Asphyxia
Encyclopedia
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).
in the lungs; the body has no way to detect the absence of oxygen. Many gases, though non-toxic
, are classified as simple asphyxiant
s 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.
Other causes of oxygen deficiency include:
s 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
. Other accidents involving a similar mechanism are cave-in
s 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. 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 (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. 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. 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 Ibrox Disaster
in 1971, where 66 Rangers
fans died, and 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.
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, 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, 胴絞, "trunk strangle" or "body triangle") where you wrap the legs around the opponent's midsection and squeeze them together.
Pressing is a form of torture
or execution that works through asphyxia.
(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.
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.
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
to the body
Body
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...
that arises from being unable to breathe
Breathe
Breathe may refer to:* Breathing, to inhale and exhale consecutively, drawing oxygen from the air, through the lungs.- Albums :* Breathe , 1994* Breathe , 1996* Breathe , 1999...
normally. An example of asphyxia is choking
Choking
Choking is the mechanical obstruction of the flow of air from the environment into the lungs. Choking prevents breathing, and can be partial or complete, with partial choking allowing some, although inadequate, flow of air into the lungs. Prolonged or complete choking results in asphyxia which...
. 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).
Oxygen deficiency
The body creates the need to breathe from the excess carbon dioxideCarbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in the lungs; the body has no way to detect the absence of oxygen. Many gases, though non-toxic
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
, are classified as simple asphyxiant
Asphyxiant gas
An asphyxiant gas is a non-toxic or minimally toxic gas which reduces or diplaces the normal oxygen concentration in breathing air. Prolonged breathing of oxygen depleted air can lead to death by asphyxiation...
s 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
Inert
-Chemistry:In chemistry, the term inert is used to describe a substance that is not chemically reactive.The noble gases were previously known as inert gases because of their perceived lack of participation in any chemical reactions...
atmosphere, such as in a food oil tank that has a covering blanket of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
or argon
Argon
Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
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.
Other causes of oxygen deficiency include:
- Carbon monoxide inhalation, such as from a car exhaust: carbon monoxide has a higher affinity than oxygen to the hemoglobinHemoglobinHemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
in the blood's red blood corpuscles, bonding with it tenaciously, and, in the process, displacing oxygen and preventing the blood from transporting oxygen around the body - Contact with certain chemicals, including pulmonary agentPulmonary agentA pulmonary agent is a chemical weapon agent designed to impede a victim's ability to breathe. They operate by causing a build-up of fluids in the lungs which then leads to...
s (such as phosgenePhosgenePhosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...
) and blood agentBlood agentA blood agent is a toxic chemical agent that affects the body by being absorbed into the blood. They are fast-acting, potentially lethal poisons that typically manifest at room temperature as volatile colorless gases with a faint odor. Blood agents are either cyanide- or...
s (such as hydrogen cyanide) - Self-induced hypocapniaHypocapniaHypocapnia or hypocapnea also known as hypocarbia, sometimes incorrectly called acapnia, is a state of reduced carbon dioxide in the blood. Hypocapnia usually results from deep or rapid breathing, known as hyperventilation....
by hyperventilationHyperventilationHyperventilation or overbreathing is the state of breathing faster or deeper than normal, causing excessive expulsion of circulating carbon dioxide. It can result from a psychological state such as a panic attack, from a physiological condition such as metabolic acidosis, can be brought about by...
, as in shallow waterShallow water blackoutA shallow water blackout is a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive in water typically shallower than five metres , when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have...
or deep water blackoutDeep water blackoutA deep water blackout is a loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive or breath-hold dive, typically of ten metres or more when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have...
and the choking gameChoking gameThe fainting game , refers to intentionally cutting off oxygen to the brain with the goal of inducing temporary syncope and euphoria. There are two distinct methods used to achieve oxygen deprivation: strangulation and self-induced hypocapnia.-Differences from erotic asphyxiation:According to Dr... - A seizureSeizureAn epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
which stops breathing activity - Sleep apneaSleep apneaSleep apnea is a sleep disorder characterized by abnormal pauses in breathing or instances of abnormally low breathing, during sleep. Each pause in breathing, called an apnea, can last from a few seconds to minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally low...
- Drug overdoseDrug overdoseThe term drug overdose describes the ingestion or application of a drug or other substance in quantities greater than are recommended or generally practiced...
- Ondine's curseOndine's curseOndine's Curse, also called congenital central hypoventilation syndrome or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated...
, central alveolar hypoventilationHypoventilationIn medicine, hypoventilation occurs when ventilation is inadequate to perform needed gas exchange...
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 syndromeAcute respiratory distress syndromeAcute respiratory distress syndrome , also known as respiratory distress syndrome or adult respiratory distress syndrome is a serious reaction to various forms of injuries to the lung....
. - Exposure to extreme low pressure or vacuumVacuumIn everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
to the pattern
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. 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 sportCombat sport
A Combat sport, also known as a Fighting sport, is a competitive contact sport where two combatants fight against each other using certain rules of engagement , typically with the aim of simulating parts of real hand to hand combat...
s to distract the opponent, and create openings for transitions
Transition (grappling)
A transition in grappling is a move from one grappling hold or grappling position to another. The process is called transitioning and is one of the most important aspects of ground grappling, as it allows the combatant performing the transition to advance in positioning, for instance by using a...
, 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
Co-sleeping
Co-sleeping is a practice in which babies and young children sleep close to one or both parents, as opposed to in a separate room. It is standard practice in many parts of the world, and is practiced by a significant minority in countries where cribs are also used...
, an accident that often goes unnoticed and is mistakenly thought to be sudden infant death syndrome
Sudden infant death syndrome
Sudden infant death syndrome is marked by the sudden death of an infant that is unexpected by medical history, and remains unexplained after a thorough forensic autopsy and a detailed death scene investigation. An infant is at the highest risk for SIDS during sleep, which is why it is sometimes...
. Other accidents involving a similar mechanism are cave-in
Cave-in
A cave-in is a collapse of a geologic formation, mine or structure which typically occurs during mining or tunneling. Geologic structures prone to cave-ins include alvar, tsingy and other limestone formations, but can also include lava tubes and a variety of other subsurface rock formations.In...
s or when an individual is buried in sand or grain.
In homicidal
Homicide
Homicide refers to the act of a human killing another human. Murder, for example, is a type of homicide. It can also describe a person who has committed such an act, though this use is rare in modern English...
cases, the term burking is often ascribed to a killing method that involves simultaneous smothering and compression of the torso. 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
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
to kill a buffalo
African Buffalo
The African buffalo, affalo, nyati, Mbogo or Cape buffalo is a large African bovine. It is not closely related to the slightly larger wild Asian water buffalo, but its ancestry remains unclear...
, by opening its mouth over the buffalo's mouth and nostrils and securing itself with its canine teeth.
Compressive asphyxia
Jack (mechanical)
A jack is a mechanical device used to lift heavy loads or apply great forces. Jacks employ a screw thread or hydraulic cylinder to apply very high linear forces.-Mechanical jack:...
to repair a car from below, only to be crushed under the weight of the vehicle. 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
Blunt trauma
In medical terminology, blunt trauma, blunt injury, non-penetrating trauma or blunt force trauma refers to a type of physical trauma caused to a body part, either by impact, injury or physical attack; the latter usually being referred to as blunt force trauma...
from trampling. This is what occurred at the Ibrox Disaster
Ibrox disaster
The Ibrox disaster refers to two accidents, in 1902 and 1971, which led to major loss of life at the Ibrox Stadium in Glasgow, Scotland.-First Ibrox disaster:...
in 1971, where 66 Rangers
Rangers F.C.
Rangers Football Club are an association football club based in Glasgow, Scotland, who play in the Scottish Premier League. The club are nicknamed the Gers, Teddy Bears and the Light Blues, and the fans are known to each other as bluenoses...
fans died, and at the Hillsborough Disaster
Hillsborough disaster
The Hillsborough disaster was a human crush that occurred on 15 April 1989 at Hillsborough, a football stadium, the home of Sheffield Wednesday F.C. in Sheffield, England, resulting in the deaths of 96 people, and 766 being injured, all fans of Liverpool F.C....
in 1989, when 96 Liverpool
Liverpool F.C.
Liverpool Football Club is an English Premier League football club based in Liverpool, Merseyside. Liverpool has won eighteen League titles, second most in English football, seven FA Cups and a record seven League Cups...
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.
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
Grappling
Grappling refers to techniques, maneuvers, and counters applied to an opponent in order to gain a physical advantage, such as improving relative position, escaping, submitting, or injury to the opponent. Grappling is a general term that covers techniques used in many disciplines, styles and martial...
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, 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
Budo
is a Japanese term describing martial arts. In English, it is used almost exclusively in reference to Japanese martial arts.-Etymology:Budō is a compound of the root bu , meaning war or martial; and dō , meaning path or way. Specifically, dō is derived from the Buddhist Sanskrit mārga...
referred to as do-jime, 胴絞, "trunk strangle" or "body triangle") where you wrap the legs around the opponent's midsection and squeeze them together.
Pressing is a form of torture
Torture
Torture is the act of inflicting severe pain as a means of punishment, revenge, forcing information or a confession, or simply as an act of cruelty. Throughout history, torture has often been used as a method of political re-education, interrogation, punishment, and coercion...
or execution that works through asphyxia.
Perinatal asphyxia
Perinatal asphyxia is the medical condition resulting from deprivation of oxygenOxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
(hypoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
or interference during delivery
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...
with blood flow to the infant's brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. This can occur due to inadequate circulation
Circulatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...
or perfusion
Perfusion
In physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue. The word is derived from the French verb "perfuser" meaning to "pour over or through."...
, impaired respiratory effort, or inadequate ventilation
Ventilation (physiology)
In respiratory physiology, ventilation is the rate at which gas enters or leaves the lung. It is categorized under the following definitions:-Sample values:...
. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term.
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
- Asphyxiant gasAsphyxiant gasAn asphyxiant gas is a non-toxic or minimally toxic gas which reduces or diplaces the normal oxygen concentration in breathing air. Prolonged breathing of oxygen depleted air can lead to death by asphyxiation...
- Erotic asphyxiationErotic asphyxiationErotic asphyxiation or breath control play is the intentional restriction of oxygen to the brain for sexual arousal. The sexual preference for that behavior is variously called asphyxiophilia, autoerotic asphyxia, hypoxyphilia. Colloquially, a person engaging in the activity is sometimes called a...
- HypercapniaHypercapniaHypercapnia or hypercapnea , also known as hypercarbia, is a condition where there is too much carbon dioxide in the blood...
- Respiratory acidosisRespiratory acidosisRespiratory acidosis is a medical condition in which decreased ventilation causes increased blood carbon dioxide concentration and decreased pH ....