Injury scoring systems for blast injuries: a narrative review.

Injury scoring systems can be used for triaging, predicting morbidity and mortality, and prognosis in mass casualty incidents. Recent conflicts and civilian incidents have highlighted the unique nature of blast injuries, exposing deficiencies in current scoring systems. Here, we classify and describe deficiencies with current systems used for blast injury. Although current scoring systems highlight survival trends for populations, there are several major limitations. The reliable prediction of mortality on an individual basis is inaccurate. Other limitations include the saturation effect (where scoring systems are unable to discriminate between high injury score individuals), the effect of the overall injury burden, lack of precision in discriminating between mechanisms of injury, and a lack of data underpinning scoring system coefficients. Other factors influence outcomes, including the level of healthcare and the delay between injury and presentation. We recommend that a new score incorporates the severity of injuries with the mechanism of blast injury. This may include refined or additional codes, severity scores, or both, being added to the Abbreviated Injury Scale for high-frequency, blast-specific injuries; weighting for body regions associated with a higher risk for death; and blast-specific trauma coefficients. Finally, the saturation effect (maximum value) should be removed, which would enable the classification of more severe constellations of injury. An early accurate assessment of blast injury may improve management of mass casualty incidents.

Tympanic membrane perforation impact on severity of injury and resource use in victims of explosion.

PURPOSE: Though tympanic membrane perforation (TMP) is a marker of barotrauma, relation to severity of injury has been contested based on previous observations that following an explosion many victims with significant injuries do not suffer from TMP while many victims with TMP do not suffer from significant injuries. The objective of this study was to reassess the relationship of TMP to severity of injury and resource demand in patients treated in multiple casualty incidents following terrorist bombings treated in one medical center. METHODS: Retrospective review. RESULTS: Most of the patients with TMP were mildly injured. Nevertheless, TMP was more prevalent in patients with moderate and severe injuries, 53.3 % compared to 13.6 % in mildly injured patients (p = 0.0009). Patients with TMP suffered from more body areas injured (p < 0.0001). They more often needed surgery (30.6 vs. 5.5 %; p < 0.0001), ICU hospitalization (16.1 vs. 1.3 %; p < 0.0001) and secondary transfer to a level I trauma center (12.9 vs. 1.0 %; p < 0.0001). They were hospitalized longer (p < 0.0001). Fifty-three (12.6 %) patients included in this study were not examined by the ENT service. Most of those not examined were either moderately or severely injured. CONCLUSIONS: Patients with TMP were more severely injured and more often needed surgery, ICU hospitalization and need for transfer to a level I trauma center. The observation that all those who died in hospital and most of those who were unstable were not examined by the ENT services suggests that impact of TMP as an indicator of severity may be underestimated.

A descriptive analysis of injury triage, surge of medical demand, and resource use in an university hospital after 8.12 Tianjin Port Explosion, China.

OBJECTIVE: The 8.12 Tianjin Port Explosion in 2015 caused heavy casualties. Pingjin Hospital, an affiliated college hospital in Tianjin, China participated in the rescue activities. This study aims to analyze the emergency medical response to this event and share experience with trauma physicians to optimize the use of medical resource and reduce mortality of critical patients. METHODS: As a trauma centre at the accident city, our hospital treated 298 patients. We retrospectively analyzed the data of emergency medical response, including injury triage, injury type, ICU patient flow, and medical resource use. RESULTS: There were totally 165 deaths, 8 missing, and 797 non-fatal injuries in this explosion. Our hospital treated 298 casualties in two surges of medical demand. The first one appeared at 1 h after explosion when 147 wounded were received and the second one at 4 h when 31 seriously injured patients were received, among whom 29 were transferred from Tianjin Emergency Center which was responsible for the scene injury triage. After reexamination and triage, only 11 cases were defined as critical ill patients. The over-triage rate reached as high as 62.07%. Seventeen patients underwent surgery and 17 patients were admitted to the intensive care unit. CONCLUSIONS: The present pre-hospital system is incomplete and may induce two surges of medical demand. The first one has a much larger number of casualties than predicted but the injury level is mild; while the second one has less wounded but almost all of them are critical patients. The over-triage rate is high. The hospital emergency response can be improved by an effective re-triage and implementation of a hospital-wide damage control.

A prospective observational study of abdominal injury management in contemporary military operations: damage control laparotomy is associated with high survivability and low rates of fecal diversion.

OBJECTIVE: This study describes the cause, management, and outcomes of abdominal injury in a mature deployed military trauma system, with particular focus on damage control, hollow visceral injury (HVI), and stoma utilization. BACKGROUND: Damage control laparotomy (DCL) is established in military and civilian practice. However, optimal management of HVI during military DCL remains controversial. METHODS: We studied abdominal trauma managed over 5 months at the Joint Force Combat Support Hospital, Camp Bastion, Afghanistan (Role 3). Data included demographics, wounding mechanism, injuries sustained, prehospital times, location of first laparotomy (Role 3 or forward), use of DCL or definitive laparotomy, subsequent surgical details, resource utilization, complications, and mortality. RESULTS: Ninety-four of 636 trauma patients (15%) underwent laparotomy. Military injury mechanisms dominated [44 gunshot wounds (47%), 44 blast (47%), and 6 blunt trauma (6%)]. Seventy-two of 94 patients (77%) underwent DCL. Four patients were palliated. Seventy of 94 (74%) sustained HVI; 44 of 70 (63%) had colonic injury. Repair or resection with anastomosis was performed in 59 of 67 therapeutically managed HVI patients (88%). Six patients were managed with fecal diversion, and 6 patients were evacuated with discontinuous bowel. Anastomotic leaks occurred in 4 of 56 HVI patients (7%) with known outcomes. Median New Injury Severity Score for DCL patients was 29 (interquartile range: 18-41) versus 19.5 (interquartile range: 12-34) for patients undergoing definitive laparotomy (P = 0.016). Overall mortality was 15 of 94 (16%). CONCLUSIONS: Damage control is now used routinely for battlefield abdominal trauma. In a well-practiced Combat Support Hospital, this strategy is associated with low mortality and infrequent fecal diversion.

Military trauma care in Birmingham: observational study of care requirements and resource utilisation.

BACKGROUND: The Royal Centre for Defence Medicine is located at University Hospitals Birmingham (UHB). Since 2001 all UK military casualties injured on active duty have been repatriated here for their initial treatment. This service evaluation was performed to quantify the work undertaken, with the aim of providing a snapshot of a year's military trauma work in order to inform the delivery of trauma care in both the military and civilian setting. METHODS: Military patients admitted with traumatic injuries over a 12-month period were identified and the hospital notes and electronic records reviewed. Data were collected focusing on three areas - the details of the injury, information about the in-patient admission, and surgical interventions performed. RESULTS: A total of 388 patients were used in the analysis. Median total length of stay was 10.5 days (IQR: 4-26, range: 0-137 days), and a median 6.0 days (IQR: 3.0-11.0, range: 1-49 days) was spent on intensive care by 125 patients. Surgical intervention was required for 278 (71.6%) patients, with a median of 2.0 operations (IQR: 1.0-4.0, range: 1-27) or 170 min (IQR: 90.0-570.0, range 20-4735 min) operating time per patient. 77% of these patients had their first procedure within 24h of arrival. Improvised explosives accounted for 50.5% of injuries seen. Spearman rank correlation between New Injury Severity Score with length of stay demonstrated significant correlation (p<0.001), with a coefficient of 0.640. A model predicting length of stay based on New Injury Severity Score was devised for patients with battle injuries. CONCLUSION: This report of 12 months work at UHB demonstrates the service commitment to these casualties, describing the burden of care and resource requirements for military trauma patients.

Primary blast survival and injury risk assessment for repeated blast exposures.

BACKGROUND: The widespread use of explosives by modern insurgents and terrorists has increased the potential frequency of blast exposure in soldiers and civilians. This growing threat highlights the importance of understanding and evaluating blast injury risk and the increase of injury risk from exposure to repeated blast effects. METHODS: Data from more than 3,250 large animal experiments were collected from studies focusing on the effects of blast exposure. The current study uses 2,349 experiments from the data collection for analysis of the primary blast injury and survival risk for both long- and short-duration blasts, including the effects from repeated exposures. A piecewise linear logistic regression was performed on the data to develop survival and injury risk assessment curves. RESULTS: New injury risk assessment curves uniting long- and short-duration blasts were developed for incident and reflected pressure measures and were used to evaluate the risk of injury based on blast over pressure, positive-phase duration, and the number of repeated exposures. The risk assessments were derived for three levels of injury severity: nonauditory, pulmonary, and fatality. The analysis showed a marked initial decrease in injury tolerance with each subsequent blast exposure. This effect decreases with increasing number of blast exposures. CONCLUSIONS: The new injury risk functions showed good agreement with the existing experimental data and provided a simplified model for primary blast injury risk. This model can be used to predict blast injury or fatality risk for single exposure and repeated exposure cases and has application in modern combat scenarios or in setting occupational health limits.

Survival risk assessment for primary blast exposures to the head.

Many soldiers returning from the current conflicts in Iraq and Afghanistan have had at least one exposure to an explosive event and a significant number have symptoms consistent with traumatic brain injury. Although blast injury risk functions have been determined and validated for pulmonary injury, there is little information on the blast levels necessary to cause blast brain injury. Anesthetized male New Zealand White rabbits were exposed to varying levels of shock tube blast exposure focused on the head, while their thoraces were protected. The specimens were euthanized and evaluated when the blast resulted in respiratory arrest that was non-responsive to resuscitation or at 4?h post-exposure. Injury was evaluated by gross examination and histological evaluation. The fatality data from brain injury were then analyzed using Fisher's exact test to determine a brain fatality risk function. Greater blast intensity was associated with post-blast apnea and the need for mechanical ventilation. Gross examination revealed multifocal subdural hemorrhages, most often near the brainstem, at more intense levels of exposure. Histological evaluation revealed subdural and subarachnoid hemorrhages in the non-responsive respiratory-arrested specimens. A fatality risk function from blast exposure to the head was determined for the rabbit specimens with an LD(50) at a peak overpressure of 750?kPa. Scaling techniques were used to predict injury risk at other blast overpressure/duration combinations. The fatality risk function showed that the blast level needed to cause fatality from an overpressure wave exposure to the head was greater than the peak overpressure needed to cause fatality from pulmonary injury. This risk function can be used to guide future research for blast brain injury by providing a realistic fatality risk to guide the design of protection or to evaluate injury.

Pulmonary injury risk assessment for long-duration blasts: a meta-analysis.

BACKGROUND: Long-duration blasts are an increasing threat with the expanded use of thermobaric and other novel explosives. Other potential long-duration threats include large explosions from improvised explosive devices, weapons caches, and other explosives including nuclear explosives. However, there are very few long-duration pulmonary blast injury assessments, and use of short-duration exposure injury metrics is inappropriate as the injury mechanism for long-duration exposures is likely different from that of short-duration exposures. METHODS: This study develops an injury model for long-duration (>10 milliseconds positive overpressure phase) blasts with sharp rising overpressures. For this study, data on more than 2,730 large animal experiments were collected from more than 55 experimental studies on blast. From this dataset, nearly 850 large animal experiments were selected with positive phase overpressure durations of 10 milliseconds or more. Various models were evaluated to determine the best fit of injury risk as a function of pressure and duration. A linear logistic regression was performed on the experimental data for threshold injury and lethality in terms of pressure and duration. The effects of mass, pressure, and duration scaling were all evaluated, and two goodness-of-fit indicators were used to assess the different models. RESULTS AND CONCLUSIONS: New injury risk assessment curves were determined for both incident and reflected pressure conditions for reflecting surface and free-field exposures. Position dependent injury risk curves were also determined. The resulting curves are an improvement to existing assessments, because they use actual data to demonstrate theoretical assumptions on the injury risk.

Impact of the terrorist bombings of the Hong Kong Shanghai Bank Corporation headquarters and the British Consulate on two hospitals in Istanbul, Turkey, in November 2003.

BACKGROUND: The authors sought to estimate the impact of the terrorist bombings of the Hong Kong Shanghai Banking Corporation headquarters and the British consulate in Istanbul, Turkey, on November 20, 2003, on two nearby hospitals, in terms of epidemiologic outcomes, resource utilization, and time course of emergency needs. METHODS: The authors used data from hospital records of injured survivors who used the emergency departments (EDs) at the Taksim Education and Research State Hospital (TERSH) and the American Hospital (AH) in Istanbul on November 20, 2003, to determine the totals and rates of mortality (early, late, and critical), injury, critical injury (Injury Severity Score > 15), ED use, hospitalization, operative care, and in-hospital overtriage and the time intervals of ED arrival. RESULTS: The TERSH received 184 victims in the first hour after the initial blast, of which 88 (48%) were brought by emergency medical services, 171 (93%) had lacerations, 7 (4%) had penetrating eye injuries, 28 (15%) were hospitalized, 18 (10%) received operative care, and 7 (4%) were critically injured. Three deaths occurred in critically injured survivors, including one early death in the operating room and two late deaths on days 5 and 6. The AH received 16 victims, of which 14 (88%) had lacerations, 3 (19%) were hospitalized, 2 (13%) received operative care, and 1 (6%) was critically injured. An additional 4 victims were transferred to the AH from other hospitals, of which 3 were hospitalized and none were critically injured. No early or late deaths occurred. CONCLUSION: Mortality, injury, and hospitalization rates at both hospitals were consistent with previous reports of open-air mass-casualty terrorist bombings. The TERSH experienced an unprecedented demand for ED surge capacity in an open-air bombing.

Mass-casualty terrorist bombings in Istanbul, Turkey, November 2003: report of the events and the prehospital emergency response.

BACKGROUND: This paper describes the two mass-casualty, terrorist attacks that occurred in Istanbul, Turkey in November 2003, and the resulting pre-hospital emergency response. METHODS: A complex, retrospective, descriptive study was performed, using open source reports, interviews, direct measurements of street distances, and hospital records from the American Hospital (AH) and Taksim Education and Research State Hospital (TERSH) in Istanbul. RESULTS: On 15 November, improvised explosive devices (IEDs) in trucks were detonated outside the Neve Shalom and Beth Israel Synagogues, killing 30 persons and injuring an estimated additional 300. Victims were maldistributed to 16 medical facilities. For example, AH, a private hospital located six km from both synagogues, received 69 injured survivors, of which 86% had secondary blast injuries and 13% were admitted to the hospital. The TERSH, a government hospital located 1 km from both synagogues, received 48 injured survivors. On 20 November, IEDs in trucks were detonated outside the Hong Kong Shanghai Banking Corporation (HSBC) headquarters and the British Consulate (BC), killing 33 and injuring an estimated additional 450. Victims were maldistributed to 16 medical facilities. For example, TERSH, located 18 km from the HSBC site and 2 km from the the BC received 184 injured survivors, of which 93% had secondary blast injuries and 15% were hospitalized. The AH, located 9 km from the HSBC site and 6 km from the BC, received 16 victims. CONCLUSION: The twin suicide truck bombings on 15 and 20 November 2003 were the two largest terrorist attacks in modern Turkish history, collectively killing 63 persons and injuring an estimated 750 others. The vast majority of victims had secondary blast injuries, which did not require hospitalization. Factors associated with the maldistribution of casualties to medical facilities appeared to include the distance from each bombing site, the type of medical facility, and the personal preference of injured survivors.

Social cost of land mines in four countries: Afghanistan, Bosnia, Cambodia, and Mozambique.

OBJECTIVES: To document the effects of land mines on the health and social conditions of communities in four affected countries. DESIGN: A cross design of cluster survey and rapid appraisal methods including a household questionnaire and qualitative data from key informants, institutional reviews, and focus groups of survivors of land mines from the same communities. SETTING: 206 communities, 37 in Afghanistan, 66 in Bosnia, 38 in Cambodia, and 65 in Mozambique. SUBJECTS: 174,489 people living in 32,904 households in the selected communities. MAIN OUTCOME MEASURES: Effects of land mines on food security, residence, livestock, and land use; risk factors: extent of individual land mine injuries; physical, psychological, social, and economic costs of injuries during medical care and rehabilitation. RESULTS: Between 25% and 87% of households had daily activities affected by land mines. Based on expected production without the mines, agricultural production could increase by 88-200% in different regions of Afghanistan, 11% in Bosnia, 135% in Cambodia, and 3.6% in Mozambique. A total of 54,554 animals was lost because of land mines, with a minimum cash value of $6.5m, or nearly $200 per household. Overall, 6% of households (1964) reported a land mine victim; a third of victims died in the blast. One in 10 of the victims was a child. The most frequent activities associated with land mine incidents were agricultural or pastoral, except in Bosnia where more than half resulted from military activities, usually during patrols. Incidences have more than doubled between 1980-3 and 1990-3, excluding the incidents in Bosnia. Some 22% of victims (455/2100) were from households reporting attempts to remove land mines; in these households there was a greatly increased risk of injury (odds ratio 4.2 and risk difference 19% across the four countries). Lethality of the mines varied; in Bosnia each blast killed an average of 0.54 people and injured 1.4, whereas in Mozambique each blast killed 1.45 people and wounded 1.27. Households with a land mine victim were 40% more likely to experience difficulty in providing food for the family. Family relationships were affected for around one in every four victims and relationships with colleagues in 40%. CONCLUSIONS: Land mines seriously undermine the economy and food security in affected countries; they kill and maim civilians at an increasing rate. The expense of medical care and rehabilitation add economic disability to the physical burden. Awareness of land mines can be targeted at high risk attitudes, such as those associated with tampering with mines.

An assessment of the current state-of-the-art of incapacitation by air-blast.

Target vulnerability methodology requires a criticality measure for all international components which contribute to a system or to a system's weapon effectiveness, including that of the human target. Such measures have been developed for personnel targets and for kinetic energy penetrators; however, there is presently no generally accepted quantitative measure of incapacitation to infantry or crew personnel from the prime blast threat. Vulnerability analysts presently use lethality data derived from Lovelace Foundation research to infer an incapacitation level for blast, but these criteria are not very realistic in that they tend to underestimate casualty production from blast threats. Thus, a generalized criteria for estimating incapacitation to military personnel from air blast overpressures is urgently needed to provide vulnerability analysts a realistic measure of blast effectiveness as well as to establish a common base for comparing incapacitation to personnel from blast and from kinetic energy threat mechanisms.