Death and Post Mortem Changes

Nature and Definition of Death

• Death is the irreversible cessation of life in a previously viable organism.
• A dead person is an individual who has sustained:
  • Irreversible cessation of circulatory and respiratory functions.
  • Irreversible cessation of all functions of the entire brain (cortex and brain-stem).

Phases of Death

• Somatic death:
  • Irreversible loss of personality, consciousness, and ability to communicate with the environment.
  • Inability to receive sensory stimuli or initiate voluntary movement.
  • Reflexes and circulatory and respiratory functions may persist with artificial support.
• Cellular or molecular death:
  • Cessation of respiration and metabolism of body tissues and their constituent cells.
  • Followed by autolysis and decay.
• Brain death:
  • Cortical death:
    • Irreversible coma and failure of spontaneous breathing.
    • Hypoxic cardiac arrest inevitably follows within minutes.

Diagnosis of Somatic or Clinical Death

• Cessation of circulation:
  • Absent pulsations in big arteries (carotid or femoral).
  • Undetected blood pressure.
  • Absent heart beats.
  • Flat ECG on all leads.
• Cessation of respiration:
  • Apnea as checked by careful auscultation.
  • Severe hypoxia and hypercapnea inconsistent with life in Arterial Blood Gas Analysis.