Sauvageau and Boghossian developed a classification of asphyxia suitable for forensic sciences.
Types of asphyxia:
(1) suffocation (associated with deprivation of oxygen)
(1a) smothering (obstruction of the air passages above the epiglottis)
(1b) choking (obstruction of the trachea or bornchi below the epiglottis)
(1c) confined spaces/entrapment/vitiated atmosphere (inadequate atmosphere by reduction of oxygen, displacement of oxygen by other gases and/or gases that may interfere with oxygen uptake and utilization)
(2) strangulation (closure of blood vessels and/or air passages of the neck by external pressure)
(2a) ligature strangulation (constricting band tightened by a force other than by body weight)
(2b) hanging (constricting band tightened by body weight or part of body)
(2c) manual strangulation (by hands, forearm or leg)
(3) mechanical asphyxia (restriction of respiratory movements either by position of the body or by external chest compression)
(3a) positional asphyxia (respiratory movements impaired by the position of the individual)
(3b) traumatic asphyxia (external compression of the chest by a heavy object)
(4) drowning (immersion in a liquid)
where:
• A large predator may bite the neck with combined compression of the trachea and laceration of the carotid arteries. This might qualify for a type 2d.
• In 1c the first item might be altered atmosphere. Vitiated atmosphere (reduced oxygen) may be combined with a toxic gas.
• Murder, Inc would murder by tying a ligature around the neck and then around hyperflexed legs, with the legs applying the strangulating force.
• Mechanical asphyxia can be seen with boa constrictor or a person caught in a funnel shaped chimney. External compression by a boa constrictor may need to be designated 3c.
