Wednesday Wrap-up: EM Critical Care Conference June 2013

Thanks to Dr. Regan for putting together this summary of our last EM Critical Care conference!

 

The Case: Man found unresponsive underneath subway train with right hip dislocation, electrocution by third rail, multiple burns and rhabdomyolysis.

 

Electrical Injuries

Voltage:

-High voltage is >1000, low voltage is <1000

-Outlets in U.S. homes have 100V, European home 220V

-Power lines > 100,000 V, Lightning >1 million V

 

Direct Current (DC):

-travels in one direction

-used in 3rd rail in subway and batteries

 

Alternating Current (AC):

-periodically reverses direction

-can cover longer distances than DC

-used in appliances, car motors, radio towers

-is more dangerous than DC at the same voltage (tetanic contraction in DC tends to throw the person away from the source)

 

Electrocution Injuries:

-Cardiac:

  • 15% incidence of arrhythmias, Vfib most common cause of fatal arrhythmia
  • necrosis of myocardium
  • DC/lightning cause asystole, AC causes Vfib

 

-Renal:

  • acute renal failure
  • rhabdomyolysis: treat with bicarb drip to alkalinize urine

 

-Neuro:

  • both central and peripheral nervous systems can be affected
  • LOC, weakness, respiratory depression, autonomic dysfunction, sensory & motor findings

 

-Derm:

  • degree of external injury does not correlate with internal injuries
  • all types of burns
  • pediatric oral burns: watch for bleeding from labial artery injury; all should be referred to plastic surgery for follow-up

 

-MSK:

  • bone generates greatest amount of heat–>periosteal burns, osteonecrosis
  • tissue necrosis can lead to compartment syndrome
  • traumatic injuries from blunt trauma (especially lightning and high voltage DC), ie: joint dislocations

 

-Other:

  • tympanic membrane rupture
  • cataracts
  • in lightning injuries, respiratory arrest due to tetanic muscle contraction   (reverse triage is important in these patients)

 

Disposition:

-Low voltage (i.e. house): no cardiac complaints and normal EKG can be safely discharged

-High or Low voltage with significant injuries

  • treat burns, consider transfer to burn center if necessary
  • treat associated blunt traumatic injuries
  • in asystolic arrest, secure airway with ACLS. ROSC is common.

 

References

  • Browne BJ, Gaasch WR. Electrical injuries and lightning. Emerg Med Clin North Am. 1992 May; 10(2): 211-29.
  • Koumbourlis AC. Electrical Injuries. Crit Care Med. 2002;30(11 Supp):S424-30.
  • Lee RC. Injury by electrical forces: pathophysiology, manifestations and therapy. Curr Probl Surg. 1997 Sep:34(9): 677-764.
  • Rabban J, Adler J, et al. Electrical injury from subway third rails: serious injury associated with intermediate voltage contact. Burns. 1997 Sep;23(6): 515-8.
  • Wright RK, Davis JH. The investigation of electrical deaths: a report of 220 fatalities. J Forensic Sci. 1980 Jul;25(3): 514-21.
The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.
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Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital

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