Asphyxia

Asphyxia
Asphyxia
Classification and external resources
ICD-10 R09.0, T71

Asphyxia or asphyxiation (from Greek α- "without" and σφύξις sphyxis, "heartbeat") is a condition of severely deficient supply of oxygen to the body that arises from being unable to breathe normally. An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs. It can be caused by improper ventilation and charcoal burning in a closed room. Many incidents have been reported (death and coma).

Contents

Oxygen deficiency

The body creates the need to breathe from the excess carbon dioxide in the lungs; the body has no way to detect the absence of oxygen. Many gases, though non-toxic, are classified as simple asphyxiants in their pure form or in high concentrations for this very reason.

One form of asphyxiation is from entering a low oxygen atmosphere or an inert atmosphere, such as in a food oil tank that has a covering blanket of nitrogen or argon to shield the oil from atmospheric oxygen. Without sufficient oxygen to sustain life, people will act normally at first but will then abruptly feel dizzy and black out in a matter of seconds as the remaining oxygen in the blood stream is consumed. Oxygen deficient atmospheres are the basis for many occurrences of single and multiple deaths; the deceased will be found lying prone on the bottom of a tank, and then the observer will rush in to rescue them, and succumb to the same effect, hence the need to vent or purge the inert gases from all tanks before entry.[citation needed]

Other causes of oxygen deficiency include:

Smothering

Smothering is 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.[1] 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 sports to distract the opponent, and create openings for transitions, as the opponent is forced to react to the smothering.

In some cases, when performing certain routines, 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.[1] Other accidents involving a similar mechanism are cave-ins or when an individual is buried in sand or grain.

In homicidal cases, the term burking is often ascribed to a killing method that involves simultaneous smothering and compression of the torso.[2] The term "burking" comes from the method William Burke and 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.

This method is sometimes used by a lion to kill a buffalo, by opening its mouth over the buffalo's mouth and nostrils and securing itself with its canine teeth.

Compressive asphyxia

The knee-on-belly position compresses the chest, making it difficult for the person on the bottom to breathe.

Compressive asphyxia (also called chest compression) is 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 posteriorly.[3] 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 car-jack to repair a car from below, only to be crushed under the weight of the vehicle.[2] Pythons, anacondas, and other constrictor snakes kill through compressive asphyxia. In cases of co-sleeping ("overlay"), the weight of an adult or large child may compress an infant's chest, preventing proper expansion of the chest. Risk factors include large or obese adults, parental fatigue or impairment (sedation by drugs or alcohol) of the cosleeping adult and a small shared sleeping space (for example, both adult and infant sharing a couch).

In fatal crowd disasters, compressive asphyxia from being crushed against the crowd causes the large part of the deaths, rather than blunt trauma from trampling. This is what occurred at the Hillsborough Disaster in 1989, when 96 Liverpool fans were crushed to death in an overcrowded terrace. 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 (equivalent to a weight of approximately 460 kg, or 1014 lbs). In cases where people have stacked up on each other forming a human pile, estimations have been made of around 380 kg (838 lbs) of compressive weight in the lowest layer.[4]

The cause of death of the detainees who have been restrained and left prone, for example in police vehicles, and are not able to move into safer positions has been referred to as "positional asphyxia". "Restraint asphyxia" is a term used to describe the death of people who have died or lost consciousness (to die later in a coma from anoxic brain damage) while being restrained in positions that cause asphyxia by facial compression, neck compression or chest compression. Most occur during law enforcement or psychiatric restraint situations. It may be that the "positional asphyxia" deaths of detainees are actually active chest compression deaths caused by the weight of restrainers holding uncooperative detainees down in a prone position during the process of being handcuffed and otherwise secured. Thus, the passive deaths following custody restraint presumed to be due to positional asphyxia after being secured by mechanical restraints may actually be examples of active restraint asphyxia occurring during the process of placing restraints.

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 pinning holds,[5] or sometimes even as 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 budō referred to as do-jime,[6] 胴絞, "trunk strangle" or "body triangle")[7] where you wrap the legs around the opponent's midsection and squeeze them together.[8]

Pressing is a form of torture or execution that works through asphyxia.

Perinatal asphyxia

Perinatal asphyxia is the medical condition resulting from deprivation of oxygen (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 delivery with blood flow to the infant's brain. This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term.[citation needed]

Nitrogen asphyxiation

Nitrogen asphyxiation is an occasional cause of accidental death and a theoretical method of capital punishment. After just two or three breaths of pure nitrogen, the oxygen concentration in the lungs would be low enough for some oxygen already in the bloodstream to exchange back to the lungs and be eliminated by exhalation. Crude simulation of oxygen transport through the lungs and blood stream suggests that the partial pressure of oxygen in arterial blood would be about 50 percent of saturation 1 minute after switching gases and would reach zero within 3 minutes.

See also

References

  1. ^ a b Ferris, J.A.J. Asphyxia. www.pathology.ubc.ca. URL's last accessed March 1, 2006 (DOC format)
  2. ^ a b DiMaio, Vincent; DiMaio, Dominick (2001). Forensic Pathology, Second Edition. Selected Pages from CHAPTER 8 and from Deaths Occurring Following the Application of Choke or Carotid Holds. www.charlydmiller.com. URL last accessed March 2, 2006.
  3. ^ Jones, Richard. Strangulation. www.forensicmed.co.uk. URL last accessed February 26, 2006.
  4. ^ Fruin, John. The Causes and Prevention of Crowd Disasters. www.crowddynamics.com. URL last accessed March 3, 2006.
  5. ^ Ohlenkamp, Neil Principles of Judo Choking Techniques. judoinfo.com. URL last accessed on March 3, 2006
  6. ^ Do-jime is a prohibited technique in Judo, (The Kodokan Judo Institute. 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 position.
  7. ^ International Judo Federation. IJF Referee Rules. www.ijf.org. URL last accessed March 6, 2006
  8. ^ Lewis, Bill. Katsuhiko Kashiwazaki - Shimewaza (Book Review). www.bjj.org. URL last accessed March 4, 2006.

Further reading

External links


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Look at other dictionaries:

  • Asphyxia — As*phyx i*a, Asphyxy As*phyx y, n. [NL. asphyxia, fr. Gr. ?; a priv. + ? to throb, beat.] (Med.) Apparent death, or suspended animation; the condition which results from interruption of respiration, as in suffocation or drowning, or the… …   The Collaborative International Dictionary of English

  • asphyxia — 1706, stoppage of pulse, from Modern Latin, from Gk. asphyxia stopping of the pulse, from a not + sphyzein to throb. The current sense of suffocation is from 1778, but it is a curious infelicity of etymology [OED] since victims of suffocation… …   Etymology dictionary

  • asphyxia — [as fik′sē ə] n. [ModL < Gr, stopping of the pulse < a , not + sphyzein, to throb] loss of consciousness as a result of too little oxygen and too much carbon dioxide in the blood: suffocation causes asphyxia …   English World dictionary

  • asphyxia — ► NOUN ▪ a condition caused by the body being deprived of oxygen, leading to unconsciousness or death. DERIVATIVES asphyxiant adjective & noun. ORIGIN Greek asphuxia, from a without + sphuxis pulse …   English terms dictionary

  • Asphyxia — Klassifikation nach ICD 10 R09.0 Asphyxie …   Deutsch Wikipedia

  • asphyxia — asphyxial, adj. /as fik see euh/, n. Pathol. the extreme condition caused by lack of oxygen and excess of carbon dioxide in the blood, produced by interference with respiration or insufficient oxygen in the air; suffocation. [1700 10; < NL < Gk… …   Universalium

  • asphyxia — [[t]æsfɪ̱ksiə[/t]] N UNCOUNT Asphyxia is death or loss of consciousness caused by being unable to breathe properly. [MEDICAL] Most deaths occurred from asphyxia through smoke inhalation. Syn: suffocation …   English dictionary

  • asphyxia —   n. suffocation.    ♦ asphyxial, a.    ♦ asphyxiant, n. & a. (substance) causing asphyxia.    ♦ asphyxiate, v.i. & t.    ♦ asphyxiator, n. substance causing asphyxia …   Dictionary of difficult words

  • asphyxia — noun A condition in which an extreme decrease in the concentration of oxygen in the body accompanied by an increase in the concentration of carbon dioxide leads to loss of consciousness or death. Asphyxia can be induced by choking, drowning,… …   Wiktionary

  • asphyxia — Impaired or absent exchange of oxygen and carbon dioxide on a ventilatory basis; combined hypercapnia and hypoxia or anoxia. [G. a priv. + sphyzo, to throb] cyanotic a. a. to the point of sufficient destruction of …   Medical dictionary

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