Electrical injuries: Difference between revisions

(Text replacement - "*Troponin" to "*Troponin")
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===[[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 patients are dead PTA)
**Most common [[dysrhythmia]] at presentation is [[A-fib]] ([[V-fi]]b is more common, but patients are dead PTA)
**Asymptomatic patients with normal [[ECGs]] do not develop later dysrhythmias after <1000V injuries
**Asymptomatic patients with normal [[ECGs]] do not develop later dysrhythmias after <1000V injuries


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*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
**[[LV aneurysm|Aneurysm]] formation
*Coagulation necrosis of small vessels
*Coagulation necrosis of small vessels
**Can lead to [[compartment syndrome]]
**Can lead to [[compartment syndrome]]
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===CNS Injury===
===CNS Injury===
*Occurs in 50% of patients with 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 [[syncope|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|persistent vegetative state]]


===Orthopedic Injury===
===Orthopedic Injury===
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**Document presence or absence of cataracts following all electrical injuries
**Document presence or absence of cataracts following all electrical injuries


===Auditory Injury===
===[[hearing loss|Auditory Injury]]===
*May be damaged by current or hemorrhage
*May be damaged by current or hemorrhage
*Check hearing in all patients
*Check hearing in all patients
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===Pediatric Considerations===
===Pediatric Considerations===
*In general, evaluate as for the adult, looking for multi-system involvement
*In general, evaluate as for the adult, looking for multi-system involvement
*Perform an ECG in all patients, regardless of voltage
*Perform an [[ECG]] in all patients, regardless of voltage
*An oral commissure burn (from chewing on power cord) will create significant edema and necrosis  
*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
**The child may need Plastic Surgery or Head and Neck Surgery consultation to avoid microstomia
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==Evaluation==
==Evaluation==
===Workup===
===Workup===
*12-lead ECG
*12-lead [[ECG]]
*CBC
*CBC
*CMP
*CMP
*Lactate
*[[Lactate]]
*[[Troponin]]
*[[Troponin]]
*CK
*CK
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*Abnormal [[ECG]] or observed dysrhythmia
*Abnormal [[ECG]] or observed dysrhythmia
*Cardiac biomarkers positive
*Cardiac biomarkers positive
*Persistent [[chest pain]], paresthesias, or [[hypoxia]]
*Persistent [[chest pain]], [[paresthesias]], or [[hypoxia]]
*[[Cardiac arrest]]
*[[Cardiac arrest]]
*History of significant cardiac disease or CAD risk factors
*History of significant cardiac disease or CAD risk factors

Revision as of 18:56, 28 September 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 but 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 dysrhythmia 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

CNS Injury

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
    • Urine myoglobin is poorly sensitive/specific, and most patients with rhabdomyolis will have grossly discolored urine[3]

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
    • Parkland formula frequently underestimates fluid requirements in electrical burns[4]
    • In healthy individuals start continuous fluids at 300-500 mL/hr and titrate to urine output of 100 mL/hr[5]
  • 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[6]
    • Mannitol should be given early to prevent renal tubular damage but patient must remain adequately fluid resuscitated
    • 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[7]

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
  • 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. ↑ https://emergencymedicinecases.com/electrical-injuries/
  4. ↑ https://emergencymedicinecases.com/electrical-injuries/
  5. ↑ https://emergencymedicinecases.com/electrical-injuries/
  6. ↑ Brandt CP, Yowler CJ, Fratianne RB. MetroHealth Medical Center Burn ICU Handbook (Not a policy manual), Cleveland, OH.
  7. ↑ Rai J, Jeschke MG, Barrow RE, Herndon DN. Electrical Injuries: A 30-Year Review. J Trauma Acute Care Surg. 1999;46(5):933-936.
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