Livor mortis

Livor mortis
BY / Dr :- AHMED ABDEL_RAHMAN MOHAMED ESMAIL

1. SADAT CITY UNIVERSITY FACULTY OF VETRINARY MEDICINE FORENSIC MEDICINE DEPT LIVOR MORTIS

2. PREPARED BY :- Dr / AHMED ABDEL_RAHMAN MOHAMED ESMAIL

3. LIVOR MORTIS Livor mortis   ( latin :   livor —"bluish color,"  mortis —"of death "),   postmortem lividity  (Latin :   postmortem —"after death",  lividity —"black and blue ") hypostasis   ( Greek :   hypo , meaning "under, beneath";  stasis , meaning "a standing ")

4. Defintion Bluish purple discolouration of the most dependent parts of the body due to gravitation of the blood after cessation of circulation to the most dependent capillaries . Site of appearance :   This depends on the original posture of the body after death. Most deaths occure in supine position and thus hypostasis will appear on the back of the cadaver (dorsal distribution )

5. .   In cases of hanging ,lividity is noticed in the forearms,lower legs ,ear lobules and external genitalia. In cases of drowning it is noticed in the face and shoulders. Hypostasis will not appear in 1- areas subjected to pressure either by the body wight (areas of contact flattening) 2- tight clothings eg . tight waist band 3- also not seen in skin folds. The slightest pressure by these agents will prevent capillary filling with blood.

6. Cause 1-cessation of the circulation 2-relaxation of the Bl.Ve muscle 3-fluidty of the blood after death due to releasing of fibrenolysin from wall of BL.VE

7. . Time of appearance immediately after cessation of circulation and become visible after 2 hours as discrete patches. In cases of deaths due to congestive heart faliure (sluggish circulation and high levels of reduced haemoglobine )and deaths associated with prolonged.  As time passes,hypostatic patches become confluent and more intense in colour . Maximum distribution occur after 8 hours and the distribution become fixed

8. . Blanching of hypostatic patches by finger pressure indicate that the distribution of hypostasis has not become yet fixed . Changing the posion of the body within 8hours after death (before fixing ) will result in the development additional patches of hypostasis in the new dependent parts of the body.  * Dual distribution of hypostasis indicate changing the position of the cadaver within eight hours after death.

9. The physical factors for fixation of p.m. staining are ( 1) Blood cannot pass out of the capillaries after formation of postmortem hypostasis. (2) Rigor mortis obliterates the big vessels, and as such the blood cannot pass through these vessels to settle in venules and capillaries in a new area. (3) After full development of rigor mortis, venules and capillaries are compressed and almost empty and cannot be easily distended by the resettling blood

10. . Postmortem hypostasis becomes fixed when blood leaks into the surrounding soft tissues due to haemolysis and breakdown of blood vessels. This usually occurs in 6 to 12 hours or more, but the condition of blood at the time of death exerts a considerable influence. Fixation occurs earlier in summer and is delayed in asphyxial deaths and in intracranial lesions.

11. Internal postmortem hypostasis When a body is in supine position, hypostasis is seen in the posterior portions of the cerebrum and cerebellum, the dorsal portions of the lungs, posterior wall of the stomach, dorsal portions of the liver, kidneys, spleen, larynx, heart, and the lowermost coils of intestine in the pelvic cavity. Postmortem hypostasis in the heart can simulate myocardial infarction, and in the lungs it may suggest pneumonia; dependent coils of intestine appear strangulated.

12. Medicolegal importance . 1- Sure sign of death. 2- Determination of the time of death. Judgment will depend on the extent of distribution and whether it become fixed or not. 3- Give an idea about the cause of death depending on the colour of hypostatic patches. 4- Determination of whether the position of the corps has been changed after death depending on dual distribution.

13. color Criminal case Cause of discoloration Reddish purple ___ Reduced Hb bluish asphyxia Reduced Hb   red Co poisoning Carboxy Hb Cyanide poisoning   Oxy Hb Death from cold brown Nitrate poisoning Met Hb pale hemorrage Blood loss

14. Conditions that may be mistaken with hypostasis: 1-inflammation 2-contution hypostasis inflammation 1- site Dependent area Any where Edema & swelling ______ + ve

15. 2-contution hypostasis contution 1-site Dependent area Any where 2-color Reddish purple Change with time 3-pressure on skin blanching No blanching 4-margins Clearly definet (sharp) Ill – definet (diffuse) 5-shape No specific shape Shape of instrument 6-incisin Blood within bi.ve &can be washing out Blood in sc &cannot be washed out