Phemo Electrical Injuries
Phemo Electrical Injuries
Phemo Electrical Injuries
MANAGEMENT OF
ELECTRICAL INJURIES
DEFINITION
An electrical injury is damage to the skin or
internal organs when a person comes into
direct contact with an electrical current.
Factors Determining Electrical Injury
Type of circuit
Resistance of tissues
Amperage
Voltage
Current pathway
Duration
Environmental factors
Body Tissue Resistance
Least Nerves
Blood
Mucous membranes
Muscle
Intermediate Dry skin
Tendon
Fat
Most Bone
Symptoms
Pathophysiology
Cardiac Problems
Muscle Spasm
Oral Burn
Low Voltage Electrical Injury
HIGH VOLTAGE ELECTRICAL INJURY
Pathophysiology
The pathway of current can be somewhat unpredictable,
but, in general, current passes from a point of entry
through the body to a grounded site, i.e. , a site of lower
resistance to flow compared with air, which is a poor
conductor.
Extremely high voltage sources usually exit in multiple
areas in an explosive fashion. Current passing from hand
to hand or hand to thorax has a high risk of producing
cardiac fibrillation compared to hand to foot passage.
Passage through the head is likely to cause an initial
respiratory arrest and subsequent severe neurologic
impairment.
)
HIGH VOLTAGE ELECTRICAL
INJURY
Common Complications –
Ventricular Fibrillation
Muscle necrosis,
Other rhythm abnormalities
Fractures
Respiratory arrest
Hemolysis
Seizures/Coma
Renal Failure
Mental changes
Hemorrhage
Hypertension,
Limb loss
Retinal detachment,
Anemia
Cataract (delayed),
Paresis/paralysis and other neurotic (delayed)
HIGH VOLTAGE INJURIES
Pathway of Current
The pathway of current can be somewhat
unpredictable, but, in general current passes
from a point of entry through the body to a
grounded site, i.e. , a site of lower resistance to
flow compared with air, which is a poor
conductor.
Extremely high voltage sources usually exit in
multiple areas in an explosive fashion.
Current passing from hand to hand or hand to
thorax has a high risk of producing cardiac
fibrillation compared to hand to foot passage.
Passage through the head is likely to cause an
initial respiratory arrest and subsequent severe
neurologic impairment.
MECHANISM OF ELECTRICAL
INJURY
DIRECT CONTACT
ARC
FLASH
THERMAL
BLUNT TRAUMA
MECHANISM OF ELECTRICAL
INJURY
Direct contact: Current passing directly through the body will heat the
tissue causing electrothermal burns, both to the surface of the skin as well as
deeper tissues, depending on their resistance. It will typically cause damage at
the source contact point and the ground contact point. Contact burns are shown
in the image below.
Electrical arcs: Current sparks are formed between objects of different
electric potential that are not in direct contact with each other, most often a
highly charged source and a ground. The temperature of an electrical arc can
reach 2500-5000o C, resulting in deep thermal burns where it contacts the skin.
These are high-voltage injuries that may cause both thermal and flame burns in
addition to injury from direct current along the arc pathway.
Flame: Ignition of clothing causes direct burns from flames. Both
electrothermal and arcing currents can ignite clothing.
Flash: When heat from a nearby electrical arc causes thermal burns but
current does not actually enter the body, the result is a flash burn. Flash burns
may cover a large surface area of the body but are usually only partial
thickness.
Direct contact
FLASH BURNS
Electrical arcs are formed between areas of
different electrical potential that are not in direct
contact with one another. The charge needed to
create an electrical arc is usually very high, and
associated temperatures can reach 2500-
5000°C.
FALLS
High Voltage Is More Likely to
Kill Than Low Voltage-A MYTH
JOULE’S LAW:
Mechanical Trauma
Post-trauma sequelae
10 February 2020 23
BURNS
This definition describes a burn injury as
damage to the skin and underlying tissues
such as the subcutaneous tissues, muscle
and even bone in the case of electrical
injury. Burn injuries can be caused by
heat (thermal injury), chemicals or by
contact with electricity.
Primary Complications and Causes of
Death in Electrical Injuries
Cardiopulmonary arrest
Overwhelming injuries
Cardiac arrhythmias
Hypoxia and electrolytes
Intracranial injuries
Myoglobinuric renal failure
Abdominal injuries
Sepsis
Tetanus
Iatrogenic
Suicide
SCENE SAFETY
The most common sites of contact for the current include the hands and
the skull. The most common areas of ground are the heels. There may
be multiple contact and ground points.
Because high-voltage current often flows internally and can create
massive muscle damage one should not attempt to predict the amount
of underlying tissue damage from the amount of cutaneous involvement
or use the rule of nines for calculating fluid resuscitation. Cutaneous
burns should be covered with antibiotic dressings .
Electrical burns are especially prone to tetanus infection and patients
should receive tetanus toxoid and tetanus immune globulin on the basis
of their immunization history.
A special type of burn from low-voltage injuries is the mouth burns that
occur secondary to sucking on household electrical extension cords
and are the most common electrical injury seen in children under 4
years of age.
HEAD AND NECK
10 February 2020 49
Disposition