Wednesday Conference
11/11/2015
Article Inspired By: Dr. Sui Fai Li and Dr. Andrew Chertoff
-Very little hard data as there are no randomized control trials and mostly just case series
-The first thing to do when someone presents with an electrical injury is to undress the patient and look for any burns/injuries
-Usually, if they present with just numbness, it will resolve
Classification:
- Low Voltage Injuries
- Household electrocutions
- High Voltage Injuries (>1000V)
- Occupational, Public transit, Transformers
Pathophysiology:
- Damage done depends on:
- Amperage (amount)
- Duration
- Voltage (force)
- Resistance
- and maybe Pathway
- Amp X Resistance = Volt
- Higher voltage = higher amperage
- Household (U.S.) = 120V
- Public Transit (Subway ~600 to Overhead ~15,000V)
- Substations ~11,000-400,000V
- Dry skin 10-40x more resistant than wet skin
- Alternating current (AC) can be three times worse than Direct current (DC)
- High-voltage DC is usually a single muscle spasm
- Alternating current causes prolonged/continuous muscle contraction and tetany leading to longer electrical exposure
- Higher voltage = higher amperage
What type of injuries can you see with electricity?
- Trauma
- Thermal injury
- Electrical injury
- Burns
- Arc burns
- Crease burns
What organ systems do I have to worry about?
- Neurological
- LOC, transient paralysis, or paresthesias
- Keraunoparalysis (fixed, dilated pupils; lower extremity cyanosis; paralysis from vasospasm)
- Classically with high voltage lightning injuries
- Continue resuscitation for prolonged period of time despite fixed, dilated pupils
- Most permanent injuries are secondary events
- Cardiac
- A/C induces ventricular fibrillation whereas D/C induces asystole
- Lightening causes massive direct countershock which depolarizes entire myocardium causing asystole
- Cardiac contusion common
- Acute MI is rare
- A/C induces ventricular fibrillation whereas D/C induces asystole
- Vascular
- Thrombosis/hemorrhage
- Labial artery
- Usually 3rd degree, 6-20% bleed, need referral to specialty
- Ophthalmology
- Lightning strike associated cataracts (need good follow-up)
- Respiratory- Aspiration
- Lightning can induce paralysis of medullary center leading to primary respiratory arrest
- Musculoskeletal
- Rhabdomyolysis
- Compartment syndrome
- Obstetrics
- Stillbirths
- Lightning strikes – fetal mortality close to 50%
- First trimester- confirm fetal heart tone, d/c with spontaneous abortion precautions
- Second/Third trimester- OB for fetal monitoring and significant risk for placental abruption
Okay, what should I do in the trauma bay?
- Airway
- May require intubation if intubated, major burns or for specific treatment (suxamethonium safe for 48 hours)
- Breathing
- Lung protective ventilation strategy
- Look for same life threatening chest injuries as in trauma patients
- Circulation
- Prevent effects of rhabdomyolysis (hyperkalemia, hypocalcemia, hyperphophatemia, metabolic acidosis)
- Restore normal circulating volume
- May require ionotropes/vasopressors if SIRS
- Parkland’s formula
- Disability
- R/o associated TBI
- Prevent secondary brain injury
- Normoglycemia
- Exposure
- Quantify severity of burns (depth, percent total body surface area)
Who should I admit and who can I send home?
- Low voltage, asymptomatic- Do nothing and discharge
- Low voltage, mild symptoms- Monitor and can discharge, if EKG and UA normal
- High voltage (>1000V)- Admit for monitoring
REFERENCES:
Li, S. “Conference: Electrical injuries” Jacobi Medical Center. Jacobi/Montefiore Emergency Medicine Conference. Bronx. Nov 2015. Lecture
Chertoff, A. “Conference: Electrical injuries Jeopardy” Jacobi Medical Center. Jacobi/Montefiore Emergency Medicine Conference. Bronx. Nov 2015. Lecture
“Episode 1.0 – Electrical and Lightning Injuries.” Core EM
Nickson, Chris. “Electrical Injury.” Electrical Injury. LITFL Life in the Fast Lane Medical Blog
EM Rounds 