Electrocution/Lightening strikes

Question 1

Electrical injury results from (2):

The severity of electrical injury depends on (3):

Clinical manifestations of electrical injury include (4):

Dogs and cats are less likely to be struck by lightning than are large animal species, but when struck, dogs might be:

Answer 1

direct effects of the electrical current
the transformation of electrical energy into heat

1. resistance of the affected body part
2. currant - direct vs alternating
3. voltage

burns
cardiac arrhythmias
respiratory distress
neurologic abnormalities

more susceptible than are human beings

Question 2

MoA direct injury

electroporation

Answer 2

disrupt electrophysiologic activity, leading to muscle spasms, cardiac arrhythmias, loss of consciousness, and respiratory arrest

momentary holes in cellular membranes induced by electrical shock

holes allow passage of macromolecules across membranes, which causes osmotic damage to cells

Question 3

MoA heat injury:

arcing of a current

Answer 3

electrical current is transformed into heat
-intracellular and extracellular fluids may become superheated = coagulation of tissue proteins, thrombosis of small vessels, and degenerative changes in small arterial walls

= necrosis of the superheated tissues and those tissues that become ischemic from the vascular consequences. Direct thermal injury may also occur from arcing of a current that leaves the electrical source, crosses an air gap, and strikes tissue

Question 4

resistance of the part of the body that is struck:
high resistance:

Low resistance:

Answer 4

Dry skin has high resistance; therefore less energy will be transferred in dry skin than in wet skin.

Wet skin and moist mucous membranes have low electrical resistance; therefore one can expect high flow of electricity in these tissues and a propensity for maximal tissue damage

Question 5

Currents

alternating vs direct

Answer 5

Alternating currents tend to cause more severe injury than direct currents at the same amperage

higher exposure w alternating current
because elicits muscular contractions that prevent the victim from releasing the power source

= longer exposure time

direct current electricity do not cause muscular tetany.

Question 6

voltage

current (amperage) is a function of:

Answer 6

high-voltage more damage than low-voltage electricity

• more injury from 240-volt outlets
• standard 120-volt wall outlets

current (amperage) is a function of voltage/resistance
.:.magnitude of current depends on the affected tissue

Question 7

Cardiac CS

v-fib with what current

asystole with what current

Answer 7

Sudden death

low-voltage current
high-voltage exposure may cause asystole

Question 8

respiratory CS:
dyspnea secondary to (3):

NPE

NPE from electrocution is a form of NCPE less severe than others and resolves quicker (18-24)

Answer 8

nasopharyngeal edema
diaphragmatic tetany
neurogenic pulmonary edema

Neurogenic pulmonary edema is a form of noncardiogenic pulmonary edema in which central nervous system (CNS) insult results in massive sympathetic outflow that causes pronounced vasoconstriction and systemic hypertension

marked elevation of left ventricular afterload and decreased left ventricular stroke volume, which causes blood to accumulate in the pulmonary circulation; this results in increased pulmonary capillary pressure and subsequent edema

Question 9

neurologic manifestations
due to:

Gastrointestinal (GI):

Ocular manifestations:

Answer 9

electrically induced neural activity rather than electroporation

ileus

cataracts are usually later findings noted several months after the episode

Question 10

Tx:
1.
2.

Answer 10

1. electricity turned off at the electrical panel
alternatively, the offending electrical cord may be unplugged carefully from the outlet
2. relative shock - NaCl 7.5% resusc.
3. UAO temp trach
4. O2
5. burns - wound management
-enteral nutrition
-seizures
-arrhythmias

Question 11

Lightening strike MoA:
The pathophysiology of lightning injury is similar to that of other electrical injuries, except for the mechanism by which the electricity reaches the victim and the potential for injury from mechanical energy.

There are five possible mechanisms by which lightning can deliver electrical energy to a victim:

Answer 11

(1) direct lightning strike
(2) direct strike of an object that the victim is touching
(3) side flash from a struck object
(4) step voltages produced by current flowing through the soil beneath
(5) an upward streamer that does not connect or complete a full lightning strike

upward streamer of charge that is induced from an object on the ground as a lightning leader of flash approaches the ground from a thundercloud

Question 12

In addition to electrical and thermal injury, mechanical energy can be imparted to the lightning victim.

______ rapid air movement caused when superheated air is then cooled may result in physical injury

blast effect of lightning strike has been reported to cause

Answer 12

blast effect

spinal fx pond fish
vestibular injury in horses and human beings

Although such injuries have not been reported in dogs and cats, occurrence of mechanical energy effects of those reported in other species should not be surprising