MEDICOLEGAL ASPECTS OF DEATH

Death is irreversible cessation of biological functions of life. It means stoppage of the activities performed by vital organs.

It is of prime importance to find out the cause, mode and manner of death when someone dies. The cause of death gives an idea about the reason of death.  The mode of death tells about the physiological process being affected that led to death. The manner of death tells how the cause of death came about. The manner of death could be of natural (death by disease), homicidal (murder by someone), suicidal (self-inflicted), accidental or undetermined. Section 46 of Indian Penal Code denotes the ‘death of a human being’.

The scientific study of death involving its causes and manner accompanied by postmortem changes, is known as Thanatology. Death could be classified into somatic death and molecular death.

Somatic death– heart, lungs and brain are known to be as the ‘tripods of life’. When the activity of this tripod of life stops, it is termed as somatic death.

Molecular death- it happens after somatic death when cells and tissues start dying accompanied by cooling of body.

After death it becomes extremely important to find the cause, mode and mechanism of it. Death could be natural or sudden, homicidal or accidental. So, Forensically it holds prime importance to find such answers.

Modes of Death

1. Syncope
2. Asphyxia
3. Coma

1. Syncope- here, death occurs due to the failure of heart which could be due to –

• Blood loss due to sudden and excessive hemorrhage of large blood vessel or internal organs like liver, spleen, etc. or due to bursting of aneurysm or varicose vein.  The hemorrhage could be internal when the blood accumulates inside the body or external when the blood comes out from the body.
• It could be due to the power loss of the muscle of heart as myocardial infarction.
• Inhibition of heart activity due to sudden shock as a result of blow on head, scrotum, etc. It could be due to sudden pressure on sinuses or by drinking large quantity of cold water in a heated condition.
• During Post mortem findings body would be pale in color. Heart would be in contracted state and chambers be empty because of anemia. Some amount of blood is found in chambers in case of asthenia (abnormal physical weakness).

2. Coma-  when death occurs primarily because of the failure of brain then, that mode of death is known as coma.

• Compression of brain due to outflow of blood from the cranial cavity or due to some injury or diseases.
• Due to poisons  (neurotoxins) acting on central nervous system like alcohol, opium, carbolic acid, barbiturates.
• Conditions like heatstroke, epilepsy, hepatic coma can affect brain severely.
• After post mortem examinations in case of coma injuries to the brain or effusion of blood from cranial cavity can be observed easily. Due to injuries clots can be found on surface of brain, or in between membranes or skull bones.  In coma the person becomes completely unconscious and lose all reflexes in some conditions.

3. Asphyxia- When respiration is stopped or obstructed the activity of heart and brain also suspends due to oxygen deprivation. This mode of death is called asphyxia. It could be due to following reasons-

• Mechanical obstruction of air passage by foreign bodies, smothering, suffocation, drowning, etc. In hanging, strangulation when external pressure is there to close air passage.
• Due to absence/deficiency of oxygen at high altitudes.
• Injuries to thorax or chest which collapses lungs.
• Poisons like cyanide can cause difficulty in breathing.
• In PM findings edema, cyanosis, petechial hemorrhage (Tardieu’s spots) are seen.

Clinical features of Asphyxia

• In the first stage the person feels anxious, heavy head and ringing in ears because of shortness of breath (inspiratory dyspnea).
• The second stage involves expiratory dyspnea involving higher rate of carbon dioxide and lack of oxygen causing faster respiratory rate and convulsions.
• The third stage is of exhaustion and marked by respiratory failure and it lasts for about 1-2 minutes. However, heart can still beat for some minutes but after sometime it also stops.

Gordon’s classification of Death

This concept of classification is based on tissue anoxia which stops the vital organ functions. Anoxia means complete lack of oxygen which leads to cardiac failure and death.  All different kinds of anoxia causes circulatory failure and death. It could be of following types-

1. Anoxic anoxia –  difficulty in breathing due to obstruction of air passage by foreign particles as in choking, or by smothering, throttling, hanging.

• By external pressure of chest or prevention of normal movements of chest as in case of strychnine poisoning.
• Cessation of respiratory system due to its paralysis in case of electric shock.

2.Anemic anoxia – it happens due to reduced oxygen carrying capacity of blood in cases of CO (carbon monoxide) poisoning.

3.Histotoxic anoxia – it happens due to suspension of oxidative process in tissues as in cyanide poisoning.

4.Stagnant anoxia – it arises due to impaired circulation which causes reduced oxygen delivery to the tissues such as in shock, heatstroke.