Explosives, IED’s and
Dale Carrison, DO, MS, FACEP, FACOEP
Professor/Chairman Emergency Medicine
University Medical Center
University of Nevada School of Medicine
First terrorist bombing in Belgium
6,000Kg gunpowder used to destroy
> 1,000 fatalities, many with no
external evidence of injury.
70% of all terrorists incidents are
10,000 terrorists explosions from
Goal is to induce panic and
Rapid chemical conversion of a solid
or liquid into a gas with resultant
Propellants (e.g., gunpowder) release
energy relatively slowly.
High explosives (e.g., TNT, PETN, C-4)
almost instantaneous transformation of
the physical space occupied by the
original material within a few
microseconds. Therefore, under extremely
5 Billion Pounds
Produced Each Year in U.S.
Chemicals for non-
High explosives(HE) Propellants(LE) Pyrotechnic (LE)
Singles = TNT;
Mixes = CB;
Chlorates as weed
Gas generating for
Organic peroxides as
NTG and PETN-soln
Salts of nitrated
organic acids for pest-
From Explosives, R. Meyer – 5th Edition
Virtual instantaneous increase in
pressure can be so abrupt that high-
explosive blast waves (blast wind)
are also “shock waves.”
Shock waves possess a
characteristic called “brisance”
The gas expands with an exponential
increase in pressure.
It forms a sphere.
The sphere of this compressed air is
called a shock wave, blast pressure
head, blast wind, or blast wave.
Leading edge is called the “blast
This wave of compressed air can be
measured as overpressure or direct
The magnitude of the overpressure is
proportional to the amount and type
of explosive used.
Overpressure is measured in pounds
per square inch.
Relative power is calculated by
multiplying PSI X duration in
milliseconds of the impulse.
Overpressure of 58 – 80psi is 95%
7 – 8psi can shear brick walls or
overturn rail cars.
5psi can rupture tympanic
0.5 – 1psi can break windows and
knock people down.
The shock wave has 3 components:
– Positive phase
– Negative phase
– Mass air movement.
After an Explosion
EFFECTS OF AN EXPLOSION
– Velocity and duration of the blast head.
– Size/type of the explosive
– Surrounding media
– Distance from the detonation.
Closed spaces magnify the effects of
the direct impulse.
“Shock Wave” “bounces” off hard
surfaces and is referred to as a
Shock waves all create similar rates
of rise in pressures at the blast front.
The magnitude of this “positive-
phase impulse” becomes the
important property in the generation
of the Primary Blast Injury (PBI).
– Partial vacuum is created near the
epicenter after outward movement of air
– Consumption of oxygen by the burning
The “reflected impulse” may
combine with the “direct impulse”
and increase injuries at a greater
distance from the blast site than
Effects are cumulative.
– A blast that causes a 1% mortality when
experienced once, causes a 20%
mortality when experienced twice, and
100% mortality if experienced three
1. Safety Fuse
Primary ExplosiveElectric Wires
ELECTRIC BLASTING CAPS
New research indicates that most
pathophysiologic effects on the body
result from the consequences of
extreme pressure differentials
developed at body surfaces.
Force results in rapid acceleration of
the surface, creating a relatively
high-frequency “stress wave”
propagated into the underlying
PBI – Tympanic Membrane
Tympanic membrane ruptured from
overpressure of 1 – 8 psi.
Less common is dislocation of the joints
in the inner ear.
Temporary hearing loss very common.
Structural damage to the organ of Corti
can cause permanent hearing loss.
PBI – Tympanic Membrane
Studies show no correlation between
ruptured TM and Blast Lung.
TM’s generally heal without
PBI - Lung
– Worse on side of approach of blast
waves in open air.
– Bilateral and diffuse when victim is
located in confined space.
Degree of pulmonary pathology is
proportional to the velocity of chest
PBI to lung is referred to as blast
Greater incidence in confined spaces
Major cause of death in PBI’s
Alveolar membranes torn
Minimal to massive hemorrhage with
hemothorax or air emboli
Diagnosis made clinically
Confirmed by CXR showing a
butterfly appearance with or without
Similar to Pulmonary Contusion or
Respiratory distress with hypoxemia
greatest in the first 72 hours.
Treatment similar to Pulmonary
Studies have shown no long term
Generally normal after 1 year
PBI - Hypotension
Bradycardia and hypotension
– Blast loads directly at the chest cause a
unique vagal nerve-mediated form of
cardiogenic shock without
– Occurs within seconds and resolves
over 1 – 2 hours.
PBI – Arterial Air Embolus (AAE)
emphysema, and alveolovenous
fistulas from stress-induced tears of
Lead directly to bronchopleural
fistulas or Arterial Air Embolus
PBI - AAE
AAE to the brain or head may be the
most common cause of rapid death
caused solely by PBI in immediate
May be precipitated by positive-
pressure ventilation (PPV).
Often occurs at the moment of PPV.
PBI - Abdomen
Injuries occur in similar manner and
at similar overpressures to the lungs.
Hemorrhages, from petechiae to
large hematomas are the dominant
form of pathology.
Colon most common site of
hemorrhage and/or perforation.
PBI - Abdomen
Injuries - Penetrating
Medically, usually no
different than other
Complicated by the
Bone and tissue from
suicide bombers may
– Aids, hepatitis, etc.
Injuries - Penetrating
Secondary missiles created by
container fragments or added
missiles can have velocities of up to
Rapid deceleration seconday to poor
Tertiary injuries – Blunt trauma.
– Physically thrown through the air and
strike or impale themselves on objects.
– Collapsing structures.
– Other objects propelled through the air
striking the victim.
Severe head injury is a leading cause
of death in victims of blasts.
Subdural and subarachnoid
hemorrhages are the most common
findings in fatalities.
– Few victims admitted to burn centers
– Little skin grafting needed
Large body surface area
commander to ensure
that the area is safe to
Beware of #2 or
directed at personnel
responding to the first
Recent studies suggest the PBI
victims do poorly when strenuous
physical activity follows significant
– Reduce activity of potential blast-
– Provide history of activity to ED
personnel receiving patient.
Post Mortem Care - Mass fatality event
–Identification & notification
– Family Assistance Center needed at scene!
Explosives worn on
belt or vest
Arms raised to
Prevention is difficult to impossible !
– NO SECURITY SYSTEM IS
IMPENETRABLE IF THE BOMBER HAS
A SUICIDAL INTENT
Terrorists can change targets at the
– Crude guided missile
Suicide Bombers = only 0.6% of all
attacks . . .
. . . but 66% of all fatalities!
device strapped to
body they sustain
secondary to the
injuries because of
being at ground
Remains of first terrorist in yard
Remains of third terrorist - (probably blew up with dog)
Devices designed for maximum explosive
value and fragmentation.