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Project: Ghana Emergency Medicine Collaborative
Document Title: Electrical and Lightening Injuries
Author(s): Rashmi Kotha...
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{ Content the ...
Rashmi U. Kothari MD
Associate Professor
KCMS/MSU

BotMultichillT,
Wikimedia Commons

Maksim,
3
Wikimedia Commona
¨ 

Electrical Injuries
¡  Low

Voltage
¡  High Voltage

¨ 

Pathophysiology
¨  Complications
¨  Management
¨ 

Lig...
¨ 

Electrical burns:
1000 deaths annually
¡  4-6.5% of all burn admissions
¡  Almost all involve litigation (negligenc...
¨ 

Voltage:

electrical pressure in a
circuit
¨  Resistance: tissues resistance to flow
of electrons
¨  Current:
amoun...
Current Strength (I)= Voltage/Resistance
Thermal Power (J)=(I)2 X Resistance X
duration

Severity =(Voltage) 2 X duration
...
¨  Current

(Amperage)
¨  Type of current
¨  Resistance
¨  Duration of contact
¨  Voltage
¨  Pathway of current
8
Physical Effect
Tingling
Let go current
Children
Women
Men
Freezing to circuit
Thoracic muscle tetany
Ventricular fibrilla...
¨ 

Which is more dangerous?
¡  AC

¨ 

3X more dangerous than DC

How do their mechanisms of
injuries differ?
¡  AC

...
¨ 

Source:
¡  Power

lines
¡  Household current
¨ 

Clinical Presentation
¡  3X

more dangerous than DC
¡  Continuo...
¨ 

Source:
¡  Power

generating stations
¡  Long distance transmission lines
¡  Submarine cable connections
¡  Porta...
Amount tissue resists flow of
electrons
¨ 
resistance the greater potential
to convert electric energy to heat
energy
¨ ...
Resistance of Body Tissues
Least
Nerves
Blood
Mucous membranes

Intermediate
Dry skin

Most
Tendon
Fat
Bone
14
Tissue

Resistance (W/cm2)

Calloused hands
Soles of feet
Other skin
Sweaty skin
Bathtub
Mucous Membranes

1-2 million
100...
Resistance
Dry hands
vs. Wet hands
2,000,000 W/cm2 è1,200 W/cm2

Injury=Voltage2 x Duration
Resistance
16
¨ 

Child puts key in socket
110V AC current
¡  Dry skin (10-40K W/cm2 )
¡  current = 2.75-11 mA
¡ 

¨ 

Chris Phan, ...
Physical Effect
Tingling
Let go current
Children
Women
Men
Freezing to circuit
Thoracic muscle tentany
Ventricular fibrill...
¨ 

¨ 

duration

destruction

AC increases duration due to grip
strength

19
¨ 

¨ 

¨ 

Difference in electrical potential between
two points
Low Voltage <500-1000 V
¡  24 V=Long distance commun...
¨ 

Determines tissue at risk
¡  Thorax:

V-fib, myocardial damage
¡  Head: resp. arrest, seizure, paralysis
¡  Eye: c...
¨  Current

(Amperage)
¨  Type of current
¨  Resistance
¨  Duration of contact
¨  Voltage
¨  Pathway of current
22
¨ 

¨ 

Usually minor:
¡  Tingling
¡  Local contact burns
Exception:

¡  Lower resistance (moisture)
¡  Ocular invol...
¨  Child

bites electrical cord
¨  Arc burn
¡  Electricity

jumps from high to low
potential region
¡  High temperatur...
Evaluate for any burns
¨  Cardiaorespiratory complaints
¨ 

¡  ECG/monitor
¡  Isoenzymes
¨ 

Consider ocular involvem...
Devastating burns
¨  Electrical injuries
¨  Blunt trauma
¨  Renal complications
¨ 

Source Undetermined
Xy01, Wikimedi...
¨ 

Direct contact
¡  Electrothermal

¨ 

heating

Indirect contact
¡  Arc
¡  Flame
¡  Flash

27
Source Undetermined

¨ 

Heating of tissue secondary to current
¡  Low

voltage injuries with local burns
¡  High volta...
Achgro,
Wikimedia Commons

Spark between unconnected objects
¨  Most destructive indirect burn
¨  Temperatures of 2,500°...
Occur when external objects catch on
fire and cause the burn.
¨  Most commonly, clothes
¨ 

30
Current flashes over the body, rather
than going through the tissues
¨  Seen primarily in lightening injuries.
¨ 

Sourc...
Head
¨  Cardiac
¨  Skin
¨  Extremities
¨  Neurological
¨ 

7mike5000,
Wikimedia
Commons

32
EyeMD,
Wikimedia
Commons

Common point of contact
¨  Burns
¨  Blunt trauma
¨  Cataracts
¨ 

Batholith,
Wikimedia
Commo...
¨ 

Arrhythmias
¡  V-Fib

or Asystole
¡  Sinus Tach/ A-fib/BBB
¨ 

ECG changes
¡  ST

elevation
¡  Prolonged QT
¨ 
...
Guyprocter,
Wikimedia
Commons

Common contact sites
¡  Head/hands/heels
¨  Internal flow of current
¡  Deep muscle inju...
Damage distant to skin burns
¨  Arterial injury
¨ 

¡  High
¨ 

delayed injury

Venous injury
¡  Slow

¨ 

flow è

...
Transient loss of consciousness
¨  Concussive type symptoms
¨ 

¡  Difficulty

concentrating

¡  Dizziness
¡  Flat
¨...
¨ 

Immediate
¡  Weakness/parasthesias

within hours
¡  Lower extremity >upper extremity
¡  Good prognosis
¨ 

Delaye...
Current impulse
¨  High voltage/Short duration
¨ 

¡  Very

minimal skin damage
¡  Flash over

Maksim, Wikimedia Commo...
¨ 

Direct strike
¡  Orifice

¨ 

Contact

entry
Ambika Kilaparthi, Flickr

¡  Side

flash, “splash”
¡  Ground curren...
Enters eyes, ears, mouth
¨  High incidence of:
¨ 

¡  cataracts/uveitis/detached

retina/

optic atrophy
¡  ruptured T...
object è person è ground

42
Source Undetermined

43
¨ 

¨ 

Thrown 2° to massive contraction of
current passing through body
Air superheats then quickly cools è
explosive ...
¨ 

Cardiovascular
¡  Cardiac

arrest 2° electrical shock or
vascular spasm
¡  Respiratory arrest > Cardiac arrest
¨ 
...
Source Undetermined

Source Undetermined

Source Undetermined

46
¨ 

Extremities
¡  Transient

vasospasm
¡  Cold, blue, mottled, pulseless
¡  Resolves within hours

47
¨ 

Common
¡  LOC,

confusion, antegrade amnesia
¡  Paresthesias
¨ 

Less common
¡  ICH,

seizure, paraplegia
¡  Del...
¨ 

Keraunoparalysis
¡  2/3

of patients
¡  Extremities mottled, cold, blue
¡  Legs>arms
¡  Transient (clears w/in ho...
¨ 

Evaluate for other injuries
Other burns
¡  Ocular involvement
¡ 

¨ 

Admission

Pain or poor oral intake
¡  Poor...
ABC
¨  Fluids & foley
¨ 

¡  Urine

output 0.5-1.0 cc/kg/hr
¡  Heme in urine 1-1.5 cc/kg/hr

Cardiac monitor/ECG
¨  T...
¨ 

Trans-abdominal current
¡  Hepatic,

¨ 

Altered MS
¡  CT

¨ 

lipase, PT/PTT

head

Cardio-respiratory complaint...
Status post arrest
¨  Concomitant severe injuries
¨  Loss of consciousness
¨  Suspicion of conductive injury
¨  Abnorm...
¨ 

Inhospital
¡  Trauma
¡  Burns/Plastics

¨ 

Outpatient
¡  Ophthalmology
¡  Neurology

54
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GEMC: Electrical and Lightening Injuries: Resident Training

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This is a lecture by Dr. Rashmi Kothari 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 and Lightening Injuries: Resident Training

  1. 1. Project: Ghana Emergency Medicine Collaborative Document Title: Electrical and Lightening Injuries Author(s): Rashmi Kothari, M.D. 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 { Content the copyright holder, author, or law permits you to use, share and adapt. } Public Domain – Government: Works that are produced by the U.S. Government. (17 USC § 105) Public Domain – Expired: Works that are no longer protected due to an expired copyright term. Public Domain – Self Dedicated: Works that a copyright holder has dedicated to the public domain. Creative Commons – Zero Waiver 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 Make Your Own Assessment { Content Open.Michigan believes can be used, shared, and adapted because it is ineligible for copyright. } Public Domain – Ineligible: Works that are ineligible for copyright protection in the U.S. (17 USC § 102(b)) *laws in your jurisdiction may differ { Content Open.Michigan has used under a Fair Use determination. } 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. 2
  3. 3. Rashmi U. Kothari MD Associate Professor KCMS/MSU BotMultichillT, Wikimedia Commons Maksim, 3 Wikimedia Commona
  4. 4. ¨  Electrical Injuries ¡  Low Voltage ¡  High Voltage ¨  Pathophysiology ¨  Complications ¨  Management ¨  Lightening Injuries 4
  5. 5. ¨  Electrical burns: 1000 deaths annually ¡  4-6.5% of all burn admissions ¡  Almost all involve litigation (negligence, product liability, workmen’s compensation) ¡  ¨  Lightening Injuries: 50-300 deaths annually ¡  4-5 X as many lightening strikes ¡  2nd leading cause of weather related deaths ¡  5
  6. 6. ¨  Voltage: electrical pressure in a circuit ¨  Resistance: tissues resistance to flow of electrons ¨  Current: amount of energy in a circuit ¨  Current = Voltage/Resistance 6
  7. 7. Current Strength (I)= Voltage/Resistance Thermal Power (J)=(I)2 X Resistance X duration Severity =(Voltage) 2 X duration Resistance 7
  8. 8. ¨  Current (Amperage) ¨  Type of current ¨  Resistance ¨  Duration of contact ¨  Voltage ¨  Pathway of current 8
  9. 9. Physical Effect Tingling Let go current Children Women Men Freezing to circuit Thoracic muscle tetany Ventricular fibrillation Milliamperes (mA) 1-4 4 7 9 10-20 20-50 60-120 *at 50-60 Hz (frequency of household AC current) 9
  10. 10. ¨  Which is more dangerous? ¡  AC ¨  3X more dangerous than DC How do their mechanisms of injuries differ? ¡  AC causes tetany ¡  DC throws you away 10
  11. 11. ¨  Source: ¡  Power lines ¡  Household current ¨  Clinical Presentation ¡  3X more dangerous than DC ¡  Continuous tetany ¡  V-fib ¡  Contact wounds 11
  12. 12. ¨  Source: ¡  Power generating stations ¡  Long distance transmission lines ¡  Submarine cable connections ¡  Portable generators ¨  Clinical Presentation ¡  Single contraction ¡  Associated blunt trauma ¡  Arrhythmias cardiac phase dependent ¡  Entrance/Exit wounds 12
  13. 13. Amount tissue resists flow of electrons ¨  resistance the greater potential to convert electric energy to heat energy ¨  Tissue resistance changes with charring ¨  13
  14. 14. Resistance of Body Tissues Least Nerves Blood Mucous membranes Intermediate Dry skin Most Tendon Fat Bone 14
  15. 15. Tissue Resistance (W/cm2) Calloused hands Soles of feet Other skin Sweaty skin Bathtub Mucous Membranes 1-2 million 100-200K 10-40K 2500 1200-1500 100 15
  16. 16. Resistance Dry hands vs. Wet hands 2,000,000 W/cm2 è1,200 W/cm2 Injury=Voltage2 x Duration Resistance 16
  17. 17. ¨  Child puts key in socket 110V AC current ¡  Dry skin (10-40K W/cm2 ) ¡  current = 2.75-11 mA ¡  ¨  Chris Phan, Flickr Injury=(V)2 X t R Child in tub, key in socket 110V AC current ¡  Wet skin (1,200-1,500 W/cm2 ) ¡  current =73-92 mA ¡  17
  18. 18. Physical Effect Tingling Let go current Children Women Men Freezing to circuit Thoracic muscle tentany Ventricular fibrillation Milliamperes (mA) 1-4 4 7 9 10-20 20-50 60-120 2.75-11 73-92 *at 50-60 Hz (frequency of household AC current) 18
  19. 19. ¨  ¨  duration destruction AC increases duration due to grip strength 19
  20. 20. ¨  ¨  ¨  Difference in electrical potential between two points Low Voltage <500-1000 V ¡  24 V=Long distance communication lines ¡  65 V Telephone lines ¡  110-220 V Household current High Voltage >500-1000 V ¡  Transformers, Power lines 20
  21. 21. ¨  Determines tissue at risk ¡  Thorax: V-fib, myocardial damage ¡  Head: resp. arrest, seizure, paralysis ¡  Eye: cataracts Anetode, Wikimedia Commons 21
  22. 22. ¨  Current (Amperage) ¨  Type of current ¨  Resistance ¨  Duration of contact ¨  Voltage ¨  Pathway of current 22
  23. 23. ¨  ¨  Usually minor: ¡  Tingling ¡  Local contact burns Exception: ¡  Lower resistance (moisture) ¡  Ocular involvement ¡  Oral injuries ¡  Appliance capacitor (microwave, ¡  Pregnancy Source Undetermined monitor, TV) 23
  24. 24. ¨  Child bites electrical cord ¨  Arc burn ¡  Electricity jumps from high to low potential region ¡  High temperatures ¡  Delayed bleeding ¨  Cosmetic Source Undetermined & Dental deformity 24
  25. 25. Evaluate for any burns ¨  Cardiaorespiratory complaints ¨  ¡  ECG/monitor ¡  Isoenzymes ¨  Consider ocular involvement ¡  Ophthalmology referral Short ED observation ¨  Discharge home ¨  25
  26. 26. Devastating burns ¨  Electrical injuries ¨  Blunt trauma ¨  Renal complications ¨  Source Undetermined Xy01, Wikimedia Commons 26
  27. 27. ¨  Direct contact ¡  Electrothermal ¨  heating Indirect contact ¡  Arc ¡  Flame ¡  Flash 27
  28. 28. Source Undetermined ¨  Heating of tissue secondary to current ¡  Low voltage injuries with local burns ¡  High voltage ú  Damage anywhere along current path ú  Prolonged exposure due to inability to release 7mike5000, Wikimedia Commons 28
  29. 29. Achgro, Wikimedia Commons Spark between unconnected objects ¨  Most destructive indirect burn ¨  Temperatures of 2,500° C ¡  Oral cord burns ¡  Lightening strikes ¨  Source: Brown Medical School 29
  30. 30. Occur when external objects catch on fire and cause the burn. ¨  Most commonly, clothes ¨  30
  31. 31. Current flashes over the body, rather than going through the tissues ¨  Seen primarily in lightening injuries. ¨  Source Undetermined 31
  32. 32. Head ¨  Cardiac ¨  Skin ¨  Extremities ¨  Neurological ¨  7mike5000, Wikimedia Commons 32
  33. 33. EyeMD, Wikimedia Commons Common point of contact ¨  Burns ¨  Blunt trauma ¨  Cataracts ¨  Batholith, Wikimedia Commons ¡  Days, weeks, months ¡  Complete eye exam ¡  Outpatient Ophthalmology Source Undetermined 33
  34. 34. ¨  Arrhythmias ¡  V-Fib or Asystole ¡  Sinus Tach/ A-fib/BBB ¨  ECG changes ¡  ST elevation ¡  Prolonged QT ¨  AMI ¡  Rare ¡  Elevation of CPK & CPK MB% 34
  35. 35. Guyprocter, Wikimedia Commons Common contact sites ¡  Head/hands/heels ¨  Internal flow of current ¡  Deep muscle injury ¡  Can’t estimate damage from surface burn ¨  Magnus Manske, Wikimedia Commons 35
  36. 36. Damage distant to skin burns ¨  Arterial injury ¨  ¡  High ¨  delayed injury Venous injury ¡  Slow ¨  flow è flow è acute thrombosis & edema Severe muscle necrosis ¡  Fasciotomy ¡  Rhabdomyolysis ¨  Kissing burns Source Undetermined 36
  37. 37. Transient loss of consciousness ¨  Concussive type symptoms ¨  ¡  Difficulty concentrating ¡  Dizziness ¡  Flat ¨  affect Spinal Injuries ¡  Fractures/ligamentous Source Undetermined injuries 37
  38. 38. ¨  Immediate ¡  Weakness/parasthesias within hours ¡  Lower extremity >upper extremity ¡  Good prognosis ¨  Delayed ¡  Days to years ¡  Ascending paralysis/ALS/Transverse myelitis ¡  Motor>sensory ¡  Poor prognosis 38
  39. 39. Current impulse ¨  High voltage/Short duration ¨  ¡  Very minimal skin damage ¡  Flash over Maksim, Wikimedia Commons 39
  40. 40. ¨  Direct strike ¡  Orifice ¨  Contact entry Ambika Kilaparthi, Flickr ¡  Side flash, “splash” ¡  Ground current or step voltage ¡  Blunt trauma 40
  41. 41. Enters eyes, ears, mouth ¨  High incidence of: ¨  ¡  cataracts/uveitis/detached retina/ optic atrophy ¡  ruptured TM/hearing loss, tinnitus, vertigo 41
  42. 42. object è person è ground 42
  43. 43. Source Undetermined 43
  44. 44. ¨  ¨  Thrown 2° to massive contraction of current passing through body Air superheats then quickly cools è explosive force 44
  45. 45. ¨  Cardiovascular ¡  Cardiac arrest 2° electrical shock or vascular spasm ¡  Respiratory arrest > Cardiac arrest ¨  Skin ¡  <5% deep burns ¡  Linear lesions ¡  Punctate lesions ¡  Feathering ¡  Thermal 45
  46. 46. Source Undetermined Source Undetermined Source Undetermined 46
  47. 47. ¨  Extremities ¡  Transient vasospasm ¡  Cold, blue, mottled, pulseless ¡  Resolves within hours 47
  48. 48. ¨  Common ¡  LOC, confusion, antegrade amnesia ¡  Paresthesias ¨  Less common ¡  ICH, seizure, paraplegia ¡  Delayed muscle atrophy 48
  49. 49. ¨  Keraunoparalysis ¡  2/3 of patients ¡  Extremities mottled, cold, blue ¡  Legs>arms ¡  Transient (clears w/in hours) ¡  Vascular spasm & sympathetic instability 49
  50. 50. ¨  Evaluate for other injuries Other burns ¡  Ocular involvement ¡  ¨  Admission Pain or poor oral intake ¡  Poor compliance or follow-up ¡  ¨  Discharge home Educate parents regarding bleeding ¡  Burns follow-up ¡  Dental referral ¡  ±Plastics referral ¡  ±Ophthalmology referral ¡  50
  51. 51. ABC ¨  Fluids & foley ¨  ¡  Urine output 0.5-1.0 cc/kg/hr ¡  Heme in urine 1-1.5 cc/kg/hr Cardiac monitor/ECG ¨  Trauma Evaluation ¨  Labs ¨  ¡  CBC & CMP ¡  Serum Myoglobin, U/A 51
  52. 52. ¨  Trans-abdominal current ¡  Hepatic, ¨  Altered MS ¡  CT ¨  lipase, PT/PTT head Cardio-respiratory complaints ¡  Troponin, CPK with Isoenzymes ¡  Poor correlation: CPK MB, Angio, echo, thallium studies with AMI 52
  53. 53. Status post arrest ¨  Concomitant severe injuries ¨  Loss of consciousness ¨  Suspicion of conductive injury ¨  Abnormal ECG or dysrhythmia ¨  History of CAD ¨  Significant CAD risk factors ¨  Chest pain ¨  53
  54. 54. ¨  Inhospital ¡  Trauma ¡  Burns/Plastics ¨  Outpatient ¡  Ophthalmology ¡  Neurology 54

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