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 ,