Asphyxia or asphyxiation is a condition of deficient supply of
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
to the
body which arises from abnormal
breathing
Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
All aerobic creatures need oxygen for cell ...
. Asphyxia causes
generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can induce asphyxia, all of which are characterized by the inability of a person to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death.
In 2015, about 9.8 million cases of unintentional suffocation occurred which resulted in 35,600 deaths.
[ The word asphyxia is from ]Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
"without" and , "squeeze" (throb of heart).
Causes
Situations that can cause asphyxia include but are not limited to: airway obstruction
Airway obstruction is a blockage of respiration in the airway that hinders the free flow of air. It can be broadly classified into being either in the upper airway (UPA) or lower airway (LOA).
Airway obstruction is a life-threatening condition ...
, the constriction or obstruction of airways, such as from asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, c ...
, laryngospasm, or simple blockage from the presence of foreign materials; from being in environments where oxygen is not readily accessible: such as underwater, in a low oxygen atmosphere, or in a vacuum; environments where sufficiently oxygenated air is present, but cannot be adequately breathed because of air contamination such as excessive smoke.
Other causes of oxygen deficiency include
but are not limited to:
* Acute respiratory distress syndrome
Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin col ...
* Carbon monoxide inhalation, such as that from a car exhaust
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an ...
and the smoke's emission from a lit cigarette: carbon monoxide has a higher affinity than oxygen to the hemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...
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 agent
A pulmonary agent, or choking 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 suffocation. Exposure to the eyes and skin tends to ...
s (such as phosgene
Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, es ...
) and blood agents (such as hydrogen cyanide
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on a ...
)
* Drowning
Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer a ...
* Drug overdose
A drug overdose (overdose or OD) is the ingestion or application of a drug or other substance in quantities much greater than are recommended.
* Exposure to extreme low pressure or vacuum
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or " void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often di ...
from spacesuit
A space suit or spacesuit is a garment worn to keep a human alive in the harsh environment of outer space, vacuum and temperature extremes. Space suits are often worn inside spacecraft as a safety precaution in case of loss of cabin pressure, ...
damage (see space exposure
Venturing into the environment of space can have negative effects on the human body. Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton ( spaceflight osteopenia). Other significant e ...
)
* Hanging
Hanging is the suspension of a person by a noose or ligature strangulation, ligature around the neck.Oxford English Dictionary, 2nd ed. Hanging as method of execution is unknown, as method of suicide from 1325. The ''Oxford English Dictionary' ...
, whether suspension or short drop hanging
* Self-induced hypocapnia
Hypocapnia (from the Greek words υπό meaning ''below normal'' and καπνός ''kapnós'' meaning ''smoke''), also known as hypocarbia, sometimes incorrectly called acapnia, is a state of reduced carbon dioxide in the blood. Hypocapnia usually ...
by hyperventilation
Hyperventilation is irregular breathing that occurs when the rate or tidal volume of breathing eliminates more carbon dioxide than the body can produce. This leads to hypocapnia, a reduced concentration of carbon dioxide dissolved in the blood. ...
, as in shallow water or deep water blackout and the choking game
The choking game or blackout challenge is the act of intentionally cutting off oxygen to the brain with the goal of inducing temporary loss of consciousness and euphoria.
Reasons for practice
Limited research has been conducted regarding motivat ...
* Inert gas asphyxiation
* Congenital central 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
* Respiratory disease
Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, ...
s
* Sleep apnea
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many tim ...
* A seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with l ...
which stops breathing activity
* Strangling
Strangling is compression of the neck that may lead to unconsciousness or death by causing an increasingly hypoxic state in the brain. Fatal strangling typically occurs in cases of violence, accidents, and is one of two main ways that hangin ...
* Breaking the wind pipe
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from t ...
* Prolonged exposure to chlorine gas
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...
Smothering
Smothering is a 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 sport
A combat sport, or fighting sport, is a competitive contact sport that usually involves one-on-one combat. In many combat sports, a contestant wins by scoring more points than the opponent, submitting the opponent with a hold, disabling the opp ...
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 onto an infant during co-sleeping, an accident that often goes unnoticed and is mistakenly thought to be sudden infant death syndrome
Sudden infant death syndrome (SIDS) is the sudden unexplained death of a child of less than one year of age. Diagnosis requires that the death remain unexplained even after a thorough autopsy and detailed death scene investigation. SIDS usuall ...
.[ 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.] 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.
Compressive asphyxia
Compressive asphyxia (also called chest compression) is mechanically limiting expansion of the lungs by compressing the torso, preventing breathing. " Traumatic asphyxia" or "crush asphyxia" usually refers to compressive asphyxia resulting from being crushed or pinned under a large weight or force, or in a crowd crush. An example of traumatic asphyxia is a person who jacks up a car to work on it from below, and is crushed by the vehicle when the jack fails.[ Constrictor snakes such as ]boa constrictor
The boa constrictor (scientific name also ''Boa constrictor''), also called the red-tailed boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the family ...
s kill through slow compressive asphyxia, tightening their coils every time the prey breathes out rather than squeezing forcefully. In cases of an adult co-sleeping with an infant ("overlay"), the heavy sleeping adult may move on top of the infant, causing compression asphyxia.
In fatal crowd disasters, compressive asphyxia from being crushed against the crowd causes all or nearly all deaths, rather than blunt trauma
Blunt trauma, also known as blunt force trauma or non-penetrating trauma, is physical traumas, and particularly in the elderly who fall. It is contrasted with penetrating trauma which occurs when an object pierces the skin and enters a tissu ...
from trampling. This is what occurred at the Ibrox disaster in 1971, where 66 Rangers
A Ranger is typically someone in a military/paramilitary or law enforcement role specializing in patrolling a given territory, called “ranging”. The term most often refers to:
* Park ranger or forest ranger, a person charged with protecting and ...
fans died; the 1979 The Who concert disaster
The Who concert disaster was a crowd disaster that occurred on December 3, 1979, when English rock band The Who performed at Riverfront Coliseum (now known as Heritage Bank Center) in Cincinnati, Ohio, United States, and a rush of concert-goers ...
where 11 died; the Luzhniki disaster in 1982, when 66 FC Spartak Moscow
FC Spartak Moscow (russian: Футбольный клуб «Спартак» Москва, Futbolʹnyy klub «Spartak» Moskva, ) is a Russian professional football club based in Moscow. Having won 12 Soviet championships (second only to Dy ...
fans died; the Hillsborough disaster
The Hillsborough disaster was a fatal Crowd collapses and crushes, human crush during a association football, football match at Hillsborough Stadium in Sheffield, South Yorkshire, England, on 15 April 1989. It occurred during an FA Cup semi-fina ...
in 1989, where 96 Liverpool
Liverpool is a City status in the United Kingdom, city and metropolitan borough in Merseyside, England. With a population of in 2019, it is the List of English districts by population, 10th largest English district by population and its E ...
fans were crushed to death in an overcrowded terrace, 95 of the 96 from compressive asphyxia, 93 dying directly from it and 2 others from related complications; and the Astroworld Festival crowd crush in 2021, where 10 died. More recently on the 29th of October 2022, 156 people were killed and over 152 were injured in Itaewon, South Korea on an evening of Halloween celebrations.
In confined spaces, people are forced to push against each other; evidence from bent steel railings in several fatal crowd accidents has shown horizontal forces over 4500 N (equivalent to a weight of approximately 450 kg or 1000 lbs). In cases where people have stacked up on each other in a human pile, it has been estimated that those at the bottom are subjected to around 380 kg (840 lbs) of compressive weight.
"Positional" or "restraint" asphyxia is when a person is restrained and left alone prone, such as in a police vehicle, and is unable to reposition themself in order to breathe. The death can be in the vehicle, or following loss of consciousness to be followed by death while in a coma, having presented with anoxic brain damage. The asphyxia can be caused by facial compression, neck compression, or chest compression. This occurs mostly during restraint and handcuffing situations by law enforcement, including psychiatric incidents. The weight of the restraint(s) doing the compression may contribute to what is attributed to positional asphyxia. Therefore, passive deaths following custody restraint that are presumed to be the result of positional asphyxia may actually be examples of asphyxia occurring during the restraint process.
Chest compression is a technique used in various grappling
Grappling, in hand-to-hand combat, describes sports that consist of gripping or seizing the opponent. Grappling is used at close range to gain a physical advantage over an opponent, either by imposing a position or causing injury. Grappling is ...
combat sports, where it is sometimes called wringing, 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
is a Japanese term describing modern Japanese martial arts. Literally translated it means the "Martial Way", and may be thought of as the "Way of War" or the "Way of Martial Arts".
Etymology
Budō is a compound of the root ''bu'' (武:ぶ), m ...
referred to as ''do-jime''; 胴絞, "trunk strangle" or "body triangle") where a participant wraps his or her legs around the opponent's midsection and squeezes them together.
Pressing is a form of torture
Torture is the deliberate infliction of severe pain or suffering on a person for reasons such as punishment, extracting a confession, interrogation for information, or intimidating third parties. Some definitions are restricted to acts ...
or execution
Capital punishment, also known as the death penalty, is the state-sanctioned practice of deliberately killing a person as a punishment for an actual or supposed crime, usually following an authorized, rule-governed process to conclude that t ...
using compressive asphyxia.
Perinatal asphyxia
Perinatal asphyxia is the medical condition resulting from deprivation of oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
( hypoxia) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
or interference during delivery with blood flow to the infant's brain
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...
. This can occur as a result of inadequate circulation
Circulation may refer to:
Science and technology
* Atmospheric circulation, the large-scale movement of air
* Circulation (physics), the path integral of the fluid velocity around a closed curve in a fluid flow field
* Circulatory system, a bio ...
or perfusion, impaired respiratory effort, or inadequate ventilation. There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals
In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron.
With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spon ...
, which have a role in reperfusion injury
Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue ('' re-'' + '' perfusion'') after a period of ischemia or lack of oxygen (anoxia or ...
after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
Mechanical asphyxia
Classifications of different forms of asphyxia vary among literature, with differences in defining the concept of mechanical asphyxia being the most obvious.
In DiMaio and DiMaio's 2001 textbook on forensic pathology, mechanical asphyxia is caused by pressure from outside the body restricting respiration.[ Similar narrow definitions of mechanical asphyxia have occurred in Azmak's 2006 literature review of asphyxial deaths and Oehmichen and Auer's 2005 book on forensic neuropathology.][ According to DiMaio and DiMaio, mechanical asphyxia encompasses positional asphyxia, traumatic asphyxia, and "human pile" deaths.][
In Shkrum and Ramsay's 2007 textbook on forensic pathology, mechanical asphyxia occurs when any mechanical means cause interference with the exchange of oxygen and carbon dioxide in the body.][ Similar broad definitions of mechanical asphyxia have occurred in Saukko and Knight's 2004 book on asphyxia, and Dolinak and Matshes' 2005 book on forensic pathology.][ According to Shkrum and Ramsay, mechanical asphyxia encompasses smothering, choking, positional asphyxia, traumatic asphyxia, wedging, strangulation and drowning.][
Sauvageau and Boghossian propose in 2010 that mechanical asphyxia should be officially defined as caused by "restriction of respiratory movements, either by the position of the body or by external chest compression", thus encompassing only positional asphyxia and traumatic asphyxia.][
First aid
If there are symptoms of mechanical asphyxia, it is necessary to call an ]Emergency Medical Services
Emergency medical services (EMS), also known as ambulance services or paramedic services, are emergency services that provide urgent pre-hospital treatment and stabilisation for serious illness and injuries and transport to definitive care. ...
. In some countries, such as the US, there may also be self-acting groups of voluntary first responders who have been trained in first aid. In case of mechanical asphyxia, first aid can be provided on your own. In such a situation, you need to do the following:
* Stand behind the affected person and wrap your arms around him/her.
* Push inwards and upwards under the ribs with a sudden movement by your second hand.
* If the performed actions were not effective, repeat them until you free respiratory tract of the affected person from a foreign body.
See also
*
*
*
*
References
Further reading
*
*
External links
*
Cross-side to chest compression choke
{{Authority control