Causes of asphyxic death: Restriction of respiratory movements

Restriction of respiratory movements

This is also known as traumatic or positional asphyxia, although it is actually a misnomer as no signs of trauma have to be present. Mechanical asphyxia is a more appropriate term.

In this condition movement of the chest is restricted. This may occur when the chest, and usually also the abdomen, is compressed. Movement of the chest and diaphragm muscles is therefore prevented or restricted, and inspiration cannot occur. This may occur when the chest is compressed by soil or other material/objects, including a vehicle. In recent years disasters occurred at a number of sporting and other events (eg at Ellis Park, Johannesburg) when a panicking or excited crowd pushed forward and individuals were trapped against gates or other obstructions during the stampede. A comparable situation is where an intoxicated person loses consciousness while in a position where the head is lower than the rest of the body, and the intestines press downwards on the diaphragm, restricting its movement. Cases were also reported where an intruder climbs over a high fence, and then falls in such a way that his feet are caught in the security spikes on top of the fence. In this upside-down position, the downward pressure of his intestines on the diaphragm limits inhalation. Inhalation against this gravity-effect on the diaphragm is tiring, and the individual eventually develops ``asphyxia'' and dies.

Crucifixion is another example where someone dies due to restriction of respiratory movement. During crucifixion in the upright position, the chest is fixed in a state of inspiration. The individual therefore struggles to exhale. If the individual is crucified upside down, the intestines press on the diaphragm and the thoracic organs, and the individual cannot inhale without effort.

In this group of asphyxic deaths post-mortem signs, and especially the so-called signs of ``asphyxia'' are well developed, with petechial haemorrhages, congestion and swelling present above the level where the pressure was applied. Bleeding from the mouth and ears may also be present, as well as congestion of the lungs. The skin may show wounds due to the pressure of the object on the body.