Asphyxia

Asphyxia occurs when the body is deprived of oxygen that arises from being unable to breathe normally. Asphyxia causes Generalized Hypoxia which primarily effects organs and tissues. Examples of Asphyxia include choking, smothering, and drowning (Asphyxia can also be induced by inhalation of toxic chemicals, certain toxins can interfere with the uptake of O2 by the blood cells’ use of oxygen in the body). Asphyxia is referred to as traumatic or crush Asphyxia in relation to accidents.

Mechanisms of Asphyxial death include Mechanical Constriction, Airway Obstruction, and Cardiac Arrhythmia. Several classic signs that help medical examiners acknowledge if a particular persons demise was caused by Asphyxiation, include congestion of the face due to venous congestion (venous return to the heart is prevented), facial oedema due to increased venous pressure causes tissue fluid transudation, cyanosis (excess de-oxygenated hemoglobin the venous blood), and petechial hemorrhagen the skin and eyes (particularly the eyelids, conjunctiva, sclera, face, lips and behind the ears) due to raised venous pressure. Categories in which Asphyxial deaths are classified include neck compression, chest compression, postural/positional Asphyxia, airway obstruction and exhaustion or displacement of environmental oxygen.

The air we take into our lungs contains oxygen. After it’s in the lungs’ air sacs, the O2 crosses into the blood, combines with the hemoglobin of the red blood cells, and departs with those red blood cells throughout the body. Normal air contains approximately twenty one percent oxygen. When this percentage drops to ten – fifteen, judgement and coordination are greatly impaired. You lose consciousness when the oxygen concentrations fall below ten percent, thereafter death will occur at around eight percent.

In a Stranglehold

Strangulation is the compression of the neck that leads to unconsciousness or death. In turn causing an increasingly hypoxic state in the brain. Fatal strangling typically occurs in cases where violence, accidents, and as the mechanism of suicide in hangings. Stranglings are not always fatal; limited or interrupted strangling is an important technique in many self-defence and combat sports, strangling is also ‘practiced’ in erotic asphyxiation, and in the “Fainting or Choking game”.

Strangulation is divided into three main categories. Hanging, suspension from a cord wound around the neck. Ligature strangulation, strangulation without suspension using some form of cord-like object or rope. Manual strangulation, strangulation using the fingers or other extremity.

Inside the Lungs: Drowning

Drowning is death by suffocation (Asphyxia) induced by liquid entering the lungs, in turn preventing the absorption of oxygen leading to cerebral hypoxia and myocardial infarction. Near drowning is the survival of a drowning event involving unconsciousness or water inhalation and can be the path to serious secondary complications including death (secondary complications/drowning is when biological and chemical changes occur after a near drowning incident, that can lead to death up to seventy two hours after the orginal incident).

Drowning is a common fear and a decidedly unpleasant demise. As you drown, your lungs fill with water, and they lose their ability to transfer oxygen into the bloodstream. While you struggle to breathe, you force water into your sinuses. Coughing triggers an inhalation reflex, which pulls even more water into the lungs. The loss of an air supply combines with energy you consume in the struggle for survival, and the oxygen level in the blood rapidly falls. You loose consciousness in one to two minutes. The heart stop shortly after.