Transcript Post Mortem Changes

POST MORTEM CHANGES
Signs of Death
And
Postmortem changes after death



Immediate Changes
Early Changes
Late Changes
Immediate changes
•
Permanent Cessation of Brain function
•
Complete Cessation of Circulatory function
•
Entire and permanent cessation of Respiratory
function
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
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.
Pupils should be fixed
• No Corneal reflex
• Absent of the oculo-cepralic reflex
• Absent vestibulo-ocular reflexes
• No Motor responses
• No Gag reflex
• No Respiratory movements
After disconnection of ventilator.
•
Complete Cessation of Circulatory Function
•
•
•
•
•
•
•
Magnus’s 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
•
•
•
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
•
Changes in the eye
•
Changes in the skin
•
Cooling of the body/Algor mortis
•
Post mortem lividity/Hypostasis
•
Rigor mortis/Cadaveric rigidity
Changes in the eye

•
•
•
•
•
•
Corneal Changes;
Loss of Clear Glistening
Dry, Cloudy and opaque
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
.
•
Optic disc looks pale.
•
Pupils fully dilated in the early stage and constict
later due rigor mortis.
•
Brownish discolouration of the sclera due to cellular
debris and dust
Taches Noires
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.
Cooling of the body
•
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.
•
•
•
•
Temperature is recorded by Chemical
thermometer- Thanotometer 25 cms.
Recording of temperature :
Normal temp. – Rectal temp.
Rate of temp. fall/hour
Variation of body temperature
Conditions in which heat may be retained or
increased.
-
-
-
-
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 c at death
“ Postmortem Caloricity”
The rate of cooling of the body is modified by
the following conditions;
•
•
•
•
•
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.
•
Commencement of Lividity
•
Development of lividity
•
Fixation of lividity
•
Site of distribution
•
Pattern
•
Extent
•
Difference between lividity and bruise.
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
Changes in the Muscles
•
Primary relaxation/ Flaccidity
•
Rigor mortis/Cadaveric rigidity
•
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 :
•
•
•
In wasting disease and great exhaustioncholera, 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 Rigor-Mortis
•
•
•
Heat Stiffening
Cold Stiffening
Cadaveric Spasm
Secondary Relaxation :
• Muscles become soft and Flaccid
• Do not respond to a mechnical and electrical
stimulus.
Late Signs Of Death

Decomposition / Putrefaction.

Adipocere formation / Saponification.

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.

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’
GASES OF PUTRIFACTION
 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 bodynose, 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 putrifaction’ – this process
takes place between 7-14 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.
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




Yellowish white, greasy wax with rancid
smell.
It forms at any site where fatty tissue is
present.
Time required, in summer-3 wks, in tropics5 to 15 days.
M.L.I. – to establish the identity
- cause of death
- time since death
- place of death
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.



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
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
-
-
Contents of stomach and bowels
Contents of urinary bladder
Biochemical changes
Circumstantial evidence