electrical_injury.ppt

8/9/2019 electrical_injury.ppt

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Electrical Injuries

Robert Primavesi, MDCM, CCFP(EM)

Montreal General Hospital

McGill University Health Centre


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Electrical Injuries

Goals

To identify the important complications of

electrical injuries.

To expose the pitfalls in diagnosis. To explore the controversies in management.


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Electrical Injuries

Objectives

Define the population at risk.

Determine the factors predicting the severity ofinjury.

Differentiate between high-voltage and low-voltage injuries.

Recognie which patients re!uire admission or

referral. Decide which patients need cardiac monitoring.


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Top 10 Myths of Electrical Injury

"


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Top 10 Myths of Electrical InjuryMyth #1

#lectrical $njuries %re &ncommon


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Electrical Injuries

Epidemiology

'() deaths in *uebec '+,-

'++(

/ additional patients

re!uiring emergency treatment 0-1 of all burn centre

admissions

2imodal distribution

3 Toddlers

3 4orkforce


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5oltage $s the 6ost $mportant

Determinant of $njury


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Electrical Injuries

Factors Determining Severity

1 ! " volta#e

$ i " c%rrent

& R " resistance

'HM *+- i " ! . R


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Electrical Injuries


/'U*E *+-

Po0er (0atts) " Ener#y (/o%les)

time

" ! i

" i$

R


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Electrical Injuries


M%co%s membranes

!asc%lar areas

volar arm, inner thi#het s2in

0eat

3atht%b

'ther s2in

ole o4 4oot

Heavily callo%se5 palm

2in Resistivity 6 'hms.cm$

177

&77 6 17 777

1 $77 6 1 877

$ 877

17 777 6 97 777

177 777 6 $77 777

1 777 777 6 $ 777 777


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7igh 5oltage $s 6ore 8ikely to 9ill Than

8ow 5oltage


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Electrical Injury


% momentary dose of

high voltage electricity is

not necessarily fatal.

8ow voltage is just aslikely to kill as high

voltage.

R9 4right: ;7 Davis. The investigation of electrical deaths< a report of ((= fatalities.! Forensic Sci! '+,=> (


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The #xtent of the

?urface 2urn

Determines the

?everity of $njury

Top 10 Myths of Electrical InjuryMyth #"


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Electrical Injuries

atterns o$ %nj&ry

Direct contact

3 Direct tissue heating

3 @ontact burns Aentry and

exitB3 Thermal burns


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The Cathway the #lectrical @urrent Takes

Through the 5ictim Credicts the Cattern of

$njuries

Top 10 Myths of Electrical InjuryMyth #'


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Electrical Injuries

atterns o$ %nj&ry

2in Resistivity

*east :erves

3loo5

M%co%s membranes

M%scle

;nterme5iate Dry s2in


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Electrical Injuries

E$$ects o$ () *+ ,&rrent

1 m+mp *et6#o? c%rrent

$7 m+ Possible tetany o4 resp m%scles

177 m+ !F threshol5

= + De4ibrillation

$7 + Ho%sehol5 circ%it brea2er opens


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Top 10 Myths of Electrical InjuryMyth #(

#lectricity 9ills by @ausing 6yocardial

Damage

@9 andor Troponin %re Eood 6arkers

for 6yocardial Damage in #lectrical$njury


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Electrical %nj&ries

atterns o$ %nj&ry

James T., Riddick L., Embry J. Cardiac abnormalitiesdemonstrated post-mortem in four cases of accidentalelectrocution and their potential significance relative to

non-fatal electrical injuries of the heart.AmericanHeart Journal.120: 143-57, 1990

Robinson N., Chamberlain D. Electrical injury to theheart may cause long-term damage to conductingtissue: a hypothesis and review of the literature.Int JCardiol.53: 273-7, 1996


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Top 10 Myths of Electrical InjuryMyth #-

%ll Catients 4ith #lectrical $njury Re!uire

() 7ours of @ardiac 6onitoring


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Electrical Injuries

,ardiac Monitoring

%lexander 8. #lectrical injuries of the nervous system.

.erv Ment Dis'+)'> +)< F((-F0(

;ensen C;: et! al! #lectrical injury causing ventriculararrhythmias. /r heart '+,> < (+-(,0

Norquist C., Rosen CL., Adler JN., Rabban JT.,Sheridan R. The risk of delayed dysrhythmias after

electrical injuries.Acad Emerg Med.6: 393, 1999


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Electrical %nj&ries

,ardiac MonitoringStudy Voltage No. of

patients

Initial ECG

= Normal

Initial ECG

= Abnormal

Late

Arrhythmias

Purdue and

Hunt

1000 48 40 8 0

Wrobel < 1000 35 31 4 0

Moran andMunster

110 850 42 40 2 0

Kirschmair

and Denstl

220 00 1 15 4 0

!ato"itch and

#ee

240 20 18 2 0

$unnin%ham 240 &0 5 11 0

Krein'e and

Kienst

( 220 31 2 2 0

)aile*+ et. al. 120 and 240 120 11 1 0

,rro-smith ( 220 &3 . 4 0


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Electrical %nj&ries

,ardiac Monitoring

@ardiac monitoring is not justified in

%?G6CTH6%T$@ patients:

Hr: in patients with only @&T%I#H&? burns:

4ho had a normal #@E after a '(= v or ()= v

injury.


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%88 Catients 4ho %re %symptomatic and

4ho 7ave a Iormal #@E %fter a '(=5 or

()=5 $njury @an 2e ?afely Discharged

Jrom the #D


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Electrical Injuries

atterns o$ %nj&ry

Cregnancy

3 Jetal monitoring is

mandatory for pregnant

patients

Hral commisure burns

@ataracts

Delayed neuro-

psychological se!uelae


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Top 10 Myths of Electrical InjuryMyth #

The*DO 45E/E, G5%DE6%.ES

Crovide the ?tandard of @are for #lectrical

$njuries
http://2002%20electrical%20inj%20flow%20diagram.ppt/http://2002%20electrical%20inj%20flow%20diagram.ppt/


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Electrical Injuries

S&mmary 7 8he ,hallenges

#lectrical injuries involve multiple body systems.

#ntry and exit wounds fail to reflect the trueextent of underlying tissue damage.

#lectrical current may cause injuries distant fromits apparent pathway through the victim.

@ontroversies exist regarding indications for

admission and cardiac monitoring following lowvoltage injuries.


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Electrical %nj&ries

8he F&t&re

Surveillance electrographique des patients ayant subiune lectrisation: tude prospective multicentrique.Investigateur principal: Benoit Bailey, MD MScFRCPC

21 sites across Quebec including RVH, MGH, MCH Primary objectives:1.determine the prevalence of cardiac arrhythmias in patientson initial ECG

2.determine the prevalence of late arrhythmias in patientswho undergo cardiac monitoring


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Secondary objectives:evaluate the importance of electrical injury in Quebecs EDs

given a normal initial ECG, evaluate if late arrhythmias

develop in patients with tetany, current across the heart, orwith >1000V

given a normal initial ECG, evaluate if late arrhythmiasdevelop in patients with PMHx of cardiac disease, ordecreased skin resistance

evaluate the incidence of cardiac problems in the yearfollowing electrical injury


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Secondary objectives, contd:

accumulate prospectively an experience with applying the

Hydro Quebec protocoldetermine the utility of measuring CK, CK-MB in predictingECG abnormalities and the development of late arrhythmias

determine the utility of measuring Troponin in predictingECG abnormalities and the development of late arrhythmias


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Top 10 Myths of Electrical InjuryMyth #1)

/eris an %ccurateReflection of 8ife in the #R

El t i Sh k


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Electric Shock:What Should You Do?

The victim:Felt the currentpass throughhis/her body

The currentpassed through

the heart

Was held by thesource of the

electric current

Lostconsciousness

Yes

No No

No1 secondor more

Yes

No

Yes

Cardiac Monitoring24 hours

Touched a voltagesource of more

than 1 volts

Yes

No

Yes

El t i Sh k:


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Electric Shock:What Should You Do?

Page 2.

Touched a voltagesource of more

than 1 volts

Cardiac Monitoring24 hours

!as burn mar"son his/her

s"in

The currentpassed through

the heart

Yes

No

Yes

Yes#valuate and treat burns

$surgical evaluation%

loo" for myogolbinuria% etc&'

No

Was thro(n fromthe source

#valuate trauma

No

)s pregnant#valuate fetal

activity

No

Yes

Yes

No

*#+),+ -!.C0eassure and discharge

Direction Services de SanteHydro Quebec, 1995

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electrical_injury.ppt