Late Postmortem changes - Putrefaction

Late Postmortem changes – Putrefaction

Late Changes

Decomposition / Putrefaction.
Adipocere formation / Saponification.
Mummification.

Decomposition / Putrefaction.

The 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(lecithinase — Cl. welchii) –
- Carbohydrates/fat/proteins.
Bacterial growth – warmth,moisture are conditions favourable.
Clostridium welchii, streptococci, E coli, B proteus.

CHARACTERISTIC FEATURES

COLOUR CHANGES

First external sign of putrefaction in a dead body
- Greenish discolouration of skin over caecum and flanks after death appears 18-24 hrs.
Greenish to black discolouration- ‘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.
Discolouration 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
Discoloured 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.(Post-mortem purge)
Emptying of the heart.
Changes in appearance of genitals.

APPEARANCE OF MAGGOTS

Maggots are seen on the dead body after 2-3 days
2-4 days in rainy season
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 SEQUELAE

Fall of teeth
Separation of skull sutures
Liquefied brain matter oozes out.
‘Colliquative putrefaction this process takes place between 7-14 days.

INTERNALLY

Order of appearance of putrefaction from earliest to last is

Larynx, trachea > stomach, intestine > spleen, liver> brain, lungs > heart > kidney, bladder > uterus/prostate > bone
Amongst the soft tissues uterus in female and prostate in males are last to undergo putrefaction, as uterus and prostate resist putrefaction. Otherwise bones are last to undergo putrefaction, overall

STOMACH

Dark red patches over the walls
Perforation due to autolysis

LIVER

Softens and flabby
Becomes spongy ‘Foamy liver’
Honeycombing

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, oesophagus, pancreas, diaphragm, blood vessels, prostate, testis and non gravid uterus, ovaries.

Factors causing delay of putrefaction

Temperature 48° C (very high temperature).
Dry weather and/or decreased air velocity.
More than 2 meter deep grave.
Tight clothing.
Body in dry soil, and body packed in coffin.
Infant not fed.
Wasting diseases like anemia.
Poisoning: Carbolic acid, ZnC12, strychnine (nux vomica), and heavy metals (arsenic, antimony).
In water slower than in air (casper’s dictum)

.Caspers dictum.

Rate of decomposition in soil water and air- 1:2:8.
“According to an old rule of thumb (Casper’s dictum) one week of. putrefaction in air is equivalent to two weeks in water, which is equivalent to eight. weeks buried in soil, given the same environmental temperature”

Factors facilitating putrefaction

Free access of air
Moisture
Optimum warmth (10°C – 45° C).
Thus decomposition is fast in shallow damp, marshy shallow graves, in bodies without clothes and coffin.

Exam Important