Death in Medical Jurisprudence
The medico legal study of death falls within the unit of forensic thanatology, thanatos means death and logos means science. Death occurs in tow stages;
- Somatic, systemic or clinical
- Cellular or molecular
The term death as commonly employed means somatic death. It is duet to complete and irreversible cessation of vital functions of the brain, followed by cessation of the functions of the heart and lungs. Formerly, cessation of heart beat and respiration were used as the criteria of death but now that cardiac transplantation is possible, emphasis has shifted to irreversible cessation of brain function.
After somatic death, tissues and cells survive for a varying period depending upong their oxygen requirements. When there individual tussues and cells die, it is termed cellular or molecular death. It occurs piecemeal, e.g. nervous tissues dies rapidly, say whting five minutes, while muscles survive up to about three to four hours. Molecular death is accompanied by cooling of the body, and changes in the eye, skin, muscles etc. it is generally complete with in three to four hours of somatic death.
Why Diagnosis of Somatic or Clinical Death is Necessary?
Diagnosis of somatic or clinical death is not always easy in the following condition;
- Soon after death when the body is likely to be warm.
- Suspended animation.
- Coma following excessive doses of sedatives or hypnotics especially barbiturates.
- Hypothermia, particularly in the elderly.
- Electrocution and lightning accidents .
- Drowning particularly in cold water.
Distinction between Somatic and Molecular Death
The distinction between somatic and molecular death is important for two reasons i.e. first disposal of the body and second transplantation.
Disposal of the body: in the rare instances, when the body is cremated soon after somatic death, spontaneous movements of the hands and feet may occur on the funeral pyre. This may give rise to doubt that the person was not actually dead but was prematurely disposed off.
Transplantation: the viability of transplantable organs falls sharply after somatic death – a liver must be taken within 15 minutes, a kidney within 45 minutes and a heart within an hour.
A person whose brain may have been injured irreversibly can now be kept alive by maintaining circulation of oxygenated blood to the brain stem by artificial means. Such a patient after appropriate brain stem reflex testing, can now be declared dead legally, and organs required for transplantation can be removed even though the circulation and respiration have not ceased due to artificial maintenance.