What is asphyxia. Types and their descriptions. The term mechanical asphyxia in forensic medicine implies a large oxygen starvation, which occurs due to the lack of air (full or partial) in the lungs and respiratory tract due to various mechanical obstacles. There are several varieties of asphyxiation. The classification depends on the nature of the mechanical factor (factors) that creates an obstacle to normal breathing, as well as on several other values.
The types and causes of asphyxia are listed below . Asphyxia from strangulation in the neck - strangulation (strangulation with a loop, hanging, strangulation with the hands). As a result of pressure on the abdomen and chest - compression. Mechanical asphyxia from covering the openings of the mouth and nose with various objects is obstructive asphyxia. There is also asphyxiation from the closure of the respiratory tract with various food and blood (there is no exact definition here).
In most cases, mechanical asphyxia proceeds quickly, mainly ending with the death of a person (if no measures were taken) within about 6-8 minutes. In people with various diseases associated with cardiac activity, death can occur within 2-3 minutes.
In the case of strangulation with a loop, the neck is compressed under the influence of the hands of another person, own hands (such cases are rare), or under the influence of some mechanism (also a rare case, most often used in different horror films). With this pressure, in most cases, there are fractures of the cartilage of the larynx, as well as the hyoid bone. There is an outpouring of blood into the brain and cyanosis of the face is observed.
Mechanical asphyxia in the form of strangulation with hands is nothing more than murder. In this case, various bruises and abrasions are found on the victim’s neck, as in the previous case, there are fractures of the hyoid bone and laryngeal cartilage, hemorrhage in the neck tissue, in addition to all this, in some cases there are abrasions and smudges on the body due to the struggle.
The next type is from compression of the abdomen or chest, mechanical asphyxia occurs due to a sharp cessation (increase in difficulty) of the movement of the respiratory tract of the chest. The reason for this can be situations such as a collapse in a mine, a sand pit, a crowd of crowds. A sign of this type of asphyxia is a sharp cyanosis of the face, multiple bruising on the head, puffiness of the body. If an object of large mass acted on the chest, fractures of various bones can be observed.
The evidence of death due to asphyxiation associated with obstruction of the airways by various objects is their detection at autopsy. The level of penetration of foreign bodies depends on their size. For example, such small bodies as sand, liquids, penetrate almost all parts of the chest.
Asphyxia can occur under the influence of another person. Moreover, if the victim did not show any resistance in the murder, then this type is very difficult to distinguish from others and often in the investigation of such cases the murders are taken for accidents or suicide. If the murder was committed with soft cloth or hands, then specific textures may remain on the body of the deceased, according to which the forensic medical examination draws the appropriate conclusions. But, again, there are cases when it is impossible to establish the exact cause of asphyxia exactly. When examining the bodies of the dead, investigators study all the details that can indicate the nature, type of asphyxiation. This is done in order to very correctly establish what kind of attribute it is.