Synonym:- Molecular Death/Brain Death

n The advent of human organ transplantation, in the 1960s specially the heart transplantation lead to the necessity of scrutinizing the phenomena of death. The problem increased manifolds because of the increasing use of the modern medical technology i.e. connection to the artificial means to support a dying man. This generated the newer concepts of moments of death.

n For the purpose of understanding about death and its mechanism death is divided into two types (1) somatic death, and (2) molecular death.

Somatic death/Systemic death/Clinical death

  • It is defined as irreversible cessation of functioning brain, heart, and lungs resulting in complete loss of sensibility and ability to move the body. It is the extinction of personality or the death of the body as a whole (soma means body), also known as clinical or systemic death. The cells of different tissues of the body are still alive and die after sometime at different rate.

Cessation of heart beating:-Clinical criteria

  1. Absence of pulse (central i.e. carotid )
  2. Absence of heart sound on repeated prolonged auscultation.
  3. A flat electrocardiogram (ECG).

n Cessation of breathing:- Clinical criteria

  1. Absence of respiratory movement
  2. Absence of breath sound on thorough auscultation of chest. (Central)

n Cessation of brain activity:- Clinical criteria

  1. Generalized flaccidity with generalized anesthesia.
  2. Dilated fixed pupils, not responding to light
  3. Absence of motor responses within the cranial nerve distribution on painful stimuli.
  4. Absence of corneal reflexes.

Cellular or molecular death and the concept of brain death

n Somatic death is followed by progressive disintegration of body tissues and is called as cellular or molecular death.

n In absence of circulation and respiration different cells die at different times. Death of some cells are mentioned below in sequential order from the earliest.