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ELECTROCUTION
BY
ANGELIE OROPILLA, MD
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ELECTROCUTION
Almost always due to alternating current (35-150 Hz)
Human beings are 4-6x more sensitive to alternatingcurrent (AC) than direct current (DC)
Amperage is the most important factor
Current is directly related to voltage and inverselyrelated to resistance
Greater the voltage, the higher the current
Greater the resistance, the lower the current
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FACTORS DETERMINING SEVERITY OF
ELECTRICAL INJURY
Nature of the current
Voltage involved
If alternating current, frequency involved
Amount of current
Length of time the victim is in contact with thecurrent
Condition of the earth (dry or wet), if the earth ispart of the circuit
Resistance of the body
The path of the current through the body
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LOW VOLTAGE DEATH
Voltage less than 1.000
volts Cause of death not always
obvious
Direct contact betweenvictim and the electrical
circuit Death primarily due to
ventricular fibrillation
If low current but greatcontact time= death may
still occur but mechanismof death is by muscleparalysis with secondaryasphyxia
HIGH VOLTAGE DEATH
Voltage more than 1,000
volts
Direct contact notnecessary as current mayarc to victim
Electric arc can genertehigh temp. (4000C)
Death due to respiratoryarrest or electrothermalinjuries caused by heat
generated by current
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RESISTANCE & CURRENT FLOW
Since voltage is fairly constant, changes in
resistance becomes an important factor in
determining amount of current that will flow
through the body
Blood and body fluids offer the least
resistance
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RESISTANCE & CURRENT FLOW
Human skin provides the greatest degree of
resistance
Type of Skin Resistance (ohms)
Dry,calloused,thickened 1 million ohms
Dry, non-calloused 100,000
Moist 1,000Moist, thin 100
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RESISTANCE & CURRENT FLOW
Also dependent on
type of clothing
Rubber boots andgloves
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Current
(mA)
Effect on Body
1 Threshold of perception, tingle
5 Muscle tremor
15 Muscle contraction, w/c prevents releaseof line
40 Possible loss of consciousness
75-100 Ventricular fibrillation
2000
(2 Amps)
Ventricular arrest
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ELECTRICAL BURN
OF THE SKIN
LOW VOLTAGE
Electrical burns in about
50% of cases
If victim remains in contactwith the electrical source,
severe burns may be seen
Electrical burns may be
hidden (mouth)
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ELECTRICAL BURN
OF THE SKINHIGH VOLTAGE
Electrical burns are seenin virtually all cases
Burns produced may besevere with charring oftissue
Distinctive odor = burntcork
Multiple small pittedburns may occur ascurrent arcs across body
Flash burnslargeareas of the skin
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ELECTRICAL BURN
OF THE SKINHIGH VOLTAGE
May cause explosive
injuries Loss of extremities
Rupture of organs
If burns produced by
contact: Fingertips or palms
Soles of the feet
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ELECTRICAL BURN
OF THE SKINHIGH VOLTAGE
Typical burn
Chalky white or
yellow/tan with centralcrater and raised paleborder
May have focal, smallareas of blackening
May be surrounded by azone of erythema
Punctate to 1-2 cm
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Lightning strike
Virtually all discharges are negative
Direct current (1000 million volts or more)
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Lightning strike
Direct strike
Contact- contact with object hit by lightning
Side flash- bolt strikes an object then jumps tothe individual nearby
Ground current- electrical energy from the
bolt move towards the ground and results in
injuries
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Lightning strike
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Lightning strike
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Lightning strike
Arborescent marks
Lichtenberg bodies
Filigree burns
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Lightning strike
Cardiopulmonary arrest
Electrothermal trauma
Paralysis of the nervous system Complications of burns
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THERMAL & FIRE INJURY
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CLASSIFICATION OF BURNS
ACCORDING TO
DEPTH OF INJURY
FIRST DEGREE
Limited to superficial
epidermis
Erythema & edema
Blistering not present
Painful No scarring
Ex. Mild sun burn
CLASSIFICATION OF BURNS
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CLASSIFICATION OF BURNS
ACCORDING TO
DEPTH OF INJURY
SECOND DEGREE
Partial thickness burns
Involve all of epidermis &
some of dermis
Sparing of skin appendages
Blister
Senses intact, with someassociated pain
Heal without scarring
except in deep burns which
may scar
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CLASSIFICATION OF BURNS
ACCORDING TO
DEPTH OF INJURY THIRD DEGREE
Full thickness
Necrosis of all skinlayers including skinappendages
Burned area appearswhite
Sensation is lost Severe scarring
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CLASSIFICATION OF BURNS
ACCORDING TO
DEPTH OF INJURY FOURTH DEGREE
Charring injury
Incineration of tissues Complete destruction
of the skin and
subcutaneous tissue
Complete or partialcharring of the bone
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CHARRED BODIESCharring may: Produce large splits in the
skin or muscle Occur parallel to muscle
fibers
Not due to to antemortem
trauma
Pugilistic attitude
Flexion of the upper
extremities similar to a
boxer holding hands in
front of his face Flexures develop as body
cools, not a reflexion of
position of body prior to
burning
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CHARRED
BODIES
Charring may:
Complete absence of
fingers, toes andportions ofextremities
Heat fractures
heat epidural
form as the blood
boils out of the venoussinuses
Chocolate brown,spongy or crumbly
Located over frontal,temporal or parietalareas of brain
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CHARRED BODIES
May be charred on
outside but internal
organs are usually wellpreserved
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BURN SEVERITY FACTORS
INTENSITY OF THE HEAT
Ordinary house fires = less than 1200-1600 F
industrial fuel fires = greater than 1900-2100 F
DURATION OF EXPOSURE Skin exposed to heat for 2 hrs
Hyperemic without loss of epidermis
Skin exposed to heat for 3 hours
Complete epidermal necrosis occurs
Cremation1500 F for 1-1 hrs
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EXTENT AND PATTERN OF BURN
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FACTOR AFFECTING BURN SURVIVAL
AGE
DEGREE OF THE BURN
PERCENTAGE OF TOTAL BODY SURFACE AREA
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CLOTHING & BURNS
MATERIAL
Cotton fabrics
less protection
Ignite easily
Nylon, polyester, wool produce less severe burns
Ignite less readily
TYPE / DESIGN OF GARMENT
Close fitting clothes are safer than long loose garments(i.e. nightgowns)
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT
FLAME BURNS
CONTACT BURNS
RADIANT BURNS
SCALDING BURNS
Immersion burns
Splash or spill burns
Steam burns
MICROWAVE BURNS
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT FLAME BURNS
Due to direct contact
with a flame
Severity depends upon
the length of time the
flame is applied
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT FLASH BURNS
Variant of flame burn
Caused by suddenignition or explosion of
fine particulate matter
or gas
Produces a uniform
burn (1stor 2nddegree)
of all exposed areas of
the skin, singes hair
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT CONTACT BURNS
Occur when skin is in
contact with a hot
object such as hot iron
May have
configuration or shape
of hot object that was
applied to the skin
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT RADIANT BURNS
Occur when skin is
exposed to heat waves
Contact with heat
source is not necessary
for a burn to occur
May produce blisters &
erythema
Prolonged exposure
may result in charring
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT SCALDING BURNS
When the skin is
contacted by a hot
liquid
Water at 70 C
Produce 3rddegree
burns in about one
second of contact
Water at 55 C
Almost 25 seconds to
produce same burn
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT IMMERSION BURNS
Accidental / homicidal
Homicidal example Child abuse
Immersion of child in
tub full of scalding
water
Burns with sparing ofknees, popliteal fossae
and inguinal regions
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT SPLASH BURNS
Usually accidental
Caused by spilling hot liquid over the body STEAM BURNS
Usually accidental
Superheated vapor can cause severe injury to the mucosa
of the airway Massive laryngeal edema may occur
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT MICROWAVE BURNS
Most are accidental
Occur as an individual reaches into a microwave which has notturned off completely or by ingestion of scalding hot liquid
heated in a microwave
CLASSIFICATION OF BURNS
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT CHEMICAL BURNS
Strong acids and alkalis Phosphorus, phenols
Burns produced slowerthan by thermal agents
Extent of injury dependon:
The chemical agent
Strength orconcentration of agent
Duration of contact with
the agent
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT Alkaline agents
Tend to cause moresevere injury than acid
agents Produce burns generally
have a pH greater than11.5
Frequent produce full
thickness injury Produce burns that
appear pale and feelleathery and slippery
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CLASSIFICATION OF BURNS
ACCORDING TO AGENT Acid agents
Produce only partial
thickness burns
May be accompanied
by erythema and
superficial erosion
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Death due to burn injury
Immediate death
Within minutes to hours of the injury
Delayed death Occur as result of numerous possible complications
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Death due to burn injury Immediate death may result
from
Neurogenic shock
Direct thermal injury
Large amount of fluidloss=hypovolemia = shock, acute
renal failure Inhalation injury
Soot in nares or mouth
Externsive thermal injury ofairway mucosa = mucosal
necrosis & edema =bronchospasm or upper airwayobstruction due to laryngealedema
Carbon monoxide poisoning
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Death due to burn injury
Inhalation injury
Other noxious agents
Cyanide
Acrolein
Reactive aldehyde produced by burning wood & petroleum products
Injury by protein denaturation Hydrochloric acid
Due to combustion of plastsics, furnishings building components
Pulmonary edema may be delayed for 2-12 hours after exposure
Tolouene diisocyanate
Nitrogen dioxide
h d b
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Death due to burn injury
Inhalation injury
Other noxious agents
Tolouene diisocyanate
Produced by burning polyurethane
May cause severe bronchospasm
Nitrogen dioxide
Produced in fires involving automobiles or agricultural wastes
Even brief exposure could cause broncho/larungeal spasm and
pulmonary edema
Chronic interstitial lung disease may be a late complicataion
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THANK YOU !