Asphyxia and death can arise from the closure of the entrance to the respiratory cavity of the nose and mouth by any objects (Figure 11), and the airways - by foreign bodies, food or vomit masses, loose bodies or liquids. Common to all these types of mechanical asphyxiation is the cessation of air access to the lungs due to closure (obturation), which is why they are called obturational asphyxia.
Fig. 11. Obturation of the oral cavity (gag)
Asphyxia from the closure of the respiratory tract
The entrance to the respiratory tract can be closed by any soft objects, more often as a result of the actions of the hands of an unauthorized person, a handkerchief, a glove, sometimes a palm, etc., less often as a result of an accident (for example, when a drunk falls asleep with his face buried in a pillow ).
The genesis of death in obturation is typical for mechanical asphyxia. As with other types of mechanical asphyxia, "general signs of asphyxia" (acute death) are sharply expressed.
If, with suffocation, by closing the entrance to the nasal cavity and mouth with soft objects, the victim could not resist, then there are no specific signs for diagnosing this kind of death. In these cases, the expert, stating the acute onset of death, can not substantiate the conclusion that it came precisely from mechanical asphyxia and, in particular, due to the obstruction of the cavities of the nose and mouth with soft objects.The
If during the closing of the breathing holes the victim resists and there is a fight, there may be traces of abrasions, bruises on the skin of the face or neck and mucous lips and gums. In rare cases, when the holes of the nose and mouth are closed, for example, by a pillow, individual fibers, fluffs, and feather particles can be found in the nasal passages, in the oral cavity and even in the respiratory tract. When the soft object is strongly pressed against the face, when this object remains on the face after death, it is possible to find traces - imprints of a small relief of the fabric, as well as flattening of the nose and lips and a paler coloration of these parts of the skin in comparison with the surrounding ones.
Closure of the respiratory tract by foreign bodies
Foreign bodies (pieces of food, metal, wooden, rubber or glass objects, dental removable dentures, etc.) can enter the respiratory tract and completely or partially cover their lumen, stopping or severely restricting airflow into the lungs, which leads to hypoxia and death . Such accidents are relatively rare. Even less common are suicides (usually mentally ill) and murder (young children, patients).
Foreign bodies enter the respiratory tract during meals, when the sensitivity of the mucous membrane of the respiratory tract decreases or is lost in persons suffering from disorders of the swallowing act, disorders of bulbar reflexes, as well as in drunks or during play, when children take in their balls balls, buttons, grains raw beans or corn, coins and other items.
The levels of introduction of foreign bodies into the respiratory tract may be different.
The mechanism of death in aspiration of foreign bodies can be twofold. In some cases, typical asphyxia develops with its phase flow, lasting 4-6 minutes. Naturally, in this case, there will be "general signs of asphyxia", quite pronounced. In other cases, death may occur within a few seconds due to sharp irritation of the larynx and spasm of the vocal cords, which leads to irritation of the upper-nerve nerve and reflex stopping of the heart. In these cases, "general signs of asphyxiation" do not have time to develop.
Diagnosis of this type of asphyxia on the corpse usually presents no difficulties. It is based on the detection in the larynx, trachea or large bronchi of a foreign body that closes the lumen densely or partially, and the presence in typical cases of signs of death from asphyxia.