~ National Lightning Safety Institute ~

Section 3.8

1. 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.
2. 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.
3. 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

   
   
4. 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=
5. 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.

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