Changes After Death

Remember frequently the thing that cuts off pleasures.

Death.

Learn it from forensic perspective. 

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Changes after Death

1. Immediate: ie Cardiorespiratory failure , Absent breath sounds, absent pulse , pupils unreactive, loss of cornal reflex , muscles flaccid.

2. Early Changes :

- Rigor mortis

- Hypostasis

-Cooling of body.

Rigor mortis:

·         Chemical reaction in muscle due to breakdown of ATP and increase of ADP lactates and phosphates. The muscle glycogen decreases, the pH drops. ATP drops affecting the linkages between actin and myosin.

·         It is temperature dependent with a more rapid onset at high temperatures, after exercise or fever i.e if muscle glycogen levels are already low.

·         Therefore there is more rapid onset in children elderly and wasting disease and a delayed onset in deaths from asphyxiation and severe haemorrhage.

·      Starts = 1-4 hrs in face

·      Limbs 4-6 hours jaw first

·      Maximal at 6-12 hours with secondary flaccidity within 24 -50 hours

Cadaveric spasm = instant rigidity associated with high level of physical or emotional stress before death. E.g drowning, war deaths

·            Warm and flaccid = dead <3 hrs

·            Warm and stiff = dead 3-6 hours

·            Cold and stiff = dead 8-36 hours

·            Cold and flaccid , dead more than 36 hours.

Hypostsis:

·         Gravitation and pooling of blood in veins and capillary beds. It is visible within 2 to 3 hours , usually fixed after about 12 hours.

·         There is a contact palor where body is in contact with surface, floor, bed or even clothing

·         More useful in determining if body position was altered within few hours after death than in determining the time of death. Even if the body was moved within 24 hour there may be an obvious pattern.  

·         Colour differs:

·            Bronze= Cl. Perfingens septacaemia

·            Cherry Pink = CO poisoning /cold

·            Deeper pink= cyanide poisoning              

·           Chocolate brown = methaemoglobin in pottasium chlorate nitrate or analine poisoning.

·         Can be differentiated from bruise if incise tissue blood is in vessel if hypostasis but outside vessel if bruise

Cooling down of body:

·         This is not immediate. Will begin when cell death occurs , body temperature will then begin to drop from 37 degrees. It is important to note that temp may be less than 37 degrees in deaths from hypothermia, CCF haemmorage or shock and greater than 37 degrees in deaths due to asphyxia or fever.

·         In the beginning there is a slow drop in temperature for up to 3 hours, there is then a rapid drop followed by a more gradual decrease when the body is nearing environmental temperatures..

·         More rapid decrease in cold temperatures , if wet or in water, if thin or if naked or if air movement.

·         Take internal rectal temperature with low reading thermometer not a clinical thermometer.

·         Newtons law of cooling = rate of cooling is proportional to the difference in temperature between the body and its surrounding – Exponential graph..

·         Average rate is 1 degree per hour.

3. Late Changes:

·         -Decomposition

·         -Putrefaction

·         Mummifaction

·         Adipocere

·         Skeletonisation.

Decomposition :

·         Due to initial chemical and enzyme reaction , autolysis followed by bacteria , fungi , insects and animal activity.

Putrefaction

·         Liquefaction of the tissues . More rapid if infection high temperatures or summer.

·         First presents as green discolouration of the skn of the anterior abdominal wall 36-72 hrs after death due to intestinal bacteria because conditions favour growth of anaerobic bacteria

·         Then there is gaseous distension of the abdominal cavity and soft tissue , marbling of the skin due to haemolysis in the vessels and formation of fluid filled blisters = skin slippage.

·         Gas formation causes bloody fluid from the decomposing lung to be purged from the nose and mouth , vagina and rectum.

·         Continues until tissues all liquefy and body is skeletalised within weeks to years depending on local conditions

·         Accelerated in hot conditions and if attacked by flies and other predators. Also if obese oedematous or have an injury which is infected. Retarded if body immersed in water or buried . body smells due to gases (methane) .

·         Process commences in stomach and the last thing to go is the uterus and the prostate.

        

Mummification :

·         Dehydration or drying of soft tissues.

·         Occurs in dry conditions esp if there are air currents. Also occurs in stillbirths and deaths of newborns as body is sterile. It prevent decomposition and putrefaction.

·         It may only be partial e.g fingertips or face.

Adipocere :

·         Saponification or hydrolysis of body fats. Hydrogenation of Oleic acid to opaque Stearic acid . Acids inhibit bacteria.

·         Occurs in damp or wet conditions e.g bodies in water or buried in wet ground after many weeks.

·         Causes stiffening and swelling of body fats and preserves the body fats which remain adherent to bones after the skin has rotted away. Therefore the shape and outline of the body is retained for years.

·         Retains outline of body.

Skeletalisation:

·         Loss of soft tissues over time. Tendons ligaments , uterus , prostate hair and nails survive longest.

·         Bones disarticulate after a few years. At first ones are heavy surface is greasy marrow in cavities and bones smell.

·         After 40 -50 years bones become dry and brittle and may erode. Depends on local environment. If bones are older than 70 – get archeologist.

Maceration :

·         Aseptic autolysis of foetus. Dead in uteri for several days. After delivery there are raid changes due to secondary bacterial overgrowth.

Entomology:

·         The use of insects as an indicator of time of death.

·         In this country necrophagous species are the first wave of succession including blue and green bottles and flesh flies.

·         Depends on temp: flies wont lay eggs below 6 degrees and do not lay eggs at night.

·         Eggs layed within 24 hrs of death.

·         Develop in 1st instar maggot within 24hrs, 2nd instar after another 24 hours, and 3rd instar after another 24 hours.. These develop into pupae and eventually into the fly

Rule of thumb –

·         Warm and flaccid = dead a few hours

·         Warm and rigid = dead 2-9 hours

·         Cold and rigid = dead >9 hrs.

Dont worry too much on what will happen to your body after your death as it is not your business anymore. Be worry on what will happen to your soul in hereafter because it really matters to you.