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EMERGENCY MEDICINEPRACTICE.EBMEDICINE NETAN EVIDENCE-BASED APPROACH TO EMERGENCY MEDICINEBlast Injuries:Preparing ForThe InevitableApril 2006Volume 8, Number 4AuthorCharles Stewart, MD, FAAEM, FACEPEmergency Physician—Colorado Springs, CO.Peer ReviewersYou have been working the evening shift in a Midwestern hospital and are preparing to leave at 7 am. It’s been a quiet night, and you haven’t used the “Q” wordonce. You are online reading about the improvised explosive devices (IEDs) beingused in Iraq, when the phone rings. The nurse hands it to you, saying “it’s for mediccommand.” They have had an explosion at the grain storage facility on the other sideof town, about 10 miles away. You take the phone and tell the charge nurse to contact the hospital administrator (he’s the first number on the disaster call-up roster).The dispatcher says details are still sketchy, but the grain plant exploded just as the18-person day crew assembled for the day’s work. There are at least 4 known dead,with an unknown number of casualties. Fire has 4 trucks responding, and theyhave asked for activation of the local disaster plan. The first truck on the scene hasrequested 6 additional ambulances from county and mutual aid support. The medicon the scene is triaging and says that he will have at least 10 more casualties fromthis explosion. Quiet time is over. You take a deep breath and get ready to receivemultiple simultaneous casualties.OAndy Jagoda, MD, FACEP, Professorand Vice-Chair of AcademicAffairs, Department of EmergencyMedicine; Residency ProgramDirector, Mount Sinai School ofMedicine, New York, NY.Associate EditorJohn M Howell, MD, FACEP, ClinicalProfessor of Emergency Medicine,George Washington University,Washington, DC; Director ofAcademic Affairs, Best Practices,Inc, Inova Fairfax Hospital, FallsChurch, VA.Editorial BoardWilliam J Brady, MD, AssociateProfessor and Vice Chair,Department of EM, University ofVirginia, Charlottesville, VA.Peter DeBlieux, MD, LSUHSCProfessor of Clinical Medicine;John M Howell, MD, FACEPClinical Professor of Emergency Medicine, GeorgeWashington University, Washington, DC; Director ofAcademic Affairs, Best Practices, Inc, Inova FairfaxHospital—Falls Church, VA.CME ObjectivesUpon completing this article, you should be able to:1.2.UR knowledge of the effects of blast injury dates from the Balkan warsin 1914, when Franchino Rusca, a Swiss researcher, observed 3 soldierswho had been killed by an explosion without evidence of any external injuries.1 Rusca went on to use rabbits as an animal model and demonstratedthat the cause of death was pulmonary embolism. During WWI, blast injurywas thought to be a nervous system disorder and labeled “shell shock.” (Atthat time, psychological casualties were lumped together with those whohad no visible injuries.)2In WWII, a noteworthy number of casualties were found among civilians in both German and British cities after bombing raids. “Blast lung” wasthe term coined for massive pulmonary hemorrhage from disruption of thealveolar architecture and formation of alveolar-venous fistulas resulting inair embolism.3 Following WWII, blast injury was intensively investigated inEditor-in-ChiefAndy Jagoda, MD, FACEPProfessor and Vice-Chair of Academic Affairs,Department of Emergency Medicine; ResidencyProgram Director, Mount Sinai School of Medicine—New York, NY.LSU Health Science Center, NewOrleans, LA.Wyatt W Decker, MD, Chair andAssociate Professor of EM, MayoClinic College of Medicine,Rochester, MN.Francis M Fesmire, MD, FACEP,Director, Heart-Stroke Center,Erlanger Medical Center; AssistantProfessor, UT College of Medicine,Chattanooga, TN.Michael J Gerardi, MD, FAAP, FACEP,Director, Pediatric EM, Children’sMedical Center, Atlantic HealthSystem; Department of EM,Morristown Memorial Hospital, NJ.Michael A Gibbs, MD, FACEP, Chief,Department of EM, Maine MedicalCenter, Portland, ME.Steven A Godwin, MD, FACEP,Assistant Professor and EMResidency Director, University ofFlorida HSC/Jacksonville, FL.Gregory L Henry, MD, FACEP, CEO,Medical Practice Risk Assessment,Inc; Clinical Professor of EM,University of Michigan, Ann Arbor.Keith A Marill, MD, Instructor, Department of EM, Massachusetts GeneralHospital, Harvard Medical School,Boston, MA.Charles V Pollack, Jr, MA, MD, FACEP,Chairman, Department of EM,Pennsylvania Hospital, Universityof Pennsylvania Health System,Philadelphia, PA.Michael S Radeos, MD, MPH, AssistantProfessor of Emergency Medicine,Lincoln Health Center, Bronx, NY.Robert L Rogers, MD, FAAEM,Assistant Professor and Residency Director, Combined EM/IMProgram, University of Maryland,Baltimore, MD.Alfred Sacchetti, MD, FACEP,Assistant Clinical Professor,3.4.5.Present the physics of an explosion in order tounderstand the consequent injuries that result;Differentiate high-order from low-orderexplosives and other types of explosive to helpthe clinician understand the potential medicalinjuries;Provide a systematic approach to triage andmanagement of victims of blast injuries;Discuss both the immediate and delayed medicalinjuries that can result from a blast exposure; andDiscuss operational issues related to activating adisaster plan subsequent to a blast-related masscasualty.Date of original release: April 10, 2006.Date of most recent review: April 1, 2006.See “Physician CME Information” on back page.Department of EM, ThomasJefferson University, Philadelphia,PA.Corey M Slovis, MD, FACP, FACEP,Professor and Chair, Department ofEM, Vanderbilt University MedicalCenter, Nashville, TN.Jenny Walker, MD, MPH, MSW,Assistant Professor; Division Chief,Family Medicine, Departmentof Community and PreventiveMedicine, Mount Sinai MedicalCenter, New York, NY.Ron M Walls, MD, Chairman,Department of EmergencyMedicine, Brigham & Women’sHospital; Associate Professor ofMedicine (Emergency), HarvardMedical School, Boston, MA.Research EditorsJack Choi, MD, Mount Sinai EmergencyMedicine Residency.Beth Wicklund, MD, Regions HospitalEmergency Medicine Residency,EMRA Representative.International EditorsValerio Gai, MD, Senior Editor,Professor and Chair, Department ofEmergency Medicine, University ofTurin, Italy.Peter Cameron, MD, Chair, EmergencyMedicine, Monash University; AlfredHospital, Melbourne, Australia.Amin Antoine Kazzi, MD, FAAEM,Associate Professor and Vice Chair,Department of Emergency Medicine,University of California, Irvine;American University, Beirut, Lebanon.Hugo Peralta, MD, Chair of EmergencyServices, Hospital Italiano, BuenosAires, Argentina.Maarten Simons, MD, PhD, EmergencyMedicine Residency Director,OLVG Hospital, Amsterdam, TheNetherlands.
the United States, due to the perceived threat of nuclearwarfare. But it is only since the advent of terroristsuicide bombings that civilian physicians have becomesignificantly concerned about the cause and treatment ofblast injuries.2 Unfortunately, the threat of suicide bombing seems to have spread from the Near East to the FarEast and back to Europe, as evidenced by both the Madridand London attacks. The obvious concern is when, not if,the practice will spread to the United States.Prior to 1995, most civilian emergency physiciansin the US had neither experience of nor interest in theeffects of explosive devices. This changed abruptly withthe destruction of the Alfred P Murrah Federal Building by a truck bomb — the 1995 blast rocked downtownOklahoma City and resulted in more than 750 casualties,with 167 fatalities.4 Unfortunately, many smaller devicesare exploded each year in the United States.5-7 As a resultof the casualties associated with September 11, 2001, moreUS physicians have had to face the specter of explosionand blast injuries filling their own EDs.8,9 The London andMadrid bombings (on July 7, 2005 and March 11, 2004,respectively) have forced physicians in other countries toconsider or reconsider their potential roles in explosionsand blast injuries due to terrorism.Bombings are clearly the most common cause ofcasualties from terrorist incidents.10 Recent terror tacticsinclude an increasing use of suicidal/homicidal bomberswho deliberately accompany the explosive device (oftenwearing it) to ensure its maximum effect.11 These bombers have walked or driven into buses, subways, cafes,residential areas, guard posts, and governmental buildings. The use of suicide devices in the US has yet to occur,but given the political climate, the scenario is very likely.Increasingly, information resources, such as the Internet,terrorist training camps, and even library and televisionsources, have made the knowledge needed to constructthese simple and very effective explosive devices readilyavailable.Research on blast injury is not a new study for thoseinterested in combat medicine. This issue of EmergencyMedicine PRACTICE will review the current literature,including the potential mechanisms of injury, early signsof these injuries, and the natural course of the problemscaused by explosive blasts.LE — Low-order explosivePETN — Pentaerythritol tetranitrate (explosive)RDX — Royal demolition explosiveTATP — Triacetone triperoxide, also called TCAP or acetone peroxide (non-nitrate high explosive)TM — Tympanic membraneTNT — Trinitrotoluene (explosive)Critical Appraisal Of The LiteratureFor this review, MEDLINE , Ovid, BestBETs (BestEvidence Topics), Google Scholar, and Google were allsearched using the terms blast injury, explosions, bombings, and explosives. The terms were used in Boolean combination and separately in each database, as appropriate.As might be expected, there were no prospective,randomized, placebo-controlled studies of any treatment.There were, however, multiple retrospective studies,analyses of case reports, animal studies, and many individual case reports and short series. The literature of blastinjuries is replete with case reports and data mining fromtrauma registries. There are few meta-analyses and evenfewer prospective studies. This is due partly to the natureof the injury: sudden, random, and unpredictable. Anotherreason is the dispersion in both time and space of thesekinds of injuries. Although recent bombings have had awidespread effect, they generally do not occur in the samelocation frequently enough to start a randomized studyof any treatment methodology. (Figure 1) The exceptionswould be England and Ireland in the 1980s and 1990s, andthe present-day Middle East, specifically Israel and the USmilitary in Iraq. (All of these exceptions are due to a markedly increased number of bombings in a short period oftime in the given locales.) Many of the case reports cited inthis article are from researchers in England, Israel, and theUnited States military. There are no evidence-based ATLSdata about bombings and explosive injuries. The militaryFigure 1. Historic location of United Statesbomb incidents.Abbreviations Used in This ArticleAGE — Arterial gas embolismANFO — Ammonium nitrate-fuel oil (explosive)ATF — Bureau of Alcohol, Tobacco, Firearms and ExplosivesBLEVE — Boiling liquid expanding vapor explosionCT — Computed tomographyC-4 — Composition C-4 (explosive)DPL — Diagnostic peritoneal lavageFAST — Focused abdominal sonography for traumaFBI — Federal Bureau of InvestigationHE — High-order explosiveIED — Improvised explosive deviceEmergency Medicine Practice 20062EBMedicine.net April 2006
has trauma registries, but this information is not open topublic scrutiny. There is a published summary of the jointUS Navy-Marine Corps Combat Trauma Registry available at http://www.stormingmedia.us.Figure 2. Illustration of primary, secondary,and tertiary injury from blast.Epidemiology And EtiologyAn explosion is an event that occurs when a substancerapidly releases energy and produces a large volumeof gaseous products. High-explosive, thermobaric, andnuclear detonations all provide this change in potentialenergy to kinetic injury in a very short period of time. Theextreme compression of molecules by this change in energy creates the blast wave that moves outward from theepicenter of the blast. These blast waves travel faster thanthe speed of sound. Blast products — gas, particles, debrisof the container, and items in proximity to the explosive(including human remains) — also spread outward, buttravel much more slowly. Both the blast wave and theblast products can cause injuries as described below.Trauma caused by explosions traditionally has beencategorized according to the following scheme: injurycaused by the direct effect of the blast wave (primary injuries); effects caused by other objects that are acceleratedby the explosive wave (secondary injuries); effects causedby movement of the victim (tertiary injuries); and miscellaneous effects caused by the explosion or explosives(sometimes termed quaternary injuries). (Figure 2)The injury pattern following an explosion is partlyrandom. Explosions have the potential to cause multisystem injuries involving multiple patients simultaneously.The trauma that results from an explosion depends on thecombination of the size of the explosive charge, the natureof the explosive, the container and surrounding or contained items, any shielding or protective barriers betweenthe victim and the explosion, the surrounding environment, the method of delivery, and the distance betweenthe explosion and the victim.Illustration by Charles Stewart, MD. Used with permission ofthe author, 2006, Charles Stewart. All rights reserved.monly called fuel-air explosives) are either gases mixedwith air or finely divided particles or droplets suspendedin air. Explosives are categorized as either high- or loworder, and they cause somewhat different injury patterns.The explosive effects of nuclear weapons will not bediscussed in this article.High-order ExplosivesHigh-order explosives (HE) are chemical materials thathave an extremely high reaction rate. This reaction is oftencalled a detonation. (Table 1)When a high explosive detonates, it is convertedalmost instantaneously into a gas at very high pressureand temperature. For example, the major ingredient incomposition C-4 or RDX (cyclotrimethylenetrinitramine)can generate an initial pressure of over 4 million poundsper square inch (4x106 psi).12 These high-pressure gasesrapidly expand from the original volume and generate amarked pressure wave — the “blast wave” — that movesoutward in all directions. The result is a sudden, shattering blow on the immediate surroundings.Nature of ExplosivesA conventional explosion is the rapid chemical conversionof a solid or liquid into gas. Thermobaric explosives (com-Table 1. High-Order Explosives. NitroglycerineDynamiteC-4 (Composition C-4 is a plastic explosive mixture of RDX explosive, plastic binders, and plasticizers)Picric acidSemtex is a general-purpose plastic explosive (first made by the Semtin Glassworks in the former Czechoslovakia, hence thename). It is similar to the US composition C-4 in characteristics and use.Dynamite (A mixture of diatomaceous earth and nitroglycerin patented by Alfred Nobel in 1867)Ammonium nitrate-fuel oil (ANFO) mixtureTNT (trinitrotoluene)PETNTATP (triacetone triperoxide, a nonnitrate high explosive)April 2006 EBMedicine.net3Emergency Medicine Practice 2006
High explosives are further categorized as primaryand secondary high explosives. The primary-high explosive is very sensitive, can be detonated very easily, andgenerally is used only in primary and electrical detonators. Secondary high explosives are less sensitive, requirea high-energy shock wave to achieve detonation, and aregenerally safer to handle.The blast wave refers to an intense rise in pressure— often called “overpressure” — that is created by thedetonation of a high explosive.2 A typical pressure wavefrom a high explosive explosion in air is shown in Figure 3.The blast wave transfers energy to objects or bodies inits path. The extent of damage due to the pressure wave isdependent on: rapidity with which an explosive develops its maximumpressure) — a quality that varies from high explosive tohigh explosive. When craters are formed at the site of anexplosion, this shock wave has disintegrated the materialclose to the explosion. Because the explosive gases continue to expand outward, the pressure wave rapidly deteriorates into an acoustic wave. Until the wave deterioratesenough to completely engulf the body simultaneously,tissue damage will depend on both the magnitude of thepressure spike and the duration of the force (representedby the area under the curve).A blast wave that would cause only modest injury inthe open can be lethal if the victim is in a confined area ornear a reflecting surface, such as a solid wall or a building.2 If the pressure wave is near a solid barrier, the pressure exerted at the reflecting surface may be many timesthat of the incident blast wave.For a single, sharp rising blast wave caused by detonation of a high explosive, the damage to human structures is a function of the peak pressure and the durationof the initial positive phase. The greatest energy transferoccurs at points where tissue density changes. Energytransfer at a bone/soft tissue interface may partiallyamputate limbs.13 Figure 5 illustrates the estimated blastlevels needed to cause damage in humans.Blast wind refers to the rapid bulk movement of airand other gases from the explosion site. It occurs withboth low-order and high-order explosives. Some explosives are manufactured to produce a relatively low-energyblast wave, but large amounts of gaseous products. Theseexplosives produce a sustained blast wind and localizedheaving with minimal blast. They are particularly usefulin mining and demolition projects.The peak of the initial positive pressure wave (anoverpressure of 60-80 psi is considered potentiallylethal)The duration of the overpressureThe medium in which it explodesThe distance from the incident blast waveFocusing due to a confined area or wallsAs shown in Figure 4, the blast wave has 3 components:1.2.3.A single spike of increased pressure. The leadingedge of the blast wave is called the blast front andis represented by this spike. The actual blast waveis only a few millimeters thick. This spike is also themost important factor in the pathology of primaryblast injury.An exponential decay with time.A much longer duration negative pressure wave, withpressure below initial ambient pressure.In air, the peak pressure is proportional to the cuberoot of the weight of explosives and inversely proportionalto the cube of the distance from the detonation.This shock wave can be so abrupt that it shatters materials. This effect is termed brisance (the measure of theLow-order ExplosivesLow-order explosives are designed to burn and subse-Figure 4. Pressure-time graph of blast wave.Figure 3. Blast waves from explosion.Idealized representation of pressure-time history of an explosion in air.Courtesy Harald Kleine. Used with permission, 2006, HaraldKleine. All rights reserved.Courtesy Virtual Naval Hospital, Emergency War SurgeryNATO Handbook. Available at: http://www.vnh.org.Emergency Medicine Practice 20064EBMedicine.net April 2006
quently release energy relatively slowly. These explosivesare often called propellants, because their most commonuse is to propel a projectile through the barrel of a weapon.The principle military uses for low-order explosives areas propellants and in fuses. Typical improvised low-orderexplosives include pipe bombs, gunpowder, black powder,and petroleum-based bombs, such as Molotov cocktails orgasoline tankers. Since low-order explosives do not formshock waves, they do not have the quality of brisance.The process of rapid, progressive burning of a loworder explosive is called deflagration. This burning takesplace so slowly that when the low-order explosive is setoff in the open, the gases push aside the air with only aflame and no appreciable disturbance. If the low-orderexplosive is confined, the speed of the reaction is markedly increased, but does not approach that of a high-orderexplosion. The explosion has more of a pushing effect thana shattering effect (ie, blast wind without a blast wave).The explosion from low-order devices lacks the overpressure wave; thus, injuries are due to ballistics (fragmentation), blast wind from the expansion of the gases, andthermal injuries from the heat of the explosion. Obviously,it is clinically impossible to tell whether fragment woundshave occurred because the fragment was propelled by ahigh-order versus a low-order explosive. Likewise, if thevictim is flung by a blast wind into a structure, it matterslittle to either the patient or the clinician that the explosion occurred from detonation of a high-order explosive ordeflagration of a low-order explosive.Table 2. Thermobaric/Fuel-Air Explosives. construction areas* Slowly escaping natural (or other flammable) gases† BLEVE (Boiling Liquid-Expanding Vapor Explosions)‡14*Many materials form dust clouds that can ignite and explode, injuringpersonnel and damaging equipment. This is a well-publicized occurrencein the coal mining, grain storage, and the woodworking and paper industries. Many miners have been killed and injured and massive productionlosses have resulted from coal dust explosions in underground coalmining operations. Between 1987 and 1997, 129 grain dust explosionsoccurred nationwide. Of these dust explosions, about half involved cornand corn products, while 11 were caused by wheat dust and 10 by dustfrom soybeans.†A Google search on this topic yielded over 265,000 entries.‡A BLEVE is a type of pressure-release explosion that occurs when liquefied gases, which are stored in containers at temperatures above theirboiling points, are exposed to the atmosphere, causing rapid vaporization. The result is the mixing of vapor and air that results in the characteristic fireball that occurs when the fire ignites the vapor. This happenswhen a container fails or is ruptured by an accident. A BLEVE can alsooccur when flame impinges on the tank shell at a point or points abovethe liquid level of the tank’s contents. The heat from the fire causes themetal to weaken and fail as the internal pressure increases.the explosive effects of this device. (Table 2)Since these explosive mechanisms are not uncommon in the civilian world, the emergency physician needsto know the special effects of this form of explosive. Anastute terrorist could use these mechanisms to create amassive explosion.In the military device, mixture of the fuel with airover the target may be accomplished by a dispersalcharge. After the munition is dropped or fired, the firstexplosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixeswith atmospheric oxygen (the size of the cloud varies withthe size of the munition). The cloud of fuel flows aroundobjects and into structures. After the fuel and air aremixed, a second detonation provides the spark needed forignition.There are dramatic differences between explosionsinvolving fuel-air mixtures and high explosives at closedistances. The shock wave from a trinitrotoluene (TNT)explosion is of relatively short duration, while the blastwave produced by an explosion of fuel-air mixture displays a relatively long duration. The duration of the positive phase of a shock wave is an important parameter inthe response of structures to a blast. The temperature canbe as high as 3000 C — more than twice that generatedby a conventional explosive. The blast wave can travel atapproximately 10,000 feet per second.The blast effects from vapor cloud explosions aredetermined not only by the amount of fuel, but moreimportantly by the combustion mode of the cloud. Mostvapor cloud explosions are deflagrations, not detona-Special ExplosivesThermobaric or Fuel-Air ExplosivesIn this explosive device, a substantial quantity of fuel isvaporized and mixed with air. Fuel-air explosives represent the military application of the vapor cloud explosionsand dust explosion accidents that have long plagued avariety of industries. Firefighters are all too familiar withFigure 5. Estimated blast energy needed tocause damage in humans.Courtesy Virtual Naval Hospital, Emergency War SurgeryNATO Handbook. Available at: http://www.vnh.org.April 2006 EBMedicine.netDust/air mixtures in grain silos and other storage or5Emergency Medicine Practice 2006
tions.15 Flame speed of a deflagration is subsonic, withflame speed increasing in restricted areas and decreasingin open areas.Flame propagation speed has a significant influenceon the blast parameters, both inside and outside the sourcevolume. High flame front speeds and resulting high blastoverpressures are seen in accidental vapor cloud explosions, where there is a significant amount of confinementand congestion that limits flame front expansion andincreases flame turbulence. These conditions are more difficult to achieve in the unconfined environment in whichmilitary fuel-air explosives are intended to operate.Since the fuel uses up the atmospheric oxygen,asphyxia for those who are not immediately killed bythe explosive device can be a problem. Likewise, sincethe temperature of the burning fuel is greater than thatof conventional explosives, extensive burns can occur insurvivors.front of a shaped explosive charge. These explosive devices with wide-angle cones and other liner shapes, suchas plates or dishes, do not jet, but instead give an explosively formed projectile. (Figure 7) When the explosive isdetonated, the shock wave deforms the liner in a presetway to create a symmetric projectile traveling at very highspeeds. Varying the liner shape and explosive confinement changes the shape and velocity. These sophisticateddevices have been used in Iraq against Allied forces. Theyroutinely defeat armor and can cause significant injuries.(Figure 8)Source of ExplosiveExplosive devices may also be characterized based ontheir source. The Bureau of Alcohol, Tobacco, Firearmsand Explosives (ATF) categorizes explosives into “manufactured” and “improvised.” A “manufactured” explosiveimplies a standard, mass-produced, and quality-testedweapon. “Improvised” describes the use of alternative materials, weapons produced in small quantities, or a devicethat is used outside of its intended purpose. Improvisedexplosive devices (IEDs) may be professional in appearance, and their operation may be quite lethal, if designedby someone with training in explosives. (Note that by thisdefinition, any experimental explosive device is an “improvised” device, since it is not set to standards, mass-produced, and quality-tested. This rather unwieldy definitionencompasses all experimental military devices producedby professional arms manufacturers.)Improvised explosive devices (and many militarymunitions) can be triggered in a variety of ways, including electronic transmitters and switches, tilt switches,thermal switches, and various types of motion detectors.Improvised weapons vary in quality of the explosive used,from commercial explosives, TNT, Semtex, C-4, ammoniabased fertilizer, and fuel oil (used widely as an industrialexplosive) to a simple, match-filled pipe bomb. High-quality IEDs may resemble military weapons in effect andappearance. The variety of initiation methods, explosivefillings, and fabrication techniques creates a threat that canbe quite daunting to the professional explosive ordinanceExplosively Formed Projectiles and Shaped ChargesCharles Edward Munroe coined the term “The Munroe Effect” in 1885. He noted that a high explosive with a cavityfacing a target left an indentation. The earliest known reference to the effect appears to be 1792, and there is someindication that mining engineers may have exploited thephenomenon over 150 years ago. A typical shaped chargeconsists of a solid cylinder of explosive with a conicalhollow on one end, lined with a dense ductile metal, suchas copper. (Figure 6) When detonated from the other end,the force of the explosive detonation wave is great enoughto project the copper into a thin, effectively liquid stretching that has a tip speed of up to 12 km/sec. The enormouspressures generated cause the target material to yield andflow plastically.Explosively formed projectiles (EFPs) are related toshaped charges, but form a fragment rather than a jet. Acomputer-designed, dish-shaped metal liner is placed inFigure 6. Shaped charge.Figure 7. Explosively formed projectile.Emergency Medicine Practice 20066EBMedicine.net April 2006
disposal crew.Recent improvised devices have been manufacturedwith nonnitrogen explosives (TATP) in order to defeatexplosive sniffing devices and dogs. These nonnitrogenexplosives are often quite unstable and may spontaneously detonate — this means that, no matter how innocuous an improvised device may appear, the amateur shouldnever touch the device.air; this jumps to 49% when the blast occurs in a confinedspace. One meta-analysis reported a 70% incidence ofminor soft tissue injuries.21 Traumatic amputations willoccur in about 11% of cases. Traumatic amputations serveas a marker of severe multisystem trauma and subsequenthigh mortality.13 The World Trade Center was an exceptionin that most victims had either few injuries or died as thebuilding crashed down on them.Medium in Which the Explosion OccursPrimary Blast InjuryAnother important factor that defines blast injury patternsis the medium in which the blast occurs. An underwaterblast wave causes far more damage, because water isessentially incompressible.2,16 A wave resulting from anunderwater blast travels farther and moves faster than awave from a similar explosion in the air. Blast injuries inwater occur at greater distances and may be much moresevere.17,18 Personnel treading water are at higher risk forabdominal than thoracic injury from an underwater explosion. Fully submerged victims are at equal risk of combined thoracic and abdominal blast injuries, but the blastinjury occurs at 3 times the distance from the underwaterexplosion.19Another characteristic of blast waves i
Discuss both the immediate and delayed medical injuries that can result from a blast exposure; and . OUR knowledge of the effects of blast injury dates from the Balkan wars in 1914, when Franchino Rusca, a Swiss researcher, observed 3 soldiers . “Blast lung” was the term coine
8000 7200 11.9 49.1 91.9 139 189 29.8 91.9 164 242 Eaton 9155 8-15 kVA UPS Backup Times (In Minutes) VA Watt UPS Internal 32 Battery (1) EBM 64 (2) EBM 64 (3) EBM 64 (4) EBM 64 UPS Internal 64 Battery (1) EBM 96 (2) EBM 96 (3) EBM 96 7500 6750 13.1 53.2 99.7 151 205 32.3 99.7
Blast injuries occur through multiple mechanisms.12 13 15 1njuries directly related to the initial blast wave are referred to as primary blast injuries. In addition to primary injuries, the blast wind that follows the overpressure wave can propel objects including shrapnel contained within the lED, causing secondary injury.
Workplace fatal injuries in Great Britain 2018 Contents Summary 2 Introduction 3 Fatal injuries to workers 3 Headline figures 3 Injuries by industry 4 Injuries by accident kind 6 Injuries by gender and age 7 Injuries by employment status 8 Injuries by country within GB 9 Injury comparison with other countries 10 .
Prevalence and Epidemiology of Combat Blast Injuries from the Military Cohort 20012014- . VA ESP Project #09-009; 2016. . Overview of Study Characteristics - Key Question 3 . 8 Executive Summary Table 4. Overview of Outcomes According to Blast versus Non-blast TBI .
Workplace fatal injuries in Great Britain, 2019 Contents Summary 2 Introduction 3 Fatal injuries to workers 3 Headline figures 3 Injuries by industry 4 Injuries by accident kind 6 Injuries by gender and age 7 Injuries by employment status 8 Injuries by country within GB 9 Injury comparison with other countries 10 .
of rupture of the TM, primary blast injuries on other air-con-taining organs are less likely. For example, in the Madrid train bombings, of 17 critically ill victims with lung injuries from the blast, 13 had ruptured TMs and four did not.3,7,8 A graphic depiction of TM rupture is shown in Figure 4. Figure 3: Effect of peak pressure
should help guide the overall program toward an ecosystem-based approach. EBM is a process to achieve a certain result; therefore, EBM should not be undertaken simply for the sake of doing EBM. Instead it should ta
Use the English phonemic alphabet page, which you find at the beginning of good dictionaries, as a guide to pronouncing new words. Effective English Learning ELTC self-study materials Tony Lynch and Kenneth Anderson, English Language Teaching Centre, University of Edinburgh 2012 9 3. Don't forget to learn the word stress of a new word. Every English word has its own normal stress pattern. For .
