Electrical injuries: Difference between revisions
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==Background== | ==Background== | ||
#Tissue damage occurs via electrical energy, heat, and mechanical injury from trauma | #Tissue damage occurs via electrical energy, heat, and mechanical injury from trauma | ||
##Skin, bone, tendon all have very high resistance | |||
##Muscle, nerves, vasculature have lower resistance, more often damaged | |||
#Types: | #Types: | ||
##Low-Voltage | ##Low-Voltage | ||
##High-Voltage (>1000V) | ##High-Voltage (>1000V), seen in industrial settings or transmission line injuries | ||
###Associated with electrical burns | ###Associated with electrical burns | ||
##Electric Arc | ##Electric Arc | ||
Line 10: | Line 12: | ||
###Blast force may result in trauma | ###Blast force may result in trauma | ||
#Burn from biting an electric cord assoc w/ delayed labial bleeding (5d later) in ~10% of peds | #Burn from biting an electric cord assoc w/ delayed labial bleeding (5d later) in ~10% of peds | ||
#Direct (lightening) vs. alternating (household) current | |||
##Alternating has combination of the following mechanisms | |||
###Current arcs onto body, envelops surface of body, then arcs to lower electromotive potential (ground) | |||
###Current flows through body tissues | |||
##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 | |||
==Clinical Features== | ==Clinical Features== |
Revision as of 14:56, 4 September 2014
Background
- Tissue damage occurs via electrical energy, heat, and mechanical injury from trauma
- Skin, bone, tendon all have very high resistance
- Muscle, nerves, vasculature have lower resistance, more often damaged
- Types:
- Low-Voltage
- High-Voltage (>1000V), seen in industrial settings or transmission line injuries
- Associated with electrical burns
- Electric Arc
- Associated with high voltage sources
- May radiate enough heat to burn persons 10ft or more away from the arc
- Blast force may result in trauma
- Burn from biting an electric cord assoc w/ delayed labial bleeding (5d later) in ~10% of peds
- Direct (lightening) vs. alternating (household) current
- Alternating has combination of the following mechanisms
- Current arcs onto body, envelops surface of body, then arcs to lower electromotive potential (ground)
- Current flows through body tissues
- 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
- Alternating has combination of the following mechanisms
Clinical Features
Immediate Effects
- Cardiac dysrhythmias
- Respiratory arrest
- Seizures
Cardiac Dysrhythmias
- Fatalities due to asystole or V-fib usually occur prior to arrival
- Asymptomatic pts w/ normal ECGs do not develop later dysrhythmias after <1000V injuries
Cardiovascular Injury
- Contraction band necrosis[1]
- 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
Orthopedic Injury
- Forceful muscle contractions can cause fx 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
- 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 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
Treatment
- Usual trauma evaluation and resuscitation applies
- Use Parkland formula as starting point for fluid resuscitation
- Treat rhabdo and compartment syndrome in usual manner
Disposition
- Discharge
- Asymptomatic pts w/ normal ECG on presentation after a <600V injury
- Admit
- All pts with high-voltage injuries (even if asymptomatic)
- Pts w/ low-voltage injury if symptomatic (e.g. chest pain, burns, abnl ECG, abnl CK)
Source
- ↑ Koumbourlis AC. Electrical injuries. Crit Care Med. 2002 Nov;30(11 Suppl):S424-30.