Management of blast injuries and shock lung

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.

The first case of C4-Blast related death in Malaysia: A multidisciplinary approach illustrated with emphasis on conjoint anthropologic and radiologic expertise in forensic identification of skeletal remains

BACKGROUND

Blast related deaths are often shrouded by diagnostic and medicolegal complexities requiring multidisciplinary expertise in order to gauge accurate identification of the victims and document scientific investigations comprehensively. In the advent of more sophisticated technology, anthropologic methods can now be applied into post mortem imaging interpretation. The traditional imaging roles of characterizing osseous fragmentation, detecting and localizing foreign bodies can be expanded to simulate and support physical anthropologic examination to assist in documentation for court proceedings.

CASE PRESENTATION

An assemblage of unidentified, incomplete, highly fragmented skeletal remains were found scattered on a bare area of land in a forest. There was evidence of an explosion given the pattern of scattered evidentiary material of explosive and ballistic nature. Laboratory analysis of white powder found within the explosive material confirmed the presence of high impact C4-explosive trace containing cyclotrimethylene trinitramin [Royal Demolition Explosive (RDX)] & pentaerythritol tetranitrate (PETN). It took meticulous multidisciplinary efforts to confirm the identity of the victim that was marred by the severe fragmentation and skeletalization of the remains. The initial radiologic interpretation focused more on identification of foreign bodies and supporting documentation of fragmentation. With the current availability of post computed tomography (PMCT) in our center, we reexamined the value and potential of PMXR and PMCT as an adjunctive tool for biological profiling.

CONCLUSION

This was the first case of C4-blast related death reported in Malaysia. The multidisciplinary approach in efforts to identify the victim may serve as a guide in managing, coordinating and maximizing the expertise of different forensic specialists, with emphasis on anthropologic and radiologic collaboration.

Shock waves increase pulmonary vascular leakage, inflammation, oxidative stress, and apoptosis in a mouse model

Severe lung damage is a major cause of death in blast victims, but the mechanisms of pulmonary blast injury are not well understood. Therefore, it is important to study the injury mechanism of pulmonary blast injury. A model of lung injury induced by blast exposure was established by using a simulation blast device. The effectiveness and reproducibility of the device were investigated. Eighty mice were randomly divided into eight groups: control group and 3 h, 6 h, 12 h, 24 h, 48 h, 7 days and 14 days post blast. The explosive device induced an explosion injury model of a single lung injury in mice. The success rate of the model was as high as 90%, and the degree of lung injury was basically the same under the same pressure. Under the same conditions, the thickness of the aluminum film can be from 0.8 mm to 1.6 mm, and the peak pressure could be from 95.85 ± 15.61 PSI to 423.32 ± 11.64 PSI. There is no statistical difference in intragroup comparison. A follow-up lung injury experiment using an aluminum film thickness of 1.4 mm showed a pressure of 337.46 ± 18.30 PSI induced a mortality rate of approximately 23.2%. Compared with the control group (372 ± 23 times/min, 85.9 ± 9.4 mmHg, 4.34 ± 0.09), blast exposed mice had decreased heart rate (283 ± 21 times/min) and blood pressure (73.6 ± 3.6 mmHg), and increased lung wet/dry weight ratio(2.67 ± 0.11), marked edematous lung tissue, ruptured blood vessels, infiltrating inflammatory cells, increased NF-κB (4.13 ± 0.01), TNF-α (4.13 ± 0.01), IL-1β (2.43 ± 0.01) and IL-6 (4.65 ± 0.01) mRNA and protein, decreased IL-10(0.18 ± 0.02) mRNA and protein ( P < 0.05). The formation of ROS and the expression of MDA5 (4.46 ± 0.01) and IREα (3.43 ± 0.00) mRNA and protein were increased and the expression of SOD-1 (0.28 ± 0.02) mRNA and protein was decreased ( P < 0.05). Increased expression of Bax (3.54 ± 0.00) and caspase 3 (4.18 ± 0.01) mRNA and protein inhibited the expression of Bcl-2 (0.39 ± 0.02) mRNA and protein. The changes of pulmonary edema, inflammatory cell infiltration, and cell damage factor expression increased gradually with time, and reached the peak at 12-24 h after the outbreak, and returned to normal at 7-14 days. Detonation injury can lead to edema of lung tissue, pulmonary hemorrhage, rupture of pulmonary vessels, induction of early inflammatory responses accompanied by increased oxidative stress in lung tissue cells and increased apoptosis in mice experiencing blast injury. The above results are consistent with those reported in other literatures. It is showed that the mouse lung blast injury model is successfully modeled, and the device can be used for the study of pulmonary blast injury. Impact statement The number of patients with explosive injury has increased year by year, but there is no better treatment. However, the research on detonation injury is difficult to carry out. One of the factors is the difficulty in making the model of blast injury. The laboratory successfully developed and produced a simulation device of explosive knocking through a large amount of literature data and preliminary experiments, and verified the preparation of the simulation device through various experimental techniques. The results showed that the device could simulate the shock wave-induced acute lung injury generated, which was similar to the actual knocking injury. The experimental process was controlled. Under the same condition, there was no statistical difference between the groups. It is possible to realize miniaturization and precision of an explosive knocking simulation device, which is a good experimental tool for further research on the mechanism of organ damage caused by detonation and the development of protective drugs.

Trauma and critical care III: chest trauma

Patients requiring intensive care for chest trauma are often severely injured and may have suffered trauma elsewhere. The single largest cause of significant blunt chest trauma is road traffic accidents (RTAs). RTAs account for 70-80% of such injuries. Falls and acts of violence are other causative mechanisms. Blast injuries can also result in significant blunt thoracic trauma. Penetrating chest trauma comprises a broad spectrum of injuries and severity. Particular challenges occur in patients with associated polytrauma, as well as those with a combination of blunt and penetrating chest trauma. Chest injury is the most important injury in polytrauma patients with reported incidences of 45-65% and an associated mortality of up to 60%. The treatment of these patients can be prolonged and the initial injury may become of secondary importance to the effects of systemic inflammatory response syndrome, acute lung injury (ALI), nosocomial infection and intercurrent multiorgan dysfunction syndrome (MODS). Multiply-injured patients with thoracic injuries require significantly longer periods of mechanical ventilation and longer intensive care unit lengths of stay compared with nonthoracic injury trauma patients. The use of a variety of therapeutic interventions may have to be considered during management of the disease process.

The Acute Respiratory Distress Syndrome (ARDS) in mechanically ventilated burn patients: An analysis of risk factors, clinical features, and outcomes using the Berlin ARDS definition

BACKGROUND

The Berlin definition of Acute Respiratory Distress Syndrome (ARDS) has been applied to military burns resulting from combat-related trauma, but has not been widely studied among civilian burns. This study's purpose was to use the Berlin definition to determine the incidence of ARDS, and its associated respiratory morbidity, and mortality among civilian burn patients.

METHODS

Retrospective study of burn patients mechanically ventilated for ≥48h at an American Burn Association-verified burn center. The Berlin criteria identified patients with mild, moderate, and severe ARDS. Logistic regression was used to identify variables predictive of moderate to severe ARDS, and mortality. The outcome measures of interest were duration of mechanical ventilation and in-hospital mortality. Values are shown as the median (Q1-Q3).

RESULTS

We included 162 subjects [24% female, age 48 (35-60), % total body surface area (TBSA) burn 28 (19-40), % body surface area (BSA) full thickness (FT) burn 13 (0-30), and 62% with inhalation injury]. The incidence of ARDS was 43%. Patients with ARDS had larger %TBSA burns [30.5 (23.1-47.0) vs. 24.8 (17.1-35), p=0.007], larger FT burns [20.5(5.4-35.5) vs. 7 (0-22.1), p=0.001], but had no significant difference in the incidence of inhalation injury (p=0.216), compared to those without ARDS. The % FT burn predicted the development of moderate to severe ARDS [OR 1.034, 95%CI (1.013-1.055), p=0.001]. ARDS developed in the 1st week after burn in 86% of cases. Worsening severity of ARDS was associated with increased days of mechanical ventilation in survivors (p=0.001), a reduction in ventilator-free days/1st 30 days in all subjects (p=0.004), and a strong indication of increased mortality (0% in mild ARDS vs. 50% in severe ARDS, unadjusted p=0.02). Neither moderate ARDS nor severe ARDS were significant predictors of death.

CONCLUSIONS

ARDS is common among mechanically ventilated civilian burn patients, and develops early after burn. The extent of full thickness burn predicted development of moderate to severe ARDS. Increasing severity of ARDS based upon the Berlin definition was associated with a significantly greater duration of mechanical ventilation and a trend toward higher mortality.

Imaging features of blast injuries: experience from 2015 Ankara bombing in Turkey

OBJECTIVE

To present the radiological features of blast-related injuries in the victims of the 10 October 2015 Ankara bombing and emphasize the importance of imaging.

METHODS

This retrospective descriptive study included a total of 28 patients who underwent CT scan or radiographic imaging within 6 h after the bombing on 10 October 2015. CT scans and plain radiographs were evaluated regarding mechanisms of injuries. Injuries were categorized as primary, secondary, tertiary and quaternary. The number of shrapnel and distribution of injuries were noted. Injury Severity Score (ISS) was used to rank the severity of the injury.

RESULTS

Primary blast injuries consisted of only tympanic membrane rupture. A high rate of patients (21/28 patients) in the study group suffered from secondary blast injuries. Tertiary injuries were detected in only three patients. Of the severely injured patients, five had abdominal injuries, three had thoracic injuries and six had extremity injuries. ISS was significantly higher in patients with thoracic and abdominal injuries.

CONCLUSION

Our results after the suicide bomb attacks showed that the most common injury pattern was secondary blast injury. The torso was the most commonly injured body region, followed by the extremities. This specific injury pattern requires the use of immense radiological imaging. Hence, radiologists should be aware of the mechanisms and spectrums of blast-related injuries.

ADVANCES IN KNOWLEDGE

Both the unique injury pattern and the following chaos make blast-related injuries a challenge in terms of triage, diagnosis and management. Radiologists should be familiar with the wide spectrum of these unique injuries.

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.

Challenges in management of blast injuries in Intensive Care Unit: Case series and review

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.

Blast lung injury in a 20-year-old man after a home explosion

A large family home exploded after a propane leak ignited. Initial reports from the scene noted that 11 people were injured, with many sustaining critical injuries. Immediately, multiple helicopter emergency medical services aircraft were dispatched to respond to the scene, and ground emergency medical services (EMS) providers were en route. Of the five aircraft requested, only two were available to respond; one aircraft was out for maintenance, and two others were committed to other missions.

Injury pattern of suicide bomb attacks in Pakistan

PURPOSE

The aim of our study was to analyze the pattern of injuries, hospital care, and outcome of the victims of suicide bomb attacks in Pakistan.

METHODS

This prospective, cohort study was conducted at the Combined Military Hospital Rawalpindi during the last 3 years. Seriously injured patients in the "immediate category" were resuscitated in the emergency operation theater adjacent to the emergency room and, after resuscitation, the patients were transferred to the main operation theaters, where consultant surgeons were available.

RESULTS

During the study period, 1,296 terrorist victims presented to the emergency department and (86.9%) were admitted, with a mean hospital stay of 8.2 ± 2.1 days. The majority of patients arrived by ambulance (91%) and only 38 (3%) were evacuated by air. Penetrating splinter injuries were the most prevalent (87%), and 29% patients also had associated injuries. Open bone fractures were found in 48% and 42% had injured hollow and solid viscous. Overall, 33% of patients had thoracic injuries and neuro-trauma was observed in 16% of the study population. Deafness was a feature in 33% patients, 121 had to undergo limb amputations, and mortality remained in 7% of patients.

CONCLUSION

Most of the problems encountered were logistic in nature. Early evacuation of the victims remains pivotal in saving lives. The major causes of death in peripheral patients was hypovolemic shock, sepsis, and hypothermia. Mortality and morbidity can be enhanced by ample fluid resuscitation, tetanus prophylaxis, and proficient first aid at the site of injury.

Field intensive care--weaning and extubation

Injury following ballistic trauma is the most prevalent indication for providing organ system support within an ICU in the field. Following damage control surgery, postoperative ventilatory support may be required, but multiple factors may influence the indications for and duration of invasive mechanical ventilation. Ballistic trauma and surgery may trigger the systemic inflammatory response syndrome (SIRS) and are important causative factors in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, their pathophysiological effect on the respiratory system is unpredictable and variable. Invasive mechanical ventilation is associated with numerous complications and the return to spontaneous ventilation has many physiological benefits. Following trauma, shorter periods of ICU sedation-amnesia and a protocol for early weaning and extubation, may minimize complications and have a beneficial effect on their psychological recovery. In the presence of stable respiratory function, appropriate analgesia and favourable operational and transfer criteria, we believe that the prompt restoration of spontaneous ventilation and early tracheal extubation should be a clinical objective for casualties within the field ICU.

Operational critical care. Intensive care and trauma

Trauma management involves good prehospital, emergency, surgical, anaesthetic and intensive care decision-making. Optimal outcome depends on keeping abreast of the latest thinking in an ever-changing and increasingly technology-rich environment. The intensive care unit needs to represented as early as possible in the damage-control resuscitation phase. Improved trauma system care has resulted in an increasing number of multiply injured military patients surviving their initial trauma. These patients require intensive care and are at risk from sepsis and multiple organ failure. Attention to detail is important, preservation of organ function, infection control and nutrition to maintain muscle strength allowing normal metabolic function to return. Multiply injured patients often require lengthy periods of mechanical ventilation and a variety of therapeutic interventions may have to be considered during management of the disease process. As we are now seeing more survivors in the military trauma system the focus now needs to be morbidity reduction in order for these survivors to be best prepared for their rehabilitation phase of care.

Blast injuries from Madrid terrorist bombing attacks on March 11, 2004

Blast injuries after terrorist attacks are seen with increasing frequency worldwide. Thousands of victims were attended in the hospitals of Madrid, Spain, on March 11, 2004 after the bombing attacks against the commuter trains. Thirty-six patients were attended in our institution. Seventeen of them suffered from severe or life-threatening injuries, and 19 had mild injuries. The most common lesions were thoracic trauma and blast lung injury, acoustic trauma, and orbital and paranasal sinus fractures. Other findings were hepatic and splenic lacerations, and vertebral and limb fractures. Emergency radiology had an important role in the correct management of the victims. Prompt radiological diagnoses of these complex lesions are crucial to efficient treatment. Therefore, radiologists have to become familiar with the injury patterns and specific lesions caused by blast wave.

Critical care delivery: the experience of a civilian terrorist attack

It has been recognised for some time that a terrorist incident was threatened in the U.K. and it has been noted previously in the JRAMC that the locations for terrorist atrocities are likely to be more diverse than previously experienced. July 7th 2005 witnessed the first terrorist suicide bombing on the U.K. mainland, targeting the public transport system in London. These attacks were unprecedented in both scale and intensity but they were anticipated in London. However there were clear difficulties, relating to multiple sites, their location underground and early problems with communication (2). This article highlights some of the experiences and learning points of the Intensive Care Medicine Service at the Royal London Hospital (RLH) in the wake of the July 7th bombings. The RLH was the single biggest receiver of casualties (195); seven of whom were admitted to the Intensive Care Unit. The Defence Medical Services have tri-service representation (both regular and reserve) at the RLH in Emergency Medicine and Pre-hospital Care, Surgical Services and Intensive Care Medicine.