Electrical injuries: Difference between revisions

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==Background==
==Background==
*Tissue damage occurs via electrical energy (becomes thermal energy once it enters the body) and mechanical injury from trauma
*Tissue damage occurs via electrical energy (becomes thermal energy once it enters the body) and mechanical injury from trauma
**Skin, bone, tendon all have very high resistance
**Fat, bone, tendon, dry skin all have very high resistance
**Muscle, nerves, vasculature have lower resistance, more often damaged
**Muscle, nerves, vasculature have lower resistance, more often damaged
*'''The primary determinant of injury is the amount of current flowing through the body, which depends on:'''
*'''The primary determinant of injury is the amount of current flowing through the body, which depends on:'''
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#'''Electric Arc'''
#'''Electric Arc'''
#*Associated with high voltage sources
#*Associated with high voltage sources
#*Ionized particles with temp 3000 °C–20,000 C<ref name="Epidemiology">Kym D, Seo DK, Hur GY, Lee JW. Epidemiology of electrical injury: Differences between low- and high-voltage electrical injuries during a 7-year study period in South Korea. Scand J Surg. 2015 Jun;104(2):108-14.</ref>
#*Ionized particles with temperature 3000 °C–20,000 C<ref name="Epidemiology">Kym D, Seo DK, Hur GY, Lee JW. Epidemiology of electrical injury: Differences between low- and high-voltage electrical injuries during a 7-year study period in South Korea. Scand J Surg. 2015 Jun;104(2):108-14.</ref>
#*Can jump 2-3cm per 1000V<ref name="Epidemiology" />
#*Can jump 2-3cm per 1000V<ref name="Epidemiology" />
#*May radiate enough heat to burn persons 10ft or more away from the arc
#*May radiate enough heat to burn persons 10ft or more away from the arc
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==Clinical Features==
==Clinical Features==
===Immediate Effects===
===Immediate Effects===
#[[Cardiac dysrhythmias]]
*[[Cardiac dysrhythmias]]
#[[Respiratory arrest]]
*[[Respiratory arrest]]
#[[Seizures]]
*[[Seizures]]


===[[Cardiac Dysrhythmias]]===
===[[Cardiac Dysrhythmias]]===
#Fatalities due to [[asystole]] or [[V-fib]] usually occur prior to arrival
*Fatalities due to [[asystole]] or [[V-fib]] usually occur prior to arrival
#*Most common [[dysrrhythmia]] at presentation is [[A-fib]] ([[V-fi]]b is more common, but pts are dead PTA)
**Most common [[dysrrhythmia]] at presentation is [[A-fib]] ([[V-fi]]b is more common, but patients are dead PTA)
#*Asymptomatic pts w/ normal [[ECGs]] do not develop later dysrhythmias after <1000V injuries
**Asymptomatic patients with normal [[ECGs]] do not develop later dysrhythmias after <1000V injuries


===Cardiovascular Injury===
===Cardiovascular Injury===
#Contraction band necrosis<ref>Koumbourlis AC. Electrical injuries. Crit Care Med. 2002 Nov;30(11 Suppl):S424-30.</ref>
*Contraction band necrosis<ref>Koumbourlis AC. Electrical injuries. Crit Care Med. 2002 Nov;30(11 Suppl):S424-30.</ref>
#Medial necrosis of large vessels
*Medial necrosis of large vessels
#*Aneurysm formation
**Aneurysm formation
#Coagulation necrosis of small vessels
*Coagulation necrosis of small vessels
#*Can lead to [[compartment syndrome]]
**Can lead to [[compartment syndrome]]


===CNS Injury===
===CNS Injury===
#Occurs in 50% of pts w/ high-voltage injuries
*Occurs in 50% of patients with high-voltage injuries
#Brain injury ranges from transient LOC to [[CVA]] to [[respiratory arrest]]
*Brain injury ranges from transient LOC to [[CVA]] to [[respiratory arrest]]
#High voltage injuries involving head are frequently associated with coma and persistent vegetative state
*High voltage injuries involving head are frequently associated with coma and persistent vegetative state


===Orthopedic Injury===
===Orthopedic Injury===
#Forceful muscle contractions can cause [[fracture]] and [[joint dislocations]] (especially shoulder)
*Forceful muscle contractions can cause [[fracture]] and [[joint dislocations]] (especially shoulder)
#*May occur with voltages as low as 120V
**May occur with voltages as low as 120V
#[[Compartment Syndrome]]
*[[Compartment Syndrome]]
#*Usually a/w high-voltage injuries
**Usually associated with high-voltage injuries
#*May occur even with 120V shocks if contact is sustained for longer than few seconds
**May occur even with 120V shocks if contact is sustained for longer than few seconds
#*Pt experiences ongoing muscle pain with movement
**Patient experiences ongoing muscle pain with movement
#*Need for [[fasciotomy]] predicted by:
**Need for [[fasciotomy]] predicted by:
#**Myoglobinuria
***Myoglobinuria
#**Burns >20% BSA
***Burns >20% [[BSA]]
#**Full-thickness [[burn]] >12% BSA
***Full-thickness [[burn]] >12% [[BSA]]
#[[Rhabdomyolysis]]
*[[Rhabdomyolysis]]
#*Associated with:
**Associated with:
#**Contact with >1000V
***Contact with >1000V
#**Prehospital [[cardiac arrest]]
***Prehospital [[cardiac arrest]]
#**[[Crush injury]]
***[[Crush injury]]
#**[[Compartment syndrome]]
***[[Compartment syndrome]]
#**Full-thickness skin [[burns]]
***Full-thickness skin [[burns]]


===Ocular Injury===
===Ocular Injury===
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===Auditory Injury===
===Auditory Injury===
*May be damaged by current or hemorrhage
*May be damaged by current or hemorrhage
*Check hearing in all pts
*Check hearing in all patients


===Cutaneous [[Burns]]===
===Cutaneous [[Burns]]===
*Often seen at electrical contact areas
*Often seen at electrical contact areas
**Seriously injured pts often have burns on either arm or skull + feet
**Seriously injured patients often have burns on either arm or skull + feet
*Most pts w/ burns from electrical injury require admission and care by burn specialist
*Most patients with burns from electrical injury require admission and care by burn specialist
*Lichtenberg figures (not true burns) are pathognomonic for lightning strike


===GI Injury===
===GI Injury===
*Suspect in pts with:
*Suspect in patients with:
**Electrical burns of abdominal wall
**Electrical burns of abdominal wall
**History of a fall, nearby explosion, or other mechanical trauma
**History of a fall, nearby explosion, or other mechanical trauma
*Labial artery bleeding may be delayed well after injury, warranting admission (typically peds pts who chew power cords)


==Workup==
===Pediatric Considerations===
*12-lead EKG
*In general, evaluate as for the adult, looking for multi-system involvement
*Perform an ECG in all patients, regardless of voltage
*An oral commissure burn (from chewing on power cord) will create significant edema and necrosis. 
**The child may need Plastic Surgery or Head and Neck Surgery consultation to avoid microstomia.
**1-2 weeks after the burn, the eschar may fall off, exposing the labial artery and causing significant hemorrhage
***Provide clear and thorough precautionary advice including first aid for bleeding (pinch buccal mucosa against outside of cheek until arrival to hospital)
 
==Differential Diagnosis==
{{Burn DDX}}
 
==Evaluation==
===Workup===
*12-lead ECG
*CBC
*CBC
*CMP
*CMP
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*Troponin
*Troponin
*CK
*CK
*UA and urine myoglobin
*[[Urinalysis]] and urine myoglobin


==Treatment==
===Diagnosis===
*Typically a clinical diagnosis
 
==Management==
*Usual trauma evaluation and resuscitation applies
*Usual trauma evaluation and resuscitation applies
*Use [[Parkland formula]] as starting point for [[fluid resuscitation]]
*Use [[Parkland formula]] as starting point for [[fluid resuscitation]]
**Fluids in first 24 hrs = TBSA burned(%) x Wt(kg) x 4ml; Give 1/2 in first 8 hours, then give other 1/2 over next 16 hrs
**Fluids in first 24 hrs = [[T[[BSA]]]] burned(%) x Wt(kg) x 4ml; Give 1/2 in first 8 hours, then give other 1/2 over next 16 hrs
*Treat [[rhabdo]] and [[compartment syndrome]] in usual manner
*Treat [[rhabdomyolysis]] and [[compartment syndrome]] in usual manner
**If RBCs and/or myoglobin in UA, urine should be alkalinized at minimum of 2 cc/kg/hr until pigments eliminated<ref>Brandt CP, Yowler CJ, Fratianne RB. MetroHealth Medical Center Burn ICU Handbook (Not a policy manual), Cleveland, OH.</ref>
**If RBCs and/or myoglobin in UA, urine should be alkalinized at minimum of 2 cc/kg/hr until pigments eliminated<ref>Brandt CP, Yowler CJ, Fratianne RB. MetroHealth Medical Center Burn ICU Handbook (Not a policy manual), Cleveland, OH.</ref>
**[[Mannitol]] should be given early to prevent renal tubular damage
**[[Mannitol]] should be given early to prevent renal tubular damage
**High voltage injuries to the hand frequently require carpal tunnel decompression as soon as pt is stable for OR
**High voltage injuries to the hand frequently require carpal tunnel decompression as soon as patient is stable for OR


==Disposition==
==Disposition==
*Discharge
===Discharge===
**Asymptomatic pts w/ normal ECG on presentation after a low-voltage electrical injury
*Asymptomatic patients with normal ECG on presentation after a low-voltage electrical injury<ref>Rai J, Jeschke MG, Barrow RE, Herndon DN. Electrical Injuries: A 30-Year Review. J Trauma Acute Care Surg. 1999;46(5):933-936.</ref>
*Admit
 
**All pts with high-voltage injuries (even if asymptomatic)
===Admit===
**Pts w/ low-voltage injury if symptomatic (e.g. LOC, severe burns, EKG changes, ↑ CK)
*All patients with high-voltage injuries (even if asymptomatic)
**Abnormal EKG or observed dysrhythmia
*Patients with low-voltage injury if symptomatic (e.g. LOC, severe [[burns]], ECG changes, ↑ CK)
**Cardiac biomarkers positive
*Abnormal [[ECG]] or observed dysrhythmia
**Persistent CP or hypoxia
*Cardiac biomarkers positive
**Cardiac arrest
*Persistent [[chest pain]], paresthesias, or [[hypoxia]]
**Documented LOC
*[[Cardiac arrest]]
**Hx of significant cardiac disease or CAD risk factors
*Documented LOC
*History of significant cardiac disease or CAD risk factors


==See Also==
==See Also==
*[[Lightning Injuries]]
*[[Lightning Injuries]]
==External Links==
*[http://pemplaybook.org/podcast/electrical-injuries-hertz-so-bad/ Electrical Injuries: Hertz So Bad - Pediatric Emergency Playbook]


==References==
==References==
<references/>
<references/>


[[Category:Environ]]
[[Category:Environmental]]
[[Category:Trauma]]
[[Category:Trauma]]

Revision as of 08:25, 12 February 2019

Background

  • Tissue damage occurs via electrical energy (becomes thermal energy once it enters the body) and mechanical injury from trauma
    • Fat, bone, tendon, dry skin all have very high resistance
    • Muscle, nerves, vasculature have lower resistance, more often damaged
  • The primary determinant of injury is the amount of current flowing through the body, which depends on:
    • Voltage
    • Amperage
    • Resistance
    • Type of current (DC or AC)
    • Current pathway
    • Duration of contact

Electrical Injury Types

  1. Low-Voltage <1000V
  2. High-Voltage >1000V - typically seen in industrial settings or transmission line injuries
    • Associated with electrical burns
  3. Lightning Strike
  4. Electric Arc
    • Associated with high voltage sources
    • Ionized particles with temperature 3000 °C–20,000 C[1]
    • Can jump 2-3cm per 1000V[1]
    • May radiate enough heat to burn persons 10ft or more away from the arc
    • Blast force may result in trauma

DC vs AC

Direct current (DC) injuries typically due to lightning while alternating current (AC) are household injuries

DC

  • Direct current most often demonstrates flow-over phenomenon
  • Lightening can reach 1-5 million volts, but current flows over the body and exits to the ground
  • May result in little tissue damage and cardiac dysrrhythmias are still of great concern

AC

  • Current arcs onto body, envelops surface of body, then arcs to lower electromotive potential (ground)
  • With alternative cycle of the current there is contraction and release of muscle preventing full release from source
  • Current flows through body tissues

Clinical Features

Immediate Effects

Cardiac Dysrhythmias

  • Fatalities due to asystole or V-fib usually occur prior to arrival
    • Most common dysrrhythmia at presentation is A-fib (V-fib is more common, but patients are dead PTA)
    • Asymptomatic patients with normal ECGs do not develop later dysrhythmias after <1000V injuries

Cardiovascular Injury

  • Contraction band necrosis[2]
  • Medial necrosis of large vessels
    • Aneurysm formation
  • Coagulation necrosis of small vessels

CNS Injury

  • Occurs in 50% of patients with high-voltage injuries
  • Brain injury ranges from transient LOC to CVA to respiratory arrest
  • High voltage injuries involving head are frequently associated with coma and persistent vegetative state

Orthopedic Injury

Ocular Injury

  • Cataract formation has been described weeks to years after electrical injury
    • Document presence or absence of cataracts following all electrical injuries

Auditory Injury

  • May be damaged by current or hemorrhage
  • Check hearing in all patients

Cutaneous Burns

  • Often seen at electrical contact areas
    • Seriously injured patients often have burns on either arm or skull + feet
  • Most patients with burns from electrical injury require admission and care by burn specialist
  • Lichtenberg figures (not true burns) are pathognomonic for lightning strike

GI Injury

  • Suspect in patients with:
    • Electrical burns of abdominal wall
    • History of a fall, nearby explosion, or other mechanical trauma

Pediatric Considerations

  • In general, evaluate as for the adult, looking for multi-system involvement
  • Perform an ECG in all patients, regardless of voltage
  • An oral commissure burn (from chewing on power cord) will create significant edema and necrosis.
    • The child may need Plastic Surgery or Head and Neck Surgery consultation to avoid microstomia.
    • 1-2 weeks after the burn, the eschar may fall off, exposing the labial artery and causing significant hemorrhage
      • Provide clear and thorough precautionary advice including first aid for bleeding (pinch buccal mucosa against outside of cheek until arrival to hospital)

Differential Diagnosis

Burns

Evaluation

Workup

  • 12-lead ECG
  • CBC
  • CMP
  • Lactate
  • Troponin
  • CK
  • Urinalysis and urine myoglobin

Diagnosis

  • Typically a clinical diagnosis

Management

  • Usual trauma evaluation and resuscitation applies
  • Use Parkland formula as starting point for fluid resuscitation
    • Fluids in first 24 hrs = [[TBSA]] burned(%) x Wt(kg) x 4ml; Give 1/2 in first 8 hours, then give other 1/2 over next 16 hrs
  • Treat rhabdomyolysis and compartment syndrome in usual manner
    • If RBCs and/or myoglobin in UA, urine should be alkalinized at minimum of 2 cc/kg/hr until pigments eliminated[3]
    • Mannitol should be given early to prevent renal tubular damage
    • High voltage injuries to the hand frequently require carpal tunnel decompression as soon as patient is stable for OR

Disposition

Discharge

  • Asymptomatic patients with normal ECG on presentation after a low-voltage electrical injury[4]

Admit

  • All patients with high-voltage injuries (even if asymptomatic)
  • Patients with low-voltage injury if symptomatic (e.g. LOC, severe burns, ECG changes, ↑ CK)
  • Abnormal ECG or observed dysrhythmia
  • Cardiac biomarkers positive
  • Persistent chest pain, paresthesias, or hypoxia
  • Cardiac arrest
  • Documented LOC
  • History of significant cardiac disease or CAD risk factors

See Also

External Links

References

  1. 1.0 1.1 Kym D, Seo DK, Hur GY, Lee JW. Epidemiology of electrical injury: Differences between low- and high-voltage electrical injuries during a 7-year study period in South Korea. Scand J Surg. 2015 Jun;104(2):108-14.
  2. Koumbourlis AC. Electrical injuries. Crit Care Med. 2002 Nov;30(11 Suppl):S424-30.
  3. Brandt CP, Yowler CJ, Fratianne RB. MetroHealth Medical Center Burn ICU Handbook (Not a policy manual), Cleveland, OH.
  4. Rai J, Jeschke MG, Barrow RE, Herndon DN. Electrical Injuries: A 30-Year Review. J Trauma Acute Care Surg. 1999;46(5):933-936.