POST%20MORTEM%20CHANGES

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POST MORTEM CHANGES

• Postmortem changes after death
• Immediate Changes
• Early Changes
• Late Changes

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

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• 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

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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
• 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.

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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.

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

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• Entire and permanent cessation of respiratory
  function
• Mirror test
• Feather test
• Winslows glass water test.

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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.

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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

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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.

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• 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

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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.

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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.

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• 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.

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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

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

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

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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

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Changes in the Muscles

• Primary relaxation/ Flaccidity
• Rigor mortis/Cadaveric rigidity
• Secondary relaxation

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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.

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• 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.

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• 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.

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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

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• 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.

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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.

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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.

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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 201031 8788)

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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.

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Late Signs Of Death

• Decomposition / Putrefaction.
• Adipocere formation / Saponification.
• Mummification.

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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.

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• 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.

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• 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.

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• 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.

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• 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.

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

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• INTERNALLY
• STOMACH
• Dark red patches over the walls
• Perforation due to autolysis
• LIVER
• Softens and flabby
• Becomes spongy Foamy liver

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• 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 10C and occurs rapidly at
  37C.
• Freezing point bacterial growth inhibited and
  putrefaction will not occur.
• Clothing hastens putrefaction initially and
  protects against flies and insects.

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• 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

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• 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.

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• INTERNAL FACTORS
• Age and condition of the body
• Sex
• Mode of death

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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

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• Thank you