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Home , Blast injury, Blast wave, Destroyed in Seconds, Pressure cooker bomb

9/4/2014

Blast Objectives

• An Overview of the Effects of Blast Injuries at the • Describe the basic physics, mechanisms of , and Medical Level pathophysiology of blast injury • List the four types or categories of blast injuries • List the factors associated with increased risk of Presented by: Jay Wuerker, EMT-P primary blast injury EMS Instructor II

Objectives…cont. Why?

• Recognize the key diagnostic indicators of serious • Combat primary blast injury • Terrorism • State the most common cause of death following an • Accidents

Combat: Iraq & Terrorism: USS Cole

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Terrorism: ??? Terrorism

• Bombings are clearly the most common cause of casualties in terrorist incidents. • Recent terrorism has shown increasing numbers of suicidal bombers wearing or driving the device • A poor man’s guided missile!

Boston Marathon April 15, 2013 Pressure cooker device

• Pressure cooker device (2), form of an IED • “Inspire” magazine Summer 2010, “Make a in • Same type of device used in Mumbai train bombings the Kitchen of your Mom”, by “The AQ chef”. in 2006 and Time Square attempt in 2010 • Al-Qaeda publication article on the step by step • Often packed with nails, ball bearings and other small process for making a Pressure cooker bomb. metal objects

Boston Marathon Results

• Three killed, 264 wounded – many with amputations, scene described as a war zone • One Police officer killed in shoot out with bomber suspect

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Not in ?

• Steve Preisler - aka “Uncle Fester” , from Green Bay , graduated from Marquette University in 1981 with a degree in Chemistry and Biology. • Many books, including “Secrets of Methamphetamine Manufacture” and “Home Workshop ” • Has a website

MacGyver MacGyver Bombs cont.

• Park High school – October 2, 2012 • Chemicals used include Drain or Toilet bowl cleaners, • Plastic bottle – soda or water (different sizes) Calcium Hypochlorite or such items as Dry Ice • Use combination of a strong acid or base and things • Injury from blast effects and chemical that may cause like aluminum foil to create a gas that causes the or respiratory injury container to explode • Felony in many states

New Threats September 11, 2014

• ISIS – Islamic State of Iraq and Syria • ? • Estimated 100 US citizens belong to ISIS • 6000 missing foreign nationals on student visas in the US • Times Square and

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Accidents Accidents Grain elevator Fireworks Plant Explosion

First… A Little Theory Morton Thiokol …What Is An Explosive?

Destroyed in Seconds – Chemical Plant Explosion • There are four types… • High explosive • http://youtu.be/_KuGizBjDXo • Low explosives • Fuel-Air explosives • Nuclear Explosives

We won’t talk about nuclear …

Explosives High Order Explosives “HE” • Nitroglycerine • High order • Dynamite • • TNT – the “classic” • Blast formation (supersonic) • PETN – ‘det’ cord. • Low order • Deflagration • C-4 – familiar to all military • No blast wave formation (always subsonic) • Semtex (Warsaw pact version of C-4) • ANFO • Ammonium nitrate, fuel oil mixture

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High Order Explosives Low Order Explosives “HE” (Propellants)

• When a high explosive detonates, it is converted • Gunpowder instantaneously into a gas at high pressure and • Nitrocellulose temperature. • Smokeless powder • (This is also is a high explosive under certain • The expansion of these gases creates the blast wave. conditions) • Brisance is the shattering effect of the blast wave • Match heads • Multiple other compounds • Abnormal explosion of a high order explosive may occur

Deflagration Fuel-Air Explosives Low-Order Explosive Combustion (Thermobaric Weapons)

• Neither a high explosive nor a low order explosive • Has features of both • Most often has deflagration • May have supersonic detonation • May have much longer, broader blast wave than high explosive

Deflagration is very rapid burning…. The speed is increased by confinement

Thermobaric Weapons Fuel-Air Mixtures Fuel-Air Mixtures (not just military explosives)

• Particularly effective in enclosed spaces • Fireball and blast can travel around corners • Blast are intensified when reflected by walls and other surfaces. • Grain/dust explosions • Optimized to produce heat and blast • BLEVE • Secondary effects through flying fragments • Toxic detonation gases • Boiling Liquid Expanding • Anoxia Vapor Explosion • Slow escape of natural or LP gas

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IED IED (A very, very bad terminology) Has many shapes

• Improvised Explosive Device • ANY device that doesn’t have a military issue number…somewhere • Ranges from • crude match-head pipe bombs Low explosive • Experimental professional munitions that don’t yet have issue numbers Often high explosives

Issued Munitions …can be part of an IED

Roadside IED…

155 mm shells linked with detonation cord

Injuries From Blast Blast Effects Definitions • Primary • The direct effect of the blast • Secondary • Due to projectiles from the blast • Tertiary • The victim is thrown by the blast wind • Quaternary • All other effects – burns, building collapse, etc.

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Primary Blast Injury Primary Blast Injury

• Primary Blast Injury (PBI) is caused directly by the • Compression of surrounding air or water sudden increase in air pressure after an explosion • Differential pressures at interfaces • Blast wave or shock front that travels faster than the speed • Differential pressures in tissues of sound • Organ distortion • Tensile strength of the tissue is exceeded • How will this injure tissue??? • Tissue tearing

Variables Affecting Severity Variables Affecting Severity Primary Blast Injury Primary Blast Injury • "Blast Environment" is a very important • Distance is the most important factor determining the extent of injuries. • Intensity varies by the third power of the distance… • Nearby structures may either act as a shield or • Double the distance from the explosion and may reflect the blast wave onto a casualty. reduce the injury by a factor of 8 • Confined environment increases damage • The most effective way to minimize injury • Foxhole or shelter is a confined environment from primary blast injury is to increase the • Inside the bus is bad… distance from the center of the explosion (stand-off distance) • Orientation of body relative to blast wave – end-on orientation minimizes injury

Variables Affecting Severity Blast Inside of a Closed Space Reflected Primary Blast Injury Blast Waves • A blast wave that is reflected can create • Peak of the initial positive wave a peak pressure 10X greater than that • Overpressure >60-80 PSI potentially lethal of the incident wave. • Duration of the overpressure • Blast waves inside buildings are repeatedly • Longer is bad – See thermobaric weapons reflected creating a “complex blast wave” • Medium in which it travels • Marked increase in injuries related to primary blast effects when explosion • Water is a special case occurs in a closed space

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Primary Blast Injury Primary Blast Injury • Organs most sensitive to blast effects are air filled (damage is produced at the • Direct trauma interface between air and water) • Amputations • middle ear: ear drum rupture @ 5 psi • Death • the respiratory system – • lungs and bronchi: lung damage at 15 psi • Hollow organ damage • upper airways (trachea, pharynx and larynx) • Ear • nasal passages and sinuses • the bowels. • Lung • LD is around 50 psi. • GI tract 50 • Air is 1o cause of sudden death due to blast

Primary Blast Injury Primary Blast Injury Traumatic Amputation

• Blast wave creates stress wave through skin and muscles • Stress wave shatters solid bone • Landmines • Expanding gases enter and expand tissues while ripping off distal part Death Amputation

Primary Blast Injury Primary Blast Injury Pulmonary Injury Pulmonary Injury • Hemorrhage: • Blood vessels stretched and torn • causing • Hemoptysis pulmonary • contusion • Escape of Air: • • Interstitial • Pneumomediastinum hemorrhage with • Pulmonary pseudocyst oxygen diffusion Bruises on lungs produced problems • Arterial gas embolism (AGE) when primary blast wave • Apnea rapidly accelerates ribs into underlying lung tissue

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Primary Blast Injury Primary Blast Injury Pulmonary Injury Pulmonary Injury • Respiratory difficulty • With exertion • Signs of blast lung are usually present at • At rest !! the time of the initial evaluation. • Asymmetrically or patchy • Presentation may be delayed by 48 hours. decreased breath sounds Blood • In one series, all patient with blast lung required or inspiratory crackles & ventilation support within 6 hours of presentation • Decreased SaO2 on ambient air Fluids • All were in enclosed space (bus bomb) or 100% oxygen therapy in • Pulmonary infiltrates on lungs • Wheezing or SOB on arrival should be chest radiograph presumed to be blast lung

Primary Blast Injury Primary Blast Injury Pulmonary Injury Brain Injury • Alveoli disrupted • Concussion • Pneumothorax • Tension pneumothorax • TBI • Asymmetrically decreased • Arterial gas embolism breath sounds • Signs and symptoms include headache, fatigue, poor • Tracheal deviation concentration, lethargy, anxiety, and insomnia • JVD • Shock if enough pressure in hemithorax to cause mediastinal shift (tension pneumothorax)

Primary Blast Injury Primary Blast Injury Arterial Gas Embolism Ear Injury

• Arterial gas embolism (AGE) – [air bubbles enter blood stream • Middle ear: and travel to brain and/or heart • Ruptured tympanic membrane (TM) causing stroke and/or heart attack • Cerebral circulation • Temporary conductive • Stroke • Inner ear: • Seizures • Altered mental status • Temporary sensory hearing loss • Coronary circulation • Permanent sensory hearing loss • Dysrhythmias • Ischemia or infarction • Cardiogenic shock Arterial gas embolism in liver

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Primary Blast Injury Primary Blast Injury Ear Injury Gastrointestinal Injury • More common in underwater blasts • TM rupture thought to be marker for • Acute/Delayed perforation of the bowel pulmonary injury? • No obvious external wound – easily missed • Good study showed that this is NOT true • Early hemorrhage • Earplugs/hearing protection • Delayed sepsis • In water? • Pathology • Ruptures at 5 psi • Mesenteric tears • Hematomata in bowel wall • Intraluminal hemorrhage • Delayed perforation up to 8 days after injury

Primary Blast Injury Identifying Underwater Blast Injury Abdominal Injury

• Serial abdominal • More devastating at a greater distance examinations • Pressure wave travels much faster in water • Serial hematocrit • Force does not dissipate as quickly • Underwater exposure to the explosion of a 1 lb. charge causes death at 23 ft. determinations This is 3X farther than the lethal range in air • Diagnostic studies • If vertically oriented in the water at/near the surface • Ultrasonography • significantly greater amount of blast energy imparted on the • Peritoneal lavage abdomen than on the lungs. • Computed tomography

Bomb Fragment Damage Primary blast injury is lethal…. Terrorist Bomb

But SECONDARY blast injuries are the real killer of explosions.

Parts of the bomber can be fragments that strike victims

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Secondary Blast Injury Fragments Can Travel… #1 source of injury/death from explosions …a long distance…. • Fragments from munitions (design) • Fragments from “spiked” terrorist bomb (Nails, Glass, Unique IED’s…) • Fragments from blast environment • Glass fragments are a common cause of injury/death related to blast in civilian settings • From the bomber… • At least one paper reports infections from They travel at HIGH velocity bomber fragments…. Conventional military explosives create fragments with initial velocity > 8000 fps. Fragments are often (erroneously) called shrapnel… M16 round travels at 2800 fps!

Fragments Kill! Fragments…. Come from many sources

Normally, if the victim is close enough to be seriously injured by blast wave…. victim is killed by fragments The real Terrorist devices Munitions (design) (Not true for enhanced blast weapons) shrapnel….

Fragments Fragments Eye Injuries

• Glass causes up to 50% of secondary blast injuries • 88% of Khobar Towers patients were injured by flying glass • Occur most often in exposed areas such as head, neck and • 10% of blast victims extremities will have significant eye injuries.

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EFP EFP Vehicle Damage The results of the fragment

Tertiary Blast Injuries Quaternary Blast Injury

The blast wind • The building collapses pushes/throws the • The products of the blast are poisonous victim onto something else. • Nitrogen oxides (NOx) are poison • Depleted uranium The trauma is due to the impact. • The patient is burned Blast wind occurs • White phosphorous with both HE and • Exacerbation of underlying COPD, CAD, etc. LE explosions.

EMS Providers…

• BE WARY OF SECONDARY DEVICES • Device command detonated or timed to occur 30-100 Medical Management minutes after the first device Issues In Blast Injury

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Management of secondary, tertiary, and quaternary blast injuries is unchanged from usual • Dead…stays dead • CPR has no place in the MASCAL principles of care. • Confined space explosions will have FAR more injuries and higher incidence of primary blast injury. • There may be LOTS of casualties…. • Structure collapse markedly increases mortality • They may have LOTS of injuries…

EMS Providers EMS Providers

• Airway control - minimize airway pressures as much • Identify and treat hemorrhage at once as possible. • Tourniquet is the appropriate treatment • Positive pressure ventilation only when necessary • Good IV access – • Pulse oximetry if possible • Monitor fluid administration carefully • Avoid overhydration/ARDS! • Frequent vital signs

EMS Providers Evacuation

• MANDATORY LITTER PATIENT – • Casualties with pneumothorax and AGE will get worse • Left lateral decubitus position w/head with altitude lower than feet (AGE position), if possible • Consider field chest tube • Don’t allow the patient to assist in own rescue or exert him/her self in any way • Avoid initial evacuation by long-distance high-altitude flights • Bad oxygenation will get worse with altitude

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Evacuation History Civilian/Mass Casualty Variant Important historical questions…

• Minor injuries skip EMS and go to hospital • Can you hear me? Do you have ear pain? • Expect LEAST injured to arrive first in hospital • Tympanic membrane rupture • Double first hour’s count for a rough prediction of the ‘first • Hearing loss wave’ of casualties • Ear injuries do not need special care in the field

History History Important historical questions… Important historical questions…

• Are you short of breath? • Do you have nausea, abdominal pain, urge to • First subjective complaints of pulmonary contusion, defecate, or blood in your stools pneumothorax, hemothorax, or shock. • Early markers for GI injuries • The more exertion required to elicit dyspnea… the better your patient is • May be absent/altered with other trauma • Do you have chest pain?

History Examination Important historical questions… Important physical findings…

• Do you have eye pain or problems with your vision? • Respiratory system • Markers for blunt and penetrating eye trauma • Ecchymosis or petechiae in hypopharynx • 10% of explosion victims will have eye trauma • This is more sensitive than ear findings • This doesn’t take into account military protective eyewear. • Cough • Tachypnea • Dyspnea

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Examination Examination Important physical findings… Important physical findings…

• Respiratory, cont… • Cardiovascular • Tachycardia • Hemoptysis • Stress, hemorrhage, hypoxia, exertion • Rales or crepitations • Bradycardia • Wheezes • Vasovagal • Delayed capillary refill • Chest pain • Hypotension • Asymmetric chest movement • Hemorrhage, AGE, vasovagal reaction • • Arrhythmias • Shock, coronary AGE

Examination Examination Important physical findings… Important physical findings…

• Gastrointestinal • Neurologic • • Nausea/vomiting • Vertigo is NOT usually due to auditory trauma • Abdominal tenderness • Coma • Hematochezia • Altered sensorium • Hematemesis • Focal numbness • Paresthesias • Seizures • Retrograde

Examination Examination Important physical findings… Important physical findings…

• Eye • • Difficulty focusing • Blood oozing from mouth or nose • Blindness • Hyperemia, hemorrhage or rupture of TM • Fundoscopic findings of retinal artery • Deafness • Loss of red reflex on fundoscopic examination •

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Diagnostic Studies Diagnostic Studies • Chest X-ray • Should be done on almost all patients • CBC • Pulse oximetry • Serial hemoglobin / hematocrit measurements • With multiple casualties consider • Stool occult blood intermittent monitoring • Other labs may be helpful… but order on case-by-case • FAST ? basis • CT of head, chest, or abdomen if HX and PE suggest • NOT optional in comatose • CT is often biggest bottleneck in MASCAL

Treatment Treatment

• Pulmonary • Hypotension - CONSIDER • High flow oxygen • Blood loss from wounds • Consider intubation • Blood loss due to GI hemorrhage • Respiratory distress • Blood loss due to intra-abdominal organ rupture • Hemoptysis • Pneumothorax • Use lowest airway pressure possible • Air embolism − PEEP and high ventilation pressures cause POP • If intubated, consider chest tube(s). • Vagal reflex

Treatment Treatment

• Hypotension • Auditory • Most resolve spontaneously • Volume support • Avoid irrigating or probing the auditory canal • ?? Keep dry?? • Avoid swimming • Refer to ENT if no healing or complications occur • Consider blood products – early • Complications include ossicle disruption, cholesteatoma, perilymphatic fistula, and permanent hearing loss (1/3) • LOOK for the CAUSE! • Steroids may be helpful in sensorineural hearing loss

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Treatment Air Embolism

• Wound management • High flow oxygen • Avoid primary closure • Position patient • DO NOT Suture without exploration • Use delayed primary closure • Injured lung in dependent position • Consider all wounds to be puncture wounds and have an • Left lateral recumbent position imbedded FB. • head down ??? • Carefully explore every wound. • Hyperbaric oxygenation • Consider CT, US, or MRI to look for radiolucent foreign bodies • Navy dive table 6

Air Embolism • 28% of blast survivors sustain eye injuries • Aspirin may be helpful in AGE • This may not be true with military eyewear • May reduce inflammation-mediated injury in pulmonary • Objects penetrating eye (or any other body barotrauma part) should not be removed in an emergency setting • Weigh risk in acute trauma setting • Cover affected eye with a paper cup that will not exert pressure on the globe • Remove object in operating room under controlled conditions • Refer patient to ophthalmology for definitive treatment

Disposition Disposition • Limited data prevent establishing optimal • Depends on the injury duration of observation • Don’t be hasty to discharge • Low risk and may be discharged with • Consider observation for 8-24 hours strict precautions after 6-8 hours of observation: • Persons exposed to open-space explosions with no apparent significant injury, normal vital signs and unremarkable lung and abdominal examination

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Disposition CDC BLAST INJURY App

• Moderate risk and should be observed for longer • For the iPhone, iPad and iPod touch periods of time for delayed complications: • App store, search for CDC and select Blast Injury • Persons exposed to confined area explosion or in-water • It’s FREE explosions • Persons with TM rupture ? • Persons with intra-oral petechiae

Summary Summary

• Explosions cause familiar trauma • Primary blast injuries of the lung • There may be LOTS of casualties with LOTS of injuries • Leads to pulmonary contusion with possible arterial gas • Secondary blast trauma is the biggest killer embolism to the brain or heart • May rapidly worsen if casualty exercises (including walking) • May affect evacuation decisions (air vs. ground) – air evac only at LOW altitude

Summary

• Management of other injuries adjusted • Spontaneous breathing or low airway pressures • Highest level of oxygen supplementation • Just enough fluid or blood to restore perfusion • May help to position differently than supine

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