Section 3.8
Manifestations of Lightning Deaths and Injuries
By Richard Kithi, President & CEO, NLSI
- Abstract. Although most lightning morbidity and mortality is
through cardiac and neurologic events, other organ systems can be affected.
Further complications may include respiratory distress syndrome, cataracts,
pulmonary edema, renal failure, retinal lesions, rhabdomyolysis, and
tympanic membrane rupture (6.1). This paper reviews investigations and
observations used to determine if lightning was the proximate cause
of death or injury. The author has no medical background or education,
but has collated and summarized technical information from experts which
is available in the literature. The reader is directed to Section 6.0
References for in-depth research results from foremost medical authorities.
- Attachment Mechanisms. The body can be modeled, according to
Geddes (6.10), as an electrolytic resistor surrounded by an insulator
(the skin). Lightning attachment's high voltage breaks down the skin
dielectric. Pathophysiological response is a function of the nature
and intensity of the current and its pathway through the body. Cooper
and Andrews (6.2) describe five primary mechanisms of lightning: direct
hit; splash; contact, step voltage, and blunt trauma. Direct vs indirect
processes are described as:
- Direct Lightning Strikes. Hundreds of millions of volts impact
the victim during the direct attachment process. According to Ohm's
Law E = I X R, 14,000,000 volts can be generated from a 20kA lightning
flash attaching to a (nominal) 700 ohm body surface resistance object.
Calculations of voltages when considering lightning inductance (L)
and the double exponential waveform, E = L (di/dt), yields even higher
voltages. Burns, subcutaneous fluid explosions (steam), and blunt
trauma from self-inflicted opisthotonic contractions may be among
the results.
- Indirect Lightning Strikes. Observations from Sandia Laboratories
lightning testing (6.3) confirm that lightning exhibits radial horizontal
arcing in excess of 40m. This ground surface lightning spreads according
to local soils impedance characteristics, resulting in step and touch
voltage hazards. Capacitive, inductive and ohmic attachment processes
also come into play (6.4). Victims insulted while near trees, or touching
electrical appliances, or in contact with water or other unintended
conductors often are recipients of fatal currents and voltages after
lightning strikes them indirectly.
- Difference Between Lightning and High Voltage Electricity,
adapted from Cooper et al. (6.2).
Factor
|
Lightning
|
High Voltage
|
Energy Level |
25 kA typical, millions of volts |
Usually much lower |
Time of Exposure |
Brief, instantaneous |
Prolonged |
Pathway |
Flashover, orifice |
Deep, internal |
Burns |
Superficial and minor |
Deep with major injury |
Cardiac |
Primary & secondary arrest, asystole |
Fillibration |
Renal |
Rare myoglobinuria or hemoglobinuria |
Myoglobinuric renal failure often |
Fasciotomy |
Rarely if ever necessary |
Common, early and extensive |
Blunt injury |
Explosive thunder effect |
Falls, being thrown |
- Safety from Lightning's Effects. Absolute and total safety
from lightning is not possible in a practical sense. But following well-described
"do's and dont's" as promulgated by national organizations
can contribute to a very high level of safety from lightning's effects.
See the following Internet WWW sites:
National Lightning Safety Institute: www.lightningsafety.com
National Weather Service: www.nssl.noaa.gov
National Collegiate Athletic Associaton: www.ncaa.org/library/sports_sciences/sports_med_handbook/2003-04/1d.pdf=
- Some Manifestations in the Human Body. According to Shockley (6.5) lightning
damage runs a wide range from burns to multi-organ disruption.Therefore
it is convenient to discuss manifestations system by system:
- Skin Effects. Burns are described as linear, punctuate, full-thickness
burns, feathering or flowering (Lichtenberg figures), thermal burns
from ignited clothing or heated metal, or combinations (6.2). Animals
should be shaved to investigate keraunographic markings. Wetli (6.6)
also describes epidermis separating from the papillary dermis, nuclear
streaming (palisading) and in volar skin the keratin often containing
vacuoles. Clothing melting into the skin has been noted. Hair burning
and skin lacerations also are characteristic of lightning. Steam burns
secondary to lightning are caused by vaporization of sweat or rainwater
on the victim's skin, according to Cooper et al (6.2). Geddes (6.10)
describes lightning victims giving off a particular odor like burning
sulphur or ozone or nitrous fumes or dilute sulphuric acid or ammonia.
He cites earlier reports (Jex-Blake, 1913) of lightning having amputated
legs, arms and fingers.
- Vascular Effects. Shockley (6.5) reported electrical injuries
to blood vessels causing disruption of the endothelium as well as disintegration
of the media producing considerable hemorrhage or thrombosis. Hematologic
abnormalities indicated by Cooper et al (6.2) include disseminated intravascular
coagulation, transiently positive Coombs' test, and DiGuglielmo's syndrome,
a type of erythroleukemia characterized by erythroblastosis, thrombocytopenia,
and hepatosplenomegaly. Close analysis of causation by lightning or
by high voltage electricity is suggested here.
- Musculoskeletal Effects. Mechanical blunt force injury may
be the result of falls or of spontaneous nerve excitation. One unusual
eye-witnesss case is that of a lightning-induced muscle spasms ejecting
a young adult male fifteen feet off a chair into a brick wall, with
a broken back and a broken collar bone resulting (6.9). Muscle cells
exposed to extreme heat create pores in the cell membrances in a process
called electroporation: cell rupture and myonecrosis may result from
either (6.5). Brumback (6.13) writes that lightning's electricity often
is associated with rhabdomyolysis, evident from massively elevated serum
creatine (CK) levels. Wetli (6.6) notes that while lightning tends to
travel along outer surfaces (skin effect), observed cases of morphologically
evident cardiovascular damage (pericardial and aortic tears and myocardial
contusion) indicate this is not always the case.
- Cardiac Effects. Aortic evidence include tearing of a portion
of the media and extravasated blood in the aortic adventitia. Further
evidence is seen in torn posterior pericardium, subepicardial blood
distribution over the distal third of the anterior descending branch
of the left coronary artery, broad transmural hemorrhagic areas noted
in the left ventrical myocardium, subepicardial blood in the apex ,
massive suffision of blood in the interventricluar septum as well as
the anterior and posterior left ventriclar free wall, and myocardial
contusions confirmed microscopically (6.6). Shockley (6.5) describes
how deaths from electrical accidents usually are due to cardiac arrhythmias.
They occur when current travels across the thorax. He notes AC current
usually is associated with ventricular fibrillation and DC current with
asystole. In some cases arrhythmias are delayed for up to 12 hours however.
- Neurologic Effects. Cherington et al (6.1) lists useful tables
of neurologic complications as well as an extensive literature review
of lightning neurologic sequelae. The reader is directed to this citation
for a most comprehensive discussion of CNS complications to lightning
victims. Neuropathologic findings include focal petechial hemorrhages
and chromatolysis of pyramidial cells, Purkinje's cells of the cerebellum,
and anterior horn cells. Often seen is as a leading indicator is localized
ballooning of myelin sheaths. MRI and CT Scans provide investigators
with conclusive results here. Lesions of the brain should be investigated,
especially processes involving cerebral infarction, hypoxic encephalopathy
due to cardiac arrest, basal ganglial degeneration and intracranial
hematomas. Less often seen are myelopathies and cerebellar lesions.
- Pulmonary Effects. In domestic animals lightning evidence may
be found in cellular damage to the respiratory and cardiac centers in
the fourth ventrical as well as with damage to the anterior surface
of the brainstem (6.2).
- Renal Effects. In 5%-22% of cases observed, Shockley (6.5)
reports electrical injury to kidneys. This is due to massive tissue
destruction as a result of related rhabdomyolysis and myoglobinuria.
Hyperkalemia, hypocalcemia, hyperglycemia, and acidosis are associated
with renal injury.
- Abdominal and GI Effects. Shockley (6.5) reports the potential
for such problems as hemorrhagicnecrosis of the intestines and gallbladder,
liver failure, gastrointestinal hemorrhage from stomach and duodenal
ulcers, curling ulcers, acute appendicitis, pancreatitis, small bowel
perforation, slenic injuries, and mesenteric abdominal trauma. He suggests
always looking for occult abdominal trauma since electrical injuries/deaths
often are followed by falls.
- Eye Effect. Cooper et al (6.2) propose that 55% of lightning
victims suffer ocular effects due to thermal or electrical damage, intense
heat, contusion from the thunder shock wave or combinations of these
factors. Cataracts typically develop within a few days, although cases
have been seen where they occurred as late as two years afterwards. Cataracts
may be the typical anterior midperipheral type, posterior subcapsular
opacities and vacuolization seem to occur more often with lightning
victims. Corneal lesions, hyphema, uveitis, iridocyclitis, and vitreos
hemorrhage also have been observed. Diplopia, loss of accommodation,
and decreased color sense also have been reported.
- Ear Effects. High pressure shock waves from thunder, measuring
up to ten atmospheres (6.7), may crate blast effects leading to ruptured
tympanic membranes. Tympanic abnormalities should be a standard investigation
criterion. Wetli (6.6) reported 81% of investigated cases showed causation
here and recommends ontological inspection with temporal bone dissection.
Cooper et al (6.2) discuss sensorineural hearing loss from the intense
noise and shock wave accompanying thunder, with 30% - 50% of cases reporting
otologic damage. CSF otorrhea or hemotympanum, and disruption of the
ossicles and mastoid have been reported. Nystagmus, vertigo, tinnitus,
and ataxia may follow otologic damage. The reader is directed to Ogren
(6.12) for a comprehensive presentation of neuro-otologic findings.
- Other Effects. Cooper (6.8) noted that two thirds of lightning
survivors had some degree of lower extremity paralysis. Often they appeared
cold, clammy, mottled, insensate, and pulseless. Atrophic spinal paralysis
was reported. Also cataloged were paresis, paresthesias, incoordination,
delayed and acute cerebellar ataxia, hemiplagia and aphasia. Wetli (6.6)
suggests investigation of the brain for injuries beneath direct lightning
strikes with attention to white matter tears and location of hemorrhagic
foci. Readers are directed to Kleinschmidt-DeMasters (6.14) for a Table
of Neuropathologic Findings of seventeen lightning-related autopsies.
6. References:
6.1 Cherington M et al, West J Med 1995; 162:413-417.
6.2 Cooper M A et al, Wilderness Medicine, Auerback P ed., Mosby 1995.
6.3 Fischer RJ et al, Sandia Report SAND94-0311, UC-706, 1994.
6.4 NLSI WWW site, www.lightningsafety.com,
paper number 5.1.6.
6.5 Shockely L, Emergency Medicine, Oct. 1995.
6.6 Wetli C, Am J Forensic Med Pathol, Vol. 17, No. 2, 1996.
6.7 Uman M Lightning Dover Press 1984.
6.8 Cooper M A, Ann Emerg Med 9:134, 1980
6.9 NLSI Files, David Smith Stuart FL in correspondence with the author.
6.10 Geddes, L A, Handbook of Electrical Hazards and Accidents, CRC,
1995.
6.11 Cherington M, Seminars in Neurology, V. 15, No. 3, Sept 1995.
6.12 Ogren FP, Seminars in Neurolgy, V. 15, No. 4, Dec. 1995.
6.13 Brumback RA, Seminars in Neurology, V. 15, No. 4, Dec. 1995.
6.14 Kleinschmidt-DeMasters, BK, Seminars in Neurology, V. 15, No. 4,
Dec. 1995.
7. Appendix:
Sample Collection Protocol for Unexplained Animal Deaths.
The National Institute for Discovery Science has posted on the Internet
a "Sample Collection Protocol for Unexplained Animal Deaths."
Necessary Equipment, Routine Laboratory Examinations, and Methodology
are described. To obtain a copy of this Protocol, see the WWW site:
http://www.nidsci.org/articles/sampleprotocol.html
|