The dynamic response of human lungs due to underwater shock wave exposure.

Since the 19th century, underwater explosions have posed a significant threat to service members. While there have been attempts to establish injury criteria for the most vulnerable organs, namely the lungs, existing criteria are highly variable due to insufficient human data and the corresponding inability to understand the underlying injury mechanisms. This study presents an experimental characterization of isolated human lung dynamics during simulated exposure to underwater shock waves. We found that the large acoustic impedance at the surface of the lung severely attenuated transmission of the shock wave into the lungs. However, the shock wave initiated large bulk pressure-volume cycles that are distinct from the response of the solid organs under similar loading. These pressure-volume cycles are due to compression of the contained gas, which we modeled with the Rayleigh-Plesset equation. The extent of these lung dynamics was dependent on physical confinement, which in real underwater blast conditions is influenced by factors such as rib cage properties and donned equipment. Findings demonstrate a potential causal mechanism for implosion injuries, which has significant implications for the understanding of primary blast lung injury due to underwater blast exposures.

A systematic review of otologic injuries sustained in civilian terrorist explosions.

PURPOSE: Determine the prevalence of otological symptoms and tympanic membrane perforation, healing rates of tympanic membrane perforation with surgical and conservative management, and hearing function in civilian victims of terrorist explosions. METHODS: A systematic review was conducted with searches on Medline, Embase, EMCare and CINAHL for publications between the 1st January 1945 and 26th May 2023. Studies with quantitative data addressing our aims were included. This review is registered with PROSPERO: CRD42020166768. Among 2611 studies screened, 18 studies comprising prospective and retrospective cohort studies were included. RESULTS: The percentage of eardrums perforated in patients admitted to hospital, under ENT follow up and attending the emergency department is 69.0% (CI 55.5-80.5%), 38.7% (CI 19.0-63.0%, I2 0.715%) and 21.0% (CI 11.9-34.3%, I2 0.718%) respectively. Perforated eardrums heal spontaneously in 62.9% (CI 50.4-73.8%, I2 0.687%) of cases and in 88.8% (CI 75.9-96.3%, I2 0.500%) of cases after surgery. Common symptoms present within one month of bombings are tinnitus 84.7% (CI 70.0-92.9%, I2 0.506%), hearing loss 83.0% (CI 64.5-92.9%, I2 0.505%) and ear fullness 59.7% (CI 13.4-93.4%, I2 0.719). Symptomatic status between one and six months commonly include no symptoms 57.5% (CI 46.0-68.3%), hearing loss 35.4% (CI 21.8-51.8%, I2 0.673%) and tinnitus 15.6% (CI 4.9-40.0%, I2 0.500%). Within one month of bombings, the most common hearing abnormality is sensorineural hearing loss affecting 26.9% (CI 16.9-40.1%, I2 0.689%) of ears 43.5% (CI 33.4-54.2%, I2 0.500) of people. CONCLUSION: Tympanic membrane perforation, subjective hearing loss, tinnitus, ear fullness and sensorineural hearing loss are common sequelae of civilian terrorist explosions.

Blunt force trauma and blast injuries to head and chest caused by a potent pyrotechnic device: a case report.

In times of peace and except for terrorist attacks, fatalities by explosions are rare. Fireworks have deadly potential, especially self-made or illegally acquired devices. The use of professional pyrotechnics by untrained persons poses a life-threatening hazard. We present a case of devastating blunt force and blast injuries to the head and chest of a young man. After ignition of a display shell (syn. a real shell or mortar shell) without the use of a launching pipe, the device hit the man's face, nearly simultaneously followed by the explosion of the burst charge. The autopsy revealed injuries to the face and forehead as well as extensive tissue structure damage and a massive contusion with a bloody edema of the lungs. Autopsy results are supplemented with CT imaging and 3D reconstruction of the fractured mid face, as well as histological and toxicological examinations. This case of a misused display shell demonstrates both its devastating destructive potential and the corresponding and rarely observed injury pattern.

Characteristics and mechanism of lower limb injury induced by landmine blast: A research in a rabbit model.

BACKGROUND: Limb injuries caused by landmine explosions are tricky to treat and difficult to protect. It is necessary to establish an animal model for studying lower limb injury and to investigate the characteristics and mechanisms of lower limb injury induced by landmine blasts. METHODS: Twenty-six mature white rabbits were randomly divided into sham group (n=10) and injury group (n=16). Landmine blast was simulated by electric detonators under the right lower limb in upright state by a special modified fixation frame. High-speed photography was used to observe the body movements. Vital signs, vascular injury (determining by digital subtraction angiography), pathological characteristics, and ATP concentration of the tibialis anterior muscle and triceps surae of shank were recorded for com-parison. RESULTS: Generally, middle and lower segment of the injured legs of the rabbits was seriously damaged. The limb stump presents a distribution of three areas, tissue free zone, contusion hematoma, and edema contusion. Sneak wound track, myofascial destruction, and periosteum stripping were typical characteristics of landmine blast injury. ATP concentration and pathological analysis showed that the tibialis anterior muscle was the most seriously injured, followed by the gastrocnemius and soleus. ATP concentration of affected muscle of both the contusion and commotio area declined remarkably over time, but the muscle in the avulsion area stayed at a low activity level with no change over the time. Small vascular injury in the contusion area was evident. The site of the sciatic nerve lesion was higher than the muscle. Injured site of sciatic nerve injury was higher than serious contusion muscle. High-speed photography demonstrated that the joints of the injured limb extremely flexed followed by a rapid stretch under the blast shock wave. CONCLUSION: The established experimental model presents typical effect of lower limbs wounded by the mine blast in war field. Landmine blast can cause typical damage on lower limbs including nerve lesion, knee injury, and microcirculation damage that is pro-gressive over time. The limb stump is divided into three zones based on gross pathology and micropathology, which can provide an important reference for clinical treatments and prognosis.

Mobile battery blast injuries: An emerging ocular health hazard in children.

PURPOSE: To assess clinical features, visual outcomes, and setting of mobile battery blast-induced eye injuries in children. METHODS: Retrospective case sheets of children with mobile battery blast injuries were reviewed at a tertiary eye care center from January 2015 to March 2022. We noted the mode of injury, battery status, and clinical presentation and analyzed the treatment outcomes. RESULTS: The study included 14 eyes of 11 patients. Three patients (27%) had bilateral ocular injuries. The most common reasons for the blast were wiring a bulb to the battery or charging the battery with a universal mobile charger, seen in four cases each. Three eyes had closed-globe injuries (CGIs), whereas 11 had open-globe injuries (OGIs). Of the 11 eyes with OGI, four also had a retained intraocular foreign body (IOFB). Only four (36%) eyes having OGI could achieve vision better than 6/60. All three eyes with CGIs developed secondary glaucoma, and two underwent trabeculectomy. However, the visual prognosis was better (>6/36) in eyes with CGI. Overall, mean visual acuity at the final follow-up was improved to 1.41 ± 1.14 logMAR from 2.32 ± 0.76 logMAR at presentation. This was also found to be statistically significant with a P value of 0.02. CONCLUSION: Battery blast-induced ocular injuries, although rare, often lead to poor outcomes. Apart from charging, playing with discarded or damaged batteries was a common reason for battery blasts in our series.

Lower Extremity Sandblast Injury: A Rarely Seen Injury Mechanism in the Civilian Population.

Blast injuries are both complex and rare in the civilian population. This combination can often lead to missed opportunities for early, effective intervention. This is a case report of a 31-year-old male who suffered a lower extremity blast injury while using an industrial sandblaster. This blast injury presented as a closed degloving, or Morel-Lavallee lesion, which can easily be mistreated and lead to infection and further disability. Following assessment, identification, and confirmation of the Morel-Lavallee lesion via radiographic imaging, this patient underwent debridement surgery, wound vac therapy, and antibiotic treatment before being discharged home with no major physiologic or neurologic deficits. The purpose of this report is to highlight the importance of assessing for closed degloving injuries when presented with blast injury traumas in the civilian trauma setting, and outlines the process utilized for assessment and treatment.

Blast syndrome - pathophysiology, diagnosis and treatment of blast injuries.

The incidence of explosions in large agglomerations is high even during peacetime and continues rising. Blast syndrome injuries are complex, with shock wave causing severe injuries of multiple organ systems. In situations with large numbers of injured persons, effective triage allows an early diagnosis and treatment of the highest number of victims. Treatment is challenging, and potentially conflicting therapeutic goals may alternate. This review provides an overview of the pathophysiology of blast injuries, current diagnostic algorithms and therapeutic procedures.

Firework injuries remain high in years after legalisation: its impact on children.

PURPOSE: We evaluated the impact of Senate Bill 489 passed in May 2017, allowing the sale and use of fireworks in Iowa 1 June to 8 July and 10 December to 3 January, on hospital presentations for firework injuries in the state. To identify the public health implications of this law, we conducted a detailed subanalysis of hospital presentations to the two level I trauma centres. METHODS: Hospital presentations for firework injuries from 1 June 2014 to 31 July 2019 were identified using the Iowa Hospital Admission database and registries and medical records of Iowa's two level 1 trauma centres. Trauma centres' data were reviewed to obtain demographics, injury information and hospital course. Prefirework and postfirework legalisation state data were compared using negative binomial regression analysis. Trauma centre data detailing injuries were compared using χ2 and Mann-Whitney U tests as appropriate. RESULTS: Emergency department (ED) visits and hospital admissions for firework injuries increased in Iowa post-legalisation (B-estimate=0.598±0.073, p<0.001 and B-estimate=0.612±0.322, p=0.058, respectively). ED visits increased postlegalisation in July (73.6% vs 64.5%; p=0.008), reflecting an increase in paediatric admissions (81.8% vs 62.5%; p=0.006). Trauma centres' data showed similar trends. The most common injury site across both study periods was the hands (48.5%), followed by the eyes (34.3%) and face (28.3%). Amputations increased from 0 prelegalisation to 16.2% postlegalisation. CONCLUSION: Firework legalisation led to an increase in the number of admissions and more severe injuries.

Injuries From Explosions: More Differences Than Similarities Between Various Types.

OBJECTIVE: To compare injury patterns of different types of explosions. METHODS: A retrospective study of 4508 patients hospitalized due to explosions recorded in the Israel National Trauma Registry between January 1997 and December 2018. The events were divided into 4 groups: terror-related, war-related, civilian intentional explosions, and civilian unintentional explosions. The groups were compared in terms of injuries sustained, utilization of hospital resources, and clinical outcomes. RESULTS: Civilian intentional and terror-related explosions were found to be similar in most aspects except for factors directly influencing mortality and a larger volume of severely injured body regions among terror-victims. Comparisons between other groups produced some parallels, albeit less consistent. Civilian intentional explosions and civilian unintentional explosions were different from each other in most aspects. The latter group also differed from others by its high volume of life-threatening burns and a higher proportion of children casualties. CONCLUSIONS: While consistent similarities between explosion casualties exist, especially between victims of intentional civilian and terror-related explosions, the general rule is that clinical experience with a type of explosion cannot be directly transferred to other types.

Review of blast noise and the auditory system.

The auditory system is particularly vulnerable to blast injury due to the ear's role as a highly sensitive pressure transducer. Over the past several decades, studies have used a variety of animal models and experimental procedures to recreate blast-induced acoustic trauma. Given the developing nature of this field and our incomplete understanding of molecular mechanisms underlying blast-related auditory disturbances, an updated discussion about these studies is warranted. Here, we comprehensively review well-established blast-related auditory pathology including tympanic membrane perforation and hair cell loss. In addition, we discuss important mechanistic studies that aim to bridge gaps in our current understanding of the molecular and microstructural events underlying blast-induced cochlear, auditory nerve, brainstem, and central auditory system damage. Key findings from the recent literature include the association between endolymphatic hydrops and cochlear synaptic loss, blast-induced neuroinflammatory markers in the peripheral and central auditory system, and therapeutic approaches targeting biochemical markers of blast injury. We conclude that blast is an extreme form of noise exposure. Blast waves produce cochlear damage that appears similar to, but more extreme than, the standard noise exposure protocols used in auditory research. However, experimental variations in studies of blast-induced acoustic trauma make it challenging to compare and interpret data across studies.

Fireworks Injuries to the Head and Neck: A Retrospective Analysis Between 2008 and 2017.

This study examines firework-associated head and neck injuries in the United States from 2008 to 2017 obtained from a single epidemiology source. The National Electronic Injury Surveillance System (NEISS) was used to collect epidemiologic data and retrospectively analyze firework-associated injuries from 2008 to 2017. Injury types included burns, concussions, contusions, foreign bodies, hematomas, internal organ injury, lacerations, and puncture wounds. Four hundred and thirty-one individuals were originally included; however, 14 participants were excluded due to inadequate injury information. Chi-squared analyses were performed between the following categorical variables: gender vs body part injured, patient age vs injury type, and patient age vs body part injured. About 417 injuries to the head and neck (67.4% male, 32.6% female) were treated in NEISS-reporting emergency departments during the 10-year period. Sixty-nine percent of the injuries occurred in July. Body parts injured included the ear (10.6%), face (61.6%), head (13.0%), mouth (4.8%), and neck (10.0%). Chi-squared analysis demonstrated an association between gender and body part injured (P = .0001). Patient age (P = .066) was independent of injury type. Children aged 0 to 12 years had the highest probability of being injured (40.2%), then adults 22 and older (33.1%) and adolescents 13 to 21 years (26.9%). Given that the preponderance of injuries caused by fireworks occurred primarily in minors, pediatricians should screen for any household firework use during the anticipatory guidance portion of well-child checks, which we believe would improve patient safety and decrease injury rates.

Blast injury on harbour porpoises (Phocoena phocoena) from the Baltic Sea after explosions of deposits of World War II ammunition.

Harbour porpoises are under pressure from increasing human activities. This includes the detonation of ammunition that was dumped in large amounts into the sea during and after World War II. In this context, forty-two British ground mines from World War II were cleared by means of blasting in the period from 28 to 31 August 2019 by a NATO unit in the German Exclusive Economic Zone within the marine protected area of Fehmarn Belt in the Baltic Sea, Germany. Between September and November 2019, 24 harbour porpoises were found dead in the period after those clearing events along the coastline of the federal state of Schleswig-Holstein and were investigated for direct and indirect effects of blast injury. Health evaluations were conducted including examinations of the brain, the air-filled (lungs and gastrointestinal tract) and acoustic organs (melon, acoustic fat in the lower jaw, ears and their surrounding tissues). The bone structure of the tympano-periotic complexes was examined using high-resolution peripheral quantitative computed tomography (HR-pQCT). In 8/24 harbour porpoises, microfractures of the malleus, dislocation of middle ear bones, bleeding, and haemorrhages in the melon, lower jaw and peribullar acoustic fat were detected, suggesting blast injury. In addition, one bycaught animal and another porpoise with signs of blunt force trauma also showed evidence of blast injury. The cause of death of the other 14 animals varied and remained unclear in two individuals. Due to the vulnerability and the conservation status of harbour porpoise populations in the Baltic Sea, noise mitigation measures must be improved to prevent any risk of injury. The data presented here highlight the importance of systematic investigations into the acute and chronic effects of blast and acoustic trauma in harbour porpoises, improving the understanding of underwater noise effects and herewith develop effective measures to protect the population level.

Pre-hospital continuous positive airway pressure after blast lung injury and hypovolaemic shock: a modelling study.

BACKGROUND: In non-traumatic respiratory failure, pre-hospital application of CPAP reduces the need for intubation. Primary blast lung injury (PBLI) accompanied by haemorrhagic shock is common after mass casualty incidents. We hypothesised that pre-hospital CPAP is also beneficial after PBLI accompanied by haemorrhagic shock. METHODS: We performed a computer-based simulation of the cardiopulmonary response to PBLI followed by haemorrhage, calibrated from published controlled porcine experiments exploring blast injury and haemorrhagic shock. The effect of different CPAP levels was simulated in three in silico patients who had sustained mild, moderate, or severe PBLI (10%, 25%, 50% contusion of the total lung) plus haemorrhagic shock. The primary outcome was arterial partial pressure of oxygen (Pao2) at the end of each simulation. RESULTS: In mild blast lung injury, 5 cm H2O ambient-air CPAP increased Pao2 from 10.6 to 12.6 kPa. Higher CPAP did not further improve Pao2. In moderate blast lung injury, 10 cm H2O CPAP produced a larger increase in Pao2 (from 8.5 to 11.1 kPa), but 15 cm H2O CPAP produced no further benefit. In severe blast lung injury, 5 cm H2O CPAP inceased Pao2 from 4.06 to 8.39 kPa. Further increasing CPAP to 10-15 cm H2O reduced Pao2 (7.99 and 7.90 kPa, respectively) as a result of haemodynamic impairment resulting from increased intrathoracic pressures. CONCLUSIONS: Our modelling study suggests that ambient air 5 cm H2O CPAP may benefit casualties suffering from blast lung injury, even with severe haemorrhagic shock. However, higher CPAP levels beyond 10 cm H2O after severe lung injury reduced oxygen delivery as a result of haemodynamic impairment.

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.

Tinnitus after Blast Injury; a Prospective Study in Basrah, Iraq.

BACKGROUND: There is many civilians and soldiers who exposed to explosions in Iraq each month and they need an otolaryngological and audiological assessment. OBJECTIVE: To recognize the possible auditory insults and the recovery period of the acquired damages that may resulted from explosion and help for planning of optimal management strategies of otological manifestations and prevent undesirable consequences. PATIENTS AND METHODS: A prospective, descriptive study included forty-seven patients who were exposed to blast injuries within two weeks came to otolaryngology unit in Basrah Teaching Hospital complaining from otological symptoms from July 2017 tell January 2019. Three periodic assessments were done for each patient. An initial evaluation was done in the 1st visit included a detailed history and examination to evaluate the symptoms and assess the associated non-otological injury. An otological examination were done for all patients in the three visits, included microscopic ear examination, photos for the perforated tympanic membrane were taken to grade the perforations depending on their surface area, Pure tone audiometry and tympanometry. Thirty-eight patients were available to follow up in the 2nd and 3rd visits. RESULTS: All of the 47 patients were young and middle age male, hearing loss and tinnitus were the most presenting symptoms, which improved with time. Hearing impairment mostly in the high frequencies however there was improvement in the subsequent visits. The majority of patients (93.6%) presented with tympanic membrane perforation mostly grade I which usually healed spontaneously. There was a statistically significant associations between the degree of tympanic membrane perforation and associated nonotological injuries and with the explosions if occurred in closed space. CONCLUSION: Blast related otological injury constitute the main cause of morbidity as the ear is the most sensitive organ to explosive blast injury. Hearing loss was the dominant symptoms at presentation mainly in high frequencies, but fortunately most of patients improved with time. Tympanic membrane perforation constituted the mostly seen sign, however spontaneous healing can be expected in the majority of cases.