Project: Ghana Emergency Medicine Collaborative
Document Title: Electrical Misadventures
Author(s): Joe Lex, MD, FACEP, FA...
Attribution Key
for more information see: http://open.umich.edu/wiki/AttributionPolicy
Use + Share + Adapt
Make Your Own A...
Joe Lex, MD, FACEP, FAAEM
Department of Emergency Medicine
Temple University School of Medicine
Philadelphia, PA
Electrica...
Objectives
Discuss controversies about…
…microwave injuries
…cord-biting injuries
…lightning injuries
…TASER® injuries
Ste...
Objectives
• Explore some controversies in
management of electrical injuries
• Determine who really requires
hospital admi...
Microwave
Mk2010, Wikimedia Commons
Microwave
• More similar to electric burns than
to conventional oven burns
• Tend to be sharply demarcated
• Can burn skin...
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 proble...
Cord Biting Injury
• Severe bleeding from labial artery
in up to 10% when eschar
separates, usually 5 days – 2
weeks
• Old...
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...
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 rarel...
Lightning Injury
• Unlike other multiple victim
trauma, give priority to people
who appear dead
• Aggressively resuscitate...
Lightning Injury
• Hypotension is unexpected and
should prompt investigation for
hemorrhage
• Treat ventricular tachycardi...
Lightning Injury
• Admit patients with minor injuries
for cardiac and neurologic
monitoring
• Admit all pregnant patients ...
Taser
United States Military, Wikimedia Commons
Taser
• Series of damped sinusoidal
electrical impulses designed to
induce involuntary muscle
contraction and incapacitati...
Taser
• Uses Electro-Muscular Disruption
(EMD) technology to cause
neuromuscular incapacitation
(NMI) and strong muscle
co...
Taser
• Considered safe
• Function appropriately on calm,
healthy, individual in relaxed and
controlled environment
• 2001...
Taser
http://en.wikipedia.org/wiki/Taser_safety_issues
• 7 cases: ME said Taser was
cause or contributing factor
• 16 case...
Taser
• ACEP now recognizes “excited
delirium” as a diagnosis
• Doubt other specialties will join us
– they don’t see what...
Taser
• But no evidence taser on chest
can cause R-on-T phenomenon,
leading to Vfib and death
• No evidence taser can caus...
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 ...
Some Epidemiology
Three distinct populations at risk
• Toddlers: household electrical
sockets and cords
• Adolescents: ris...
Some Epidemiology
• Easy electric flow: conductors
• Poor electric flow: insulators
• Best conductors: tissues with
high f...
Some Epidemiology
• High voltage  severe burns
despite fraction of a second
contact time
• Household voltages (110v) 
mi...
Some Epidemiology
• Even in low-voltage electrocution
deaths, electrical burns absent in
> 40% of cases
• Somebody “thrown...
Types of Burns
• Flash burns: heat from nearby arc
causes thermal burns
• Electrothermal burns: current
passage through bo...
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 pati...
Arc Burns
Source Undetermined
High vs. Low Voltage
• Brief dose of high voltage
electricity is not necessarily fatal
• Low voltage just as likely to kil...
Specific Injuries: Cardiac
• Low-voltage AC: VFib
• High-voltage AC, DC: transient
ventricular asystole
• Cardiac arrhythm...
Specific Injuries: Cardiac
All stops out resuscitation
1) many victims young, no prior
cardiovascular disease
2) often not...
Specific Injuries: CNS
• Neurologic impairment in ~50%
with high-voltage injuries
• Transient loss of conscious
common
• O...
Specific Injuries: Spinal Cord
• Immediate from vertebral
fractures, usually found in workup
• Delayed from electrical cur...
Specific Injuries: Spinal Cord
• If purely electrical, MRI results not
closely correlated with prognosis
– Rarely initial ...
Specific Injuries: Peripheral
• Peripheral nerve injuries often
involve hands
• Paresthesias can be immediate
and transien...
Specific Injuries: Eyes
• Cataract formation described
weeks to years after electrical
injury to head, neck, upper chest
•...
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
receivin...
Specific Injuries: Pregnancy
Fatovich DM. J Emerg Med. 1993 Mar-Apr;11(2):175-7.
1) Monitor fetal heart rate and
uterine a...
Specific Injuries: Pregnancy
• Fetal ultrasonography also
recommended immediately and
at 2 weeks, but…
• No proof that mon...
Cardiac Monitoring
James T at al. Cardiac abnormalities
demonstrated post-mortem in four cases of
accidental electrocution...
Cardiac Monitoring
Alexander L. Electrical injuries of the nervous
system. J Nerv Ment Dis 1941; 94: 622-632
Jensen PJ, et...
Cardiac Monitoring
• Common knowledge: All patients
with electrical injury require 24
hours of cardiac monitoring
Bionerd,...
Cardiac Monitoring
9 articles
Authors Voltage
Number
of
patients
Initial
ECG
Normal
Initial
ECG
Abnormal
Late
Rhythm
Probl...
Cardiac Monitoring
• Not justified in asymptomatic
patient
• Not justified in patient with only
cutaneous burn
• Not justi...
Felt current pass
through body
Current passed
through heart
Was held to source
of electric current
Held to source
for >1 s...
Burn marks on skin
Evaluate and treat
burns
Thrown from source Evaluate and treat
trauma
Pregnant
BENIGN SHOCK
Reassure an...
Indications for Heart Monitor
1. Loss of consciousness
2. Cardiac dysrhythmia
3. Abnormal ECG
4. Abnormal mental status or...
Failure to Document Normals
Conditions that can arise after
initial presentation include
• Cataracts
• Vascular occlusion
...
Summary
• Electrical injuries involve multiple
body systems
• Entry and exit wounds fail to
reflect true extent of underly...
Summary
• Controversies exist regarding
indications for admission and
cardiac monitoring following low
voltage injuries
Thank you
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GEMC- Electrical Misadventures- Resident Training

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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/.

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GEMC- Electrical Misadventures- Resident Training

  1. 1. Project: Ghana Emergency Medicine Collaborative Document Title: Electrical Misadventures Author(s): Joe Lex, MD, FACEP, FAAEM, (Temple University) 2013 License: 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/ We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. These lectures have been modified in the process of making a publicly shareable version. The citation key on the following slide provides information about how you may share and adapt this material. Copyright holders of content included in this material should contact open.michigan@umich.edu with any questions, corrections, or clarification regarding the use of content. For more information about how to cite these materials visit http://open.umich.edu/privacy-and-terms-use. Any medical information in this material is intended to inform and educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition. Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers. 1
  2. 2. Attribution Key for more information see: http://open.umich.edu/wiki/AttributionPolicy Use + Share + Adapt Make Your Own Assessment Creative Commons – Attribution License Creative Commons – Attribution Share Alike License Creative Commons – Attribution Noncommercial License Creative Commons – Attribution Noncommercial Share Alike License GNU – Free Documentation License Creative Commons – Zero Waiver Public Domain – Ineligible: Works that are ineligible for copyright protection in the U.S. (17 USC § 102(b)) *laws in your jurisdiction may differ Public Domain – Expired: Works that are no longer protected due to an expired copyright term. Public Domain – Government: Works that are produced by the U.S. Government. (17 USC § 105) Public Domain – Self Dedicated: Works that a copyright holder has dedicated to the public domain. Fair Use: Use of works that is determined to be Fair consistent with the U.S. Copyright Act. (17 USC § 107) *laws in your jurisdiction may differ Our determination DOES NOT mean that all uses of this 3rd-party content are Fair Uses and we DO NOT guarantee that your use of the content is Fair. To use this content you should do your own independent analysis to determine whether or not your use will be Fair. { Content the copyright holder, author, or law permits you to use, share and adapt. } { Content Open.Michigan believes can be used, shared, and adapted because it is ineligible for copyright. } { Content Open.Michigan has used under a Fair Use determination. } 2
  3. 3. Joe Lex, MD, FACEP, FAAEM Department of Emergency Medicine Temple University School of Medicine Philadelphia, PA Electrical Misadventures
  4. 4. Objectives Discuss controversies about… …microwave injuries …cord-biting injuries …lightning injuries …TASER® injuries Steve and Sara, Flickr
  5. 5. Objectives • Explore some controversies in management of electrical injuries • Determine who really requires hospital admission • Discuss how pregnancy changes management
  6. 6. Microwave Mk2010, Wikimedia Commons
  7. 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. 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. 9. Cord Biting Injury Fg2, Wikimedia Commons
  10. 10. Cord Biting Injury Source Undetermined
  11. 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. 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. 13. Lightning Injury National Oceanic and Atmospheric Association, Wikimedia Commons
  14. 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. 15. Lightning Injury Source: New England Journal of Medicine
  16. 16. Lightning Injury James Heilman, MD, Wikimedia Commons
  17. 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. 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. 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. 20. Lightning Injury • Admit patients with minor injuries for cardiac and neurologic monitoring • Admit all pregnant patients for fetal monitoring
  21. 21. Taser United States Military, Wikimedia Commons
  22. 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. 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. 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. 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. 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. 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. 28. Taser •Go to 1:25 •Series
  29. 29. Electrical Shock Injury Magnus Manske, Wikimedia Commons
  30. 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. 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. 32. Some Epidemiology • Easy electric flow: conductors • Poor electric flow: insulators • Best conductors: tissues with high fluid and electrolyte content
  33. 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. 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. 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. 36. Flash Burns Ben Watts, Flickr
  37. 37. Flash Burns Source Undetermined
  38. 38. Electrothermal Burns Occupational Safety and Health Administration, Wikimedia Commons
  39. 39. Electrothermal Burns Source Undetermined
  40. 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. 41. Arc Burns Source Undetermined
  42. 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. 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. 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. 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. 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. 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. 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. 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. 50. Specific Injuries: Shoulders • Posterior dislocations and scapular fractures both reported Source Undetermined
  51. 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. 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. 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. 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. 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. 56. Cardiac Monitoring • Common knowledge: All patients with electrical injury require 24 hours of cardiac monitoring Bionerd, Wikimedia Commons
  57. 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. 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. 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. 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. 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. 62. Failure to Document Normals Conditions that can arise after initial presentation include • Cataracts • Vascular occlusion • Compartment syndrome • Brain and spinal cord dysfunction
  63. 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. 64. Summary • Controversies exist regarding indications for admission and cardiac monitoring following low voltage injuries
  65. 65. Thank you

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