ELECTRICAL INJURIESELECTRICAL INJURIES

DEFINITIONDEFINITION e·lec·tric·i·tye·lec·tric·i·ty             (ĭ-lěk-trĭs'ĭ-tē, ē'lěk-)   (ĭ-lěk-trĭs'ĭ-tē, ē'lěk-)

n.   n.   – The physical phenomena arising from the behavior of The physical phenomena arising from the behavior of

electrons and protons that is caused by the attraction of electrons and protons that is caused by the attraction of particles with opposite charges and the repulsion of particles with opposite charges and the repulsion of particles with the same charge. particles with the same charge.

– The physical science of such phenomena. The physical science of such phenomena. Electric current used or regarded as a source of power. Electric current used or regarded as a source of power. Intense, contagious emotional excitement. Intense, contagious emotional excitement.

ELECTRICITY ELECTRICITY 101101

HISTORYHISTORY

1600’s1600’s Electricity was studied by William GilbertElectricity was studied by William Gilbert

Gilbert published a book on electricity and Gilbert published a book on electricity and magnetism using for the first time the word magnetism using for the first time the word electriaelectria

16601660 Otto von Guericke invented a machine that Otto von Guericke invented a machine that

produced static electricity, this was the first produced static electricity, this was the first electric generator.electric generator.

17291729 Charles Francois du Fay discovered Charles Francois du Fay discovered

electricity comes in two forms, now known electricity comes in two forms, now known as positive and negativeas positive and negative

17451745 Almost simultaneously in Holland and Almost simultaneously in Holland and

Germany the Leyder jar was invented. This Germany the Leyder jar was invented. This was the first capacitor ( a device that stores was the first capacitor ( a device that stores and releases electricity)and releases electricity)

17471747 Henery Cavendish began measuring the Henery Cavendish began measuring the

conductivity of different materialsconductivity of different materials

17521752 Ben Franklin discovered that lightning and Ben Franklin discovered that lightning and

electricity are one in the same leading to electricity are one in the same leading to Franklins invention of the lightning rod, the Franklins invention of the lightning rod, the first practical application of electricityfirst practical application of electricity

17861786 Luigi Galvani discovered what we now Luigi Galvani discovered what we now

know to be the electrical basics of nerve know to be the electrical basics of nerve impulses by making a frogs muscles twitch impulses by making a frogs muscles twitch when jolted with electricity.when jolted with electricity.

18311831 The principle of conducting electricity was The principle of conducting electricity was

used to create the telegraph.used to create the telegraph.

18351835 Thomas Davenport built the first roadworthy Thomas Davenport built the first roadworthy

electric car, but due to battery cost it was electric car, but due to battery cost it was not practical.not practical.

18701870 Thomas Edison was working with DC Thomas Edison was working with DC

current and in 1885 Edison’s lighting system current and in 1885 Edison’s lighting system was developedwas developed

1900’s1900’s Finely in the early 1900’s George Finely in the early 1900’s George

Westinghouse pioneered the use of AC Westinghouse pioneered the use of AC current that we use today.current that we use today.

ELECTRICITY ELECTRICITY 101101

MathMath

Electric ShockElectric Shock The severity of a electric shock The severity of a electric shock

depends on?depends on?–The current that passes through The current that passes through

the body. the body.

–Where the current passes.Where the current passes.

–The length of time for exposure.The length of time for exposure.

Electric ShockElectric Shock Household current can feel as Household current can feel as

only a mild tingle to a fatal only a mild tingle to a fatal shock. Why?shock. Why?

–The amount of resistance in the The amount of resistance in the body.body.

Electric ShockElectric Shock Body Area Resistance (ohms)Body Area Resistance (ohms)

– Dry skin100,000 to 600,000 Dry skin100,000 to 600,000

– Wet skin1,000Wet skin1,000

– Internal body (hand to Internal body (hand to foot)400 to 600 foot)400 to 600

– Ear to ear~100Ear to ear~100

Electric ShockElectric Shock AC vs. DCAC vs. DC

– AC, particularly of the common 50-60 Hz AC, particularly of the common 50-60 Hz (cycles/second) variety, is three to five times (cycles/second) variety, is three to five times more dangerous than DC (direct current) of the more dangerous than DC (direct current) of the same voltage and amperage (current strength). same voltage and amperage (current strength).

Electric ShockElectric Shock Lets look at resistance and current.Lets look at resistance and current.

– Current is determined by Volts over ohms.Current is determined by Volts over ohms.

– Or Or

– 1.2mA……….or just enough to feel.1.2mA……….or just enough to feel.

Electric ShockElectric Shock Then in this example we have decreased Then in this example we have decreased

the ohms.the ohms.

SCENE SAFETYSCENE SAFETY

HouseholdHousehold

IndustrialIndustrial

High voltageHigh voltage

HOUSEHOLDHOUSEHOLD Who is the MOST important person when Who is the MOST important person when

responding to a electrocution in the responding to a electrocution in the household? household?

What hazards do we need to be aware of?What hazards do we need to be aware of?– Has the Pt. been removed from the power Has the Pt. been removed from the power

source.source.– Has the power been shut off.Has the power been shut off.

HOUSEHOLDHOUSEHOLD What can we do to assure that there will be What can we do to assure that there will be

no danger of becoming a victim?no danger of becoming a victim? What type voltage and current will we be What type voltage and current will we be

dealing with.dealing with.– 110 to 220 & 1mA to 300mA110 to 220 & 1mA to 300mA

Voltages in this range will take the path of Voltages in this range will take the path of least resistance.least resistance.

HOUSEHOLDHOUSEHOLD 1mA Is the threshold of being able to feel a 1mA Is the threshold of being able to feel a

small tingle.small tingle. 5mA Is the accepted maximum harmless 5mA Is the accepted maximum harmless

current.current. 10-20mA Beginning of sustained muscle 10-20mA Beginning of sustained muscle

contraction (“I cant let go”).contraction (“I cant let go”). 100-300mA V-fib, fatal if continued.100-300mA V-fib, fatal if continued.

INDUSTRIALINDUSTRIAL Who is the MOST important person on the Who is the MOST important person on the

call?call? Are there any additional hazards when we Are there any additional hazards when we

respond to the industrial site?respond to the industrial site? What types of voltage a current will we find What types of voltage a current will we find

here?here?– 120 to 460 volts or more in AC or DC120 to 460 volts or more in AC or DC

INDUSTRIALINDUSTRIAL What can we do to assure that there will be What can we do to assure that there will be

no danger of becoming a victim?no danger of becoming a victim? What type voltage and current will we be What type voltage and current will we be

dealing with.dealing with.– 110 to 480 or more & 1mA to 300mA110 to 480 or more & 1mA to 300mA

Lower voltages will take the path of least Lower voltages will take the path of least resistance, while the higher voltages will resistance, while the higher voltages will follow the most direct to ground.follow the most direct to ground.

INDUSTRIALINDUSTRIAL In the industrial setting we will find all the In the industrial setting we will find all the

amperages we discussed in household.amperages we discussed in household.

Plus up to 6A or more.Plus up to 6A or more.

In this range we can expect to see sustained In this range we can expect to see sustained ventricular contraction followed by normal ventricular contraction followed by normal heart rhythm, temporary respiratory heart rhythm, temporary respiratory paralysis & possibly burns.paralysis & possibly burns.

HIGH VOLTAGEHIGH VOLTAGE Who is the MOST important person on this Who is the MOST important person on this

call?call? Are there additional hazards to this call?Are there additional hazards to this call? Who will we need to contact with this type Who will we need to contact with this type

call?call? What type voltages will we find here?What type voltages will we find here?

– 1000 to 1,000,000 volts 1000 to 1,000,000 volts

HIGH VOLTAGEHIGH VOLTAGE Who will be exposed to this type hazard?Who will be exposed to this type hazard?

– Auto accidentsAuto accidents– Ice stormsIce storms– Tree servicesTree services– RoofersRoofers– Cable TVCable TV– Power company crewsPower company crews– Construction sitesConstruction sites

HIGH VOLTAGEHIGH VOLTAGE This type of voltage will take the shortest This type of voltage will take the shortest

path to ground.path to ground. There will be entrance & exit burns.There will be entrance & exit burns. Extensive tissue damage between the Extensive tissue damage between the

entrance & exit.entrance & exit. Upon exit the electricity can cause the Upon exit the electricity can cause the

tissue to explodtissue to explod

HIGH VOLTAGEHIGH VOLTAGE Entrance Wound: High Entrance Wound: High

resistance of skin resistance of skin transforms electrical transforms electrical energy into heat, which energy into heat, which produces burns around produces burns around the entrance point the entrance point (dark spot in center of (dark spot in center of wound). This man was wound). This man was lucky, the current lucky, the current narrowly missed his narrowly missed his spinal cord. spinal cord.

HIGH VOLTAGEHIGH VOLTAGE Exit Wound: Current flows Exit Wound: Current flows

through the body from the through the body from the entrance point, until finally entrance point, until finally exiting where the body is exiting where the body is closest to the ground. This closest to the ground. This foot suffered massive foot suffered massive internal injuries, which internal injuries, which weren't readily visible, and weren't readily visible, and had to be amputated a few had to be amputated a few days later. days later.

HIGH VOLTAGEHIGH VOLTAGE This man was near a This man was near a

power box when an power box when an electrical explosion electrical explosion occurred. Though he did occurred. Though he did not touch the box, not touch the box, electricity arced through electricity arced through the air and entered his the air and entered his body. The current was body. The current was drawn to his armpits drawn to his armpits because perspiration is because perspiration is very conductive. very conductive.

HIGH VOLTAGEHIGH VOLTAGE This worker was This worker was

shocked by a tool he shocked by a tool he was holding. The was holding. The entrance wound and entrance wound and thermal burns from the thermal burns from the overheated tool are overheated tool are apparent apparent

HIGH VOLTAGEHIGH VOLTAGE This worker fell and This worker fell and

grabbed a power line to grabbed a power line to catch himself. The catch himself. The resulting electric shock resulting electric shock mummified his first two mummified his first two fingers, which had to be fingers, which had to be removed. The acute angle removed. The acute angle of the wrist was caused by of the wrist was caused by burning of the tendons, burning of the tendons, which contracted, drawing which contracted, drawing the hand with them. the hand with them.

CONCLUSIONCONCLUSION BE SAFE DON’T BECOME PART OF THE BE SAFE DON’T BECOME PART OF THE

PROBLEM!!!! THINK!!!PROBLEM!!!! THINK!!! Airway.Airway. Breathing.Breathing. Control bleedingControl bleeding Treat the cardiac issues per A.C.L.S.Treat the cardiac issues per A.C.L.S. This is a trauma Pt.This is a trauma Pt.