GEMC- Electrical Misadventures- Resident Training

Project: Ghana Emergency Medicine Collaborative

Document Title: Electrical Misadventures

Author(s): Joe Lex, MD, FACEP, FAAEM, (Temple University) 2013

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Joe Lex, MD, FACEP, FAAEM Department of Emergency Medicine

Temple University School of Medicine

Philadelphia, PA

Electrical Misadventures

Objectives

Discuss controversies about…

…microwave injuries

…cord-biting injuries

…lightning injuries

…TASER® injuries

Steve and Sara, Flickr

Objectives

• Explore some controversies in

management of electrical injuries

• Determine who really requires

hospital admission

• Discuss how pregnancy changes

management

Microwave

Mk2010, Wikimedia Commons

Microwave

• More similar to electric burns than

to conventional oven burns

• Tend to be sharply demarcated

• Can burn skin and muscle, but

not hurt subcutaneous tissues

• Biopsy layered sparing

Microwave

Source: Dixon JJ, et al. Burns. 1997

May;23(3): 268-8. Source: Dixon JJ, et al. Burns. 1997

May;23(3): 268-8.

Cord Biting Injury

Fg2, Wikimedia Commons

Cord Biting Injury

Source Undetermined

Cord Biting Injury

• Chew through cord insulation

• Most injuries unilateral: lateral

commissure, tongue

• Systemic problems uncommon

• Labial artery injury not apparent

immediately due to vascular

spasm, thrombosis, eschar

Cord Biting Injury

• Severe bleeding from labial artery

in up to 10% when eschar

separates, usually 5 days – 2

weeks

• Old recommendation: admit

• Newer recommendation: reliable

parents outpatient adequate

Garcia CT, et al. Ann Emerg Med. 1995 Nov;26(5):604-8.

Lightning Injury

National Oceanic and Atmospheric Association,

Wikimedia Commons

Lightning Injury

• Annual US Deaths Reported: 60

• Annual US Injuries Reported: 400

• Odds of being struck by lightning

in a given year: 1/400,000

• Odds of being struck in your

lifetime: 1/5000

Lightning Injury

Source: New England Journal of Medicine

Lightning Injury

James Heilman, MD, Wikimedia Commons

Lightning Injury

• Typical industrial shock: 20 – 63

kilovolts

• Lightning strike: 300 kilovolts

• Industrial shocks rarely last

longer than 500 milliseconds

• Lightning strikes last only few

milliseconds

Lightning Injury

• Unlike other multiple victim

trauma, give priority to people

who appear dead

• Aggressively resuscitate; survival

has been reported after

prolonged respiratory arrest

• Immobilize spine when mental

status altered

Lightning Injury

• Hypotension is unexpected and

should prompt investigation for

hemorrhage

• Treat ventricular tachycardia or

fibrillation and asystole with

standard ACLS protocols

• Treat seizures with standard

therapy

Lightning Injury

• Admit patients with minor injuries

for cardiac and neurologic

monitoring

• Admit all pregnant patients for

fetal monitoring

Taser

United States Military, Wikimedia Commons

Taser

• Series of damped sinusoidal

electrical impulses designed to

induce involuntary muscle

contraction and incapacitation

• High voltage (50 kilovolt) low

amperage, low average energy

Taser

• Uses Electro-Muscular Disruption

(EMD) technology to cause

neuromuscular incapacitation

(NMI) and strong muscle

contractions through involuntary

stimulation of both sensory and

motor nerves

Taser

• Considered safe

• Function appropriately on calm,

healthy, individual in relaxed and

controlled environment

• 2001-2007: >245 deaths

occurred after Taser use

http://www.amnesty.org/en/library/info/AMR51/030/2006

Taser

http://en.wikipedia.org/wiki/Taser_safety_issues

• 7 cases: ME said Taser was

cause or contributing factor

• 16 cases: ME said Taser was

secondary or contributory factor

• Dozens of cases: ME cited

excited delirium (not in DSM-IV)

• Several cases: fall caused by

Taser implicated as cause

Taser

• ACEP now recognizes “excited

delirium” as a diagnosis

• Doubt other specialties will join us

– they don’t see what we see

• Should help exonerate some law-

enforcement people accused for

“deaths in custody”

Taser

• But no evidence taser on chest

can cause R-on-T phenomenon,

leading to Vfib and death

• No evidence taser can cause

malfunction of pacemaker or

AICD

• Should victims be monitored? No

clear evidence

Heart Rhythm Society. Abstract presented 5/11/07.

Taser

• Go to 1:25

• Series

Electrical Shock Injury

Magnus Manske, Wikimedia Commons

Some Epidemiology

• Severe nonlethal electrical

injuries account for 3 to 5% of

admissions to burn centers

• About 17,000 victims of electrical

injury treated each year in U.S.

emergency departments

Some Epidemiology

Three distinct populations at risk

• Toddlers: household electrical

sockets and cords

• Adolescents: risky behavior

around electrical power lines

• Electrical utility workers: annual

death in US of ~1 per 10,000

Some Epidemiology

• Easy electric flow: conductors

• Poor electric flow: insulators

• Best conductors: tissues with

high fluid and electrolyte content

Some Epidemiology

• High voltage severe burns

despite fraction of a second

contact time

• Household voltages (110v)

minimal burns, even after several

seconds of contact time

Some Epidemiology

• Even in low-voltage electrocution

deaths, electrical burns absent in

> 40% of cases

• Somebody “thrown” from electric

source actually having tetany

• AC current can also cause flexor

tetany unable to release

Types of Burns

• Flash burns: heat from nearby arc

causes thermal burns

• Electrothermal burns: current

passage through body

• Flame burns: clothing ignition

• Arc burns: current arcs to victim

– May be mix of flash, electrothermal

and flame

Flash Burns

Ben Watts, Flickr

Flash Burns

Source Undetermined

Electrothermal Burns

Occupational Safety and Health Administration, Wikimedia Commons

Electrothermal Burns

Source Undetermined

Electrical Arc

• Spark of current through air

between objects of differing

electrical potential

• Typically source to patient

• Voltages are extreme

• Temperatures can reach

2500°C (4532°F)

Arc Burns

Source Undetermined

High vs. Low Voltage

• Brief dose of high voltage

electricity is not necessarily fatal

• Low voltage just as likely to kill as

high voltage

RK Wright, et al. J. Forensic Sci. 1980; 25:514-521.

Sonarpulse, Wikimedia Commons

Specific Injuries: Cardiac

• Low-voltage AC: VFib

• High-voltage AC, DC: transient

ventricular asystole

• Cardiac arrhythmias in up to 30%

of high-voltage victims

– Sinus tach, PACs, PVCs, SVT,

AFib, 1o or 2o AV block

Specific Injuries: Cardiac

All stops out resuscitation

1) many victims young, no prior

cardiovascular disease

2) often not possible to predict

outcome based on age and initial

rhythm

Specific Injuries: CNS

• Neurologic impairment in ~50%

with high-voltage injuries

• Transient loss of conscious

common

• Others: agitation, coma, seizures,

confusion, quadriplegia, aphasia

hemiplegia, vision changes

Specific Injuries: Spinal Cord

• Immediate from vertebral

fractures, usually found in workup

• Delayed from electrical current

itself: may present as ascending

paralysis, complete or incomplete

spinal cord syndromes,

transverse myelitis

Specific Injuries: Spinal Cord

• If purely electrical, MRI results not

closely correlated with prognosis

– Rarely initial MRI will be normal in

electrical trauma patients with

permanent spinal cord injury

– Majority of patients with spinal cord

impairment following mechanical trauma

who have a normal initial spinal MRI will

have complete resolution of neurologic

dysfunction

Specific Injuries: Peripheral

• Peripheral nerve injuries often

involve hands

• Paresthesias can be immediate

and transient or delayed up to 2

years after injury

• Contact with palm produces

median or ulnar neuropathy more

than radial nerve injury

Specific Injuries: Eyes

• Cataract formation described

weeks to years after electrical

injury to head, neck, upper chest

• Also reported after electric arc or

flash burns

• High-voltage: retinal detachment,

corneal burns, intraocular

hemorrhage and thrombosis

Specific Injuries: Shoulders

• Posterior dislocations and

scapular fractures both reported

Source Undetermined

Specific Injuries: Pregnancy

Fatovich DM. J Emerg Med. 1993 Mar-Apr;11(2):175-7.

• Case reports of pregnant women

receiving apparently harmless

contacts with electric current later

suffering fetal damage or loss

• In most cases, mechanism of

fetal injury is uncertain

Specific Injuries: Pregnancy

Fatovich DM. J Emerg Med. 1993 Mar-Apr;11(2):175-7.

1) Monitor fetal heart rate and

uterine activity for 4 hours if

>20-24 weeks’ gestation

2) Monitor maternal cardiac and

fetal heart rate and uterine

activity for 24 hours if ECG

changes, loss of consciousness,

history of heart disease

Specific Injuries: Pregnancy

• Fetal ultrasonography also

recommended immediately and

at 2 weeks, but…

• No proof that monitoring or

treatment can influence fetal

outcome in pregnant women

following electric injury without

mechanical trauma

Einarson A, et al. Am J Obstet Gynecol. 1997 Mar;176(3):678-81

Cardiac Monitoring

James T at al. Cardiac abnormalities

demonstrated post-mortem in four cases of

accidental electrocution and their potential

significance relative to non-fatal electrical injuries

of the heart. American Heart Journal. 120: 143-

57, 1990.

Robinson N et al. Electrical injury to the heart

may cause long-term damage to conducting

tissue: a hypothesis and review of the literature.

Int J Cardiol. 53: 273-7, 1996.

Cardiac Monitoring

Alexander L. Electrical injuries of the nervous

system. J Nerv Ment Dis 1941; 94: 622-632

Jensen PJ, et al. Electrical injury causing

ventricular arrhythmias. Br Heart J 1987; 57:

279-283

Norquist C, et al. The risk of delayed

dysrhythmias after electrical injuries. Acad

Emerg Med. 6: 393, 1999

Cardiac Monitoring

• Common knowledge: All patients

with electrical injury require 24

hours of cardiac monitoring

Bionerd, Wikimedia Commons

Cardiac Monitoring

9 articles

Authors Voltage

Number

of

patients

Initial

ECG

Normal

Initial

ECG

Abnormal

Late

Rhythm

Problems

Purdue and Hunt 1000 48 40 8 0

Wrobel < 1000 35 31 4 0

Moran and Munster 110 – 850 42 40 2 0

Kirschmair and Denstl 220 – 900 19 15 4 0

Fatovitch and Lee 240 20 18 2 0

Cunningham 240 70 59 11 0

Kreinke and Kienst > 220 31 29 2 0

Bailey, et. al. 120 & 240 120 119 1 0

Arrowsmith > 220 73 69 4 0

Cardiac Monitoring

• Not justified in asymptomatic

patient

• Not justified in patient with only

cutaneous burn

• Not justified in patient who has

normal ECG after a 120v or 240v

injury

Felt current pass

through body

Current passed

through heart

Was held to source

of electric current Held to source

for >1 second Lost

consciousness

Voltage source

>1000 volts

Cardiac monitor for

24 hours

No

No

No

No

Burn marks on skin Evaluate and treat

burns

Thrown from source Evaluate and treat

trauma

Pregnant

BENIGN SHOCK

Reassure and release

No

No

No

Evaluate fetal

activity

Indications for Heart Monitor

1. Loss of consciousness

2. Cardiac dysrhythmia

3. Abnormal ECG

4. Abnormal mental status or

physical examination

5. Injury expected to cause

hemodynamic instability or

electrolyte problem

Fish RM. J Emerg Med. 2000 Feb;18(2):181-7.

Failure to Document Normals

Conditions that can arise after

initial presentation include

• Cataracts

• Vascular occlusion

• Compartment syndrome

• Brain and spinal cord dysfunction

Summary

• Electrical injuries involve multiple

body systems

• Entry and exit wounds fail to

reflect true extent of underlying

tissue damage

• Electrical current may cause

injuries distant from its apparent

pathway through the victim

Summary

• Controversies exist regarding

indications for admission and

cardiac monitoring following low

voltage injuries

Thank you