Blast injuries

A POWER POINT PRESENTATION
BY
DR.SANGEETA CHOWDHRY
&
DR.SUNIL SHARMA
DEPARTMENT OF FORENSIC MEDICINE
&
TOXICOLOGY
GOVT. MEDICAL COLLEGE
JAMMU (JAMMU AND KASHMIR)

A blast injury is a complex type of physical
trauma resulting from direct or indirect exposure
to an explosion.
Blast injuries occur with the detonation of high-
order explosives as well as the deflagration of low
order explosives. These injuries are compounded
when the explosion occurs in a confined space.

CONTENTS
INTRODUCTION.
CLASSIFICATION OF EXPLOSIVE.
CLASSIFICATION OF INJURIES.
MECHANISM.
NEUROTRAUMA.
EFFECTS OF INJURIES ON HUMAN BODY.
SELECTED BLAST INJURIES.
MEDICO-LEGAL ASPECT.
POST –MORTEM FINDINGS.
CONCLUSION

INTRODUCTION
Bomb blast injuries to civilians are becoming
increasingly common over the last two decades mainly
due to terrorist attacks and are not only confined to
wars but also become pandemic with ever increasing
acts of terrorism though the incidences are sporadic.
Explosions cause life-endangering unique type of
injuries involving multi organ system especially lungs
& central nervous system in single or multiple victims
simultaneously thereby producing mass casualties.
Every person from medical field or law enforcement
agencies should be well conversant about the pattern,
severity, mechanism, nature of injuries as they have to
deal with hundreds to thousands of victims with
different types of injuries.

CLASSIFICATION OF
EXPLOSIVE
High-order explosives (HE) as a result of detonation
produces almost instantaneous high pressure
rapidly expanding gases which compress the
surrounding air resulting into supersonic over
pressurization shock or blast wave followed by
negative pressure (suction) wave which lasts for
about 5 times. Examples: - Trinitrotoulene (TNT), C-
4, Semtex, nitroglycerin, dynamite and ammonium
nitrate fuel oil (ANFO).
Low-order explosives (LE) undergo deflagration
instead of detonation thereby releasing slow energy
as compared to HEs resulting in subsonic explosion
lacking over-pressurization blast wave Examples: -
Pipe bombs, gunpowder and most pure petroleum-
based bombs such as Molotov cocktails or aircraft
improvised as guided missiles.

FACTORS-THAT DETERMINE THE
MAGNITUDE OF DAMAGE
Surroundings & Medium in which
it explodes.
The distance from the incidence.
Pressure wave & its duration.
Amount and composition of the
explosive material.

CLASSIFICATION OF BLAST
INJURIES
 Primary injuries
 Secondary injuries
 Tertiary injuries
 Quaternary injuries

ILLUSTRATIONS OF PRIMARY, SECONDARY AND TERTIARY
INJURIES FROM BLAST

CLASSIFICATION OF BLAST
INJURIES
Primary injuries are caused by blast overpressure waves, or shock waves.
These are especially likely when a person is close to exploding
ammunition, such as a land mine. Gas filled structures are most
susceptible as air is easily compressible than water.
 lungs, GI tract, Ear, Eye, Brain
 Blast lung (pulmonary barotrauma)
 Abdominal haemorrhage and perforation
 TM rupture and middle ear damage
 Globe (eye) rupture
 Concussion
The ears are most often affected by the overpressure, followed by the lungs
and the hollow organs of the gastrointestinal tract. Gastrointestinal
injuries may present after a delay of hours or even days. Injury from blast
overpressure is a pressure and time dependent function. By increasing
the pressure or its duration, the severity of injury will also increase.
In general, primary blast injuries are characterized by the absence of
external injuries; thus internal injuries are frequently unrecognized and
their severity underestimated.

CLASSIFICATION OF BLAST INJURIES
Secondary injuries are caused by fragmentation and other
objects propelled by the explosion. Results from flying
debris, broken glass, loose pieces and bomb fragments
any body part can be affected. These injuries may affect
any part of the body and sometimes result in penetrating
trauma with visible bleeding. At times the propelled
object may become embedded in the body, obstructing
the loss of blood to the outside. However, there may be
extensive blood loss within the body cavities.
Fragmentation wounds may be lethal and therefore
many anti-personnel bombs are designed to generate
fragments.
Most casualties are caused by secondary injuries. Some
explosives, such as nail bombs, are deliberately designed
to increase the likelihood of secondary injuries. In other
instances, the target provides the raw material for the
objects thrown into people, e.g., shattered glass from a
blasted-out window or the glass facade of a building.

Tertiary injuries:- Displacement of air by the
explosion creates a blast wind that can throw victims
against solid objects. Injuries resulting from this type
of traumatic impact are referred to as tertiary blast
injuries. Tertiary injuries may present as some
combination of blunt and penetrating trauma,
including bone fractures and coup contre-coup
injuries.
(An injury, usually involving the brain, in which the
tissue damage is on the side opposite the trauma site,
as when a blow to the left side of the head results in
brain damage on the right side.)
Young children, because they weigh less than adults,
are at particular risk of tertiary injury.

Quaternary injuries or other miscellaneous named injuries, All explosion-
related injuries, illnesses or diseases not due to primary, secondary, or
tertiary mechanisms.
 Includes exacerbation or complications of existing conditions e.g. on 9/11 the
crash of two jet airplanes into the World Trade Centre created a relatively low-
order pressure wave resulting into fire and building collapse producing
thousands of mortalities. Any body part can 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
Traumatic amputations quickly result in death, and are thus rare in
survivors, and are often accompanied by significant other injuries. The rate
of eye injury may depend on the type of blast. Psychiatric injury, some of
which may be caused by neurological damage incurred during the blast, is the
most common quaternary injury, and post-traumatic stress disorder may
affect people who are otherwise completely uninjured.

MECHANISM OF BLAST
INJURIES
The explosive pressure that accompanies the
bursting of bombs or shell, ruptures their casing
and imparts a high velocity to the resulting
fragments. These fragment have the potencial to
cause more devastating injury to tissues than
bullets.
In addiction, all explosives are accompanied by a
“COMPLEX WAVE”. The main component of this
wave are a “BLAST WAVE”( known as dynamic
overpressure) with a positive and a negative
phase, and the “BLAST WIND” ( mass movement
of air). Injuries are mainly due to the initial shock
wave, but are aggravated by the sub-atmospheric
phase.

MECHANISM OF BLAST
INJURIES
The mass movement of air blast (blast wind)
disrupts the environment, throwing debris and
people. This phenomenon results in injuries
ranging from traumatic amputation to
disruption.
When the body is impacted by a blast pressure
wave, it couples into the body and sets up a
series of. stress waves which are capable of
injury, particularly at air-fluid interfaces.
Thus, injuries to the ear, heart and GIT are
notable

NEUROTRAUMA
Blast injuries can cause hidden brain damage and
potential neurological consequences. Its complex clinical
syndrome is caused by the combination of all blast effects,
i.e., primary, secondary, tertiary and quaternary blast
mechanisms. It is noteworthy that blast injuries usually
manifest in a form of polytrauma, i.e. injury involving multiple
organs or organ systems. Bleeding from injured organs such
as lungs or bowel causes a lack of oxygen in all vital organs,
including the brain. Damage of the lungs reduces the surface
for oxygen uptake from the air, reducing the amount of the
oxygen delivered to the brain. Tissue destruction initiates
the synthesis and release of hormones or mediators into the
blood which, when delivered to the brain, change its
function. Irritation of the nerve endings in injured peripheral
tissue and/or organs also significantly contributes to blast-
induced neurotrauma.
…………….CONT………………………

NEUROTRAUMA
Individuals exposed to blast frequently manifest loss of
memory for events before and after explosion,
confusion, headache, impaired sense of reality, and
reduced decision-making ability. Patients with brain
injuries acquired in explosions often develop sudden,
unexpected brain swelling and
cerebral vasospasm despite continuous monitoring.
However, the first symptoms of blast-induced
neurotrauma (BINT) may occur months or even years
after the initial event, and are therefore categorized
as secondary brain injuries. The broad variety of
symptoms includes weight loss, hormone imbalance,
chronic fatigue, headache, and problems in memory,
speech and balance. These changes are often
debilitating, interfering with daily activities. Because
BINT in blast victims is underestimated, valuable time
is often lost for preventive therapy and/or timely
rehabilitation.

EFFECTS OF INJURIES ON
HUMAN BODY
Disruptive Effect: It affects the person
who is quite close to bomb. When
bomb explodes, the person may be
blown into pieces. If the victim is a
bit far away, he may have his limb
blown off. These disruptive injuries
are quite extensive and victim dies
immediately.

HUMAN BODY
Shock Wave: It is also called „air blast‟. As a result of blast
a zone of compressed air is created and it travels further.
This wave of compression is followed by a wave of negative
pressure. So, the victim bears first impact of compressed air
and then negative pressure. The high pressured compressed
air can knock down a person easily. This wave causes
maximum damage to lungs. It leads to disruptive effect
causing rupture of alveolar septa and cause haemorrhage in
alveoli. The air passages are filled up with blood and fluid.
The fluid in the alveolar space can cause respiratory failure.
These injuries are sometimes referred to as „blast lung.‟
The shock wave also causes damage to ears. The tympanic
membrane is ruptured. The alimentary system also suffers
damage due to the pressure of air. The stomach and
intestine may rupture. The solid tissues like liver, kidneys,
etc. resist the impact of shock wave better than hollow
organs like stomach containing air.

HUMAN BODY
Burns: When a bomb is
exploded, the temperature
reaches around 2000°C and
heated gases are released. They
produce burns on victims who are
in vicinity of the bomb blast. The
exposed areas of the body are
severely affected as compared to
the covered ones.

HUMAN BODY
Flying Missiles: These may originate from
bomb itself as some bombs contain
metal pins, small metal balls or metallic
nails which act as missiles and cause
injuries to all those present around the
site of the bomb blast. Sometimes, as a
result of shock wave, small objects may
also be thrown as missiles and may
cause injuries. The small pins or metal
nails used in the bomb may cause
multiple abrasions and lacerations due
to these flying missiles.

HUMAN BODY
Falling Masonry: Sometimes a bomb
blast in a building may result in its
collapse due to shock wave and
persons may be caught in the
falling debris. People may suffer
traumatic asphyxia once caught
in the debris. They may sustain
head injury or other injuries due
to falling stones.

HUMAN BODY
Asphyxia: In bomb blast, a lot of
gases are produced which can
cause asphyxia, if the explosion
has occurred in a closed area.
Common gases are carbon
dioxide, carbon monoxide, and
hydrogen sulphide.

SELECTED BLAST INJURIES
Respiratory system
 The Blast lung (Pulmonary barotraumas)
the most common fatal primary blast injury.
 “Butterfly” pattern on chest X-ray is the
characteristic of blast lung.
 Bronchopleural fistulae, pneumo-
thoraces, pseudocyst formations.
 ARDS and air embolism
 Diffuse lung damage even after two days.
 Pulmonary blast injury carries the highest
mortality and morbidity and consumed the
most resources in the major bombings.

Ear
Deafness.
Rupture/ perforation of Tympanic
Membrane
Fracture/ dislocation of ossicles
Cochlear damage
Foreign body in ear
Long-term ENT sequel--- vertigo/
tinnitus, dizziness and ear pain.

Central nervous system
Headache, fatigue, poor
concentration, lethargy, depression,
anxiety, insomnia, loss of memory
Closed and open brain injury
Intracranial, subdural and extradural
haemorrhages
Stroke
Spinal cord injury

Abdominal Injury
Symptoms: Abdominal pain, nausea,
vomiting, haematemesis, rectal
pain, tenesmus, testicular pain,
unexplained hypovolemia.
Acute/delayed signs of peritonitis
Mesenteric shear injuries.
Blunt trauma to the abdomen can
cause solid organ injuries like liver,
renal and splenic contusion,
lacerations and haemorrhage.

MEDICO LEGAL ASPECTS
Injuries from bombs used to be mainly
accidental in the past. Their homicidal use is
now common with the use of bombs by
terrorists to destroy specific targets, such as
government building, bridges, public
transport vehicles, premises occupied by
their opponents. The composition of bombs
varies.
Few examples of bombs in common use include
Time Bomb, Impact bomb, Napalm bomb,
Molotiv Cocktail, etc.

TIME BOMB
IMPACT BOMB
NAPALM BOMB MOLOTIV COCKTAIL BOMB

The main concern in modern era is the destruction
of commercial aircraft in flight has important
medico-legal implications. The main difficulty
facing the investigators is to distinguish sabotage
from explosive decompression due to structural
failure. This issue is important as the
responsibility of insurance claims passes from
“ALL RISK” to “WAR RISKS”. In these days of
advanced technology, any unexplained disaster in
air should be suspected to be due to sabotage
until the contrary is proved. The major part of the
aircraft would be found scattered over wide area
without any logical pattern in a case of mid-air
explosion caused by sabotage.

Forensic personnel should be familiar with the pattern
and severity of injuries so that the proper injury report
in case of survivors and post mortem report in cases
of death of persons can be prepared and collect
properly any foreign body (shrapnel, empty shell etc.)
and hand over to investigation officer. Recognition,
proper interpretation and documentation of these
types of injuries would assist with reconstruction of
the incident.
Sometimes Forensic personnel have to give opinion
regarding time of injuries so that actual and needy
should get the benefit of state machinery and ex gratia
announced by the government. Forensic personnel
should have eagle‟s eyes to catch the moles.

Following things are of vital importance in
bomb blasts/explosions
 Whether a bomb has caused the explosion
 Number of dead persons
 Identification of the dead
 Enlisting the injuries
 External
 Internal
 Cause of death
 Circumstances of death

WHETHER A BOMB HAS CAUSED THE EXPLOSION
 Full body photographs and complete X-rays of the whole
body are indicated before the clothes are removed. Any
radio-opaque fragments and radiolucent material (paper
fragments, wood and plastic) may be component of an
explosive device.
 Residues are either burnt(black or gray) or unburnt
(yellow, brown, gray) material. Swab the soiled skin and
hands. Collect hair and fingernail scrapings.
 Foreign body (shrapnel or empty shell) may be found during
autopsy.
 Toxicological analysis may help.
 Extensive burns are usually not caused by localised bomb
explosion.

NUMBER OF DEAD PERSONS
A major initial problem,
correct fragment are to be
allocated to the right
individuals.

IDENTIFICATION OF THE DEAD
The injuries can be extreme and thus make
the identification and interpretation difficult
for the autopsy surgeon. All body parts and
clothing are recovered (clothing is submitted
in air tight containers).
 Dentition, dentures and artificial teeth also
help in identification.
 Fingerprinting may also help.

ENLISTING THE INJURIES
These include:-
External and internal injuries
External injuries:- total disintegration indicates high- order condensed
explosive at close range.
 There may be mangling of body near explosion with parts of
extremities amputated; cranio-facial injuries re seen in a case of
suicide. Lower limb amputation is typical of standing or seated
individual. Hand injuries are seen, of explosive was held.
 There may be projectile injury.
 Punctate laceration, dust tattooing and black soiling from
explosive materials may be seen. “TRIAD” of bruises, abrasions and
puncture lacerations with tattooing of the body indicates bomb
explosion.
 Injuries may be seen due to fallen rubble.
 Burns(flash burns and singed hair seen on victims in immediate
vicinity).

Internal injuries:- have been described in detail under the headings
of :-
 PRIMARY INJURIES
 SECONDARY INJURIES
 TERTIARY INJURIES
 QUATERNARY INJURIES
&
• &&&&&

CAUSE OF DEATH
Death may result from variety of causes, i.e.
 Complete disintegration of body as a result of blast
effect while in the vicinity of blast. (Blast shock)
 While one is at some distance away from the site,
death may result from burns, blunt force injuries, and
falling debris
 Crush syndrome/ asphyxia (due to inhalation of
products of combustion)
 A victim may be little injured but may die of profound
shock
 Another possible cause of rapid death----Systemic air
embolism

CIRCUMSTANCES OF DEATH
NEED TO LOOKED FOR

POST-MORTEM EXAMINATION
The post-mortem examination of bomb blast cases should be carefully
done, and following guidelines should be followed:
Identification: It poses serious problems as bodies are mutilated and
disfigured. Sometimes, even pieces of various bodies may be found
together. In all such cases, first the reconstruction of bodies should
be done, by organs. The number of heads show the number of
persons killed. The soft parts should be carefully collected and
applied in anatomical positions to know the side to which they
belong. Apart from injuries due to burns, flying missiles, falling
debris, and the effect of poisonous gases liberated by the
explosive, the blat wave produces scattered foci of small
haemorrhages in brain, lungs, bowel, and in mesentery. Passive
hyperaemia and/or oedema cause serious secondary brain and lung
lesion. Intracranial haemorrhages, contusion of brain and heart, and
aortic injuries, ruptured stomach / bowel and bladder may be seen.
…………………….cont…………………………..

POST-MORTEM EXAMINATION
Further identification can be done by:
(a) X-ray examination of skull and then subjecting to super-imposition
technique.
(b) Matching dental record if previous records are available. Compare dental
fillings and old fracture in dental record.
(c) Preserving tissues, like parts of liver and bone marrow for DNA test to
establish identity.
Clothing: It must be thoroughly inspected and any pieces of explosives may
be preserved. The clothes should be preserved and sent for forensic
science laboratory.
Injuries: All injuries should be carefully noted. Any missing parts should be
clearly mentioned in post-mortem report.
The cause of death should be ascertained taking into consideration all
injuries. Usually shock is the cause of death. Death may be instant if
the person is blown into pieces.

CONCLUSIONS
 Blast injuries are not confined to the battlefield but are
pandemic.
 Seal the hospital entrances and scan the hospital properly to
prevent the tactic of setting of dual explosion to produce
more mortalities as first explosion for civilians and second
for caregivers and rescuers.
 Consider exposure to carbon monoxide, cyanide, or
methemoglobin-forming toxins in industrial as well as
terrorist explosion.
 Penetrating/blunt trauma to anybody surface is the most
common injury seen among survivors.
 Patients should require 4-6 hours of observation.
 Radiological imaging of the head, chest and abdomen will
help with the early identification of blast lung injury, head
injury, abdominal injury, eye and sinus injuries, as well as
any penetration by foreign bodies.
 Isolated TM rupture is not a reliable marker of morbidity.
 Delay the primary closure in contaminated wound and give
tetanus toxoid and anti-tetanus serum.

Blast injuries

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