Postmortem changes after death

Immediate Changes Early Changes Late Changes

Immediate changes

• Permanent Cessation of Brain function

• Complete Cessation of Circulatory function

• Entire and permanent cessation of Respiratory

function

Pallor and loss of elasticity of skin Changes in eye Primary flaccidity of muscles Cooling of the body Postmortem lividity Rigor mortis

Putrefaction Adipocere formation Munmmification

Permanent Cessation of Brain function:

• Loss of Sensations; viz, touch, pain and temperature• Loss of reflexes• Total loss of E.E.G. Rhythem• Confirmation of Brain- stem death

Brain –stem death:

• The patient must be comatose state at least six hours.

• No Abnormal Decorticate or decerebrate postures should be present

• All brain-stem reflexes must be absent.

• Pupils should be fixed• No Corneal reflex• Absent of the oculo-cepralic reflex• Absent vestibulo-ocular reflexes• No Motor responses• No Gag reflex• No Respiratory movementsAfter disconnection of ventilator.

Cessation of respiration Cessation of circulation

It is a condition in which the vital functions of the body are at such a low level that they cannot be appreciated by clinical examination

Apparent death

This may last few seconds to minutes. Voluntary- by yogis

Involuntary – drowning, electrocution, heat stroke, typhoid fever etc.

• Changes in the eye

• Changes in the skin

• Cooling of the body/Algor mortis

• Post mortem lividity/Hypostasis

• Rigor mortis/Cadaveric rigidity

Corneal Changes;

• Loss of Clear Glistening• Dry, Cloudy and opaque• Loss of reflexes• Light reflex abolished

• Intra Ocular tension falls, eye balls become flaccid and sink in the orbit

• Blood flow in the retina becomes dotted and segmented look -. Kevorkian sign

• Optic disc looks pale.

• Pupils fully dilated in the early stage and

constict later due rigor mortis.

• Brownish discolouration of the sclera due to

cellular debris and dust

Taches Noires

• Loss of its translucency• Pale and Ashy white appearance• Loss of Elasticity• Wounds will not gape if it is inflicted after

death• Wounds caused during life will retain their

characteristic features.

• Imbalance between heat production and heat loss.

• Loss of heat of body by means of conduction convection and radiation, till it balances with the temperature of surroundings.

• Rate of cooling is fast during first few hours and later slows.

Measurement of body temperature Rate of cooling Estimation of time since death Factors modifying cooling

• Temperature is recorded by Chemical thermometer- Thanotometer 25 cms.

• Recording of temperature : Normal temp. – Rectal temp. Rate of temp. fall/hour• Variation of body temperature• Conditions in which heat may be retained or

increased.

The rate of cooling of the body is modified by the following conditions;

• Age• Condition of the body• Mode of death• Surroundings• Environmental temperature

- Sun stroke and pontine haemorrhage, disturbed heat regulating mechanism.

- Tetanus and strychnine poisoning, due to increase in heat production in the muscle.

- Acute bacterial or viral infection, lobar pneumonia, typhoid fever, encephalitis, etc.

- Intense asphyxial conditions- rise of temp by 2-3 c at death

“ Postmortem Caloricity”

It means discolouration or staining of the skin and organs after death due to accumulation of fluid blood in the dependent parts of the body.

Post mortem staining/Hypostasis/Suggilation/ Vabices/ Livour mortis.

1- 3 hr. Starts6-8 hr. Fixes.

• Commencement of Lividity

• Development of lividity

• Fixation of lividity

• Site of distribution

• Pattern

• Extent

• Difference between lividity and bruise.

• It is a reliable sign of death• It gives the information about the position of

the body at the time of death• Time since death can be estimated• Colour suggest the cause of death• Distribution of lividity may give the

information about the manner of death

• Primary relaxation/ Flaccidity

• Rigor mortis/Cadaveric rigidity

• Secondary relaxation

Starts immediately after death with generalised relaxation of muscle tone:

• Drop of lower Jaw• Eye balls lose their tension• Pupils are dilated• Joints are flabby• Smooth relaxation- incontinence of Urine and

Faeces.

Rigor Mortis/ Cadaveric rigidity :

This phenomenon comes immediately after the muscles have lost the power of contractility and is irreversible changes in the muscles of the body, both voluntary and involuntary.

MyofibrilsMyosin and ActinAdenosine Triphosphate – A.T.P.

Time of Onset :Temperate climates – 3-6 hoursTropical climates – 1-2 hours• Rigor mortis generally occurs when body is

cold.• Not related to nerves action• Develops in paralysed limbs also• First appear in involuntary muscles• Last to be affected finger and toes muscles.

* Temperate climate – lasts for 2-3 days.• Tropical climate – 24 – 48 hours in winter 18 - 36 hours in summer• In general – 1-2 hours sets on for , 12 hours develops for - 12 hours maintaines and after 12 hours passes of

Circumstances modifying the Onset and Duration of Rigor mortis.

Age- Rigor – Mortis is very rare in premature infants. Rigor –mortis is slow in adolescent and healthy adultsMuscular conditon and activity before death.Onset is slow and duration is longer in muscular

and healthy body at rest.

• In wasting disease and great exhaustion- cholera, plague, typhoid, T.B. Cancer etc. the onset is early and disappears soon.

• In diseases – Pneumonia, asphyxia and nervous conditions- onset is delayed Atmospheric condtions:

• In dry and cold air-onset slow and lost for long time. Warm and moist air onset is rapid and duration short.

• Heat Stiffening• Cold Stiffening• Cadaveric Spasm

Secondary Relaxation :• Muscles become soft and Flaccid• Do not respond to a mechnical and electrical

stimulus.