FM PM changes

1. POST MORTEM CHANGES
Postmortem changes after death
 Immediate Changes
 Early Changes
 Late Changes

2. Immediate changes
• Permanent Cessation of Brain function
• Complete Cessation of Circulatory function
• Entire and permanent cessation of Respiratory function

3. Permanent Cessation of Brain function:
• Loss of Sensations; viz,
touch, pain and temperature
• Loss of reflexes
• Total loss of E.E.G. Rhythem
• Confirmation of Brain- stem death

4. BRAIN DEATH
 Death of brain cell occurs earliest after stoppage of
the circulation but the process of death may be
initiated by the failure of the function of brain.
Classification:
 Cortical death
 Brain-stem death
 Both cortical & brain stem death

5. Brain –stem death:
• The patient must be comatose state at least six hours.
• No Abnormal Decorticate or decerebrate postures should
be present
• All brain-stem reflexes must be absent.

6. • Pupils should be fixed
• No Corneal reflex
• Absent of the oculo-cephalic reflex
• Absent vestibulo-ocular reflexes
• No Motor responses
• No Gag reflex
• No Respiratory movements after test withdrawal of
ventilator for 30 sec.

7. Complete Cessation of Circulatory Function
• Magnus test
• Finger nail test
• Diaphanous test
• Icard’s Fluorescein test
• Heat test
• Artery incision test
• A flat E.C.G. for a continuous period of five minutes

8. Entire and permanent cessation of respiratory
function
• Mirror test
• Feather test
• Winslow’s glass water test.

9. SUSPENDED ANIMATION
It is a condition in which the vital functions of
the body are at such a low level that they
cannot be appreciated by clinical
examination
Apparent death
This may last few seconds to minutes.
Voluntary- by yogis
Involuntary – drowning, electrocution, heat
stroke, typhoid fever etc.

10. EARLY CHANGES
• Facial pallor (pallor mortis)
• Changes in the skin
• Changes in the eye
• Cooling of the body/Algor mortis
• Post mortem lividity/Hypostasis
• Rigor mortis/Cadaveric rigidity

11. CHANGES IN THE EYE
 Corneal Changes-
• Loss of Clear Glistening
• Dry, becomes permanently hazy after 10-12
hrs.
• Loss of reflexes
• Light reflex abolished
• Intra Ocular tension falls, eye balls become
flaccid and sink in the orbit
• Blood flow in the retina becomes dotted and
segmented look.

12. • Optic disc looks pale and slowely become hazy.
• Pupils fully dilated in the early stage and constrict
later due rigor mortis.
• Discoloration of the sclera which is initially yellow
and later turn brownish due to drying and desiccation
of the exposed conjunctiva and the sclera
underneath.
k/a Taches Noires Scleroitiques

13. CHANGES IN THE SKIN
• Loss of its translucency
• Pale and Ashy white appearance
• Loss of Elasticity
• Wounds will not gape if it is inflicted after death
• Wounds caused during life will retain their
characteristic features.

14. COOLING OF THE BODY(ALGOR MORTIS)
• Imbalance between heat production and heat loss.
• Loss of heat of body by means of conduction
convection and radiation, till it balances with the
temperature of surroundings.
• Rate of cooling is fast during first few hours and
later slows.

15. • Temperature is recorded by Chemical thermometer-
Thanotometer 25 cms.
• Recording of temperature :
Normal temp. – Rectal temp 4 inch above anus.
Rate of temp. fall/hour
• Variation of body temperature
• There are some Conditions in which heat may be
retained or increased.

16. - Sun stroke and pontine haemorrhage, disturbed heat
regulating mechanism.
- Tetanus and strychnine poisoning, due to increase in
heat production in the muscle.
- Acute bacterial or viral infection, lobar pneumonia,
typhoid fever, encephalitis, etc.
- Intense asphyxial conditions- rise of temp by 2-3 degree
c at death
“ Postmortem Caloricity”

17. The rate of cooling of the body is modified by the following
conditions;
• Age
• Condition of the body
• Mode of death
• Surroundings
• Environmental temperature

18. POSTMORTEM LIVIDITY
It means discolouration or staining of the skin and
organs after death due to accumulation of fluid
blood in the dependent parts of the body.
Post mortem staining/Hypostasis/Suggilation/ Vibices/
Livour mortis.
1- 3 hr. Starts
6-8 hr. Fixes.

19. • Development of lividity
• Fixation of lividity
• Site of distribution
• Pattern
• Extent
• Difference between lividity and bruise.

20. MEDICO-LEGAL IMPORTANCE
• It is a reliable sign of death
• It gives the information about the position of the
body at the time of death
• Time since death can be estimated
• Colour suggest the cause of death
• Distribution of lividity may give the information
about the manner of death

21. CHANGES IN THE MUSCLES
• Primary relaxation/ Flaccidity
• Rigor mortis/Cadaveric rigidity
• Secondary relaxation

22. PRIMARY RELAXATION
Starts immediately after death with generalised
relaxation of muscle tone:
• Drop of lower Jaw
• Eye balls lose their tension
• Pupils are dilated
• Joints are flabby
• Smooth relaxation- incontinence of Urine and
Faeces.

23. Rigor Mortis/ Cadaveric rigidity :
This phenomenon comes immediately after the muscles
have lost the power of contractility and is irreversible
changes in the muscles of the body, both voluntary and
involuntary.
Myofibrils
Myosin and Actin
Adenosine Triphosphate – A.T.P.

24. Time of Onset :
Temperate climates – 3-6 hours
Tropical climates – 1-2 hours
• Rigor mortis generally occurs when body is cold.
• Not related to nerves action
• Develops in paralysed limbs also
• First appear in involuntary muscles
• Last to be affected finger and toes muscles.

25. DURATION :
* Temperate climate – lasts for 2-3 days.
• Tropical climate – 24 – 48 hours in winter
18 - 36 hours in summer
• In general – 1-2 hours sets on
for , 12 hours develops
for - 12 hours maintaines
and after 12 hours passes of

26. Circumstances modifying the Onset and Duration of Rigor
mortis.
Age- Rigor – Mortis is very rare in premature
infants.
Rigor –mortis is slow in adolescent
and healthy adults
Muscular conditon and activity before death.
Onset is slow and duration is longer in muscular and
healthy body at rest.

27. MANNER OF DEATH :
• In wasting disease and great exhaustion- cholera,
plague, typhoid, T.B. Cancer etc. the onset is early
and disappears soon.
• In diseases – Pneumonia, asphyxia and nervous
conditions- onset is delayed Atmospheric condtions:
• In dry and cold air-onset slow and lost for long time.
Warm and moist air onset is rapid and duration
short.

28. CONDITIONS SIMULATING RIGOR-
MORTIS
• Heat Stiffening
• Cold Stiffening
• Cadaveric Spasm
Secondary Relaxation :
• Muscles become soft and Flaccid
• Do not respond to a mechnical and electrical
stimulus.

29. CASE SIMULATING RIGOR MORTIS BEFORE
DEATH
 A case of rigor mortis in a living patient occurring
possibly due to severe vasoconstriction limiting
blood supply to the muscles -Murali Chakravarthy,
“Rigor Mortis” in a Live Patient; (Am J Forensic Med
Pathol 2010;31: 87–88)

30. SOME POINT TO BE DISCUSSED IN
RIGOR
 Kobayashi et al have suggested that the onset and
passing off of rigor mortis in various groups of
muscles depends on the glycogen and lactic acid
levels.They also observed that the glycogen level at
death and 1 hour after death and the lactic acid
level 1 hour after death in masticatory muscles
were lower than in the leg muscles. It is possible
that the differences in the proportion of muscle fiber
types and in glycogen level in muscles influence the
postmortem change in ATP and lactic acid, which
would accelerate or retard rigor mortis of the
muscles.

31. LATE SIGNS OF DEATH
 Decomposition / Putrefaction.
 Adipocere formation / Saponification.
 Mummification.

32. DECOMPOSITION / PUTREFACTION
 Last stage in the resolution of the body,from the organic to
the inorganic state, is a certain sign of death.
AUTOLYSIS
 Rise of enzyme levels in the tissue cells after death.
 Softening & liquefying of the body tissue.
 Starts 3-4 hrs after death and continues for 2-3 days.

33. BACTERIAL ACTION
 Action of bacterial enzymes on tissue components –
carbohydrates/fat/proteins.
 Bacterial growth – warmth,moisture are conditions
favourable.
 Clostridium welchii, streptococci, E coli, B proteus.

34. CHARACTERISTIC FEATURES
COLOUR CHANGES
 Greenish discoloration of skin over caecum and flanks
after death appears 18-24 hrs.
 Greenish to black discoloration-
‘Sulphmethahaemoglobin’ formed by H2S due to
microorganisms in the large intestine.
 Appears early in summer & delayed in winter.

35.  Discoloration spreads- front of abdomen, external
genitals, chest, neck, face, arms and legs – spreads
whole body in 24-36 hrs.
 Discoloration of vessel walls due to pigmentation from
decomposed blood over the shoulder and groin.
Arborescent pattern- ‘Marbling’

36. GASES OF PUTREFACTION
 Development of gases under the skin and hollow
viscera 18-36 hrs. 24-48 hrs in solid viscera.
 H2S, ammonia, phosphated hydrogen, CO2 and
methane.
 Causes pseudo rigidity, exerts pressure.
 More gases accumulation, body floats in water.

37. PRESSURE EFFECTS OF PUTREFACTIVE GASES
 Displaces the diaphragm upwards.
 Discolored fluid and liquefied tissue mixes with gases
producing froth.
 Bloating of the features.
 Shifting of the area of hypostasis.
 Changes in skin, hair and wound.
 Extrusion of fluid from the mouth and nose.
 Emptying of the heart.
 Changes in appearance of genitals.

38. APPEARANCE OF MAGGOTS
 Flies lay eggs over the decomposed body- nose,
mouth, vagina and anus in 18-36 hrs.
 After 24-36 hrs eggs hatch into larvae or maggots,
enter the body and destroy the tissues.
 After 4-5 days develop into pupae.
 After 7-8 days into adult fly.

39. OTHER SEQULAE
 Fall of teeth
 Separation of skull sutures
 Liquefied brain matter oozes out.
 ‘Colliquative putrefaction’ – this process takes
place between 5-10 days.

40. INTERNALLY
STOMACH
 Dark red patches over the walls
 Perforation due to autolysis
LIVER
 Softens and flabby
 Becomes spongy ‘Foamy liver’

41.  Early putrefaction 24-48hrs
Larynx, trachea, brain of infants, stomach, intestines,
spleen, omentum and mesentery, liver and adult
brain.
 Late putrefaction 2-3 weeks
Heart, lungs, kidneys, bladder, esophagus, pancreas,
diaphragm, blood vessels, prostate, testis and non
gravid uterus, ovaries.

42. FACTORS MODIFYING PUTREFACTION
 EXTERNAL
Warmth and clothing
 Putrefaction begins at 10°C and occurs rapidly at
37°C.
 Freezing point – bacterial growth inhibited and
putrefaction will not occur.
 Clothing hastens putrefaction initially and protects
against flies and insects.

43. Moisture
 Help in rapid multiplication of organisms.
 Bodies recovered from water if left in air, decomposes
rapidly.
Air
 1 week in air = 2 weeks in water = 8 weeks buried –
‘Casper dictum’

44. Manner of burial
 In air tight coffins, very little change of body for long
periods.
 Without coffins, putrefaction is very rapid.
 Bodies in deep graves putrefy very slow.
 Bodies buried in lime, decomposition is retarded.
 Bodies in sandy and porous soils are conducive to
mummification.

45. INTERNAL FACTORS
 Age and condition of the body
 Sex
 Mode of death

46. ADIPOCERE
 Modification of the process of putrifaction in the dead
body is (checked and is replaced) adipocere
formation.
 Hydrolisation of fatty tissue into fatty acids.
 Bacterial fat splitting enzymes and moisture are
essential – Lecithinase.
 Composed of saturated fatty acids by palmitic, stearic,
hydroxystearic, olic acids

47.  Yellowish white, greasy wax with rancid smell.
 It forms at any site where fatty tissue is present.
 Time required, in summer-3 wks, in tropics-5 to 15
days.
 M.L.I. – to establish the identity
- cause of death
- time since death
- place of death

48. MUMMIFICATION
 It is a peculiar desiccation of a dead body where by its
soft parts shrivel up but retain the natural appearance
and the features of the body.
 Rusty brown color, dry, leathery skin adherent to
bones.
 Internal organs get transformed into a thick brown
mass.

49.  Mummification occurs in bodies buried in shallow
graves, in dry sandy soils.
 Time – 3 months to 1-2 yrs
 M.L.I. – Identification
- Cause of death
- Time since death
- Place of death

50. TIME SINCE DEATH/ POST MORTEM INTERVAL
 Important clue for investigation of time.
 It helps apprehend the person likely to be involved.
 Point to be ascertained are;
-cooling of the body
-post mortem lividity
-rigor mortis
-decomposition changes

51. - Contents of stomach and bowels
- Contents of urinary bladder
- Biochemical changes
- Circumstantial evidence