Forensic 2022 Changes After Death PDF

Forensic 2022 up to date Changes after death M.khalil  Changes after death M.khalil early changes : within few hours after death 1)heart stops 2)breathing cases 3)falling of blood pressure 4)Loss of all reflexes & muscle ton...

Forensic 2022 up to date Changes after death M.khalil  Changes after death M.khalil early changes : within few hours after death 1)heart stops 2)breathing cases 3)falling of blood pressure 4)Loss of all reflexes & muscle tone (primary flaccidity) ‫الوزن يثقل بعد الوفاه‬ 5)Loss of muscle tone in the Sphinchers 6)pupil stop reacting to light 7)Loss of Corneal reflex 8)Loss of intraocular pressure & trucking appearance of retinal vessels 9)rigor mortis 10)post mortem cooling 11)postmortem hypostasis post mortem changes in the eye (Imp) 1) fixed bilateral dilated pupil (mydriasis) 2) Dark brown color of sclera due to air exposure called tache noir 3) corneal opacity 4) segmentation of retinal vessels (trucking) (Very early sure sign of death) 12)Pallor of skin & mucous membrane 13)loss of skin elasticity >>> The earliest sign of death primary flaccidity >>> then Rigor mortis (post mortem rigidity) >>> Then secondary flaccidity Rigor mortis early post mortem change It occurs after primary flaccidity It is Called Post mortem rigidity It is a sure sign of death (Occurs only post mortality)  Time taken for rigor mortis is Variable So should Never used alone in the estimation of time of death because alone it doesn’t give accurate determination of death time It is a temperature dependent physio chemical reaction Occurs within muscle cell Decrease in oxygen >>> decrease in ATP >>> increase in lactic acid >>> acidosis >>> binding of actin and myosin >>> muscle stiffness ( not contraction, not relaxation) This stiffness involves all muscles of the body skeletaL, smooth muscles, eye muscles and cardiac muscles uniformaly throughout the body, but first detectable in the smallest muscle groups (face) >>> first evident in eyelids can be first detected in the face between 1-4 hours and in limbs between 4- 6 hours Difficult to detect in People with low muscle bulk Develops faster in hot environment & delay in onset in deaths associated with hypothermia, so rigor mortis is affected by environmentaL temperature >>> so rigor mortis is a chemicaL process, modified by temperature. occurs rapidly >>> exercise, fighting, running, epilepsy, electrical injury (faster with hyperthermia) Secondary flacidity becomes apparent from 24 to 50 hours Postmortem hypostasis early post mortem change Time taken for hypostasis is Variable (within 4 hours), so it has no significant role in time of death determination (post mortem interval) but Can help Called postmortem lividity or livor mortis or postmortem staining cessation of the circulation and relaxation of the muscular tone of the blood vessels allow simple fluid movement into blood vessels filling the dependent body vessels >>> passive settling of the red blood cells under the effect of gravity to the blood vessels in Lowest areas of the body (Gravitation of blood in the dilated blood vessels) seen in skin and internal organs (not only skin) not occur in all sides of the body at the same time movement of the red blood cells will make the movement of hypostasis possible by changing the position of the cadaver So it is related to the position of the dead body site & distribution is important & must be considered in the light of the position of the body after death >>> (Important medicolegally) Can be masked in dark skin & jaundice may be absent in young, old & anaemic cases or in those who have died from sever blood loss It is a sure sign of death. ‫ االماكن اللي فيها ضغط مش حتلقاها‬ >>> pale areas are the result of pressure against a hard supporting surface >>> ‫تعرف هل الجثه تم تحريكها والال‬  may help in reaching the cause of death because the color of Hypostasis is significant >>> ( important medicolegally) 1)blue in Some congestive hypoxic states & here need to be differentiated from bruises Bruise (contusion) vs hypostasis Ass with other type of wound caused by blunt trauma eg: laceration, abrasion different colors Ass' with swelling (inflammation) presents in dependent or independent areas incision with clean Cotton inside the wound if clean >>> bruise if there is blood >>> hypostasis (Superfacial) 2)Cherry pink of carbon monoxide poisoning 3)Dark red with cyanide Poisoning 4)Bronze with clostridium perfringes infection 5)pink with prominent distribution around large joints as well as over the dependent areas of the body in cases of death from hypothermia Note: Color of hypostasis >>> may extend from pink to dark pink to deep purple. Dark red color in cyanide toxicity while cherry red in Co poisoning (NOT dark red in Co) >>> Imp medicolegal importance >>> know the position and Cause puterfaction (Decomposition) late post mortem change Autolytic enzymic process of each cell by digestive enzymes turn cells into pus (liquefaction of soft tissues) It is affected by the cause of death and enhanced quickly in hot dry weather & slow (Not enhanced)by cold weather >>> slow in immersion and deep burial >>> so putrefaction is related to environmental temperature  Bacteria multiply within the vasculature >>> Decomposion of the blood >>> Blood vessel discoloration (superfaciaL blood vessels) >>> marbling Sign (Decomposition of superfacial vessels) ‫كيف الرخام‬ So marbling is a sign of putrefaction maceration Is a controlled type of puterfaction to obtain a clean Skeleton by leaving it to decompose inside a closed Container at constant temperature Starts at Rt iliac fossa (Greenish colored Rt.iliac fossa is the earliest sign) >>> This color is due to Sulphmet Hb >>> may be confused with the signs of voilence or trauma (external Sign) Sloughed skin , bloating and swelling of the face , tongue protrusion , bleeding from orifices from ear and nose and protrusion of the eyeball Immersion >>> body floating due to gas of putrefaction first internal organ to puterfy is larynx & trachea while the last internal organ is uterus & prostate cheif agent for bacterial puterfaction is Colustridium welchii. Worms >>> eggs >>> orifices >>> entamology >>> estimation of time of death postmortem cooling and putrefaction >>> estimation of time of death (medicolegal importance)  skeletalization ‫ايصير سواء الجثه مدفونه والال او بسبب الحيوانات‬ late post mortem change Puterfaction then skeletalization Increase in temp >>> making puterfaction is quick >>> making the skeletalization Occurs Quickly >>> So skeletalization Occur quickly in hot climate, but can happen in immersioned body but very slowly Identification by extraction of DNA from bone marrow In the formally buried body, the soft tissues will be absent in 2 years and at about 5 years the bones will be bare and disarticulated Anthropologist required for identification Postmortem Cooling early post mortem change By special chart you can estimate the time of death Affected by body temperature at time of death clothing affect the cooling process environmental temperature can slow or accelerate the post mortem cooling Posture of body can be important Avearage rate = 1 degree per hour factors affecting body temperature (affecting cooling of the body after death) 1) site of reading of body temperature 2) position of the body 3) clothing 4) obesity and emaciation 5) winds , rain and humidity 6) body mass and surface area 7) environmental temperature 8) more reading of postmortem temperature 9) diurnal variation , excercise , illness (body temperature at time of death)  cadaveric spasm Called also Cadaveric rigidity stiffness of group of muscles occur at the moment of death NoT after death (Ante mortem) before rigor mortis and Before Primary flaccidity Doesnt occur in all groups of the muscles Commonly seen in hands existence is not sure because it is a rare condition persists to the period of rigor mortis, but NoT Persist after puterfaction Associated with unnatural death in high levels of emotionaL & physical state. which maybe suicidal or homicidal or accidental DDX of rigor mortis 1)cadaveric spasm 2)heat stifness >>> thermal injury >>> thermal effect >>> coagulation of protein >>> Stiffness eg: Pugilistic attitude: Thermal injury leads to coagulation of protein >>> stiffness in flexion position 3)cold stifness (body recovered from very cold places) So it has medicolegal importance NoT Sure sign of death Adipocere (saponification) late post mortem change Hydrolysis & hydrogenation of fat and adipose tissue into Wax early >>> pale, Rancid greasy semifluid material late >>> Brittle & whiter (chalky) >>> After months and years most seen in bodies found in Wet ( cold and moist ) condition, so the wetness is necessary for adipocere formation NoT dryness Allows the body recognizable  preserve injuries >>> you can know the cause of death (medicolegal importance) starts in face, breast and buttock NoT chest wall Occurs post mortally NoT antemortally may be occured in body found in dry vault due to original body Water mummification late post mortem change Dehydration & Shriveling of cadaver >>> Odorless cadaver Occurs post mortem NoT antemortem Desiccate instead of putrefying (sterile) facial recognition is possible mummified tissue is dry , leathery & brown in Color Doesnt Show Skin blisters most commonly seen in hot environment as in desert (Dry conditions) weather must be dry either hot or cold pattern injury in the skin will be maintained showing hole of bullet injury or skin defect of stabbing you can know the cause of death (medicalegal importance) no bacteria but may be moulds (white in Color) putrefaction, adipocere , mummification and skeletalization are late signs of death if compared with rigor mortis postmortem injuries occured during collapse or due to predation by land animals and insects or from marine animals Post mortem injuries, do not have a rim of inflammatory response on the wound edges but absence of this response doesn’t exclude an injury inflicted in the last moment of life Mohammed Khalil