiology and characteristics of the injuries and their initial management that could be useful for healthcare workers and policymakers in case of a similar massive accident in the future.

MATERIALS AND METHODS

A retrospective study was conducted. All charts of patients admitted to the emergency room and outpatient clinics on the day of the blast and during the following 2 weeks were thoroughly reviewed. Due to initial chaos during triage, direct phone contact with patients was utilized in certain situations to confirm their identity or for further information. All acute injuries were recorded based on the region, severity, degree of emergency, initial and later management, type of injured organs, and surgical procedures.

RESULTS

A total of 159 patients presented to our facility. 153 patients presented to the ER on the same day of the blast. The mean age was 47.07 years and around 60% of the patients were males (n = 93). Most of the patients presented either from zone 1 (n = 67, 42%) or zone 3 (n = 68, 43%). The majority of injuries were secondary injuries due to glass (n = 131, 82.3%), with the head (34%) and upper extremities (31.2%) being most commonly affected. A total of 94 patients (62.6%) underwent a type of imaging and 64 patients (40.2%) had at least one surgery performed during their hospitalization in which 71% of the surgeries being related to the limbs.

CONCLUSION

This study demonstrated a unique injury pattern due to this type of blast. Injuries were mostly due to glass shrapnel. Contrary to bomb blasts, most injuries were located in the head and upper extremities rather than on the lower extremities.

Effects of orientation and distance of goats on blast lung injury characteristics on a plateau above 4500 m

PURPOSE

High explosives are used to produce blast waves to study their biological effects. The lungs are considered as the critical target organ in blast-effect studies. The degree of lung hemorrhaging is related to both the explosive power and the increased lung weight. We studied the characteristics of the biological effects from an air explosion of a thermobaric bomb in a high-altitude environment and the lethality and lung injury severity of goats in different orientation and distances.

METHODS

Goats were placed at 2.5, 3, 4, and 5 m from the explosion center and exposed them to an air blast at an altitude of 4700 m. A group of them standing oriented to the right side and the other group seated facing the explosion center vertically. The lung injuries were quantified according to the percentage of surface area contused, and using the pathologic severity scale of lung blast injury (PSSLBI) to score the 4 injury categories (slight, moderate, serious and severe) as 1, 2, 3, and 4, respectively. The lung coefficient (lung weight [g]/body weight [kg]) was the indicator of pulmonary edema and was related to lung injury severity. Blast overpressure data were collected using blast test devices placed at matching locations to represent loadings to goats. All statistical analyses were performed using SPSS, version 26.0, statistical software (SPSS, Inc., Chicago, IL, USA).

RESULTS

In total, 127 goats were involved in this study. Right-side-standing goats had a significantly higher mortality rate than those seated vertical-facing (p < 0.05). At the 2.5 m distance, the goat mortality was nearly 100%, whereas at 5 m, all the goats survived. Lung injuries of the right-side-standing goats were 1-2 grades more serious than those of seated goats at the same distances, the scores of PSSLBI were significantly higher than the seated vertical-facing goats (p < 0.05). The lung coefficient of the right-side-standing goats were significantly higher than those of seated vertical-facing (p < 0.05). Mortality, PSSLBI, and the lung coefficient results indicated that the right-side-standing goats experienced severer injuries than the seated vertical-facing goats, and the injuries were lessened as the distance increased. The blast overpressure was consistent with these results.

CONCLUSION

The main killing factors of the thermobaric bomb in the high-altitude environment were blast overpressure, blast wind propulsions and burn. The orientation and distances of the goats significantly affected the blast injury severity. These results may provide a research basis for diagnosing, treating and protecting against injuries from thermobaric explosions.

Reinforced Concrete Building with IED Detonation: Test and Simulation

There is growing concern about the possibility of a suicide bomber being immolated when the army forces or the law enforcement agencies discover the place where they prepare their material or simply find themselves inside a building. To study the possible effects that these improvised explosive devices (IEDs) would have on the structures, eight tests were carried out with various configurations of IEDs with vest bombs inside a reinforced concrete (including walls and roof) building constructed ad hoc for these tests. These vests were made with different explosives (black powder, ANFO, AN/AL, PG2). For the characterization of these tests, a high-speed camera and pressure and acceleration sensors were used. The structure behaved surprisingly well, as it withstood all the first seven detonations without apparent structural damage. In the last detonation, located on the ground and with a significant explosive charge, the structural integrity of the roof and some of the walls was compromised. The simulation of the building was carried out with the LS-DYNA software with a Lagrangian formulation for the walls, using the LBE (based on CONWEP) module for the application of the charge. Despite the difficulty of this simulation, the results obtained, in terms of applied pressures and measured accelerations, are acceptable with differences of about 20%.

The Beirut Port Explosion Injuries and Lessons Learned: Results of the Beirut Blast Assessment for Surgical Services (BASS) Multicenter Study

OBJECTIVE

This multicenter study aims to describe the injury patterns, emergency management and outcomes of the blast victims, recognize the gaps in hospital disaster preparedness, and identify lessons to be learned.

SUMMARY BACKGROUND DATA

On August 4th, 2020, the city of Beirut, Lebanon suffered the largest urban explosion since Hiroshima and Nagasaki, resulting in hundreds of deaths and thousands of injuries.

METHODS

All injured patients admitted to four of the largest Beirut hospitals within 72 hours of the blast, including those who died on arrival or in the emergency department (ED), were included. Medical records were systematically reviewed for: patient demographics and comorbidities; injury severity and characteristics; prehospital, ED, operative, and inpatient interventions; and outcomes at hospital discharge. Lessons learned are also shared.

RESULTS

An estimated total of 1818 patients were included, of which 30 died on arrival or in the ED and 315 were admitted to the hospital. Among admitted patients, the mean age was 44.7 years (range: 1 week-93 years), 44.4% were female, and the median injury severity score (ISS) was 10 (5, 17). ISS was inversely related to the distance from the blast epicenter (r = --0.18, P = 0.035). Most injuries involved the upper extremities (53.7%), face (42.2%), and head (40.3%). Mildly injured (ISS <9) patients overwhelmed the ED in the first 2 hours; from hour 2 to hour 8 post-injury, the number of moderately, severely, and profoundly injured patients increased by 127%, 25% and 17%, respectively. A total of 475 operative procedures were performed in 239 patients, most commonly soft tissue debridement or repair (119 patients, 49.8%), limb fracture fixation (107, 44.8%), and tendon repair (56, 23.4%). A total of 11 patients (3.5%) died during the hospitalization, 56 (17.8%) developed at least 1 complication, and 51 (16.2%) were discharged with documented long-term disability. Main lessons learned included: the importance of having key hospital functions (eg, laboratory, operating room) underground; the nonadaptability of electronic medical records to disasters; the ED overwhelming with mild injuries, delay in arrival of the severely injured; and the need for realistic disaster drills.

CONCLUSIONS

We, therefore, describe the injury patterns, emergency flow and trauma outcome of patients injured in the Beirut port explosion. The clinical and system-level lessons learned can help prepare for the next disaster.

Imaging findings in patients after the bomb explosion in Somalia on December 28, 2019

INTRODUCTION

This study aimed to present the radiological findings of injuries in victims as a result of a suicide bombing in Mogadishu, Somalia.

METHODS

Of the 82 injured cases admitted to the emergency department within the first six hours after the explosion, those who were radiologically evaluated were included in this retrospective and descriptive study. To analyze and identify the distribution of primary, secondary, and tertiary injuries, they were classified according to the body areas as head-neck, thorax, abdominopelvic, extremity, and vertebra.

RESULTS

The mean age (mean ± SD) of 63 patients included in the study was 28.6 ± 10.2 years. Twenty-four (38.1%) of the injured patients were female and 39 (61.9%) were male. Secondary blast injury was the most common type of injury in the study group with a rate of 39/63 (62%). The total number of bomb fragments was 235, of which 113 (47.8%) were seen in the head and neck region, followed by 86 (36.5%) in the extremities. There were 10 patients (15.9%) with lung injury and 13 (20.6%) with tympanic membrane perforation due to the primary blast mechanism.

CONCLUSION

Radiological imaging plays an important role in identifying specific findings and patterns of explosive injuries. Therefore, we consider that patients with stable hemodynamics should be radiologically examined for a fast and accurate diagnosis or treatment.

3D Finite Element Modeling of Blast Wave Transmission from the External Ear to Cochlea

As an organ that is sensitive to pressure changes, the ear is often damaged when a person is subjected to blast exposures resulting in hearing loss due to tissue damage in the middle ear and cochlea. While observation of middle ear damage is non-invasive, examining the damage to the cochlea is difficult to quantify. Previous works have modeled the cochlear response often when subjected to an acoustic pressure input, but the inner ear mechanics have rarely been studied when the ear is exposed to a blast wave. In this study we aim to develop a finite element (FE) model of the entire ear, particularly the cochlea, for predicting the blast wave transmission from the ear canal to cochlea. We utilized a FE model of the ear, which includes the ear canal, middle ear, and uncoiled two-chambered cochlea, to simulate the cochlear response to blast overpressure (BOP) at the entrance of the ear canal with ANSYS Mechanical and Fluent in a fluid-structure interface coupled analysis in the time domain. This model was developed based on previous middle and inner ear models, and the cochlea was remeshed to improve BOP simulation performance. The FE model was validated using experimentally measured blast pressure transduction from the ear canal to the middle ear and cochlea in human cadaveric temporal bones. Results from the FE model showed significant displacements of the tympanic membrane, middle ear ossicles, and basilar membrane (BM). The stapes footplate displacement was observed to be as high as 60 µm, far exceeding the displacement during normal acoustic stimulation, when the 30 kPa (4.35 psi, 183 dB (SPL), Sound Pressure Level) of BOP was applied at the ear canal entrance. The large stapes movement caused pressures in the cochlea to exceed the physiological pressure level [< 10 Pa, 120 dB (SPL)] at a peak of 49.9 kPa, and the BM displacement was on the order of microns with a maximum displacement of 26.4 µm. The FE model of the entire human ear developed in this study provides a computational tool for prediction of blast wave transmission from the ear canal to cochlea and the future applications for assisting the prevention, diagnosis, and treatment of blast-induced hearing loss.

Damage-Associated Molecular Patterns and Their Signaling Pathways in Primary Blast Lung Injury: New Research Progress and Future Directions

Primary blast lung injury (PBLI) is a common cause of casualties in wars, terrorist attacks, and explosions. It can exist in the absence of any other outward signs of trauma, and further develop into acute lung injury (ALI) or a more severe acute respiratory distress syndrome (ARDS). The pathogenesis of PBLI at the cellular and molecular level has not been clear. Damage-associated molecular pattern (DAMP) is a general term for endogenous danger signals released by the body after injury, including intracellular protein molecules (HMGB1, histones, s100s, heat shock proteins, eCIRP, etc.), secretory protein factors (IL-1β, IL-6, IL-10, TNF-α, VEGF, complements, etc.), purines and pyrimidines and their derived degradation products (nucleic acids, ATP, ADP, UDPG, uric acid, etc.), and extracellular matrix components (hyaluronic acid, fibronectin, heparin sulfate, biglycan, etc.). DAMPs can be detected by multiple receptors including pattern recognition receptors (PRRs). The study of DAMPs and their related signaling pathways, such as the mtDNA-triggered cGAS-YAP pathway, contributes to revealing the molecular mechanism of PBLI, and provides new therapeutic targets for controlling inflammatory diseases and alleviating their symptoms. In this review, we focus on the recent progress of research on DAMPs and their signaling pathways, as well as the potential therapeutic targets and future research directions in PBLI.

The effect of blast overpressure on the mechanical properties of the human tympanic membrane

The rupture of the tympanic membrane (TM) is one of the major indicators for blast injuries due to the vulnerability of TM under exposure to blast overpressure. The mechanical properties of the human TM exhibit a significant change after it is exposed to such a high intensity blast. To date, the published data were obtained from measurement on TM strips cut from a TM following an exposure to blast overpressure. The dissection of a TM for preparation of strip samples can induce secondary damage to the TM and thus potentially lead to data not representative of the blast damage. In this paper, we conduct mechanical testing on the full TM in a human temporal bone. A bulging experiment on the entire TM is carried out on each sample prepared from a temporal bone following the exposure to blast three times at a pressure level slightly below the TM rupture threshold. Using a micro-fringe projection method, the volume displacement is obtained as a function of pressure, and their relationship is modeled in the finite element analysis to determine the mechanical properties of the post-blast human TMs, the results of which are compared with the control TMs without an exposure to the blast. It is found that Young's modulus of human TM decreases by approximately 20% after exposure to multiple blast waves. The results can be used in the human ear simulation models to assist the understanding of the effect of blast overpressure on hearing loss.

Anthropogenic Disasters

Anthropogenic disasters may be defined as any disaster caused by human action or inaction. Natural disasters occur without human interference. Injuries caused by terrorists and related criminal activities may be broadly grouped into 3 categories: blunt, blast, and penetrating trauma. Most terrorist and criminal activities that create a mass-casualty situation are performed using the weapons most readily available, such as firearms or explosives. A consistent pattern, comparing terrorism with interpersonal violence, is the greater severity of impact on the victim.

[Terrorist attack trauma - an individual entity of polytrauma : A 10-year update]

The incidence of terrorist attacks is increasing worldwide, and they have also become a permanent threat in European cities. Due to its complexity, terrorist attack trauma places high demands on the strategy of surgical treatment. The combination of various mechanisms, explosions and gunshot injuries, with the characteristic pressure (blast) damage and a high proportion of penetrating trauma with simultaneous burns are characteristic features. Unlike in military conflicts, injuries to people of all ages and without ballistic body protection (body armor) are to be expected. The mechanism of the attack and its local conditions are of relevance for the assessment of the situation and the expected injury patterns. Thus, suicide attacks result in several times higher numbers of fatalities and casualties. Explosions on free ground lead to different types of injury than those in closed or semi-enclosed spaces. The treatment principles of the Advanced Trauma Life Support (ATLS®) are based on the intrahospital care of casualties as well as damage control strategies with trigger factors. In order to prepare and educate clinics and surgeons in Germany for such scenarios, various course formats of the professional societies, the German Society for General and Visceral Surgery (DGAV) and the German Society for Trauma Surgery (DGU) have now been established.

Numerical assessment of the human body response to a ground-level explosion

This paper presents the results of a numerical analysis of the behaviour of a human body after a ground-level explosion. The explosions were generated by condensed charges for different stand-off distances and various masses of explosive. The detonations points were located at distances of 1.0 and 2.0 meters from the dummy (human model) obstacle. The different masses of spherically-shaped TNT charges (0.4-1.0 kg) were initiated centrally. The blast wave propagation was generated using a coupled numerical design, which included Eulerian and Lagrangian descriptions for different domains, i.e. the dummy, air, and explosive domains. The main objective of this work was to present the actual pressures and accelerations around the dummy and the body motion caused by the rapid shock of the pressure action. Reaction forces and moments of anatomical joints were provided. Furthermore, the safety criteria presented in the official standards were compared to the simulation results. In this research, different positions against the loading masses were analysed. In each analysis the same standing human model was used. The dummy geometry was based on a medium size male (1.79 m, 84.8 kg). The human body was modelled as consisting of separate, rigid parts (with adequate masses and inertia moments) connected by joints exhibiting nonlinear behaviour. Anatomical ranges of motion were taken into consideration, and a dedicated numerical technique was proposed to model the resistance moment vs. the range of motion relations for the most important human body joints.

Tube Thoracostomy Management in the Combat Wounded

The intent of this study was to characterize the management and subsequent complications of combat injury tube thoracostomies and to determine risk factors for the development of pneumonia (PNA) and retained hemothorax (RH). One hundred fifteen patients with 173 tube thoracostomies met the inclusion criteria and were analyzed. The mean injury severity score was 30.8 1 11.6, 23.5 per cent had traumatic amputations, 49.7 per cent had a hemothorax, and 50.3 per cent had a pneumothorax as indications for tube thoracostomy (TT) placement. Within 24 hours of injury, 89.6 per cent were intubated, the majority (54%) were injured by improvised explosive devices, 35.6 per cent sustained rib fractures, and 12.2 per cent had a diaphragm injury. A mean of 1.5 1 0.7(range 1–4) tube thoracostomies were placed, 18.3 per cent of patients had bilateral tube thoracostomies, and the average TT duration was 6.7 1 3.9 days. The incidence of PNA was 27 per cent (n = 31), RH was 9.6 per cent (n = 11), and empyema was 1.7 per cent (n = 2). Multivariable analysis identified the duration of ventilation [OR 1.2, 95% confidence interval (CI): 1.097–1.313, P < 0.001] as independently associated with the development of PNA. Bilateral TT placement (OR 3.848, 95% CI: 1.219–12.143, P = 0.0216) and injury severity score (OR 1.050, 95% CI: 1.001–1.102, P = 0.0443) were independently associated with PNA development when a patient was intubated for eight days or less. The number of tube thoracostomies placed (OR 3.08, 95% CI: 1.03–9.18, P = 0.0439) was independently associated with the development of RH. Further research is warranted to identify modifiable risk factors to reduce the incidence of PNA and RH in patients with TT placed for traumatic injuries.

Where is the fracture? Penetrating injury with a foreign bone

Injuries in the explosion scenarios are usually hollow organ injuries including rapid gas expansion, thermal injuries, penetrating injuries due to secondary projectiles and secondary injuries like falls and burns. Our case is a penetrating injury that was considered open knee fracture (Gustilo Anderson Type 3A) and peroneal nerve palsy in the emergency service after bomb attack but later it was seen that the secondary projectile was a foreign bone and the patient's bone integrity was intact. Our aim is to show that specific human tissues must be considered as a factor in the secondary injuries.

Lethal explosions in a non-terrorist civilian setting

A study was undertaken to investigate the range and nature of deaths that may result from explosions in a civilian population that has not been exposed to terrorist attacks or significant military activities. A search was conducted of autopsy files at Forensic Science SA, Adelaide, Australia, from July 2000 to June 2017 for all cases where death had been attributed to an explosion. Twenty cases were identified, consisting of 10 accidents, five suicides, two homicides, one murder-suicide with two decedents and one case where the manner of death was undetermined. Explosives were involved in nine deaths, petrol in seven and propane/butane/natural gas in a further four. Deaths caused by explosions were a rare event, with most cases being caused by accidents in a domestic or industrial environment. Although suicides formed the next most-common group, it is possible that explosions caused by petrol in cases of self-immolation were not intended.

Penetrating Foreign Bodies in Head and Neck Trauma: A Surgical Challenge

Penetrating foreign bodies of different origins in the head and neck are rare and potentially dangerous injuries, which might pose problems for their detection, primary care, and final treatment. Depending on the severity of the underlying trauma, some injuries present a higher risk for the presence of foreign bodies. Minor wounds, including common lacerations, are likely to be contaminated with loose gravel debris or dental fragments, and need to be distinguished from severe wounds caused by impalement, shootings, stabbings, and explosions. Blast injuries resulting from terror attacks are challenging recent therapeutic concepts. Even though these injury patterns are uncommon, they carry the risk of impacted objects with dramatic consequences. Despite improving medical imaging techniques, detection remains a challenge as it is dependent on the material of the foreign body, the affected anatomical site, and the injury severity. Therefore, a detailed history of the circumstances leading to trauma is essential when foreign objects are not visible during clinical examination. Precise detection of the foreign body, its anatomical position, and the affected surrounding structures are vital, especially for impalement injuries of the head and neck area. Therefore, an interdisciplinary planning approach is essential prior to removal of the foreign object. Finally, tension-free anatomical adaptation of the corresponding structures is crucial for maintaining and restoring aesthetic and function. Here, we give an overview of the diagnosis and treatment of cases of foreign body injuries encountered in our department.

Nano- and micro-materials in the treatment of internal bleeding and uncontrolled hemorrhage

Internal bleeding is defined as the loss of blood that occurs inside of a body cavity. After a traumatic injury, hemorrhage accounts for over 35% of pre-hospital deaths and 40% of deaths within the first 24 hours. Coagulopathy, a disorder in which the blood is not able to properly form clots, typically develops after traumatic injury and results in a higher rate of mortality. The current methods to treat internal bleeding and coagulopathy are inadequate due to the requirement of extensive medical equipment that is typically not available at the site of injury. To discover a potential route for future research, several current and novel treatment methods have been reviewed and analyzed. The aim of investigating different potential treatment options is to expand available knowledge, while also call attention to the importance of research in the field of treatment for internal bleeding and hemorrhage due to trauma.

The role of neutrophil gelatinase-associated lipocalin (NGAL) in the detection of blast lung injury in a military population

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 PaO₂/FiO₂ ratio (P/F ratio2) were recorded at 24h.

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 24h in blast injured group but not GSW group that warrants further investigation.

Response of the cerebral vasculature following traumatic brain injury

The critical role of the vasculature and its repair in neurological disease states is beginning to emerge particularly for stroke, dementia, epilepsy, Parkinson's disease, tumors and others. However, little attention has been focused on how the cerebral vasculature responds following traumatic brain injury (TBI). TBI often results in significant injury to the vasculature in the brain with subsequent cerebral hypoperfusion, ischemia, hypoxia, hemorrhage, blood-brain barrier disruption and edema. The sequalae that follow TBI result in neurological dysfunction across a host of physiological and psychological domains. Given the importance of restoring vascular function after injury, emerging research has focused on understanding the vascular response after TBI and the key cellular and molecular components of vascular repair. A more complete understanding of vascular repair mechanisms are needed and could lead to development of new vasculogenic therapies, not only for TBI but potentially vascular-related brain injuries. In this review, we delineate the vascular effects of TBI, its temporal response to injury and putative biomarkers for arterial and venous repair in TBI. We highlight several molecular pathways that may play a significant role in vascular repair after brain injury.

Perfluorocarbon reduces cell damage from blast injury by inhibiting signal paths of NF-κB, MAPK and Bcl-2/Bax signaling pathway in A549 cells

Background and objective

Blast lung injury is a common type of blast injury and has very high mortality. Therefore, research to identify medical therapies for blast injury is important.

Perfluorocarbon (PFC) is used to improve gas exchange in diseased lungs and has anti-inflammatory functions in vitro and in vivo. The aim of this study was to determine whether PFC reduces damage to A549 cells caused by blast injury and to elucidate its possible mechanisms of action.

Study design and methods

A549 alveolar epithelial cells exposed to blast waves were treated with and without PFC. Morphological changes and apoptosis of A549 cells were recorded. PCR and enzyme-linked immunosorbent assay (ELISA) were used to measure the mRNA or protein levels of IL-1β, IL-6 and TNF-α. Malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity levels were detected. Western blot was used to quantify the expression of NF-κB, Bax, Bcl-2, cleaved caspase-3 and MAPK cell signaling proteins.

Results

A549 cells exposed to blast wave shrank, with less cell-cell contact. The morphological change of A549 cells exposed to blast waves were alleviated by PFC. PFC significantly inhibited the apoptosis of A549 cells exposed to blast waves. IL-1β, IL-6 and TNF-α cytokine and mRNA expression levels were significantly inhibited by PFC. PFC significantly increased MDA levels and decreased SOD activity levels. Further studies indicated that NF-κB, Bax, caspase-3, phospho-p38, phosphor-ERK and phosphor-JNK proteins were also suppressed by PFC. The quantity of Bcl-2 protein was increased by PFC.

Conclusion

Our research showed that PFC reduced A549 cell damage caused by blast injury. The potential mechanism may be associated with the following signaling pathways:

1) the signaling pathways of NF-κB and MAPK, which inhibit inflammation and reactive oxygen species (ROS); and 2) the signaling pathways of Bcl-2/Bax and caspase-3, which inhibit apoptosis.

Blast Injuries: From Improvised Explosive Device Blasts to the Boston Marathon Bombing

Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries.

Evaluation of blast injury patients from the 2015 Tianjin explosions in China

OBJECTIVES

To perform a descriptive analysis of blast injury patients from the Tianjin explosions that occurred August 12, 2015 and provide a reference for triage and treatment of patients in similar situations in the future.

METHODS

The medical records of patients with blast injuries admitted to our hospital following the 2015 Tianjin explosions were retrospectively reviewed. The results were compared with the literature for other recent mass casualty events.

RESULTS

The 75 patients with blast injuries included 58 men (77.3%) and 17 women (22.7%), who had an average age of 36.39±12.3 years. Multidimensional injuries affecting almost every organ system were observed in these patients. The distribution of the types of blast injuries included 36 (48.0%) with primary blast injuries, 63 (84.0%) with secondary injuries, 33 (44.0%) with tertiary injuries and 32 (42.6%) with quaternary injuries. A total of 52 (69.3%) patients suffered more than two types of blast injury. Burns affecting different areas and different depths were present in 41.3% of the patients with blast injuries, and these were divided into the following four groups: a minor group (18.7%), a moderate group (10.7%), a severe group (5.3%), and an extra severe group (6.7%). The total body surface area (TBSA) affected by the burn ranged from 1% to 75%. Additionally, 6.7% of the patients were diagnosed with an inhalational injury, and 2.7% of the patients were diagnosed with chemical poisoning. There were significant differences in the department distribution (especially in the burn unit and ophthalmology department) and ICU treatment between civilians and firefighters.

CONCLUSION

Various types of injury, with overlapping injuries present in many patients, were observed in the victims after the Tianjin explosions. An evaluation of the distribution of blast injuries is important for optimizing strategies to triage and treat survivors after mass casualty events.

Traumatic lung injury attributed to tornadic activity-induced barometric pressure changes in two dogs

CASE DESCRIPTION A 7-year-old castrated male Italian Greyhound (dog 1) and an approximately 1-year-old female Labrador Retriever (dog 2) were evaluated because of respiratory distress 8 and 10 days, respectively, after a tornado. CLINICAL FINDINGS No obvious external injuries were identified auscultation revealed decreased bronchovesicular sounds in the affected hemithorax of both dogs. Clinicopathologic changes were mild, with evidence of inflammation in both dogs. Thoracic radiography of both dogs revealed pneumothorax and pleural effusion with effacement of the diaphragm; findings on CT included severe pulmonary atelectasis of affected lung lobes with normal bronchial tree configurtion and no evidence of diaphragmatic hernia. TREATMENT AND OUTCOME Exploratory thoracotomy of both dogs confirmed CT findings Pulmonary parenchymal damage consistent with a large rupture was found in both patients. A large hematoma was adhered to the ruptured lung lobe of dog 1. Grossly affected lung tissue was removed; histologic examination revealed atelectasis, pulmonary fib osis, thrombosis, and minimal (dog 1) to marked (dog 2) inflammation Microbial culture of lung tissue yielded no growth for dog 1 and Streptococcus spp and Escherichia coli susceptible to amoxicillin-clavulanic acid for dog 2. Dog 1 had a recurrence of pneumothorax treated by drainage with a thoracostomy tube 1 month after surgery. Eighteen months after surgery, both dogs were reportedly doing well. CLINICAL RELEVANCE Development of clinical signs after a tornado, together with clinical, diagnostic imaging, surgical, and histologic findings led to a presumptive diagnosis of pulmonary barotrauma for both dogs. Long-term outcome for these dogs, treated at a referral hospital, was good.

Suicide by Bomb, with Decapitation

Suicide by explosion is rare outside of the context of terrorist activities. We present a case of a man with a history of explosives expertise who committed suicide by bomb/decapitation. The case serves to remind forensic pathologists of several important issues when presented with a case involving explosives, such as ensuring the safety of all those involved in the investigation and the importance of interagency cooperation. Potentially invaluable ancillary tests at autopsy include performing radiology, collecting trace evidence, retaining clothing, ensuring the positive identity of the decedent, and recognizing the importance of documenting injury types and patterns.

White matter compromise in veterans exposed to primary blast forces

OBJECTIVE

Use diffusion tensor imaging to investigate white matter alterations associated with blast exposure with or without acute symptoms of traumatic brain injury (TBI).

PARTICIPANTS

Forty-five veterans of the recent military conflicts included 23 exposed to primary blast without TBI symptoms, 6 having primary blast with mild TBI, and 16 unexposed to blast.

DESIGN

Cross-sectional case-control study.

MAIN MEASURES

Neuropsychological testing and diffusion tensor imaging metrics that quantified the number of voxel clusters with altered fractional anisotropy (FA) radial diffusivity, and axial diffusivity, regardless of their spatial location.

RESULTS

Significantly lower FA and higher radial diffusivity were observed in veterans exposed to primary blast with and without mild TBI relative to blast-unexposed veterans. Voxel clusters of lower FA were spatially dispersed and heterogeneous across affected individuals.

CONCLUSION

These results suggest that lack of clear TBI symptoms following primary blast exposure may not accurately reflect the extent of brain injury. If confirmed, our findings would argue for supplementing the established approach of making diagnoses based purely on clinical history and observable acute symptoms with novel neuroimaging-based diagnostic criteria that "look below the surface" for pathology.

SIMULATION STUDY TO COMPARE THE RELATIONSHIP BETWEEN THE BLAST-INDUCED OBJECTIVE INDICES AND THE SURVIVAL RATE OF SUBJECTS WITH PRIMARY BLAST LUNG INJURY

When an injury due to blast overpressure (BOP) is generated, it is important to estimate the severity of the injury using information about the blast conditions and to supply proper treatments according to the degree of the damage. However, there have been no investigations that have tried to verify the relationship between the blast-related objective indices and the degree of blast-induced injury. In this study, the correlations between the survival rate of the subjects with BOP-induced lung damage and each of four blast-induced indices, first principal strain, first principal strain rate, first principal stress and pulmonary inner pressure, were investigated using a simplified thorax model by introducing the concept of the V ACC –V LUNG ratio graph which represents the volume ratio between the seriously-damaged meshes and the overall meshes of the thorax model in respect to each index. Experimental results demonstrated that the decay parameters of the sigmoidal curve-fitted graphs of the first principal stress are the most effective of the analyzed indices for the estimation of the survival rate in patients with blast-induced lung damage. The results have a potential clinical application to improve the efficacy of treatment for blast injury patients.

Role of Microvascular Disruption in Brain Damage from Traumatic Brain Injury

Traumatic brain injury (TBI) is acquired from an external force, which can inflict devastating effects to the brain vasculature and neighboring neuronal cells. Disruption of vasculature is a primary effect that can lead to a host of secondary injury cascades. The primary effects of TBI are rapidly occurring while secondary effects can be activated at later time points and may be more amenable to targeting. Primary effects of TBI include diffuse axonal shearing, changes in blood-brain barrier (BBB) permeability, and brain contusions. These mechanical events, especially changes to the BBB, can induce calcium perturbations within brain cells producing secondary effects, which include cellular stress, inflammation, and apoptosis. These secondary effects can be potentially targeted to preserve the tissue surviving the initial impact of TBI. In the past, TBI research had focused on neurons without any regard for glial cells and the cerebrovasculature. Now a greater emphasis is being placed on the vasculature and the neurovascular unit following TBI. A paradigm shift in the importance of the vascular response to injury has opened new avenues of drug-treatment strategies for TBI. However, a connection between the vascular response to TBI and the development of chronic disease has yet to be elucidated. Long-term cognitive deficits are common amongst those sustaining severe or multiple mild TBIs. Understanding the mechanisms of cellular responses following TBI is important to prevent the development of neuropsychiatric symptoms. With appropriate intervention following TBI, the vascular network can perhaps be maintained and the cellular repair process possibly improved to aid in the recovery of cellular homeostasis.

Blast Injuries

BACKGROUND

Blast injuries in the United States and worldwide are not uncommon. Partially due to the increasing frequency of both domestic and international terrorist bombing attacks, it is prudent for all emergency physicians to be knowledgeable about blasts and the spectrum of associated injuries.

OBJECTIVE

Our aim was to describe blast physiology, types of blast injuries associated with each body system, and manifestations and management of each injury.

DISCUSSION

Blast injuries are generally categorized as primary to quaternary injuries. Primary injuries result from the effect of transmitted blast waves on gas-containing structures, secondary injuries result from the impact of airborne debris, tertiary injury results from transposition of the entire body due to blast wind or structural collapse, and quaternary injuries include almost everything else. Different body systems are affected and managed differently. Despite previous dogma, multiple studies now show that tympanic membrane perforation is a poor predictor of other blast injury.

CONCLUSIONS

Blast events can produce a myriad of injuries affecting any and every body system. All emergency physicians should be familiar with the presentation and management of these injuries. This knowledge may also be incorporated into triage and discharge protocols guiding management of mass casualty events.

Steroid-Loaded Hemostatic Nanoparticles Combat Lung Injury after Blast Trauma

In response to the lack of therapeutics for internal bleeding following a traumatic event, we synthesized hemostatic dexamethasone nanoparticles (hDNP) to help alleviate internal hemorrhaging. hDNP consist of a block copolymer, poly(lactic-co-glycolic acid)-poly(l-lysine)-poly(ethylene glycol) conjugated to a peptide, glycine-arginine-glycine-aspartic acid-serine (GRGDS). These particles were evaluated as treatment for primary blast lung injury in a rodent model. Animals were randomly placed into test and control groups, exposed to blast and given immediate injection. Recovery was assessed using physiological parameters and immunohistochemistry. We found that dexamethasone-loaded hemostatic nanoparticles alleviate physiological deprivation caused by blast injury and reduce lung injury damage.

Transcriptional profiling in rat hair follicles following simulated Blast insult: a new diagnostic tool for traumatic brain injury

With wide adoption of explosive-dependent weaponry during military activities, Blast-induced neurotrauma (BINT)-induced traumatic brain injury (TBI) has become a significant medical issue. Therefore, a robust and accessible biomarker system is in demand for effective and efficient TBI diagnosis. Such systems will also be beneficial to studies of TBI pathology. Here we propose the mammalian hair follicles as a potential candidate. An Advanced Blast Simulator (ABS) was developed to generate shock waves simulating traumatic conditions on brains of rat model. Microarray analysis was performed in hair follicles to identify the gene expression profiles that are associated with shock waves. Gene set enrichment analysis (GSEA) and sub-network enrichment analysis (SNEA) were used to identify cell processes and molecular signaling cascades affected by simulated bomb blasts. Enrichment analyses indicated that genes with altered expression levels were involved in central nervous system (CNS)/peripheral nervous system (PNS) responses as well as signal transduction including Ca2+, K+-transportation-dependent signaling, Toll-Like Receptor (TLR) signaling and Mitogen Activated Protein Kinase (MAPK) signaling cascades. Many of the pathways identified as affected by shock waves in the hair follicles have been previously reported to be TBI responsive in other organs such as brain and blood. The results suggest that the hair follicle has some common TBI responsive molecular signatures to other tissues. Moreover, various TBI-associated diseases were identified as preferentially affected using a gene network approach, indicating that the hair follicle may be capable of reflecting comprehensive responses to TBI conditions. Accordingly, the present study demonstrates that the hair follicle is a potentially viable system for rapid and non-invasive TBI diagnosis.

Modeling clinically relevant blast parameters based on scaling principles produces functional & histological deficits in rats

Blast-induced traumatic brain injury represents a leading cause of injury in modern warfare with injury pathogenesis poorly understood. Preclinical models of blast injury remain poorly standardized across laboratories and the clinical relevance unclear based upon pulmonary injury scaling laws. Models capable of high peak overpressures and of short duration may better replicate clinical exposure when scaling principles are considered. In this work we demonstrate a tabletop shock tube model capable of high peak overpressures and of short duration. By varying the thickness of the polyester membrane, peak overpressure can be controlled. We used membranes with a thickness of 0.003, 0.005, 0.007, and 0.010 in to generate peak reflected overpressures of 31.47, 50.72, 72.05, and 90.10 PSI, respectively. Blast exposure was shown to decrease total activity and produce neural degeneration as indicated by fluoro-jade B staining. Similarly, blast exposure resulted in increased glial activation as indicated by an increase in the number of glial fibrillary acidic protein expressing astrocytes compared to control within the corpus callosum, the region of greatest apparent injury following blast exposure. Similar findings were observed with regard to activated microglia, some of which displayed phagocytic-like morphology within the corpus callosum following blast exposure, particularly with higher peak overpressures. Furthermore, hematoxylin and eosin staining showed the presence of red blood cells within the parenchyma and red, swollen neurons following blast injury. Exposure to blast with 90.10 PSI peak reflected overpressure resulted in immediate mortality associated with extensive intracranial bleeding. This work demonstrates one of the first examples of blast-induced brain injury in the rodent when exposed to a blast wave scaled from human exposure based on scaling principles derived from pulmonary injury lethality curves.

Resuscitation in a multiple casualty event

A major weakness in the emergency medical response to multiple casualty events continues to be the resuscitation component, which should consist of the systematic application of basic, advanced, and prolonged life support and definitive care within 24 hours. There have been major advances in emergency medical care over the last decade, including the feasibility of point-of-care ultrasound to aid in rapid assessment of injuries in the field, damage control resuscitation, and resuscitative surgery protocols, delivered by small trauma/resuscitation teams equipped with regional anesthesia capability for rapid deployment. Widespread adoption of these best practices may improve the delivery of resuscitative care in future multiple casualty events.