Electrical injuries Flashcards
What are the characteristic signs post lighting strike?
- Keraunoparalysis (transient weakness to lower > upper limbs)
- Lichtenburg figures (feathering pattern burns to skin)
- Eye injuries, ear TM rupture
- Initial apnoea due to transient medullary paralysis (can cause hypoxic arrest)
- Asystole although can self resolve (rarely VF)
- Lightning is DC and doesnt cause tetanic contractions
Why do people appear dead post lighting strike?
Often have fixed dilated pupils (massive catecholamine surge), prolonged apnoea (transient medullary paralysis) pale and pulsless + paralysis (Keraunoparalysis, ANS mediated vasospasm)
Most of the above are transient so attempts should be made at resuscitation
What is the difference in arrest between lighting and electrocution?
Electrocution usually causes VF
Lighting strikes cause Asystole and hypoxic arrest from transient apnoea
What is the difference in presentation between DC and AC electrocution?
AC
- causes tetany, people often cannot let go of the source
- Currents above 6-9mA are most likely to cause tetnay
DC
- doesnt cause tetany and often launches the patient away, leading to concussive/blunt trauma
- VF occurs at 60-120mA
- Skin is the primary resistor to the flow of current in the body
How does the ALS protocol change post lightning strike?
- No change to ALS
- Only that prognosis is better than would otherwise be expected based on examination, thus perform more aggressive resuscitation
What are the differences between lightning and electrical injuries?
What are the potential injuries from electric currents?
CVS
- arrhythmias, myocardial ischaemia, autonomic dysfunction, pulmonary oedema
MSK
- Compartment syndrome, Rhabdomyolysis, fractures, dislocations (ie posterior shoulder)
Neurological
- Coma, encephalopathy, ICH, seizures, amnesia, spinal cord injury, head injury, peripheral neuropathy
Skin
- Burns deeper than expected
Vascular
- Blood clots, ischaemic limb
Renal
- AKI from myoglobinuria
