Positional Asphyxia

There are a number of potential adverse effects related to the application of restraints. These include; being unable to breathe, feeling sick or vomiting, developing swelling to the face and neck, and the developments of petechiae (small blood-spots associated with asphyxiation) to the head, neck and chest.

Restraining an individual in a position that compromises the airway or expansion of the lungs (i.e. in the prone position) may seriously impair an individual’s ability to breathe and can lead to asphyxiation. This includes pressure to the neck region, restriction of the chest wall and impairments of the diaphragm. When the head is forced below the level of the heart, drainage of the blood from the head is reduced. Swelling and bloodspots to the head and neck are signs of increased pressure to the head and neck which are often seen in asphyxiation.

Pressure should not be placed on the neck, especially around the angle of the jaw or the windpipe. Pressure on the neck, particularly in the region below the angle of the jaw (carotid sinus) can disturb the nervous controls to the heart and lead to a sudden slowing or even stoppage of the heart.

This effect is even more liable to occur in persons:

(i) With angina

(ii) Who have had a heart attack

(iii) With high blood pressure

(iv) With diabetes

(v) In older people, especially those with hardening of the arteries

A degree of positional asphyxia can result from any restraint position in which there is restriction of the neck, chest wall or diaphragm, particularly in those where the head is forced downwards towards the knees. Restraints where the subject is seated require caution, since the angle between the chest wall and the lower limbs is already decreased. Compression of the torso against or towards the thighs restricts the diaphragm and further compromises lung inflation. This also applies to prone restraints, where the body weight of the individual acts to restrict the chest wall and the abdomen, restricting diaphragm movement.

Factors that predispose a person to positional asphyxia and sudden death under restraint include:

· Drug/alcohol intoxication (because sedative drugs and alcohol act to depress breathing so reducing oxygen taken into the body)

· Physical exhaustion (or any factors that increase the body’s oxygen requirements, for example a physical struggle or anxiety)

· Obesity

Warning signs related to positional asphyxia:

· An individual struggling to breathe

· Complaining of being unable to breathe

· Evidence or report of an individual feeling sick or vomiting

· Swelling, redness or bloodspots to the face or neck

· Marked expansion of the veins in the neck

· Individual becoming limp or unresponsive

· Changes in behaviour (both escalative and de-escalative)

· Loss of, or reduced levels of, consciousness

· Respiratory or cardiac arrest.

ACTION: Immediately release or modify the restraint as far as practicable to effect the reduction in body wall restriction, and summon medical attention.

No prisoner should be restrained face down (or in the case of a pregnant prisoner, on her side) for longer than is absolutely necessary to gain control. There must be continuous observation of a prisoner following relocation in the prone position until such time as the prisoner is no longer lying face down (or in the case of a pregnant prisoner, on her side).

N.B. There is a common misconception that if an individual can talk then they are able to breathe, this is NOT the case. An individual dying from positional asphyxia may well be able to speak or shout prior to collapse.