View source for Electrical injuries

==Background==
*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
**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 Injuries|Lightning]] Strike'''
#'''Electric Arc'''
#*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>
#*Can jump 2-3cm per 1000V<ref name="Epidemiology" />
#*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]]
#[[Respiratory arrest]]
#[[Seizures]]

===[[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 pts are dead PTA)
#*Asymptomatic pts w/ normal [[ECGs]] do not develop later dysrhythmias after <1000V injuries

===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===
#Occurs in 50% of pts w/ 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 a/w high-voltage injuries
#*May occur even with 120V shocks if contact is sustained for longer than few seconds
#*Pt 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===
*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 pts

===Cutaneous [[Burns]]===
*Often seen at electrical contact areas
**Seriously injured pts often have burns on either arm or skull + feet
*Most pts w/ burns from electrical injury require admission and care by burn specialist

===GI Injury===
*Suspect in pts 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)

==Workup==
*12-lead EKG
*CBC
*CMP
*Lactate
*Troponin
*CK
*UA and urine myoglobin

==Treatment==
*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 [[rhabdo]] 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>
**[[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

==Disposition==
*Discharge
**Asymptomatic pts w/ normal ECG on presentation after a low-voltage electrical injury
*Admit
**All pts with high-voltage injuries (even if asymptomatic)
**Pts w/ low-voltage injury if symptomatic (e.g. LOC, severe burns, EKG changes, ↑ CK)
**Abnormal EKG or observed dysrhythmia
**Cardiac biomarkers positive
**Persistent CP or hypoxia
**Cardiac arrest
**Documented LOC
**Hx of significant cardiac disease or CAD risk factors

==See Also==
*[[Lightning Injuries]]

==References==
<references/>

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