POST MORTEM CHANGES
Postmortem changes after death
 Immediate
Changes
 Early Changes
 Late Changes
Immediate changes
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Permanent Cessation of Brain function
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Complete Cessation of Circulatory function
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Entire and permanent cessation of Respiratory function
Permanent Cessation of Brain function:
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Loss of Sensations; viz,
touch, pain and temperature
Loss of reflexes
Total loss of E.E.G. Rhythem
Confirmation of Brain- stem death
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
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Brain –stem death:
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The patient must be comatose state at least six hours.
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No Abnormal Decorticate or decerebrate postures
should be present
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All brain-stem reflexes must be absent.
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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.
Complete Cessation of Circulatory Function
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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
Entire and permanent cessation of respiratory
function
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Mirror test
Feather test
Winslow’s glass water test.
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.
EARLY CHANGES
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Facial pallor (pallor mortis)
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Changes in the skin
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Changes in the eye
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Cooling of the body/Algor mortis
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Post mortem lividity/Hypostasis
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Rigor mortis/Cadaveric rigidity
CHANGES IN THE EYE
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Corneal Changes-
Loss of Clear Glistening
Dry, becomes permanently hazy after 1012 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
.
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Optic disc looks pale and slowely become hazy.
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Pupils fully dilated in the early stage and constrict
later due rigor mortis.
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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
CHANGES IN THE SKIN
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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.
COOLING OF THE BODY(ALGOR MORTIS)
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Imbalance between heat production and heat
loss.
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Loss of heat of body by means of conduction
convection and radiation, till it balances with the
temperature of surroundings.
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Rate of cooling is fast during first few hours and
later slows.
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Temperature is recorded by Chemical thermometerThanotometer 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.
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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”
The rate of cooling of the body is modified by the
following conditions;
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Age
Condition of the body
Mode of death
Surroundings
Environmental temperature
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.
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Development of lividity
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Fixation of lividity
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Site of distribution
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Pattern
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Extent
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Difference between lividity and bruise.
MEDICO-LEGAL IMPORTANCE
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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
CHANGES IN THE MUSCLES
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Primary relaxation/ Flaccidity
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Rigor mortis/Cadaveric rigidity
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Secondary relaxation
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.
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.
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.
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
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.
MANNER OF DEATH :
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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.
CONDITIONS SIMULATING RIGORMORTIS
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Heat Stiffening
Cold Stiffening
Cadaveric Spasm
Secondary Relaxation :
• Muscles become soft and Flaccid
• Do not respond to a mechnical and electrical
stimulus.
CASE SIMULATING RIGOR MORTIS BEFORE
DEATH
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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)
SOME POINT TO BE DISCUSSED IN
RIGOR
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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.
LATE SIGNS OF DEATH
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Decomposition / Putrefaction.
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Adipocere formation / Saponification.
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Mummification.
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.
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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.
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.
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’
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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.
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.
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.
OTHER SEQULAE
 Fall of teeth
 Separation of skull sutures
 Liquefied brain matter oozes out.
 ‘Colliquative putrefaction’ – this process takes
place between 5-10 days.
INTERNALLY
STOMACH
 Dark red patches over the walls
 Perforation due to autolysis
LIVER
 Softens and flabby
 Becomes spongy ‘Foamy liver’
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.
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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.
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’
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.
INTERNAL FACTORS
 Age and condition of the body
 Sex
 Mode of death
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
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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
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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.
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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
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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
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Contents of stomach and bowels
Contents of urinary bladder
Biochemical changes
Circumstantial evidence