Early Post-Mortem Changes

Introduction

• Video on early post-mortem changes after death.
• Key changes discussed: Algor mortis, Rigor mortis, and Liver mortis.

Algor Mortis (Post-Mortem Cooling)

• Body temperature begins to fall after death.

• Initial Phase:

  • No immediate decrease in body temperature due to endogenous heat production from living tissues.
  • Metabolic processes in tissues maintain temperature for about 1 hour (Plateau phase).

• Phase Two:

  • Core body temperature decreases linearly at a rate of 0.4 to 0.6 °C per hour for approximately 12 to 16 hours.

• Phase Three:

  • Terminal plateau phase after 16 hours; temperature remains above baseline due to bacterial activity (putrefaction).

• Measurement Sites:

  • Rectum or subhepatic space.

• Conditions Causing Delay in Temperature Decline:

  • Heat stroke, tetanus, and certain poisonings (excessive muscle contraction leads to heat production).

Liver Mortis (Post-Mortem Staining)

• Also known as lividity or hypostasis.

• Color Changes:

  • Bluish-purple discoloration occurs in dependent parts of the body due to pooling of blood (hypostasis).
  • Areas in contact with surfaces (bony prominences) remain pale (contact pallor).

• Stages of Liver Mortis:

  • Initiation within the first 30 minutes.
  • Confluent staining by 4 hours.
  • Fixation occurs by 6 to 8 hours (post-mortem staining pattern becomes permanent).

• Secondary Lividity:

  • Occurs if body position is changed before fixation.

• Absence of Liver Mortis:

  • Can occur in drowning (continuous movement in water) or severe blood loss (inadequate blood for staining).

• Color Variations Due to Poisoning:

  • Carbon monoxide: Cherry red
  • Cyanide: Brick red
  • Nitrites: Reddish brown
  • Potassium chlorate: Chocolate brown
  • Hydrogen sulfide: Bluish-green
  • Opium: Gray
  • Hypothermia: Bright pink
  • Septic abortion: Pale bronze

Rigor Mortis (Cadaveric Rigidity)

• Often confused with cadaveric spasm.

• Cadaveric Spasm:

  • Immediate muscle contraction after death, indicative of cause of death.

• Rigor Mortis Process:

  • Initial stage: Primary flaccidity (muscles relaxed).
  • Progresses to rigidity; begins within 1-2 hours after death and lasts about 24-48 hours depending on temperature (longer in cooler climates).

• Mechanism:

  • Calcium leaks from the sarcoplasmic reticulum into the sarcomeres, causing sustained contraction without ATP.
  • Peak rigor mortis occurs when ATP levels drop to 15% of normal.

• Nishtan Rule (Sequence of Onset):

  1. Involuntary muscles (heart)
  2. Eyelids
  3. Neck
  4. Lower jaw
  5. Face
  6. Chest and upper limbs
  7. Abdomen
  8. Lower limbs
  9. Fingers and toes

Summary of Post-Mortem Changes

• Algor mortis helps determine time since death.
• Liver mortis helps ascertain body position at time of death.
• Rigor mortis also aids in estimating time since death.

Conclusion

• Encouragement to subscribe for more forensic content.
• Reminder to check related channels and videos.