Asphyxia and Strangulation
In
case of suicidal deaths the most common one is strangulation, the deaths caused
by asphyxia. In this article asphyxial deaths will be explained. These are
caused by the failure of cells to receive or utilize oxygen. The deprivation of
oxygen can be partial (hypoxia) or total (anoxia). The classical signs of
asphyxia are visceral congestion, petechiae, cyanosis, and fluidity of blood.
These are nonspecific and can occur in deaths from other causes. Visceral
congestion is due to obstructed venous return and capillovenous congestion. We
can differentiate two most common hemorrhages;
petechiae are hemorrhages produced by rupture
of small vessels, predominantly small venules. Rupture is caused by sudden over
distention of the vessels following abrupt increases in intravascular pressure.
Cyanosis death is nonspecific and caused
by an increase in the amount of reduced hemoglobin. It does not become
observable until at least 5 g
of reduced hemoglobin is present. Postmortem fluidity of blood is not
characteristic of asphyxia or any cause of death, but rather the result of a
high rate of fibrinolysis that occurs in rapid deaths, possibly by high agonal
levels of catecholamines. Asphyxial deaths can be grouped into three categories
and the following deaths might be accidental, suicidal or homicidal,
respectively:
1.
Suffocation
2.
Strangulation
3. Chemical asphyxia
The
deaths from suffocation are characterized by failure of oxygen to reach the
blood. There are six general forms of suffocation:
1.
Entrapment/environmental suffocation
2.
Smothering
3.
Choking
4.
Mechanical asphyxia
5.
Mechanical asphyxia combined with smothering
6.
Suffocating gases.
In
suffocation by entrapment or environmental hazard, asphyxia is caused
inadequate oxygen in the environment. Asphyxia by smothering is caused by the
mechanical obstruction or occlusion of the external airways, i.e., the nose and
mouth. Deaths are usually either homicide or suicide, very rarely accident. The
most common form of suicidal smothering is the placing of a plastic bag over an
individual’s head, or pressing a pillow against individual’s head. There are allegations of infants smothering
in their cribs because of heavy blankets or bedding placed over them. These
cases are examples of sudden infant death syndrome (SIDS) and that it is just
coincidental that they are found covered by bed clothes. One can pile a number
of blankets on an infant without causing any respiratory difficulty. During In
choking, asphyxia is caused by obstruction within the air passages. The manner
of death can be natural, homicide, or accident. Natural deaths are seen in
individuals with acute fulminating epiglottitis, where there is obstruction of
the airway by the inflamed epiglottis and adjacent soft tissue. Such
individuals represent medical emergencies and can die literally in front of a
physician. The individual develops a sore throat, hoarseness, respiratory
difficulty, inability to speak and then suddenly collapses as the airway is
completely obstructed. Inhalation of steam can cause a similar picture, with a
markedly edematous, beefy-red mucosa in the larynx with obstruction. Most
choking deaths are accidental in manner. Traumatic asphyxia occurs when a heavy
weight presses down on an individual’s chest or upper abdomen, making respiration
impossible.
Positional
asphyxia is virtually always an accident and is associated with alcohol or drug
intoxication. In this entity, individuals become trapped in restricted spaces,
where, because of the position of their bodies, they cannot move out of that
area or position. This results in death.
Strangulation
is a form of asphyxia characterized by closure of the blood vessels and air
passages of the neck as a result of external pressure on the neck. There are
three forms of strangulation:
1.
Hanging
2.
Ligature strangulation
3.
Manual strangulation
Virtually
all hangings are suicide and all ligature and manual strangulations homicide.
In total numbers per year, murder by strangulation is uncommon. In the last ten
years, murders ascribed to strangulation have averaged 286 a year, with a range of
366 to 211.4 The numbers may be slightly higher in that some deaths ascribed
simply to asphyxiation were strangulation. The increase would be minor, as the
total number of homicides ascribed to just asphyxiation in that same time
period averaged 107 a
year. In all three forms of strangulation, the cause of death is cerebral
hypoxia secondary to compression and, thereby, occlusion of the vessels
supplying blood to the brain. The arteries supplying blood to the brain are:
•
The internal carotids
•
The vertebrals
•
The small spinal arteries
•
Anastomatic connections of branches of the external carotid and subclavian
arteries. The venous drainage is chiefly by way of the jugular veins and the
cervicalis profunda veins. The carotid arteries, by virtue of their location,
are easily compressed by direct pressure to the front of the neck.
Hemorrhage
over the back of the larynx and in soft tissue overlying the cervical spine
should be interpreted as traumatic in etiology only with great care. In the
majority of cases, it is not due to trauma to the neck, but rather is an
artifact produced by over-distention and rupture of the venous sinuses, forming
the pharyngolaryngeal plexus. Such hemorrhage can and does occur in deaths from
natural causes and might be either peri- or early postmortem in origin. In
hanging, asphyxia is secondary to compression or constriction of the neck
structures by a noose or other constricting band tightened by the weight of the
body. There is either complete or incomplete suspension of the body. Death is
caused by compression of the blood vessels of the neck, an insufficient amount
of oxygenated blood reaches the brain. Obstruction of the airway can occur,
either through compression of the trachea or, when the noose is above the
larynx, elevation and posterior displacement of the tongue and floor of the
mouth. Blockage or compression of the air passages is not necessary to cause
death in hanging. A number of individuals have hanged themselves with the noose
above the larynx and a permanent tracheostomy opening below. Virtually all
hangings are suicidal. Depending on the area of the country and the sex of the
victim, hanging is either the second or third most popular method of suicide.
Most common are ropes, electrical cords, and belts. The best way to examine the
interior of the neck in strangulation deaths, whether manual or caused by
hanging or ligature, is to remove the viscera from the chest and abdominal
cavities and then remove the brain. After there has been drainage through the
cranial and chest cavities, the neck can be dissected in a relatively
blood-free field. Fractures of the thyroid cartilage, the cricoid cartilage or
the hyoid bone can only be considered antemortem if there is blood at the
fracture site. Homicidal hanging is very rare.
In
manual strangulation, there is usually trauma to both the external and internal
aspects of the neck. Because of the way the neck is usually grasped, the tips
of the four fingers with their associated fingernails dig into the neck.
The
cause why people strangulate themselves is unknown, the reasons are always a
deep mystery which is hidden behind the tragedy. It is a violent and
desperate act which leads to demise. The individuals must have
been deeply hurt by life, partners, small factors such as argumentation,
words, gestures, even, which, pile up and suddenly, it is enough, Someone gives up and
ends One’s life. Sometimes others trigger One to hurt himself or herself, the
consequences of telling a little bit too much are fatal. Remember, apology is not a
policy!
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Acknowledgements:
The Police Department;
https://www.politie.nl/mijnbuurt/politiebureaus/05/burgwallen.html and a Chief Inspector – Mr. Erik Akerboom ©
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