This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.

1. Project: Ghana Emergency Medicine Collaborative
Document Title: Electrical Misadventures
Author(s): Joe Lex, MD, FACEP, FAAEM, (Temple University) 2013
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3. Joe Lex, MD, FACEP, FAAEM
Department of Emergency Medicine
Temple University School of Medicine
Philadelphia, PA
Electrical Misadventures

4. Objectives
Discuss controversies about…
…microwave injuries
…cord-biting injuries
…lightning injuries
…TASER® injuries
Steve and Sara, Flickr

5. Objectives
• Explore some controversies in
management of electrical injuries
• Determine who really requires
hospital admission
• Discuss how pregnancy changes
management

6. Microwave
Mk2010, Wikimedia Commons

7. 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

8. 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.

9. Cord Biting Injury
Fg2, Wikimedia Commons

10. Cord Biting Injury
Source Undetermined

11. 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

12. 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.

13. Lightning Injury
National Oceanic and Atmospheric Association,
Wikimedia Commons

14. 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

15. Lightning Injury
Source: New England Journal of Medicine

16. Lightning Injury
James Heilman, MD, Wikimedia Commons

17. 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

18. 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

19. 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

20. Lightning Injury
• Admit patients with minor injuries
for cardiac and neurologic
monitoring
• Admit all pregnant patients for
fetal monitoring

21. Taser
United States Military, Wikimedia Commons

22. Taser
• Series of damped sinusoidal
electrical impulses designed to
induce involuntary muscle
contraction and incapacitation
• High voltage (50 kilovolt) low
amperage, low average energy

23. 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

24. 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

25. 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

26. 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”

27. 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.

28. Taser
•Go to 1:25
•Series

29. Electrical Shock Injury
Magnus Manske, Wikimedia Commons

30. 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

31. 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

32. Some Epidemiology
• Easy electric flow: conductors
• Poor electric flow: insulators
• Best conductors: tissues with
high fluid and electrolyte content

33. 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

34. 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

35. 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

36. Flash Burns
Ben Watts, Flickr

37. Flash Burns
Source Undetermined

38. Electrothermal Burns
Occupational Safety and Health Administration, Wikimedia Commons

39. Electrothermal Burns
Source Undetermined

40. 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)

41. Arc Burns
Source Undetermined

42. 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

43. 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

44. 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

45. 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

46. 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

47. 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

48. 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

49. 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

50. Specific Injuries: Shoulders
• Posterior dislocations and
scapular fractures both reported
Source Undetermined

51. 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

52. 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

53. 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

54. 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.

55. 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

56. Cardiac Monitoring
• Common knowledge: All patients
with electrical injury require 24
hours of cardiac monitoring
Bionerd, Wikimedia Commons

57. 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

58. 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

59. 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

60. 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

61. 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.

62. Failure to Document Normals
Conditions that can arise after
initial presentation include
• Cataracts
• Vascular occlusion
• Compartment syndrome
• Brain and spinal cord dysfunction

63. 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

64. Summary
• Controversies exist regarding
indications for admission and
cardiac monitoring following low
voltage injuries

65. Thank you