Lightning current may flow internally for an incredibly short
time, causing a "short circuit" of electrical systems but it seldom causes
significant burns or tissue destruction. Cardiac and respiratory arrest,
neurologic damage and autonomic instability are more common seen.
Lightning will tend to cause asystole rather than V-fib.
Clinical Manifestations [Keraunopathology]:
In this section, I wish to briefly review manifestations of
lightning injuries with regards to body systems, and discuss acute treatment
in the following section.
A. Cardiac and vascular:
Immediate cardiac arrest is the most
common cause of death after a direct strike, this in effect, a "celestial"
counter-shock as lightning is high voltage, large impulse and of short
duration. Asystole is commonly seen, but V-fib may occur. Spontaneous
conversion to NSR may occur. ST-T wave changes may occur, along with
prolonged QT, enzyme levels may elevate, but true myocardial infarction is
noted to be rare. In a review of "CV Effects of Lightning Strikes" by
Lichtenberg, important differences were seen with re: to the type of strike.
Direct strike resulted in a high incidence of life-threatening pericardial
effusion or severe global cardiac dysfunction. Splash injuries manifested
CK-MB release but had normal echos and no ECG evidence of injury.
Ground strikes had only non-specific ECG changes. Injury as assessed by
CK-MB release was seen in 75% of direct hit victims, 66% of splash and
12% of ground strike. Late sequela is limited to a single case of recurrent
pericarditis.
Autonomic instability with unexplained hypertension and
peripheral vasospasm may occur, but usually will resolve over hours.
Keraunoparalysis is an intense vascular spasm, which results in loss of
pulses, mottling and absent sensation in an extremity...thought due to
sympathetic nervous system instability and again usually resolves
spontaneously.
B.
Respiratory: At the time of a strike, concomitant respiratory arrest
may occur due to paralysis of the brainstem respiratory center, and this
may outlast cardiac arrest. If timely ventilatory assistance is not provided,
secondary hypoxic cardiac arrest will occur...the duration of apnea rather
than the duration of asystole appears to be the critical factor in mortality.
C.
Cutaneous:
The skin manifestations of lightning strikes are varied
and usually superficial secondary to "flashover"...deep burns are
reported to occur in less than 5% of cases. Manifestations include:
