Keraunomedicine
5759189
190094345
2008-02-09T02:20:12Z
DumZiBoT
6085301
Bot: Converting bare references, see [[User:DumZiBoT/refLinks|FAQ]]
[[Image:Lightning3.jpg|thumb|350px|Multiple lightning bolts strike a populated area.]]
'''Keraunomedicine''' is the medical study of [[lightning]] casualties. The term may have been coined by Chris Andrews, a lightning and electrical injury researcher.<ref>[http://www.jolr.org/Editors/Adrews.html Chris Andrews - JOLR<!-- Bot generated title -->]</ref> Lightning [[injury|injuries]] result from three factors: electrical damage, intense heat, and the mechanical energy which these generate. While sudden death is common because of the huge voltage of a lightning strike, survivors often fare better than victims of other electrical injuries caused by a more prolonged application of lesser voltage.<ref name = match2heart> {{cite book | author=[[Gretel Ehrlich]] | title= A match to the heart | publisher=Penguin Books | year=1994 | id = ISBN 0-14-017937-2}} The author tells of her slow recovery after being struck by lightning. </ref>
==Path to victim==
Lightning can incapacitate humans in four different ways:
* Direct strike
* 'Splash' from nearby objects struck
* Ground strike near victim causing a difference of potential in the ground itself (due to resistance to current in the Earth), amounting to several thousand volts per foot, depending upon the composition of the earth that makes up the ground at that location (sand being a fair insulator and wet, salty and spongy earth being more conductive).
* [[Electromagnetic pulse|EMP]] or electromagnetic pulse from close strikes - especially during positive lightning discharges
In a ''direct hit'', the [[electrical charge]] strikes the victim first.
''Splash'' hits occur when lightning prefers a victim (with lower resistance) over a nearby object that has more resistance, and strikes the victim on its way to ground.
''Ground'' strikes, in which the bolt lands near the victim and is conducted through the victim and his or her connection to the ground (such as through the feet, due to the voltage ''gradient'' in the earth, as discussed above), can cause great damage.
==Damaging Forces==
===Heat===
A bolt of lightning can reach [[temperature]]s approaching 28,000 degrees [[Celsius]] (50,000 degrees [[Fahrenheit]]) in a split second. This is about five times hotter than the surface of the [[sun]]<ref>[http://weathersavvy.com/Q-lightning1.html Lightning?<!-- Bot generated title -->]</ref>. There is sometimes spectacular and unconventional lightning damage. ''Hot lightning'' (high-current lightning) which lasts for more than a second can deposit immense energy, melting or [[carbonization|carbonizing]] large objects. One such example is the destruction of the basement [[Electrical insulation|insulator]] of the 250-metre-high central [[radio mast|mast]] of [[longwave transmitter Orlunda]], which led to its collapse. The intense heat generated by a lightning strike can burn tissue, and cause lung damage, and the chest can be damaged by the mechanical force of rapidly expanding heated air.
===Electricity===
Counterintuitively, if the victim's skin [[electrical resistance|resistance]] is high enough, much of the current will ''flash'' around the skin or clothing to the ground in a ''direct strike'', resulting in a surprisingly benign outcome.
The lightning often leaves skin burns in characteristic [[Lichtenberg figure]]s, sometimes called ''lightning flowers''; they may persist for hours or days, and are a useful indicator for medical examiners when trying to determine the cause of death. They are thought to be caused by the rupture of small [[capillaries]] under the skin, either from the current or from the [[shock wave]]. The intense electrical energy can cause a loss of consciousness; it is also speculated that the [[electromagnetic pulse|EMP]] created by a nearby lightning strike can cause [[cardiac arrest]].
===Mechanical force===
The extreme mechanical force generated by a lightning strike may result in a loss of consciousness.
{{Expand|section|date=May 2007}}
==Effects & Treatment==
===Immediate===
[[Image:CPR-oxygen-defibrillator.jpg|thumb|Typical view of defibrillation in progress, with the operator at the head, but clear of contact with the patient]]
The most critical injuries are to the [[circulatory system]], the [[lung]]s, and the [[central nervous system]]. Many victims suffer immediate [[cardiac arrest]] and will not survive without prompt emergency care, which is safe to administer because the victim will not retain any [[electrical charge]] after the lightning has struck (of course, the helper could be struck by a separate bolt of lightning in the vicinity). Others incur [[myocardial infarction]] and various [[cardiac arrhythmias]], either of which can be rapidly fatal as well. Loss of consciousness is very common immediately after a strike. [[Amnesia]] and [[confusion]] of varying duration often result as well.
===Long-term===
A complete physical examination by [[paramedic]]s or [[physician]]s may reveal ruptured [[eardrum]]s, and ocular [[cataract]]s may develop, sometimes more than a year after an otherwise uneventful recovery. Long-term injuries are usually neurological in nature, including memory deficit, sleep disturbance, chronic pain, and chronic dizziness.<ref name="lightningsafe">http://www.lightningsafety.noaa.gov/resources/Ltg%20Safety-Facts.pdf OSAA Lightning Safety Facts</ref>
==Notes==
===See also===
*[[Keraunopathy]]
*[[Lightning safety]]
===External links===
*[http://www.lightning-strike.org Lightning Strike & Electric Shock Survivors International, Inc.], a non-profit support group by and for survivors, their families, and other interested parties.
* [http://www.nssl.noaa.gov/users/holle/public_html/medical-alpha.html National Oceanic and Atmospheric Administration bibliography]
===References===
<references/>
* [http://wgntv.trb.com/news/weather/wgntv-weatherwords-k,0,2044572.story?coll=wgntv-weather-4 WGN-TV weather words]
[[Category:Lightning]]
[[Category:Injuries]]