ASPHYXIA: Asphyxia is the LACK OF OXYGEN to the tissues.

Signs of asphyxia(asphyxial triad/ stigmata):

1. Cyanosis
2. Petechial hemorrhages(tar dieu spots)
3. Congestion of all visceras.

                                                    Cyanosis

                                                     tar dieu spots

                      Congestion of liver

Classification of asphyxia:

Asphyxia can be classified on different basis.

1. Mechanical asphyxia
2. Pathological asphyxia
3. Postural asphyxia
4. Toxic asphyxia
5. Environmental asphyxia
6. Iatrogenic asphyxia.

 Mechanical asphyxia includes hanging, strangulation and suffocation deaths.

SUFFOCATION DEATH: 

1.SMOTHERING:

• It is a type of mechanical asphyxia done by the closure of the mouth and nostrils.

Postmortem features:

1. Contusion and abrasion over the mouth and nostrils.

MEDICO-LEGAL IMPORTANCE:

      1. Usually homicidal

      2. Rarely accidental.i.e., when a mother feeds a baby it can sometime lead to smothering.

      3. suicidal is also not uncommon.

2.CHOKING:

• It is a type of mechanical asphyxia which is due to the obstruction by the bolus of food or piece of bone.

CAFE CORONARY:

• In chronic alcoholics there is a reduced Gag reflux. Such persons after food die due to choking. These people have symptoms mimicking symptoms of a heart attack including chest pain, clenching the wrist, etc.,

POSTMORTEM FEATURES:

1. Signs of asphyxia
2. Presence of foreign body in the trachea or larynx.

MEDICO-LEGAL IMPORTANCE:

      1. Usually homicidal

      2. Can be accidental as in case of cafe coronary.

3.GAGGING:

• It is a type of mechanical asphyxia caused by thrushing a pad of cloth into the mouth against the posterior wall of pharynx.

POSTMORTEM FEATURES:

1. Contusion on the inner aspect of the mouth.
2. Abrasions of the inner aspect of the mouth.
3. Dislocation of the teeth.

MEDICO-LEGAL IMPORTANCE:

           Homicidal.

4.TRAUMATIC ASPHYXIA:

• It is a type of mechanical asphyxia caused by the fall of the building on the chest, run over of the tyre over the body, etc.,

POSTMORTEM FEATURES:

1. Marked congestion of the area above the site of contact.
2. Other signs of asphyxia.

MEDICO-LEGAL IMPORTANCE:

          Usually accidental.

5.BURKING:

• It is the combination of smothering and traumatic asphyxia.

POSTMORTEM FEATURES:

1. Contusion and abrasion over the mouth and nostrils.
2. Marked congestion of the area above the site of contact.
3. Other signs of asphyxia.

MEDICO-LEGAL IMPORTANCE:

          Only homicidal.

PATHOLOGICAL ASPHYXIA:

Pathological asphyxia is given by GORDON’S CLASSIFICATION.

It is classified as

1. Hypoxic hypoxia(anoxic anoxia)
2. Anemic hypoxia
3. Stagnant hypoxia
4. Histotoxic hypoxia.

1.HYPOXIC HYPOXIA(ANOXIC ANOXIA): 

Decreased oxygenation of blood in lungs.

Eg. Hanging, Strangulation, Suffocation death.

2.ANEMIC HYPOXIA:

Decreased O₂ carrying capacity of the blood.

Eg. Carbon monoxide poisoning, chlorates,nitrates.

3.STAGNANT HYPOXIA: 

Ineffective circulation of blood to tissues.     Eg. Shock, Heat stroke.

4.HISTOTOXIC HYPOXIA:

Depression of oxidation process in tissues.

Eg. Cyanide poisoning.