Transcript Slide 1

Evaluation and Treatment
of Blast Injuries
Charles Stewart MD
FACEP, FAAEM
Jacarta Hotel bombing
Objectives –
• Describe the basic physics, mechanisms
of injury, and pathophysiology of blast
injury
• List the four types or categories of blast
injuries
• List the factors associated with
increased risk of primary blast injury
Objectives…cont.
• Recognize the key diagnostic
indicators of serious primary blast
injury
• State the most common cause of
death following an explosion
Why?
• Combat
• Terrorism
• Accidents
Combat: Iraq
Combat: Iraq
Combat: Viet Nam
• Dong Ha
ammunition
dump
explosion
September 3,
1967
• 20,000 tons of
explosives
Terrorism: NYC
Terrorism: USS Cole
Terrorism: Dhahran
Khobar Towers in
Dhahran, Saudi
Arabia, after a
terrorist bomb
exploded and
killed 19 Air Force
members.
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 explosive device
• A poor man’s guided missile!
Texas City Texas
• USS Grandcamp was loading ammonium
nitrate fertilizer. 2,300 tons were already
onboard.
• A fire was discovered in the hold of the ship.
• At 0912 hrs the ammonium nitrate exploded
Ship’s
Anchor
Fragments can travel…
…a long distance….
Accidents
Grain elevator
Accidents
Gasoline tanker: I-95
Accidents
Fireworks Plant Explosion
First… a little theory
…What is an explosive?
There are four types…
•High explosive
•Low explosives
•Fuel-Air explosives
•Nuclear Explosives
We won’t talk about nuclear explosions…
Explosives
• High order
• Detonation
• Blast wave formation (supersonic)
• Low order
• Deflagration
• No blast wave formation (always
subsonic)
High order explosives
“HE”
• Nitroglycerine
• Dynamite
• TNT – the “classic”
• PETN – ‘det’ cord.
• C-4 – familiar to all military
• Semtex (Warsaw pact version of C-4)
• ANFO
• Ammonium nitrate, fuel oil mixture
High order explosives
“HE”
• When a high explosive detonates, it
is converted instantaneously into a
gas at high pressure and
temperature.
• The expansion of these gases
creates the blast wave.
• Brisance is the shattering effect of
the blast wave
The blast wave…
A shock wave
High Speed Photography of Blast Wave
Low order explosives
(propellants)
• Gunpowder
• Nitrocellulose
• Smokeless powder
• (This is also is a high explosive under
certain conditions)
• Match heads
• Multiple other compounds
Deflagration
Low-order explosive combustion
Deflagration is very rapid burning….
The speed is increased by confinement
Fuel-air explosives
(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
Thermobaric explosives
Fuel-air mixtures
Thermobaric weapons
Fuel-air mixtures
• Optimized to produce heat and
blast
• Secondary effects through flying
fragments
• Toxic detonation gases
• Anoxia
Thermobaric weapons
Fuel-air mixtures
• Particularly effective in enclosed spaces
• Fireball and blast can travel around corners
• Blast waves are intensified when reflected
by walls and other surfaces.
Fuel-air explosives
Thermobaric weapons
Fuel-Air Mixtures
(not just military explosives)
• Grain/dust
explosions
• BLEVE
• Slow escape of
natural or LP gas
IED
(A very, very bad terminology)
• 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
IED
Has many shapes
Issued munitions
…can be part of an IED
But are not IED’s themselves
M-79/M-203
155 mm Artillery
M-18 “Claymore mine”
C-4
Issued munitions
…can be part of an IED
Roadside IED…
155 mm Artillery
shells linked
with detonation
cord
Blast effects
Injuries from blast
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.
Primary Blast Injury
• Primary Blast Injury (PBI) is caused
directly by the sudden increase in
air pressure after an explosion
• Blast wave or shock front that travels
faster than the speed of sound
• How will this injure tissue???
Primary Blast Injury
• Compression of surrounding air or
water
• Differential pressures at interfaces
• Differential pressures in tissues
• Organ distortion
• Tensile strength of the tissue is exceeded
• Tissue tearing
Variables Affecting Severity
Primary Blast Injury
• Distance is the most important
• Intensity varies by the third power of the
distance…
• Double the distance from the explosion and
reduce the injury by a factor of 8
• The most effective way to minimize injury
from primary blast injury is to increase the
distance from the center of the explosion
(stand-off distance)
“Stand-off” distance
Distance works….
Stand-off distance
Variables Affecting Severity
Primary Blast Injury
• "Blast Environment" is a very important factor
determining the extent of injuries.
• Nearby structures may either act as a shield or
may reflect the blast wave onto a casualty.
• Confined environment increases damage
• Foxhole or shelter is a confined environment
• Inside the bus is bad…
• Orientation of body relative to blast wave –
end-on orientation minimizes injury
Blast inside of a closed space
Reflected Blast Waves
• A blast wave that is reflected can create
a peak pressure 10X greater than that
of the incident wave.
• Blast waves inside buildings are repeatedly
reflected creating a “complex blast wave”
• Marked increase in injuries related to
primary blast effects when explosion
occurs in a closed space
Blast inside of a closed space
In the Foxhole
• Blast occurring over simple
foxholes can readily generate
complex blast waves.
• The static overpressure from
an explosion directly over a
foxhole causes a wave to
propagate into the foxhole
and reverberate.
• Depending upon the size and
shape of the foxhole and the
location of soldier in it, the
effective overpressure loading
can be much greater than the
incident blast wave itself.
Variables Affecting Severity
Primary Blast Injury
• Peak of the initial positive wave
• Overpressure >60-80 PSI potentially lethal
• Duration of the overpressure
• Longer is bad – See thermobaric weapons
• Medium in which it travels
• Water is a special case
Potential for Occult Injury
Primary Blast Injury
• Blast shock waves may pass through a
solid structure (hull of a ship or wall of
a tank) and produce serious injury
• Multiple fractures,
• Disruption of major blood vessels,
• Damage to internal organs without
disruption of the solid structure itself.
• These injuries may occasionally occur
without damage to the skin.
Primary blast injury
• Direct trauma
• Amputations
• Death
• Hollow organ damage
• Ear
• Lung
• GI tract
Primary blast injury
• Organs most sensitive to blast effects are air
filled (damage is produced at the interface
between air and water)
• middle ear: ear drum rupture @ 5 psi
• the respiratory system –
• lungs and bronchi: lung damage at 15 psi
• upper airways (trachea, pharynx and larynx)
• nasal passages and sinuses
• the bowels.
• LD50 is around 50 psi.
• Air embolism is 1o cause of sudden death due to
blast
Primary Blast Injury
Death
Amputation
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
Primary blast injury
Pulmonary injury
• Hemorrhage:
• Pulmonary contusion
• Hemoptysis
• Hemothorax
• Escape of Air:
•
•
•
•
Pneumothorax
Pneumomediastinum
Pulmonary pseudocyst
Arterial gas embolism (AGE)
• Apnea
Primary blast injury
Pulmonary injury
Bruises on lungs produced
when primary blast wave
rapidly accelerates ribs into
underlying lung tissue
• Blood vessels
stretched and
torn causing
pulmonary
contusion
• Mild interstitial
hemorrhage
with minor
oxygen diffusion
problems
Primary blast injury
Pulmonary injury
• Blood vessels
stretched and torn
causing pulmonary
contusion
(bruising)
• Severe interstitial
and alveolar blood
and fluid with
major oxygenation
and ventilation
problems
Primary blast injury
Pulmonary injury
• Respiratory difficulty
• With exertion
• At rest !!
• Asymmetrically or patchy
decreased breath sounds or
inspiratory crackles
• Decreased SaO2 on ambient air
or 100% oxygen therapy
• Pulmonary infiltrates on chest
radiograph
Blood &
Fluids
in
lungs
Primary blast injury
Pulmonary injury
• Signs of blast lung are usually present
at the time of the initial evaluation.
• Presentation may be delayed by 48 hours.
• In one series, all patient with blast lung
required ventilation support within 6 hours of
presentation
• All were in enclosed space (bus bomb)
• Wheezing or SOB on arrival should be
presumed to be blast lung
Primary blast injury
Pulmonary injury
• Alveoli disrupted
• Pneumothorax
• Tension pneumothorax
• Asymmetrically decreased
breath sounds
• Tracheal deviation
• JVD
• Shock if enough pressure
in hemithorax to cause
mediastinal shift (tension
pneumothorax)
Primary blast injury
Cardiac problems
• Arrhythmias
• Bradycardia
• Thought to be vagal
• Hypotension
Primary Blast Injury
Brain Injury
•
•
•
•
Concussion
TBI
Arterial gas embolism
Signs and symptoms include
headache, fatigue, poor
concentration, lethargy, anxiety, and
insomnia
Primary blast injury
Arterial Gas Embolism
• Arterial gas embolism
(AGE) – [air bubbles enter
blood stream and travel to
brain and/or heart causing
stroke and/or heart attack]
• Cerebral circulation
• Stroke
• Seizures
• Altered mental status
• Coronary circulation
• Dysrhythmias
• Ischemia or
infarction
• Cardiogenic shock
Arterial gas embolism in liver
Primary blast injury
Ear injury
• Middle ear:
• Ruptured tympanic membrane (TM)
• Temporary conductive hearing loss
• Inner ear:
• Temporary sensory hearing loss
• Permanent sensory hearing loss
Primary blast injury
Ear injury
• TM rupture thought to be marker
for pulmonary injury?
• Good study showed that this is NOT
true
• Earplugs/hearing protection
• In water?
• Ruptures at 5 psi
Primary blast injury
Gastrointestinal injury
• More common in underwater blasts
• Acute/Delayed perforation of the bowel
• No obvious external wound – easily missed
• Early hemorrhage
• Delayed sepsis
• Pathology
•
•
•
•
Mesenteric tears
Hematomata in bowel wall
Intraluminal hemorrhage
Delayed perforation up to 8 days after injury
Primary blast injury
Identifying Abdominal Injury
• Serial abdominal
examinations
• Serial hematocrit
determinations
• Diagnostic studies
• Ultrasonography
• Peritoneal lavage
• Computed
tomography
Primary Blast Injury
Identifying Abdominal Injury
Sometimes, you can see it on the CXR.
Primary blast injury
Repeated injury
• Larynx is most sensitive nonauditory structure to repeated blast
followed by GI and lungs.
• Repeated exposure to blast waves
significantly increases severity of
injury/likelihood of death
Underwater Blast
& Blast Injury Inside
Ships
Underwater Blast Injury
• More devastating at a greater distance
• Pressure wave travels much faster in water
• Force does not dissipate as quickly
• If vertically oriented in the water
at/near the surface
• significantly greater amount of blast
energy imparted on the abdomen than on
the lungs.
Underwater Blast Injury
• During WWII Sir Zachary Cope
observed that:
“…if the person were floating on the back so
that neither the abdomen nor the chest were
directly opposed to the blast, no serious
injury was sustained.”
• Underwater exposure to the explosion
of a 1 lb. charge causes death at 23 ft.
This is 3X farther than the lethal range
in air
Underwater Blast Injury
If underwater explosion
is expected get as
horizontal and as close
to the surface as
possible
Underwater blast injury
• Eliat Destroyer Sunk by torpedo
• 32 sailors exposed to underwater blast survived
to be rescued.
• 31 suffered primary blast injury (PBI)
• 27 had blast lung with 5 requiring ventilation
support
• 24 had abdominal signs and underwent
laparotomy –
• 22 had bowel perforations
• 4 of the 32 rescued died –
• 3 expired during or shortly after general anesthesia
(Arab-Israeli 1967 War)
Underwater Blast Injury
• 13 soldiers swimming for recreation were
exposed to a nearby underwater explosion
•
•
•
•
•
•
All quickly got out of the water
Within a minute 2 had cardiac arrest
Within 10 minutes 2 more died
Within 30 minutes 2 more died.
The remaining 7 were evacuated by helicopter
Only 3 survived.
Primary blast injury is lethal….
But SECONDARY blast injuries are
the real killer of explosions.
Secondary Blast Injury
#1 source of injury/death from explosions
• 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 bomber
fragments….
Fragments are often (erroneously) called shrapnel…
Fragments can travel…
…a long distance….
It is not clinically
possible to
determine if the
explosive was HE
or LE from the
fragment patterns.
Remember the anchor?
Fragments kill!
Normally, if the victim is close enough to be seriously injured by blast
wave…. victim is killed by fragments
(Not true for enhanced blast weapons)
Fragments
• Travel at HIGH velocity
• Conventional military explosives
create fragments with initial velocity
> 8000 fps.
• M16 round travels at 2800 fps!
Bomb fragment damage
Terrorist bomb
Parts of the bomber can be
fragments that strike victims
Fragments….
Come from many sources
The real
shrapnel….
Terrorist
devices
Munitions
(design)
Fragments
A car bomb
Fragments
• 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 extremities
Fragments
Eye injuries
• 10% of blast
victims will have
significant eye
injuries.
EFP…
a special kind of fragment
FORM OF PROJECTILE UPON EXPLOSION
= HOT KNIFE
= Butter
EFP
Explosively formed projectile
A special
case of the
shaped
charge
explosive
EFP
Vehicle Damage
Entry Hole
EFP
Entry Hole
EFP
Vehicle Damage
EFP
The results of the fragment
EFP
Results…cont.
EFP
Another…
EFP
The hardware
Often paired with another device that simply uses
fragments to increase the number/severity of injuries
EFP
• Explosively formed projectiles are
professionally designed and
manufactured munitions…even if
they are labeled as IED’s.
• These are NOT the work of the
amateur.
Body Armor
Mixed blessing
• Use of body armor significantly
increases primary blast injury
• May magnify primary blast injury
when the explosion is focused or
close.
• However, the over all risk of
death is higher from secondary
blast injury.
• Body armor markedly decreases
number of fragment wounds
(secondary blast trauma)
Tertiary Blast Injuries
The blast wind
pushes/throws the
victim onto
something else.
The trauma is due to
the impact.
Blast wind occurs
with both HE and LE
explosions
Quaternary blast injury
• The building collapses
• The products of the blast are poisonous
• Nitrogen oxides (NOx) are poison
• Depleted uranium
• The patient is burned
• White phosphorous
• Exacerbation of underlying COPD, CAD,
etc.
Crush and compartment
syndrome
• Structural collapse may cause extensive
blunt trauma
• Crush syndrome
• Damage to muscles and subsequent release of
myoglobin, urates, potassium, and phosphates
• Oliguric renal failure
• Compartment syndrome
• Edematous muscle in an inelastic sheath
promotes local ischemia, further swelling,
increased compartment pressures, decreased
tissue perfusion, and further ischemia
Medical Management
Issues In
Blast Injury
EMS Providers…
• BE WARY OF SECONDARY DEVICES
• Device command detonated or timed
to occur 30-100 minutes after the
first device
• BE WARY of sniper coverage
• The sniper may also have control of
the secondary device
Management of secondary,
tertiary, and quaternary blast
injuries is unchanged from usual
principles of care.
• There may be LOTS of casualties….
• They may have LOTS of injuries…
Open Space Suicide Bombing
Small (5 kg TNT-eq)
• Casualties – 1-30
• (Israel - average 23, range 1-99)
• Severity
• Killed
1-5
• Admitted
5-10
• Treat & release 20
• Injury patterns
•
•
•
•
}
1/3rd killed or admitted
}
2/3rd outpatient treatment
1° Blast trauma < 5 meters
Fragment wounds < 100 meters
Temporary deafness
Risk of Hepatitis, Tetanus, HIV (Fragments of the bomber)
Open Space Suicide Bombing
Moderate - Car (50-100 kg TNT-eq)
• Casualties – 1-50
• (Israel - average 23, range 1-99)
• Severity
• Killed
5-10
• Admitted
10-20
• Treat & release 40
• Injury patterns
•
•
•
•
}
1/3rd killed or admitted
}
2/3rd outpatient treatment
1° Blast trauma < 25 meters
Fragment wounds < 500 meters
Temporary deafness
Risk of Hepatitis, Tetanus, HIV (Fragments of the bomber)
This is an upscale of the backpack suicide bomb…
Confined Space Backpack Bomb
Small (10 kg TNT-eq)
• Casualties –
• 20-50 bus and
• 150-200 train / bomb
• 70% of fatalities are Dead on Scene (DOS)
• Severity
• Killed
20%
• Admitted
20%
• Treat and release 60%
Simplified Severity Predictor
= 1/3rd killed or admitted > 24°.
• Injury patterns
• 1° Blast trauma – anywhere within bus or train cabin
• Temporary deafness
• Risk of Hepatitis, Tetanus, HIV (From fragments of the
bomber)
• Rescue may be complicated
Structural collapse bombing
(100-1,000 kg TNT-eq)
• Casualties – 100 – 3,000
• Largely based on bomb size, time of day, warning,
building structure, and evacuation proficiency
• 90% of fatalities are DOS
• Severity – follows pattern of Earthquake or
structural collapse
• Killed if in the collapse
• Treat and release if nearby, but not in direct path
• Small percentage admitted (<1-5%)
• Injury patterns
• Respiratory problems, temporary deafness
Rescue must weigh risk versus benefit of rapid ingress
Triage
• Dead…stays dead
• CPR has no place in the MASCAL
• Confined space explosions will have
FAR more injuries and higher
incidence of primary blast injury.
• Structure collapse markedly
increases mortality
Triage
• Do NOT do definitive care in
TRIAGE…
• Rapid evacuation increases the
chance of survival
EMS Providers
• Airway control - minimize airway
pressures as much as possible.
• Positive pressure ventilation only
when necessary
• Pulse oximetry if possible
EMS Providers
• Identify and treat hemorrhage at once
• Tourniquet is the appropriate treatment
• Good IV access –
• Monitor fluid administration carefully
• Avoid overhydration/ARDS!
• Frequent vital signs
EMS Providers
• MANDATORY LITTER PATIENT –
• Left lateral decubitus position w/head
lower than feet (AGE position), if
possible
• Don’t allow the patient to assist in
own rescue or exert him/her self in
any way
Evacuation
• Casualties with pneumothorax and
AGE will get worse with altitude
• Consider field chest tube
• Avoid initial evacuation by longdistance high-altitude flights
• Bad oxygenation will get worse
with altitude
Evacuation
Civilian/Mass Casualty variant
• Minor injuries skip EMS and go to
hospital
• Expect LEAST injured to arrive first in
hospital
• Double first hour’s count for a rough
prediction of the ‘first wave’ of
casualties
History
Important historical questions…
• Can you hear me? Do you have
ear pain
• Tympanic membrane rupture
• Hearing loss
• Ear injuries do not need special
care in the field
History
Important historical questions…
• Are you short of breath?
• First subjective complaints of
pulmonary contusion, pneumothorax,
hemothorax, or shock.
• The more exertion required to elicit
dyspnea… the better your patient is
• Do you have chest pain?
History
Important historical questions…
• Do you have nausea, abdominal
pain, urge to defecate, or blood in
your stools
• Early markers for GI injuries
• May be absent/altered with other
trauma
History
Important historical questions…
• Do you have eye pain or problems
with your vision?
• Markers for blunt and penetrating eye
trauma
• 10% of explosion victims will have
eye trauma
• This doesn’t take into account military
protective eyewear.
Examination
Important physical findings…
• Respiratory system
• Ecchymosis or petechiae in
hypopharynx
• This is more sensitive than ear findings
• Cough
• Tachypnea
• Dyspnea
Examination
Important physical findings…
• Respiratory, cont…
• Hemoptysis
• Rales or crepitations
• Wheezes
• Chest pain
• Asymmetric chest movement
• Subcutaneous emphysema
Examination
Important physical findings…
• Cardiovascular
• Tachycardia
• Stress, hemorrhage, hypoxia, exertion
• Bradycardia
• Vasovagal
• Delayed capillary refill
• Hypotension
• Hemorrhage, AGE, vasovagal reaction
• Arrhythmias
• Shock, coronary AGE
Examination
Important physical findings…
• Gastrointestinal
• Nausea/vomiting
• Abdominal tenderness
• Hematochezia
• Hematemesis
Examination
Important physical findings…
• Neurologic
• Vertigo
•
•
•
•
•
•
• Vertigo is NOT usually due to auditory trauma
Coma
Altered sensorium
Focal numbness
Paresthesias
Seizures
Retrograde amnesia
Examination
Important physical findings…
• Eye
• Difficulty focusing
• Blindness
• Fundoscopic findings of retinal artery
air embolism
• Loss of red reflex on fundoscopic
examination
Examination
Important physical findings…
• Auditory system
• Blood oozing from mouth or nose
• Hyperemia, hemorrhage or rupture of
TM
• Deafness
• Tinnitus
Diagnostic studies
• Chest X-ray
• Should be done on almost all patients
• Pulse oximetry
• With multiple casualties consider
intermittent monitoring
• FAST ?
• CT of head, chest, or abdomen if HX
and PE suggest
• NOT optional in comatose
• CT is often biggest bottleneck in MASCAL
Diagnostic studies
• CBC
• Serial hemoglobin / hematocrit
measurements
• Stool occult blood
• Other labs may be helpful… but
order on case-by-case basis
Treatment
• Pulmonary
• High flow oxygen
• Consider intubation
• Respiratory distress
• Hemoptysis
• Use lowest airway pressure possible
− PEEP and high ventilation pressures cause
POP
• If intubated, consider chest tube(s).
Treatment
• Hypotension
• Blood loss from wounds
• Blood loss due to GI hemorrhage
• Blood loss due to intra-abdominal
organ rupture
• Pneumothorax
• Air embolism
• Vagal reflex
Treatment
• Hypotension
• Volume support
• ?? Keep dry??
• Consider blood products – early
• LOOK for the CAUSE!
Treatment
• Auditory
•
•
•
•
Most resolve spontaneously
Avoid irrigating or probing the auditory canal
Avoid swimming
Refer to ENT if no healing or complications occur
• Complications include ossicle disruption, cholesteatoma,
perilymphatic fistula, and permanent hearing loss (1/3)
• Steroids may be helpful in sensorineural hearing
loss
Treatment
• Wound management
• Avoid primary closure
• Use delayed primary closure
• Consider all wounds to be puncture
wounds and have an imbedded FB.
• Carefully explore every wound.
• Consider CT, US, or MRI to look for
radiolucent foreign bodies
Air Embolism
• High flow oxygen
• Position patient
• Injured lung in dependent position
• Left lateral recumbent position
• head down ???
• Hyperbaric oxygenation
• Navy dive table 6
Air Embolism
• Aspirin may be helpful in AGE
• May reduce inflammation-mediated
injury in pulmonary barotrauma
• Weigh bleeding risk in acute trauma
setting
Eye injury
• 28% of blast survivors sustain eye injuries
• This may not be true with military eyewear
• Objects penetrating eye (or any other body
part) should not be removed in an emergency
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
Anesthesia
• ? Increased morbidity when
anesthesia given
• ? Unrecognized primary blast injury
• ? Barotrauma
• Consider spinal anesthesia
• Consider bilateral chest tubes
Burns
• WP burns require special management
• Copious lavage and removal or particles and
debris
• Rinse with 1% copper sulfate solution
• Combines with phosphorous particles and impedes
further combustion
• Cardiac monitor
• Hypokalemia and hyperphsophatemia common
• Consider moistened face masks to protect from
phosphorous pentoxide gas exposure
• Avoid use of flammable anesthetic agents and
excessive oxygen
Disposition
• Depends on the injury
• Don’t be hasty to discharge
• Consider observation for 8-24 hours
Disposition
• Limited data prevent establishing optimal duration of
observation
• Low risk and may be discharged with 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
• Moderate risk and should be observed for longer
periods of time for delayed complications:
• Persons exposed to confined area explosion or in-water
explosions
• Persons with TM rupture ?
• Persons with intra-oral petechiae
Transportation
• Remember primary blast injury may
have a little delay in presentation…
• Air transport
• Repeat CXR?
• Bilateral chest tubes?
No problem…???
We got 50 walking wounded in
the last 20 minutes from that
explosion three blocks away…
“Boy, I’m glad nobody got hurt
badly in this explosion!”
No problem…???
The trooper was wearing issue body
armor. The mortar round exploded
about 10 feet away. She was in a
foxhole and had overhead cover.
She had some injuries on her
extremities, but had no torso
injuries from the bomb fragments.
She developed pulmonary blast
injury?
No problem…???
The SEAL had no evidence of ear injury,
had no cough, hemoptysis, shortness of
breath, or frag wounds…
Now you tell me that he had an
abdominal blast injury with a perforated
colon? There weren’t any markers for
blast injury, were there?
Summary
• Explosions cause familiar trauma
• There may be LOTS of casualties with LOTS of injuries
• Secondary blast trauma is the biggest killer
• Primary blast injuries of the lung
• Leads to pulmonary contusion with possible arterial gas
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
• 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
Bomb injury, threat model
Bomb
Size & weight
Explosive choice
Purpose & Source
Delivery system
Adulterants
Tactic
Model
courtesy
of CDC
Human
Age, sex, & weight
Fitness, PPE
Nutrition, health
Access to care
Open Space, Confined Space,
Structural Collapse
Reflecting or Shielding surfaces
Building and non-structural debris
Within water
Air and liquid hazards
Casualties – 100 – 3,000
– largely based on bomb
size, time of day, warning, building
structure, and evacuation
proficiency
– 90% of fatalities are DOS
The end.
• I’ve covered
chaos, mayhem,
destruction and
disaster!
• My work here is
complete.
How to Reach Me
Military email.
[email protected]
Civilian email
[email protected]
Website
www.storysmith.net
Posted on website
• Handout (complete)
• Complete slide set of this lecture
• Chapter from European Master’s in
Disaster Medicine text on blast injuries