Asphyxia 98534 223616435 2008-07-04T22:15:38Z Gene Hobbs 3121896 /* Further reading */ add ref {{redirect|Suffocate|the J. Holiday song|Suffocate (song)}} {{redirect|Suffocation|the band|Suffocation (band)}} {{DiseaseDisorder infobox | Name = Asphyxia | ICD10 = {{ICD10|R|09|0|r|00}}, {{ICD10|T|71||t|66}} | ICD9 = {{ICD9|799.0}} | }} '''Asphyxia''' (from [[Greek language|Greek]] ''a-'', "without" and ''σφυγμός'' (sphygmos), "pulse, heartbeat") is a condition of severely deficient supply of [[oxygen]] to the [[body]] that arises from being unable to [[breath]]e normally. An example of Asphyxia is choking. Asphyxia causes [[generalized hypoxia]], which primarily affects the tissues and organs most sensitive to [[hypoxia (medical)|hypoxia]] first, such as the [[brain]], hence resulting in [[cerebral hypoxia]]. Asphyxia is usually characterized by [[air hunger]], but this is not always the case; the urge to breathe is triggered by rising [[carbon dioxide]] levels in the blood rather than diminishing oxygen levels. Sometimes there is not enough carbon dioxide to cause air hunger, and victims become hypoxic without knowing it. This may occur, for example, if the oxygen in the air of an enclosed space is displaced by a large amount of [[inert gas]]. In any case, the absence of effective remedial action will very rapidly lead to [[unconsciousness]], [[brain damage]], and [[death]]. The time to death is dependent on the particular mechanism of asphyxia. Asphyxia is used to maim or kill in [[capital punishment]], [[suicide]], [[torture]], and [[war]]fare. It is also used non-fatally in [[martial arts]], [[combat sport]]s, [[BDSM]], and during sex as [[erotic asphyxia]]. Because the need to breathe is triggered by the level of [[carbon dioxide]] in the blood, some victims may not experience an urgent need to breathe and may remain unaware of the onset of [[hypoxia (medical)|hypoxia]]. ==Chemical or physiological interference with respiration== {{refimprove|section|date=July 2007}} Various chemical and physiological situations can interfere with the body's ability to absorb and use oxygen or regulate blood oxygen levels: * [[Carbon monoxide]] inhalation, such as from a car exhaust: carbon monoxide has a higher affinity than oxygen to the [[hemoglobin]] in the blood's red blood corpuscles, bonding with it tenaciously, and, in the process, displacing oxygen and preventing the blood from transporting it around the body * Contact with certain chemicals, including [[pulmonary agent]]s (such as [[phosgene]]) and [[blood agent]]s (such as [[hydrogen cyanide]]) * Self-induced [[hypocapnia]] by [[hyperventilation]], as in [[shallow water blackout|shallow water]] or [[deep water blackout]] and the [[choking game]] * A [[seizure]] which stops breathing activity * [[Sleep apnea]] * [[Drug overdose]] * [[Ondine's curse]], central alveolar hypoventilation syndrome, or primary alveolar hypoventilation, a disorder of the autonomic nervous system in which a patient must consciously breathe; although it is often said that persons with this disease will die if they fall asleep, this is not usually the case * [[Acute respiratory distress syndrome]]. * Exposure to extreme low pressure or [[vacuum]]. ==Smothering== {{Wiktionary|smother}} '''Smothering''' refers to the mechanical obstruction of the flow of air from the environment into the mouth and/or nostrils, for instance, by covering the mouth and nose with a hand, pillow, or a plastic bag.<ref name=ferris>Ferris, J.A.J. [http://www.pathology.ubc.ca/path425/Others/MedicolegalInvestigationOfDeathAndForensic/AsphixiaDrJAJFerris.doc Asphyxia]. ''www.pathology.ubc.ca''. URL's last accessed [[March 1]] [[2006]] (DOC format)</ref> Smothering can be either partial or complete, where partial indicates that the person being smothered is able to inhale some air, although less than required. In a normal situation, smothering requires at least partial obstruction of both the nasal cavities and the mouth to lead to asphyxia. Smothering with the hands or chest is used in some [[combat sport]]s to distract the opponent, and create openings for [[transition (grappling)|transitions]], as the opponent is forced to react to the smothering. It is also used in [[BDSM]] as a type of [[facesitting]]. In some cases, smothering is combined with simultaneous compressive asphyxia. One example is '''overlay''', in which an adult accidentally rolls over an infant during [[co-sleeping]], an accident that often goes unnoticed and is mistakenly thought to be [[sudden infant death syndrome]].<ref name=ferris>Ferris, J.A.J. [http://www.pathology.ubc.ca/path425/Others/MedicolegalInvestigationOfDeathAndForensic/AsphixiaDrJAJFerris.doc Asphyxia]. ''www.pathology.ubc.ca''. URL accessed on [[March 1]] [[2006]]. (DOC format)</ref> Other accidents involving a similar mechanism are [[cave-in]]s or when an individual is buried in sand or grain. In [[homicide|homicidal]] cases, the term '''burking'''<ref>The term "burking" comes from the method [[William Burke]] and [[William Hare (murderer)|William Hare]] used to kill their victims during the [[West Port murders]]. They killed the usually-intoxicated victims by sitting on their chests and suffocating them by putting a hand over their nose and mouth, while using the other hand to push the victim's jaw up. The corpses had no visible injuries, and were supplied to medical schools for money.</ref> is often ascribed to a killing method that involves simultaneous smothering and compression of the torso.<ref name=dimaio>DiMaio, Vincent; DiMaio, Dominick (2001). ''Forensic Pathology, Second Edition''. [http://www.charlydmiller.com/LIB/forensicpathasphyxia.html Selected Pages from CHAPTER 8] and from [http://www.datenschlag.org/howto/atem/english/DiM89.html Deaths Occurring Following the Application of Choke or Carotid Holds]. ''www.charlydmiller.com''. URL last accessed [[March 2]] [[2006]].</ref> ==Compressive asphyxia== [[Image:Image943-knee mount.jpg|thumb|250px|The [[knee-on-belly position]] compresses the chest, making it difficult for the person on the bottom to [[breath]]e.]] '''Compressive asphyxia''' (also called '''chest compression''') refers to the mechanical limitation of the expansion of the lungs by compressing the torso, hence interfering with breathing. Compressive asphyxia occurs when the chest or abdomen is compressed [[anatomical terms of location#Usage in human anatomy|posteriorly]].<ref name=jones>Jones, Richard. [http://www.forensicmed.co.uk/strangulation.htm Strangulation]. ''www.forensicmed.co.uk''. URL last accessed [[February 26]] [[2006]].</ref> In accidents, the term '''traumatic asphyxia''' or '''crush asphyxia''' is usually used to describe compressive asphyxia resulting from being crushed or pinned under a large weight or force. An example of traumatic asphyxia includes cases in which an individual has been using a [[jack (mechanical)|car-jack]] to repair a car from below, only to be crushed under the weight of the vehicle<ref name=dimaio/> when the car-jack slips. [[Pythonidae|Pythons]], [[anacondas]], and other constrictor snakes kill through compressive asphyxia. In fatal crowd disasters, contrary to popular belief, it is not the [[blunt trauma]] from trampling that causes the large part of the deaths, but rather the compressive asphyxia from being crushed against the crowd. In confined spaces, people push and lean against each other; evidence from bent steel railings in several fatal crowd accidents have shown horizontal forces over 4500 N (comparative weight approximately 460kg). In cases where people have stacked up on each other forming a human pile, estimations have been made of around 380kg of compressive weight in the lowest layer.<ref>Fruin, John. [http://www.crowddynamics.com/Main/Fruin%20-%20causes.htm The Causes and Prevention of Crowd Disasters]. ''www.crowddynamics.com''. URL last accessed [[March 3]] [[2006]].</ref> The cause of death of detainees who have been restrained and left prone, for example in police vehicles, and are unable to move into safer positions has been referred to as 'restraint asphyxia'. Chest compression is also featured in various [[grappling]] combat sports, where it is sometimes called '''wringing'''. Such techniques are used either to tire the opponent or as complementary or distractive moves in combination with [[grappling hold#pinning hold|pinning holds]],<ref name=ohlenkamp>Ohlenkamp, Neil [http://judoinfo.com/chokes.htm Principles of Judo Choking Techniques]. ''judoinfo.com''. URL last accessed on [[March 3]] [[2006]]</ref> or sometimes even as [[grappling hold#Submission hold|submission holds]]. Examples of chest compression include the [[knee-on-stomach position]], or techniques such as '''leg scissors''' (also referred to as '''body scissors''' and in [[budo]] referred to as ''do-jime'',<ref>Do-jime is a prohibited technique in [[Judo]], (The Kodokan Judo Institute. [http://www.kodokan.org/e_waza/index.html Kodokan.Org classification of techniques]. ''www.kodokan.org''. URL last accessed [[March 4]] [[2006]].) and is considered a 'slight infringement' according to IJF rules, Section 27: Prohibited acts and penalties, article 21. It should not be confused with ''[[do-osae]]'', which is a colloquial term for the [[guard (grappling)|guard position]].</ref> 胴絞, "trunk strangle" or "body triangle")<ref name=ijf>International Judo Federation. [http://www.ijf.org/rule/rule_referee.php IJF Referee Rules]. ''www.ijf.org''. URL last accessed [[March 6]] [[2006]]</ref> where you wrap the legs around the opponent's midsection and squeeze them together.<ref>Lewis, Bill. [http://www.bjj.org/lewis/shime.html Katsuhiko Kashiwazaki - Shimewaza (Book Review)]. ''www.bjj.org''. URL last accessed [[March 4]] [[2006]].</ref> [[Pressing]] is a form of [[torture]] or [[execution]] that works through asphyxia. ==Perinatal asphyxia== {{main|Perinatal asphyxia}} '''Perinatal asphyxia''' is the medical condition resulting from deprivation of [[oxygen]] ([[Hypoxia (medical)|hypoxia]]) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal [[blood pressure]] or interference during [[childbirth|delivery]] with blood flow to the infant's [[brain]]. This can occur due to inadequate [[circulatory system|circulation]] or [[perfusion]], impaired respiratory effort, or inadequate [[Ventilation (physiology)|ventilation]]. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born a terme. ==References== <!--This article uses the Cite.php citation mechanism. If you would like more information on how to add references to this article, please see http://meta.wikimedia.org/wiki/Cite/Cite.php --> {{reflist|2}} ==Further reading== * ''The Physiology, Pathology, and Treatment of Asphyxia'' by [[James Phillips Kay-Shuttleworth]], 1834, 352 pages. * {{cite journal |author=Elsner R |title=Perspectives in diving and asphyxia |journal=Undersea Biomed Res |volume=16 |issue=5 |pages=339–44 |year=1989 |month=September |pmid=2678664 |doi= |url=http://archive.rubicon-foundation.org/2500 |accessdate=2008-07-04}} ==External links== * [http://www.lockflow.com/article_view.php?id=782 Cross-side to chest compression choke] {{Circulatory and respiratory system symptoms and signs}} {{Consequences of external causes}} [[Category:Medical emergencies]] [[Category:Causes of death]] [[Category:Diving medicine]] [[Category:Execution methods]] [[Category:Murder]] [[da:Kvælning]] [[de:Asphyxie]] [[et:Lämbumine]] [[es:Anoxia]] [[fa:خفگی]] [[fr:Asphyxie]] [[ko:질식]] [[it:Anossia]] [[lt:Uždusimas]] [[nl:Wurging]] [[ja:窒息]] [[pl:Asfiksja]] [[pt:Asfixia]] [[ru:Асфиксия]] [[simple:Suffocation]] [[fi:Asfyksia]] [[sv:Kvävning]] [[uk:Асфіксія]] [[zh:窒息]]