Positional asphyxia

Overview
Positional asphyxia, also known as postural asphyxia, is a form of asphyxia which occurs when someone's position prevents them from breathing adequately. A small but significant number of people die suddenly and without apparent reason during sex or restraint by police, prison (corrections) officers and health care staff. Positional asphyxia may be a factor in some of these deaths.


 * Positional asphyxia is a potential danger of some physical restraint techniques,
 * People may die from positional asphyxia by simply getting themselves into a breathing-restricted position they cannot get out of, either through carelessness or as a consequence of another accident.

Research has suggested that restraining a person in a face down position is likely to cause greater restriction of breathing than restraining a person face up. Many law enforcement and health personnel are now taught to avoid restraining people face down or to do so only for a very short period of time. Risk factors which may increase the chance of death include obesity, prior cardiac or respiratory problems, and the use of illicit drugs such as cocaine. Almost all subjects who have died during restraint have engaged in extreme levels of physical resistance against the restraint for a prolonged period of time. Other issues in the way the subject is restrained can also increase the risk of death, for example kneeling or otherwise placing weight on the subject and particularly any type of restraint hold around the subject's neck.

There is a degree of controversy amongst researchers regarding the extent to which restraint positions restrict breathing. Some researchers report that when they conducted laboratory studies of the effects of restraint on breathing and oxygen levels, the effect was limited. Other researchers point out that deaths in real life situations occur after prolonged, violent resistance which has not been studied in laboratory simulations.