Livor mortis

Postmortem staining/ hypostasis

situation: dependent part of the body surface: not elevated Margins: not elevated Colour: reddish purple usually Cause: due to capillovenous distension of blood Effect on pressure: pressure spot appears pale not fixed microscopic study: blood elements within blood vessels and inflammation present medicolegal importance: suggest time since death

Congestion

situation: whole or any part of organ affected with pathology cause: due to some pathology of the organ swelling/ edema: present cut surface: exudation of fluid+ blood+ from cut surface Hollow viscusL show uniform staining

hypostasis can't be seen in

anaemic person old person haemorrhagic death

Hypostasis

Situation: dependent part of the organ cause: passive capillovenous distension swelling edema: nil cut surface:oozing of blood from distended capillaries hollow viscus: like stomach or intestine when streched show alternate stained and unstained areas

Body lying on its back

- posterior , lumbar region, back of the neck , flexor of the lower limbs, extensor surface

Bruise

anywhere surface: elevated margins: ill defined colour: red- when fresh changes with time cause: extravasation of blood from the capillaries effect on pressure ; no change on application on pressure microscopic study: blood elements found outside the blood vessel and inflammation is present mI: suggest the nature of injury

Areas of contact flattening

areas that prevent pooling of blood - as they are pressed against the surface of the ground- depressed flattened pale blanched back of the head,back of the thigh, buttocks, calves

Time of appearance

begins with half an hour as mottled patches coalesce to form uniform stain by 2-3 hours gets fixed by 6-8 hours dissapears with the onset of putrefaction

Internal hypostasis

blood settle in internal organs mistaken for pathological conditons: Lungs; pneumonia Heart: MI intestine: strangulated

Body lying on one side

blood settle on one side

Colour of hypostasis

bluish reddish purple state of oxygenation at time of death Asphyxial death, carbon monoxide, cyanide poisoning, phosphorus poisoning, refrigerated blood, refrigerated body, potassium chlorate, nitrobenzene, aniline

stagnant and turbulent water

body floats in stagnant water - lividity appears on the dependent areas not develop in turbulent water

cyanide poisoning

bright red

Carbon monoxide

cherry red

potassium chlorate, nitrobenzene, aniline

chocolate or coffee brown colour

phosphorus poisoning

dark brown

Asphyxial death

dark red

Distribution

depend on the posture of the body

Development and Fixation early stage

early stage; discoloured patches 1-2 cm in diameter patches: coalesce together get deposited in independent part of the body

WHere does it present

fair skinned bodies

Body lying in prone position

in the front, petechiae and cutaneous blister

hanging

more in dependent lower limbs, genitalia, hands, distal of arms

Drowning

on face, upper part of chest, hands, lower arms, feets, lower legs abdomen full of gas - light weight- at higher level

refrigerated body

pink coloured lividity

Livor mortis

purplish and reddish purple areas of discolouration in the dependent parts of the body due to gravitation of accumulated blood in the vessels after death, showing up through the skin

How to check for hypostasis

when lividity develop first, if the end of the finger firmly pressed against the skin and held for two seconds, the lividity at that part will dissapear and the skin will be pale

Once hypostasis established/ hypostasis is fixed

will be no change in the distribution and altering the body position as the blood get coagulated ,