MSC IV_Forensic medicine - Thanatology.pdf

Thanatology

1. Forensic Medicine
Dr. Suchita Rawat (MSc, MPhil, PhD)

2. Unit 1: Thanatology
Death:causesandmannerofdeath,signsofdeathandchangesafterdeath.Somaticdeath,moleculardeath,
Earlychangesafterdeath:algormortis,rigormortis,pallormortis,livormortis,cadavericspasm,heat
stiffening,coldstiffening,changesinblood;Timesincedeathbybodyfluidanalysis;chemicalchangesin
cerebrospinalfluid;Changesinvitreoushumour;Latechanges:putrefaction:externalandinternalchanges.
Adipocere,mummification,skeletonization

3. Thanatology, Death and its Causes
●STAGES OF DEATH
Antemortem,
Postmortem
and Perimortem
Injuries
*Agonal period
Molecular
Death
Somatic
Death

4. SUSPENDED ANIMATION (synapparent death)
Causes
(1) Anesthesia, (2) Barbiturates, (3) Coma (4)
Cholera (5) Concussion, (6) Deep shock (7)
Drowning, (8) Electrocution, (9) Frozen state
(Hypothermia) (10) yoGis [voluntarily
induced, but may be remembered by the
student here as a memory aid], (11) Hanging
(12) Heat stroke, (13) Hypothermia, (14)
Hysteria (15)Illnesses [prolonged],
(16)Infections [Cholera, Typhoid]
(17)Newborn, (19) Opiates.

5. THE MOMENT OF DEATH
A. Classical
Criteria of
Death
Bichat’s
criteria/Atria
mortis
French physician Marie Bichat (1771 –1802).
[Latin, Gateways of death,
death’s portals of entry]
within 20 seconds
within 20 minutes
3 minutes
3 minutes

6. Tests to determine the death of
each organ Tests for circulation
•Magnus test (Hugo Magnus in 1872)
•Icard’stest: Vivid yellow (SéverinIcardof France in 1895)
•Diaphanous test: red and translucent vs. yellow and opaque
(transillumination test)
•Finger nail test: red-pale on pressure-red
Tests for respiration
•Winslow’s test: Jacques-BénigneWinslow (1669-1760)
•Mirror test
•Feather test
Tests for brain function
(1) Blowing a strong stimulant such as hellebore or mustard into the
nose
(2) inserting a sharp instrument under the nail
(3) cauterization or incisions
(4) scalding with hot water or oil
(5) trumpeting or loud noises.
Miscellaneous tests :X-ray fluoroscopy for body movt.
Source: Agrawal, A. (2016).
.

7. Brain Death 1)Unreceptivity and
unresponsivity
2) No movements or
breathing (at least 1
Hour)
3) No reflexes (pupil,
corneal reflexes, spinal
reflexes i.e. knee jerk
4) Flat
electroencephalogram
5)Repetivetest after
24hrs
Harvard criteria of Brain Death (1968)
1)Minnesota criteria of
Brain stem death
(1971) : In 1971,
Mohandas and Chou
(two neurosurgeons
from Minnesota)
2)Indian law on brain
stem death (The
Transplantation of
Human Organs and
Tissues Act, 1994)
Brain Stem Death (Modern Criteria of the
Moment of Death)

9. https://www.pinterest.com/pin/your-brain-structure-
what-is-the-brain-made-of--962714857820364170/

10. Minnesota criteria of Brain stem
death (1971)
(1)No spontaneous movement
(2)No spontaneous respiration
when tested for a period of 4
minutes at a time
(3)Absence of 5 major brain stem
reflexes (ref. figure)
(4)EEG not mandatory. All the
above findings must remain
unchanged for at least 12
hours

12. MODES OF DEATH

13. GORDON’S CLASSIFICATION OF DEATH
A.AnoxicAnoxia
reduced oxygen in ambient air
i.e. trap/noxious gases h2s, so2, sewer gas/ high altitude
pulmonary blood supply pulmonary gas exchange
reduced
supply of
oxygen
i.e.
mechanical
interface of
air passages

14. GORDON’S CLASSIFICATION OF DEATH
B. Anaemic
Anoxia
Oxygen carrying capacity of the blood is reduced. i.e. acute massive
hemorrhage , CO poison

15. GORDON’S CLASSIFICATION OF DEATH
C. Stagnant
Anoxia
Blood is incapable of movement
i.e. heart failure, embolism

16. GORDON’S CLASSIFICATION OF DEATH
D. Histotoxic Anoxia
1. Cellular histotoxic anoxia ( Oxygen cannot be taken up due to failure of
tissue enzyme system by poisoning, egCN , PH3 , H2S, overdose of hypnotics and
anesthetics.
2. Pericellular histotoxic anoxia
permeability of cell membrane, egin
nitrous oxide or halogenated
hydrocarbons [chloroform, cyclopropane,
ether, halothane, trilene].
3. Substrate histotoxic anoxia
failure of efficient cell metabolism,
eghypoglycemia
4. Metabolite
histotoxic
anoxia
, egCO2
poisoning,
uremia.

17. SUDDEN AND UNEXPECTED DEATH
Sudden and unexpected death is death occurring
within 24 hours of the onset of symptoms in an
individual who was not known to be suffering from any
disease, injury or poisoning.
Coronary artery disease
CVS
Acute edema of lungs / Air
embolism
(1) epilepsy (2)
hemorrhage(3)
meningitis, and (4)
tumors.
(1) Acute hemorrhagic (2)
pancreatitis (2) Appendicitis (3)
Cancer of esophagus (4)
Enlarged spleen [rupture]

18. Signs of Death and Changes Following Death
Immediate
Early
Late
1-30
minus
1hour-
Upto36
hours
Beyond
36 hours

19. IMMEDIATE CHANGES
Complete
and
irreversible
cessation of
functions of
brain, heart
and lungs.
Function]
Muscles of
the body
become
flaccid.
(primary
flaccidity)
Corneal and
pupillary
reflexes are
abolished.

21. EARLY CHANGES
Within few minutes
1)Skin ashy-white,
pale and loses
elasticity
2)Changes in lips:
dry, brownish and
hard due to drying
1. Loss of corneal reflex
2.Opacity of the cornea
3. Pupils
4. Intraocular pressure (14-
3)
4. Retinal vessels
5.Biochemical changes i.e.
Potassium levels
Source: Agrawal, A. (2016).
Source: Agrawal, A. (2016).

22. EARLY CHANGES (Algor mortis)
Important points
Core temperature (after 2 hours)
Ambient temperature
Method of recording i.erectal, sub-hepatic temperature
Formula
Factors affecting Algor Mortis
Environmental temp
Build i.eSA/BW
Physique i.eFAT/ lean
Environment i.e. air Ventilation,Humidityi.e.
water submerged, running, sewage
Position
Covering
https://stock.adobe.com/in/search?k=homeostasis
ii) Average rate of fall
-(a) during summers
-0.75°F/h (b) during
winters -1.5°F/h.

23. Postmortem caloricity
●The increase in body temperature for the first few hours after death is called
postmortem caloricity.
●The mechanism and conditions of this phenomenon are as follows:
●(i) When the heat regulatory mechanism has been severely disturbed
beforedeath. For example: sun stroke.
●(ii) When there is increased heat production in the muscles of the body before
deathdue to convulsions. For example: Tetanus, strychnine poisoning and epilepsy.
●(iii) Excessive bacterial activity during life. For example: Septicemic deaths, cholera
and other infections.

24. Postmortem Lividity (Livor mortis/Postmortem staining/postmortem lividity/postmortem hypostasis)
Development
0.5-2hours(Appearsasbluishpurplemottledpatches)<4h
(Welldevelopedlikeasheetbutnotfixed)<8h(Fixation)<
greaterthan8hPersiststillputrefactionsetsin.
*Influencing factors (vol of blood/Length
of time blood remains fluid after death/More marked
in conditions where blood does not readily coagulate,
causing more accumulation to occur. Anticoagulants i.e.
Asphyxia/ CO poisoning, Septicemia
Source: Aggrawal, A. (2016).
Source: Aggrawal, A. (2016).

26. Rigor mortis (cadaveric rigidity, death stiffening)
Source: Aggrawal, A. (2016).
Source: Aggrawal, A. (2016).
Influencing
factors: age fetus/
stillborn/children
and old /infections
gas gangrene, where
putrefaction begins
early] (b) cancer (c)
cholera (d) starvation
(e) tuberculosis (f)
typhoid/
electrocution,lightning/
late in neuromuscular
disease,
CO,hemmorage,
asphyxia/ (1) Onset
slow, duration long –
Cold dry weather(2)
Onset rapid, duration
short –Hot weather.

27. Cadaveric spasm [syn cataleptic rigidity, instantaneous rigidity, instantaneous
rigor, postmortem spasm, battle-field rigidity]] is a rare condition, in which the muscles that were in
contraction at the moment of death, remain in contraction after death

29. IV. LATE CHANGES (DECOMPOSITION)
1)Autolysis (enzymatic
degradation)
Inc. in hot/ dec cold
Brain
(liquefaction),Stomach and
GIT, pancreases
Putrefaction (bacterial action)
(i) Color changes (ii)
Production of foul smelling
gases (iii) Liquefaction of
tissues.
*Modifications of Putrefaction
*Casper Dictim
Source: Aggrawal, A. (2016).
Source: Aggrawal, A. (2016).

30. ●• 1st external sign of decomposition is the
Greenish discoloration
(sulfmethemoglobin) in the right iliac
fossa; which becomes evident in 12–24
hours in summer and 1 to 3 days in winter.
• This color change spreads to the entire
abdomen< chest< neck< face <limbs.
• Color gradually changes to dark green
then finally black.

31. ●The putrefaction bacteria spread easily in the
body fluid and colonize in the venous system.
●The superficial veins of the limbs, chest,
abdomen and neck are stained greenish blue
due to hemolysis of red cellsand stain the
walls of the vessels.
●This condition is called as “marbling” which
occurs 36 to 48 hours after death in summer
and 2 to 3 days in winter.

32. ●Evolution of foul smelling gases:
• The main gases are ammonia, carbon dioxide, hydrogen sulfide,
phosphorated hydrogen and methane.
• Due to continued accumulation of gases, there is distention of
breast in females, penis and scrotum in males< abdomen (intestines).
●• Eyes bulge out from their sockets; tongue is forced out between
the swollen lips.
●Diaphragm is pushed up compressing the lungs and heart; blood
stained frothy fluid exudes from the mouth and nostrils, which is
called “postmortem purge”.
• Involuntary urination, defecation, seminal ejaculation and delivery
of dead fetus occur at this stage.
• Gas bubbles accumulate in all the tissues; subcutaneous tissues
become emphysematous.

33. ●• Due to the formation of gas blebs,
blisters appear between the epidermis
and dermis all over the body.
• Epidermis becomes loosened (skin
slippage) producing large, fragile sacs of
clear or pink red serous fluid.

34. Liquefaction of tissues: (Colliquative putrefaction)
●begins from 5 to 10 days.
●The abdomen burstsand contents of abdomen come out of the cavity.
• All encapsulated internal organs are converted into bags of putrid fluid and
subsequently burst open into the thoracoabdominal cavity.
• The rate of putrefaction : enzyme content, water content and blood supply of the
organs: Adrenals and pancreas<stomach and intestines<spleen and liver<lungs
<heart< Kidneys and urinary bladder < Prostrate (males) and (uterus in females)
• “foamy” liver or “honey-combed” liver: accumulation of gases, multiple blisters
appear in the liver

35. References
●Aggrawal, A. (2016). Forensic Medicine and Toxicology for MBBS.Avichal
Publication Company, 325.

36. This Photoby Unknown Author is licensed under CC BY-SA