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 | ||
** | **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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==Clinical Features== | ==Clinical Features== | ||
===Immediate Effects=== | ===Immediate Effects=== | ||
*[[Cardiac dysrhythmias]] | |||
*[[Respiratory arrest]] | |||
*[[Seizures]] | |||
===[[Cardiac Dysrhythmias]]=== | ===[[Cardiac Dysrhythmias]]=== | ||
*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) | |||
**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> | |||
*Medial necrosis of large vessels | |||
**Aneurysm formation | |||
*Coagulation necrosis of small vessels | |||
**Can lead to [[compartment syndrome]] | |||
===CNS Injury=== | ===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=== | ===Orthopedic Injury=== | ||
*Forceful muscle contractions can cause [[fracture]] and [[joint dislocations]] (especially shoulder) | |||
**May occur with voltages as low as 120V | |||
*[[Compartment Syndrome]] | |||
**Usually associated with high-voltage injuries | |||
**May occur even with 120V shocks if contact is sustained for longer than few seconds | |||
**Patient experiences ongoing muscle pain with movement | |||
**Need for [[fasciotomy]] predicted by: | |||
***Myoglobinuria | |||
***Burns >20% [[BSA]] | |||
***Full-thickness [[burn]] >12% [[BSA]] | |||
*[[Rhabdomyolysis]] | |||
**Associated with: | |||
***Contact with >1000V | |||
***Prehospital [[cardiac arrest]] | |||
***[[Crush injury]] | |||
***[[Compartment syndrome]] | |||
***Full-thickness skin [[burns]] | |||
===Ocular Injury=== | ===Ocular Injury=== | ||
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**Seriously injured patients often have burns on either arm or skull + feet | **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 | *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=== | ||
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==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{Burn DDX}} | |||
==Evaluation== | ==Evaluation== | ||
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*[[Urinalysis]] and urine myoglobin | *[[Urinalysis]] and urine myoglobin | ||
===Diagnosis== | ===Diagnosis=== | ||
*Typically a clinical diagnosis | *Typically a clinical diagnosis | ||
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*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 = | **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 [[rhabdomyolysis]] 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> | ||
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==Disposition== | ==Disposition== | ||
===Discharge=== | |||
*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 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== | ==See Also== |
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
- Low-Voltage <1000V
- High-Voltage >1000V - typically seen in industrial settings or transmission line injuries
- Associated with electrical burns
- Lightning Strike
- Electric Arc
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
- Can lead to compartment syndrome
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
- Forceful muscle contractions can cause fracture and joint dislocations (especially shoulder)
- May occur with voltages as low as 120V
- Compartment Syndrome
- Usually associated with high-voltage injuries
- May occur even with 120V shocks if contact is sustained for longer than few seconds
- Patient experiences ongoing muscle pain with movement
- Need for fasciotomy predicted by:
- Rhabdomyolysis
- Associated with:
- Contact with >1000V
- Prehospital cardiac arrest
- Crush injury
- Compartment syndrome
- Full-thickness skin burns
- Associated with:
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
- Smoke inhalation injury (airway compromise)
- Chemical injury
- Acrolein
- Hydrochloric acid
- Tuolene diisocyanate
- Nitrogen dioxide
- Systemic chemical injury
- Specific types of burns
- Associated toxicities
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
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
- ↑ 1.0 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.
- ↑ Koumbourlis AC. Electrical injuries. Crit Care Med. 2002 Nov;30(11 Suppl):S424-30.
- ↑ Brandt CP, Yowler CJ, Fratianne RB. MetroHealth Medical Center Burn ICU Handbook (Not a policy manual), Cleveland, OH.
- ↑ Rai J, Jeschke MG, Barrow RE, Herndon DN. Electrical Injuries: A 30-Year Review. J Trauma Acute Care Surg. 1999;46(5):933-936.