Asphyxia (from
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
a-, "without" and
σφυγμός (sphygmos), "pulse, heartbeat") is a condition of severely deficient supply of
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
to the
bodyWith 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 normally. An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs.
A very common form of asphyxiation is from entering a low oxygen atmosphere or an inert atmosphere - such as a food oil tanks, that have a covering blanket of nitrogen or argon to shield the oil from atmospheric oxygen, thus preventing rancidity.
The body creates the need to breathe from the excess carbon dioxide in the lungs; and yet 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.
In the absence or near absence of sufficient oxygen to sustain life people act normally; and with no warning, they simply feel dizzy and then 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 single and multiple deaths occurring - as the deceased will be observed lying prone in 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.
The use of simple asphyxiant gases - such as the inhalation of pure helium for entertainment purposes - has resulted in death and brain injury from oxygen deficiency.
- Oxygen deficient atmospheres - where the oxygen has been consumed or has been displaced by inert and non-toxic gases such as methane, argon, helium, nitrogen etc.
- Carbon monoxide
Carbon monoxide is a colorless, odorless and tasteless gas, yet very toxic to humans. It consists of one carbon atom and one oxygen atom, connected by a covalent double bond and a dative covalent bond...
inhalation, such as from a car exhaust: carbon monoxide has a higher affinity than oxygen to the hemoglobinHemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of vertebrates, and 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 it around the body
- Contact with certain chemicals, including pulmonary agent
A 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 phosgenePhosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I, and is also a valued industrial reagent and building block in organic synthesis. In low concentrations, its odor resembles freshly cut hay or grass. Some...
) and blood 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 cyanideHydrogen cyanide is a chemical compound with chemical formula HCN. A solution of hydrogen cyanide in water is called hydrocyanic acid. Hydrogen cyanide is a colorless, extremely poisonous, and highly volatile liquid that boils slightly above room temperature at 26 °C...
)
- Self-induced hypocapnia
Hypocapnia 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 hyperventilationIn medicine, hyperventilation is the state of breathing faster and/or deeper than necessary, bringing about lightheadedness and other undesirable symptoms often associated with panic attacks...
, as in shallow waterA 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 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 gameThe fainting game , is a loose term that covers activities designed to induce a partial or complete loss of consciousness brought about by the intentional deprivation of oxygen to the brain for a period of time...
- A seizure
An epileptic seizure is a transient symptom of excessive or synchronous neuronal activity in the brain. It can manifest as an alteration in mental state, tonic or clonic movements, convulsions, and various other psychic symptoms...
which stops breathing activity
- Sleep apnea
Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea , lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep...
- Drug overdose
The 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 curse
Ondine's Curse , also called congenital central hypoventilation syndrome or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated...
, 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
Acute 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 vacuum
In 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," but in reality, no volume of space can ever be perfectly empty...
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 sportA Combat sport, also known as a Combative 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
transitionsA 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-sleepingCo-sleeping, also called the family bed, is a practice in which babies and young children sleep with one or both parents, as opposed to a separate infant bed...
, an accident that often goes unnoticed and is mistakenly thought to be
sudden infant death syndromeSudden infant death syndrome or crib death is a syndrome marked by the sudden death of an infant that is unexpected by history and remains unexplained after a thorough forensic autopsy and a detailed death scene investigation...
. Other accidents involving a similar mechanism are
cave-inA 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...
s or when an individual is buried in sand or grain.
In
homicidalHomicide refers to the act of a human killing a human being. A common form of homicide, for example, would be murder. 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 murdersThe Burke and Hare murders were serial murders perpetrated in Edinburgh, Scotland, from November, 1827 through October 31, 1828. The killings were attributed to Irish immigrants William Burke and William Hare, who sold the corpses of their 17 victims to provide material for dissection...
. 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
lionThe Lion is one of 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
buffaloThe African Buffalo, Affalo or Cape Buffalo is a large African bovid. It is up to 1.7 meters high, 3.4 meters long. Savannah type buffaloes weigh 500-900 kg, with only males, normally larger than females, reaching the upper weight range...
, by opening its mouth over the buffalo's mouth and nostrils and securing itself with its canine teeth.
Compressive asphyxia
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-jackA jack is 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 when the car-jack slips. Pythons, anacondas, and other constrictor snakes kill through compressive asphyxia.
In fatal crowd disasters, contrary to popular belief, it is not the
blunt traumaIn 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 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.
The cause of death of 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'.
Chest compression is also featured in various
grapplingGrappling refers to the gripping, handling, and controlling of an opponent without the use of striking, typically through the application of various grappling holds, choke holds, and counters to various hold attempts. Grappling forms an important part of both ground fighting and standing clinch...
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
budois 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
tortureTorture, according to the United Nations Convention Against Torture, is:In addition to state-sponsored torture, individuals or groups may be motivated to inflict torture on others for similar reasons to those of a state; however, the motive for torture can also be for the sadistic gratification of...
or execution that works through asphyxia.
Perinatal asphyxia
Perinatal asphyxia is the medical condition resulting from deprivation of
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
(
hypoxiaHypoxia 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 pressureBlood pressure is the pressure exerted by circulating blood on the walls of blood vessels, and is one of the principal vital signs. During each heartbeat, BP varies between a maximum and a minimum pressure...
or interference during
deliveryChildbirth is the culmination of a human pregnancy or gestation period with birth of one or more newborn infants from a woman's uterus...
with blood flow to the infant's
brainThe brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all...
. This can occur due to inadequate
circulation- [Headline text]--75.137.171.242 01:21, 21 October 2009 :bThe circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, nitrogen waste products, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pHb to maintain...
or
perfusionIn 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
ventilationIn respiratory physiology, ventilation is the rate at which gas enters or leaves the lung. It is categorised under the following definitions:-Sample values:-External links:* at rtcorner.net...
. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term.
Further reading
- The Physiology, Pathology, and Treatment of Asphyxia by James Phillips Kay-Shuttleworth
Sir James Phillips Kay-Shuttleworth, 1st Baronet was an English politician and educationalist.-Career:At first engaged in a Rochdale bank, in 1824 he became a medical student at the University of Edinburgh. Settling in Manchester about 1827, he was instrumental in setting up the Manchester...
, 1834, 352 pages.
External links