Download Blast injury

Blast Injuries
Safwat Abd El Kader
MD, FRCS, FICS
Professor of Surgery
Cairo University
Cairo - Egypt
Background
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Explosions have the capability to cause
multisystem, life-threatening injuries in single
or multiple victims simultaneously.
These types of events present complex
triage, diagnostic, and management
challenges for the health care provider.
Explosions can produce classic injury
patterns from blunt and penetrating
mechanisms to several organ systems, but
they can also result in unique injury patterns
to specific organs including the lungs and the
central nervous system CNS.
Understanding these crucial differences is
critical to managing these situations.
Background cont.
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The extent and pattern of injuries produced by an
explosion are a direct result of several factors
including the amount and composition of the
explosive material (eg, the presence of shrapnel or
loose material that can be propelled, radiological or
biological contamination).
The surrounding environment (eg, the presence of
intervening protective barriers).
The distance between the victim and the blast.
The delivery method if a bomb is involved.
Any other environmental hazards.
No two events are identical, and the spectrum and
extent of injuries produced varies widely.
Background cont.
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In many parts of the world,
undetonated military incendiary
devices such as land mines and
hand grenades contaminate the
sites of abandoned battlefields.
Such devices cause significant
numbers of civilian casualties years
and even decades after local
hostilities cease.
During wartime, injuries arising from
explosions frequently outnumber
those from gunshots with many
innocent civilians becoming victims.
Background cont.
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Much of the challenge facing
the care providers is the
potential for the sudden
creation of large numbers of
patients who require extensive
medical resources.
This scenario can overwhelm
local and hospital resources.
Emergency physicians must
remain attentive to the
possibility and consequences
of blast injuries.
Background cont.
Once notified of a possible
bombing or explosion,
hospital-based physicians
should consider
immediately activating
hospital disaster and
contingency plans,
including preparations to
care for anywhere from a
handful to hundreds of
victims.
Explosive Weights for Potential Improvised
Explosive Device (IED) Packages
Threat Type
Size
Weight
Pipes
2" x 12"
4" x 12"
8" x 24"
6 lbs.
20 lbs.
120 lbs. (Uncommon)
Bottles
2 Liter
2 Gallon
5 Gallon
10 lbs.
30 lbs.
70 lbs. (Uncommon)
Boxes
Shoe Box
Briefcase
1 Cubic Foot
Container
Suitcase
30 lbs.
50 lbs.
100 lbs. (Uncommon)
225 lbs. (Uncommon)
Pathophysiology
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Blast injuries traditionally are divided into 4
categories: primary, secondary, tertiary, and
miscellaneous also called quaternary injuries.
A patient may be injured by more than one of
these mechanisms.
A primary blast injury is caused solely by the
direct effect of blast overpressure on tissue.
Air is easily compressible, unlike water. As a
result, a primary blast injury almost always
affects air-filled structures such as the lung,
ear, and gastrointestinal (GI) tract.
Pathophysiology
A secondary blast injury is caused by
flying objects that strike people.
 A tertiary blast injury is a feature of
high-energy explosions. This type of
injury occurs when people fly through
the air and strike other objects.
 Miscellaneous quaternary blast related
injuries encompass all other injuries
caused by explosions.
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DePalma, R. G. et al. N Engl J Med 2005;352:1335-1342
Mechanisms of Blast Injury
Category
Characteristics
Body Part Affected
Types of Injuries
Primary
Unique to HE, results from the
impact of the overpressurization wave with body
surfaces.
Gas filled structures are
most susceptible - lungs,
GI tract, and middle ear.
Blast lung (pulmonary
barotrauma)
TM rupture and middle ear
damage
Abdominal hemorrhage and
perforation - Globe (eye)
rupture- Concussion (TBI
without physical signs of
head injury)
Secondary
Results from flying debris and
bomb fragments.
Any body part may be
affected.
Penetrating ballistic
(fragmentation) or blunt
injuries
Eye penetration (can be
occult)
Tertiary
Results from individuals being
thrown by the blast wind.
Any body part may be
affected.
Fracture and traumatic
amputation
Closed and open brain injury
Quaternary
All explosion-related injuries,
illnesses, or diseases not due
to primary, secondary, or
tertiary mechanisms.
Includes exacerbation or
complications of existing
conditions.
Any body part may be
affected.
Burns (flash, partial, and full
thickness)
Crush injuries
Closed and open brain injury
Asthma, COPD, or other
breathing problems from
dust, smoke, or toxic fumes
Angina
Hyperglycemia, hypertension
Mortality/Morbidity
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Mortality rates vary widely
between incidents. An analysis
of 29 large bombing events
between 1966 and 2002
showed 8,364 casualties,
including 903 immediate
deaths and 7,461 immediately
surviving injured.
Immediate death/injury rates
were higher for bombings
involving structural collapse
(25%) than for confined space
(8%) and open air detonations
(4%).
Mortality/Morbidity
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Unique patterns of injury are found in
all bombing types. Injury is caused both
by direct blast overpressure (primary
blast injury) and by a variety of
associated factors.
Enclosed-space explosions, including
those occurring in busses, and in-water
explosions produce more primary blast
injury.
Explosions leading to structure
collapse produce more orthopedic
injuries.
Land mine injuries are associated with
a high risk of below- and above-theknee amputations.
Mortality/Morbidity
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Presence of tympanic
membrane (TM) rupture
indicates that a highpressure wave (at least 40
kilopascal [kPa], 6 psi) was
present and may correlate
with more dangerous organ
injury.
Theoretically, at an
overpressure of 100 kPa
(15 psi), the threshold for
lung injury, TM routinely
ruptures.
CLINICAL
History:
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If possible, determine
what material caused
the explosion.
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High-order explosives
(HEs)
Low-order explosives
(LEs)
CLINICAL
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If possible, determine
the patient's location
relative to the center of
the explosion.
Because explosions
often cause multiple
casualties, anticipate
activating the hospital
or regional disaster
plan.
Symptoms
Acute (0-2 Hours)
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Constitutional
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Localized
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Sub-Acute (2-48
Hours)
Dyspnea
Malaise
Apathy
Amnesia
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Pleuritic Chest
Pain
Non-productive
cough
Cardiac Chest
Pain
Abdominal Pain
Hematochezia
Hematemesis
Ear Pain
Hearing Loss
Vertigo
Balance Problems
Eye Pain
Visual Changes
Focal Numbness
Paresthesias
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Chronic (>48
Hours)
Progressively
Worsening Dyspnea
Fever
New or Progressive
Chest Pain
Productive Cough
Bilious Emesis
New or Progressive
Abdominal Pain
Nausea
Urge to Defecate
Tinnitus
Persistent
Hearing Loss
Physical:
 Examine lungs for
evidence of pulmonary
contusion and
pneumothorax.
 Abdominal injuries from
explosions may be
occult, and serial
examinations are often
required.
Physical:
 Many experts recommend obtaining a chest
radiograph in the presence of isolated
tympanic membrane (TM) rupture since this
may indicate exposure to significant
overpressure.
 In a large series of victims of bombings,
mostly involving closed spaces, 22% of
patients with eardrum perforation had other
significant injuries.
Signs
Acute (0-2 Hours)
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Inspection
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Auscultation
Sub-Acute (2-48 Hours)
Penetrating trauma
Traumatic amputation
Seizure activity
Respiratory difficulty
Hemoptysis
Pharyngeal petechiae
Tongue blanching
Mottling of non-dependent
skin
Inadequate chest-wall
expansion
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Abrasions
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Asymmetric Breath Sounds
Rales
Wheezes
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Newly Asymmetric Breath
Sounds
Subcutaneous Emphysema
Abdominal Tenderness
Spinal deformity or
Tenderness
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New or progressive
abdominal tenderness
Abdominal rigidity or
rebound tenderness
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Palpation
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Percussion
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Asymmetrical Chest
Percussion
Other
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Altered Mental Status
Focal Neurologic Deficit
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Fever
Delayed Shock
Overview of Explosive-Related Injuries
System
Injury or Condition
Auditory
TM rupture, ossicular disruption, cochlear damage, foreign body
Eye, Orbit, Face
Perforated globe, foreign body, air embolism, fractures
Respiratory
Blast lung, hemothorax, pneumothorax, pulmonary contusion and
hemorrhage, A-V fistulas (source of air embolism), airway epithelial
damage, aspiration pneumonitis, sepsis
Digestive
Bowel perforation, hemorrhage, ruptured liver or spleen, sepsis,
mesenteric ischemia from air embolism
Circulatory
Cardiac contusion, myocardial infarction from air embolism, shock,
vasovagal hypotension, peripheral vascular injury, air embolisminduced injury
CNS Injury
Concussion, closed and open brain injury, stroke, spinal cord injury, air
embolism-induced injury
Renal Injury
Renal contusion, laceration, acute renal failure due to rhabdomyolysis,
hypotension, and hypovolemia
Extremity Injury
Traumatic amputation, fractures, crush injuries, compartment
syndrome, burns, cuts, lacerations, acute arterial occlusion, air
embolism-induced injury
Lung
Hemorrhage:
 Pulmonary contusion
 Hemoptysis
 Hemothorax
Escape of Air:
 Pneumothorax
 Pulmonary pseudocyst
 Arterial gas embolism
(AGE)
“Blast Lung”
White Butterfly Sign
Tension Pneumothorax
GI Tract
Hemorrhage:
 Hematoma leading to
obstruction
 Upper or lower GI bleeding
 Hemoperitoneum
Escape of Contents:
 Mediastinitis
 Peritonitis
Blast Abdomen
1. Delayed onset > 8-36 hours – more
common in submersion
 a. Intestinal intra-wall
hemorrhages
 b. Shearing of local mesenteric
vessels
 c. Sub-capsular and
retroperitoneal hematomas,
 d. Fracture of liver and spleen, and
testicular rupture
2. Symptoms – exposure + abdominal
pain, nausea, vomiting,
 hematemesis (rare), rectal or
testicular pain and tenesmus
3. Signs – abdominal tenderness,
rebound, guarding, absent bowel
 sounds, signs of hypovolemia
4. Management – Resect small bowel
contusions > 15 mm,
 and large bowel contusions > 20
mm
Neck Injury
Signs and Symptoms of a Traumatic Brain Injury (TBI)
Physical
 Headaches
 Dizziness
 Insomnia
 Fatigue
 Uneven gait
 Nausea
 Blurred Vision
Cognitive
 Attention difficulties
 Concentration problems
 Memory problems
 Orientation problems
Behavioral
 Irritability
 Depression
 Anxiety
 Sleep disturbances
 Problems with
emotional control
 Loss of initiative
 Problems related to
employment, marriage,
relationships, and home
or school management
Ear
Middle ear:
 Ruptured tympanic membrane (TM)
 Temporary conductive hearing loss
Inner ear:
 Temporary sensory hearing loss
 Permanent sensory hearing loss
Risk Factors
The closer a casualty is to an
explosion, the more likely he
will receive primary blast injury
(PBI) from the effects of blast
overpressure alone,
particularly if behind cover and
shielded from ballistic trauma.
Personnel in enclosures
(buildings, ships, armored
vehicles, etc.) are at greater
risk, regardless of whether
detonation occurred inside or
outside the enclosure.
Risk Factors:
Personnel treading water are at higher risk for
abdominal than thoracic blast injury from
underwater explosion.
 Fully submerged personnel are at equal risk
of combined thoracic and abdominal blast
injury, as are personnel in open air, but
equivalency occurs at three times distance
from explosion underwater compared to open
air.
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Body armor increases the risk of
PBI, but decreases the risk of
secondary blast injury from
fragments, shrapnel, and debris
due to its ballistic protection of
vital structures.
Tertiary blast injury occurs when
the high-velocity blast wind
generated by pressure
differentials accelerate
personnel to tumble along the
ground, strike solid objects , or
impale themselves on other
objects. Secondary and tertiary
mechanisms result in
conventional blunt and
penetrating trauma
Rubber bullet
Wael Emad 14 years old boy
Died 22 October,2000 Palestine
Time magazine