DEATH & POST MORTEM CHANGES.ppt new.ppt

DEATH
&
POST MORTEM CHANGES
 Legal Definition - Law has uniform definition of
death. Death means, “cessation of life or ceasing to
exist”.
 Medico-legal Definition of death-
Death is permanent and irreversible cessation of
functions of the three interlinked vital systems of
the body(the tripod of life), namely, the nervous,
circulatory and respiratory systems.

 Modern Definition of Death : When the brain of
a person irreversibly damaged, the person can be
kept alive by life sustaining measures. After with
drawn of the life sustaining measures if a person
can not breath spontaneously he assumed to be
death.

 The main purpose of life is to be
happy, to make others happy if
possible, to grow old gracefully,
and to die with dignity.

Death occur in two stages :
1. Somatic/systemic/clinical death
2. Molecular/cellular death

Somatic death
 It is the complete & irreversible stoppage of the
circulation, respiration and nervous (brain)
function. In somatic death, the tissues & cells are
respond to chemical, thermal or electric stimuli,
e.g. The pupil dilates with atropine & constrict
with physostigmine. After somatic death, the
tissues and cells continue to survive for varying
period depending upon their O2 requirement.

Medico-legal importance's of
somatic death
 At this stage organs/tissues can be removed
for transplantation.
 E.g., Cornea, skin, blood vessels & blood can
be removed from the body within 6 hours or
more after the death for transplantation.
 A lever must be taken within 15 minutes.
 A kidney within 45 minutes & heart within 1
hour.

Tissue and organ transplantation
 1.Homologous donation means grafting of the
tissues from one part of the body to another in the
same patient, such as skin or bone.
 2. Live donation includes blood and bone marrow
transfusion. Live organ donation include kidney and
part of the liver.
 3. Cadaveric donation: Most organ must be obtained
while the donor heart is still beating to improve
chances of success.

Molecular death
 Molecular death means death of tissues & cells
individually i.e., progressive disintegration of the
body tissues. Molecular death sets in sometime
after somatic death. During molecular death no
response to stimuli, mechanical or chemical can be
obtained.
 The period between somatic and molecular death
is of 3 to 6 hours, duration, average in 2 to 3 hours.
 According to Mackenzie, average is 1 hour 51 min.

Brain Death
 It means the patient is dead in where
permanent & irreversible loss of cerebral
function. It consist of :
 1. Absence of corneal reflex
 2. Dilated and fixed pupils, not reacting to
light.
 3. Absence of vestibulo-ocular reflex.
 4. Absence of cranial motor nerve reflexes to
painful stimuli.

 5. Absence of cough reflex.
 6. Cessation of spontaneous breathing and
cardiac rhythm without assistance.
 7. Test withdrawal of respiratory aid for half
a minute(ventilator) does not show sign of
revival of self respiration.

Types
It is of three types :
1. Cortical death
2. Brain stem death
3. Both cortical and brain stem death

Criteria for diagnosis of brain death
1. The patient must be in a deep coma
with exclusion of other causes.
2. The patient must be on mechanical
ventilation because of absent or
inadequate spontaneous respiration.

3. A firm diagnosis of the basic
pathology must be available and must
be known to be due to irremediable
brain damage.

4. Diagnostic tests for brain death must
be unequivocally positive
and should be determined by two
doctors(registered for at least 5 years
and have experience of such cases).

Harvard criteria
1. Unrecepivity & unresponsivity:
Total unawareness to externally applied
stimuli and inner need and complete
unresponsiveness to even the most
intense painful stimuli.

2. No movements : No spontaneous
muscular movements in response to
stimuli such as pain, touch, sound or
light for a period of at least one hour.

3. Apnoea : Absence of spontaneous
breathing for at least one hour and
when patient in on ventilation.
The total absence of spontaneous
breathing may be established by
turning off the respirator for 3 minutes
and observing whether patient
breathing spontaneously.

4. Absence of elicit able reflexes :
The pupils are fixed and dilated and do
not respond to a light. Ocular
movement and blinking are absent.
Corneal and pharyngeal reflexes are
also absent. Stretch tendon reflexes can
not be elicited. There is no evidence of
postural activity.

5. Isoelectric EEG : It has
confirmatory value.

 There are two distinct school of diagnosing
death :
 1. French and English schools that are
similar to Harvard Criteria's.
 2. Austro –German school that includes
Harvard criteria and bilateral serial
angiography of internal carotid and
vertebral artery. A negative angiogram for
more than 15 minutes proves death.

What are the tests :
The following tests should be
performed :
1. All brain stem reflexes are absent
with fixed pupils, nonreactive to light,
corneal reflexes are absent.

2. Vestibulo cochlear reflex negative
when ice water(20ml) is introduced
into the ears. There is no eye
movement.
3. No grimacing in response to painful
stimuli is applied either to trigeminal
territory or to the limbs.

4. No gag reflex to a catheter
introduced into the larynx or trachea.
5. No respiratory movement when the
patient is disconnected from the
ventilation, with the arterial PCO2 in
excess of 50mmHg as a stimulus to
breathing.

6. Testing must be carried out with a
body temperature not less than 35o, to
avoid hypothermia stimulating brain
stem damage.
7. Tests are usually repeated after an
interval of 6-24 hours depending on
the clinical circumstances.

Medicolegal importance of brain death
1. Brain death equals to ‘Legal
death’ which has great importance
both legally, ethically and in
relation to organ transplantation.

2. When the stage of brain death is
clinically demonstrate a doctor or
doctors can certify the death has
taken place even though the heart
is still beating.

Modes of Death
Depending on the system most
obviously affected.
There are 3 modes of death
 1. Coma, i.e., failure of functions of
nervous system(brain)
 2. Syncope, i.e., failure of
functions circulatory system (heart)
 3. Asphyxia, i.e., failure of
respiratory system(lungs)

Coma
It is a state of unreasonable
unconsciousness determined by
absence of any psychological
understandable response to any
external stimuli or internal need .
It involves the central portion of
the brain.

A man may go to coma due to-
 1. Cerebral compression resulting from
head injury. In head injury cases, cerebral
compression may be caused due to intra-
cranial haemorhages, cerebral oedema,
depressed comminuted fracture.
 2. Cerebral injuries or injuries to the
brain matter at deferent levels.

 3. Infective states like, encephalitis,
meningitis, abscess.
 4. Compression caused by a new growth.
 5. Metabolic disorders like diabetes,
uraemia.

 6. Lack of circulation in brain as in case of
embolism or occlusion of carotid and
vertebral arteries.
 7. The effects of certain drugs and poisons
like, opium, barbiturate, alcohol,
chloroform, CO, CO2, etc.
 8. Miscellaneous causes like epilepsy, heat
stroke, hypoxia of any origin.

Sign /symptoms of coma
 1. Patient is insensitive to touch, pain and
others stimuli.
 2. Reflexes are lost and sphincters relaxed.
 3. Pupils are dilated or contracted,
insensitive to light.
 4. Pulse is usually full and bounding, but
slow.

 5. Breathing is slow and irregular.
 7. Perspiration occurs and temperature is
subnormal.

Post-mortem findings
 The general external and internal findings
are insignificant. The specific cause in the
form of injury, brain edema, abscess or new
growth may be obvious during post-mortem
examination. Poisoning may give typical
physical signs and may also be detected by
chemical analysis of the viscera/organs and
blood, preserved from the dead body.

Prognosis of coma
Depends on cause, location,
severity and extent of neurological
damage, and intensity of coma.

Syncope
In syncope, there is failure of
the function of the heart and
the circulatory system.

Causes of syncope :
 1. Pathology of the heart- this may be in
the myocardium, pericardium, the heart
valves, the circulation system of the heart
and the heart circulation.
 2. Anaemia : Sudden loss of excessive
amount of blood(1/3 or more of total volume
of the body blood).

 3. Vagal inhibition of the heart: e.g., sudden
fright, accidental hanging, throttling, blow on
epigastrium with full stomach, blow over
abdomen, or over testicles, poisonous snakes or
insects bites, sudden immersion of the body in
cold water, sudden dilation of the cervix, sudden
evacuation of natural or pathological fluids from
the body, pressure over carotid sinus in the neck,
sudden instrumentation of natural orifices, e.g.,
rectum, external os of cervix, embolism, excessive
fluid loss e.g., acute gastro-enteritis.

 4. Exhausting diseases e.g., kalazor, DM,
pulmonary tuberculosis, SLE.

Sign/symptoms
1. Pallor of the face, lips and finger
nails.
2.Dilated pupils with dimness of vision.
3.Cold perspiration.
4. Feeling of sinking and impending
death.
5. Marked restlessness.

 6. Air hunger
 7. Noise in the ears.
 8. Gasping respiration
 9. Nausea and vomiting
 10. Marked fall of BP
 11. Pulse slow and weak.
 12.Slight delirium, insensibility and
convulsions
 13. Precede death

Autopsy appearance
 1. The heart is contracted and the chambers
are empty but chambers contain blood
when death occurs due to asthenia.
 2. The lungs, brain and abdominal organs
are usually pale & capillaries are congested.

Asphyxia
 Asphyxia(Greek, ‘pulselessness’ or absence of
pulse).
 Asphyxia is a condition caused by interference
with respiration or due to lack of O2 in respired air
due to which the organs and the tissues are
deprived of O2 together with failure to eliminate
CO2 causing unconsciousness and death .
 Asphyxia literally means ‘defective aeration of
blood’ due to any cause.

Types and causes
A. Mechanical –
1. Constriction around or pressure
over the neck, as in case hanging,
strangulation including throttling.
2. Closure of the respiratory orifices,
as in case of smothering.

3. Occlusion of the respiratory
passages from inside, as in case of
drowning, choking and gagging.
4. Restriction of the respiratory
movement caused due to compression
over the chest, as in cases of traumatic
asphyxia and over lying.

B. Toxic
1. Poisons which depress the
respiratory centers like – opium,
barbiturate, CO2, H2S, Chloroform,
bromides, etc.
2. Respiratory tract irritants, like –
chlorine gas, ammonia gas,

3. Poisons which affect the pick-up,
carriage, and diffuse O2 at the tissue
level, like-phosgene, CO, cyanides.
4. Lack of O2 in the inhaled air.
5. Poisons which cause paralysis of
the respiratory muscles, like muscle
relaxants, curare, cobra snake venom.

 C. Pathological cause- Infective condition
and new growth of the lungs or in the
respiratory tract.
 D. Postural Asphyxia :
 E. Traumatic Asphyxia :

Stages of asphyxia
 The progress of asphyxia manifests in three
phases. These are :
1. State of dysopnea – initially , increased
CO2 level in the blood causes respiratory
stimulation and the rate and depth of the
respiration is increased. There is
breathlessness, feelings of oppression in the
chest and headache. There is increased
pulse rate and raised BP. Mild degree
cyanosis may be noticed.

2. Stage of convulsion – The level of
CO2 in blood further increased. The
pulse rate BP is still high. The neck vein
are engorged. There is marked
cyanosis. Expiratory effort is more
prominent. There is convulsion.

 3. Stage of respiratory exhaustion-
The respiratory center is depressed.
There is gasping respiration, the rate is
much diminished. Muscles are relaxed,
reflexes are lost or very sluggish, there
are deep cyanosis, widely dilated
pupils, Fall of BP. Pulse is feeble and
slow. Involuntary passage of stool and
urine may occur. There is failure of vital
centers and death.

Anoxia
 Def. Failure of O2 to reach the cells of the body.
 Classification (Gordon’s)-
1. Anoxic
2. Stagnant
3. Anaemic
4. Histotoxic or tissue –
a. extracellular
b. intracellular
c. metabolic
d. substrate

 1. Anoxic Anoxia :
Mechanical interference –
Hanging, strangulation, suffocation, chocking,
drowning, traumatic asphyxia.
 2. Stagnant Anoxia :
Traumatic shock, heat stroke, acute irritant or
corrosive poisoning, heart failure, embolism.

 3. Anaemic Anoxia :
Acute massive haemorrahage, CO poisoning.
• 4. Histotoxic or tissue Anoxia :
a. extracellular-
i. completely destroy cytochrome enzyme system
---- hydrocyanic acid
ii. Partially inhibit cytochrome enzyme system
----- barbiturate and most hypnotics

 b. Intracellular :
decreased cellular permeability for O2 due to lipid
soluble anesthetic agents.
• c. Metabolic :
decreased removal of the end product of cellular
respiration as in Uraemia or CO poisoning.
• d. Substrate :
insufficient food stuff for efficient metabolism.

Rule : Breathing stops within
20 sec of cardiac arrest and
heart stops within 20 min of
stoppage of breathing.
Also known as Rule of Thumb.

POST MORTEM CHANGES
Signs of Death
And
Postmortem changes after death
 Immediate Changes
 Early Changes
 Late Changes

Immediate changes of death
• Permanent Cessation of Brain function
• Complete and Permanent Cessation of Circulatory
function
• Entire and Permanent cessation of Respiratory
function

Permanent Cessation of Brain function:
• Loss of Sensations; touch, pain and temperature
• Loss of reflexes
• Total loss of E.E.G. Rhythm
• Confirmation of Brain- stem death

Permanent Cessation of Brain function:
• The patient must be comatose state at least six
hours.
• All brain-stem reflexes must be absent.
• Pupils should be fixed
• No Corneal reflex
• Absent of the oculo-cephalic reflex
• Absent vestibulo-ocular reflexes

•Permanent Cessation of Brain function:
• No Motor responses
• No Gag reflex
• No Respiratory movements
After disconnection of ventilator.
Test for confirming insensibility – a flat EEG or
loss of EEG rhythm.

Complete Cessation of Circulatory
Function-
• Stoppage of heart beat for more than 4-5 min is
irrecoverable and results in death. The following
tests may be performed to test circulation:
• i. Radial, brachial, femoral and carotid pulsations
will be absent, if the circulation has stopped.
• ii. Auscultation of heart: Absent of heart beat over
the whole pre-cordial area and particularly over
the area of the apex.

• iii. ECG : In case of cessation of circulation, the
ECG curve is absent and the tracing shows a flat
line without any elevation or depression.
• iv. Other tests : (obsolete)
• Magnus’s test : (ligature test) – finger fail to show
congestion distal to a ligature applied at their base.
• Finger nail test : no blanching and filling of blood
in the fingernail on application of pressure and
release.

• Diaphanous test : (Transillumination test) if, in a
dark room the hand is held against some bright
light rays, then in presence circulation, the hand
will appear pinkish, if circulation ceases the hand
will appear yellowish.

• Icard’s Fluorescein test
• Heat test
• Artery incision test
• A flat E.C.G. for a continuous period of five
minutes is confirmatory test for permanent
cessation of circulation.

Entire and permanent cessation of
respiratory function
Complete stoppage of respiration for more than 4
min usually causes death. The stoppage of
respiration can be established by the following
tests :
i. Inspection : No visible respiratory movement.
ii. Palpation : No respiratory movement can be felt.
iii. Auscultation : Breath sound can not be heard
from any part of the lungs.
iv. Following tests :- (obsolete)

• Mirror test : mirror held in front of the nose does
not turn dim due to any moisture of breath.
• Feather test: no movement of a feather held in
front of the nose.
• Winslow’s glass water test. no movement of
surface of water in bowl kept on the chest.

Suspended Animation
(Synonym : Apparent death, death trance).
Suspended Animation is a condition,
wherein the vital functions of the
body(heart beat and respiration) are
maintained at such a low pitch reduced to a
minimum for sometimes, that they cannot
be detected by routine methods of clinical
examination.
This may last few seconds to minutes.

Classification :
Suspended animation is of two types,
Voluntary- by yogis
Involuntary – in newborn infants, drowning,
electrocution, cholera, shock, heat stroke,
after anaesthesia, typhoid fever etc.
M/L importance :
Prior to certifying death it is better to rule
out that the patient is not in suspended
animation state and then declare death and
issue death certificate.

Early Changes of death
• Changes in the eyes
• Changes in the skin
• Cooling of the body/Algor mortis
• Post mortem lividity/Hypostasis/Livor
mortis
• Rigor mortis/Cadaveric rigidity

Changes in the eye
• 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.

Early changes
 no corneal reflex
 pupils stop reacting to light
 “trucking” or “shunting” of the retinal vessels
(fragmentation of columns of blood)
 loss of intraocular tension

• Optic disc looks pale.
• Pupils fully dilated in the early stage and constrict
later due rigor mortis.
• Brownish discolouration of the sclera due to
cellular debris and dust
Taches Noires

Taches Noires Sclerotique
 This is a changes in the
sclera which occurs
when the eyes remain
open. It is the result and
desiccation of the
exposed conjunctiva and
the sclera. Within 2-3
hours, the exposed white
parts of the sclera
becomes yellowish and
 Within 2-3 days, the
areas become brown.

Changes in the Skin
• Loss of its translucency
• Pale and Ashy white appearance
• Loss of Elasticity
• Wounds gape will be minimum if it is inflicted
after death.
• Wounds caused during life will retain their
characteristic features.

Cooling of the body
• Synonym : Algor Mortis.(Algor = cooling, Mortis =
of death).
• 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.

Rate of cooling
 It is not uniform. In temperate climate, the cooling
rate is :
 In first 2 to 3 hours there is no cooling
 In the next 6 hours it is about 1.50 C/hour
 In later 6 to 12 hours it is about 0.9 degree C/hour.
 Thus, the whole body surface gets cooled by 10 to
12 hours of death.

• An approximate idea of number of hours after death
(postmortem interval-PMI) may be calculated by
using formula presented below :
• Normal body temperature (37.2 degree C) -
• Rectal temperature of the cadaver
• PMI --------------------------------------------------
• Rate of temperature fall per hour
Temperature is recorded by Chemical thermometer-
Thanatometer 25 cms.

The rate of cooling of the body is modified by the
following conditions;
• Age : The bodies of young and middle aged person
that are relatively bigger, cool more slowly than bodies
of children and old –aged people.
• Condition of the body: Obese and well nourished
large bodies retains heat for long time.

• Manner of death : Cooling is rapid in deaths due to
chronic, wasting diseases, than in deaths due to acute
disease .
• Initial body temperature : Higher temperature take
more time in cooling.
• Clothing : Bodies covered with the thick garments
cool slowly.
• Environmental temperature : Bodies in warm/hot
atmosphere, cooling is delayed.

- Postmortem Caloricity
- (Post= After; Mortem= Death, Calor = Heat)
- Definition : Postmortem caloricity is defined as an
initial rise of temperature of the body after death,
followed by cooling as usual.
- Causes : 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 Lividity
(Synonyms : Postmortem stains, postmortem hypostasis,
Postmortem Suggilation, Postmortem Vibices, Livor
Mortis)
Definition : Postmortem staining is the purplish or
reddish purple areas of discolouration of the skin and
organs after death due to accumulation of fluid blood
in the dependent parts of the body and seen through the
skin..
1- 3 hr. Starts
6-8 hr. Fixes.

STOPPAGE OF CIRCULATION
STAGNATION OF BLOOD
SINK BY FORCE OF GRAVITY

APEARS BY 1 TO 3 Hrs AS SERIES OF MOTTLED
PATCHES
INCREASES IN SIZE AND
COALESCE IN 3-6HrS
FIXED BY 6-8 Hrs

Hypostasis/Livor Mortis
(lividity or suggilation)
 after death occurs, circulation of blood ceases &
subsequent movement of blood is by gravity
 blood accumulates in the capillaries in the dependent
parts of the body  purple or reddish purple
discoloration of the adjacent skin
 in pressure areas such as the shoulder blades, buttock &
calves discoloration will be pale.
 starts immediately after death.
 apparent after 2 hrs and fixed after 8 hrs.
 may not appear at all especially in infants, old ppl and
anemic ppl.

Hypostasis (cont’d)
early hrs after death it appears in the form of
blotchy post-mortem hypostasis which usually
sinks down and becomes confluent on the most
dependant area
once hypostasis is established, there is controversy
about its ability to undergo subsequent
gravitational shift if the body is moved into a
different posture.

Primary hypostasis may either:
Remain fixed
Move completely to the newly dependant zone
Be partly fixed and partly relocated

Sites of Hypostasis
Depends on the position of the body before death:
 Supine:
 shoulders, buttocks
 heels pressing against surface give white color (pale).
 Vertical (hanging):
 distally in legs & feet.
 Drowning:
 chest, upper chest, and upper limbs.
 Face-down death:
 as in epilepsy, drunken victims
 whitening around nose & lips.
 Hypostasis may also occur in viscera:
 Heart: mistaken for MI
 Lungs: mistaken for pneumonia
 Intestine: mistaken for hemorrhagic infarction

Distribution of Hypostasis
If the body remains vertical after death as in hanging
cases, hypostasis will be most marked in the feet and
to a lesser extent the hands.

Color of Hypostasis
The color of hypostasis is variable and depends on the
state of oxygenation at death.
 Usual color is blue-pink
It’s a crude indicator of the mode of death:
 Cherry-pink: CO poisoning
 Dark blue-pink: cyanide poisoning
 Brown: methahemoglobinemia
 Bronze: septic abortion caused by Clostridium
perfringes.
 Pallor: anemia, hemorrhage (or normal in extremes of
age)

HAEMORRAGE /
ANAEMIA
PALE
ASPHYXIA DARK PURPLE
CARBON MONOXIDE CHERRY RED
CYANIDE BRIGHT PINK
POTASSIUM CHLORATE CHOCOLATE BROWN
PHOSPHOROUS DARK BROWN
HYDROGEN SULPHIDE BLUISH GREEN
OPIUM GRAYISH/BLACK
COLOR CHANGES

Timing and Permanence of
Hypostasis
 Hypostasis appears at variable times after death
 May appear half hr to many hrs after death
 In the early hrs after death it appears in the form of
blotchy post-mortem hypostasis which usually sinks
down and become confluent on the most dependant
area.

Hypostasis vs. Bruises (Ecchymosis)
Hypostasis Bruises
Dependant areas Any where
Well defined edges Ill defined edges
Blood is retained in
intact capillaries
Blood escapes through
ruptured capillaries
Superficial Deep into skin
Same level on surface Raised
Pale over pressure
areas
Red
Incision: blood flows
from the cut vessel
(washable)
Incision: blood
coagulates in tissue
No swelling May be with swelling With a bruise, blood will
not flow from the cut

Medico-legal Importance of
Hypostasis
 Sure sign of death
 Cause of death
 Time estimation
 Position before/ after death
 Indicate if the body was moved or not after
death

• Commencement of Lividity
• Development of lividity
• Fixation of lividity
• Site of distribution
• Pattern
• Extent
• Difference between lividity and bruise.

Medico-Legal Importance
• 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

Changes in the Muscles
• Primary relaxation/ Flaccidity
• Rigor mortis/Cadaveric rigidity
• Secondary relaxation

RIGOR MORTIS
( CADAVERIC RIGIDITY)
Rigor Mortis (Synonym : Cadaveric
Rigidity)
The literary meanings of the words are
rigor meaning rigidity and mortis
meaning death.
Thus Rigor Mortis is the postmortem
stiffening/rigidity of the muscles in a
dead body.

Mechanism
 The physic-chemical basis of rigor mortis is
complex. The changes occurring under these
phenomena are mainly due the irreversible fusion
of two contractile elements, the essential proteins,
namely actin and myosin filament of muscle fibers
into a dehydrated stiff gel, making them remain in
a rigid inextensible state.

This will persist till the actin and myosin filaments
undergo autolysis. Rigor mortis is basically due to
the depletion of adenosine tri-phosphate (ATP)
reserve from the muscle. It is reported that when
the ATP level falls to 85 percent of normal level,
rigor mortis is initiated and it will be maximum
when this level is 15-20 per cent of normal.

 ATP is the main source of energy for muscle
contraction. Muscle needs a continuous supply of
ATP to contract because the amount of ATP
present in muscles is sufficient to sustain muscle
contractions for only a few seconds. After death,
generation of ATP stops, though consumption
continues. With fall of ATP levels, actin and
myosin filaments become permanently complexes
(fused) into a dehydrated gel and with this rigor
mortis sets in.


 Rigor mortis disappears with onset of
decomposition. Cold and/or freezing will delay
onset of rigor mortis as well as prolong its
presence. Rigor mortis, when it develops, it
involves all the muscles at the same time and at
same rate. However, it becomes most evident in
the smaller muscles. Thus rigor mortis is said to
appear first in the smaller muscles, such as the
muscles of eyelids face, jaw and then gradually
spread to larger muscle groups.

 The classical presentation of rigor mortis in
order of appearance is – jaw, upper
extremities, and lower extremities in a
proximo-distal distribution. It passes off
also in the same order.

 NYSTEN’S RULE- Rigor dosen’t start in all
muscles simultaeneously.
 First appears in involuntary muscles
1hr- myocardium
 Eyelids  neck lower jaw  muscles of face
muscles of chest  upper limb  abdomen  lower
limb  lastly fingers and toes.
ORDER OF APPEARANCE OF RIGOR

GENERAL RULE
 When onset is rapid, its duration is relatively short.
 Rigor takes 12 hours to become fully established
 Remains for 12 hours
 Passes off during the succeeding 12 hours
RULE OF THUMB

Postmortem interval and Rigor
Mortis
 In general, rigor mortis sets on within 1 to 2 hours
after death, and is well developed from head to
toes in about 12 hours. It is then maintained so far
about 12 hours and passes off in about another 12
hours subsequently with onset of putrefaction.
This is also known as ‘March of rigor’ or ‘Rule of
12’. However, when rigor mortis sets in early, it will
tend to pass off quickly (vice versa of this is also
true).

Testing for Rigor in Cadaver
 Testing for rigor in cadaver is done by trying to
open eyelids, depressing the jaw, gently bending
the neck and various joints of the body and noting
the degree (complete, partial or absent) and
distribution.

Secondary Flaccidity
 When the molecular death has occurred in each of
the actin and myosin filaments, the muscular
stiffness that had developed earlier in the previous
stage will begin to disappear slowly and gradually,
relaxing the body back to the original state.
(however, now it shows no response to any
stimulus).

 Sequence of this relaxation commence in the same
order as that of commencement of the stiffening,
starting from eyelids downwards. Just as for
developing complete rigor mortis 12 hours time is
required, passing off of rigor also require another
12 hours.

 Age – foetus < 7 months no rigor mortis
 Nature of death –
onset early and durtion less
* Disease with great wasting and exhaution
(cholera,tb)
* Violents deaths
CONDITIONS ALTERING THE ONSET AND DURATION
OF RIGOR

Early onset
* Organophosphate poisoning - delays
appearance.
* Co poisoning , conditions causing muscle
paralysis
 Atmospheric condition
Cold – late onset and late disappearance
Very hot – disappears very early

RM: time estimation
Warm Flaccid Death < 3 hrs
Warm Stiff 3-8 hrs
Cold Stiff 8-36 hrs
Cold Flaccid Death > 36 hrs

Medicolegal Importance of RM
 Time estimation
 Cause of death
 Know position
 Sure sign of death

Conditions Resembling Rigor Mortis
Cadaveric spasm
Heat stiffening (pugilistic attitude)
Cold stiffening
Gas stiffening
(Other causes of stiffness of Muscles)

Cataleptic rigidity
Single group of voluntary muscle
Frequently involves hand
CADAVERIC SPASM

Cadaveric spasm in a drowning victim: had grass
from the river bank firmly clutched in the hand
Victim of suicide: The cadaveric spasm
has maintained the position of his arms
after the shotgun has been removed

Cadaveric Spasm
 (Synonym: Instantaneous Rigor, Death Clutch,
and Cataleptic Rigidity)
 Cadaveric spasm is a condition wherein stiffening
occurs in certain groups of muscles, which were
already in a state of contraction at the time of death. It
is a rare form of virtually instantaneous rigor that
develops at the time of death with no prior phase of
primary flaccidity.

Mechanism:
 Mechanisms of cadaveric spasm though not clear;
explanation given below is accepted:
 In cases wherein somatic death occurs rapidly,
followed by early muscle changes. e.g. in violent
deaths such as drowning.
 Great emotional tension, at the time of death, e.g.
a soldier in battlefield with fear, a person
committing suicide by cut throat injury.

 Medicolegal importance: It can help not only
to assess cause and motive of death but also
the attitude of the deceased at the time of
death.

 Findings: Drowning
victims hands are tightly
clenched gripping
seaweeds/plants.

 A cut throat suicide
victim will tightly hold
the blade/knife used to
cut in a firmly gripping
hand. Findings thus
suggest antemortem
drowning/cut throat
injury.

Cold Stiffening
 Here muscles are stiff due to solidification
of fat and freezing of body fluid due to the
extreme cold. Noise of cracking of the ice is
heard on attempting the flexed elbow to
open.

 Gas stiffening
 This is due to
accumulation of
putrefaction gases
in the tissues so as
to cause a false
rigidity resulting in
stiff limbs (Fig.
13.14).


HEAT STIFFENING
 When body is
exposed to
temperature
> 65 degree a rigidity
is produced which is
much more marked
than that found in
rigor .

Late Changes(Signs) Of Death
 Decomposition / Putrefaction.
 Adipocere formation / Saponification.
 Mummification.
 Skeletelization

Decomposition / Putrefaction
 Last stage in the resolution of the body, from
the organic to the inorganic state, is a surest
sign of death.
AUTOLYSIS
 Rise of enzyme levels in the tissue cells after
death.
 Softening & liquefying of the body tissue.
 Starts 3-4 hrs after death and continues for 2-3
days.

BACTERIAL ACTION
 Action of bacterial enzymes on tissue
components –
carbohydrates/fat/proteins.
 Bacterial growth – warmth, moisture are
conditions favourable.
 Clostridium welchii, streptococci, E coli,
B. proteus.

CHARACTERISTIC FEATURES
COLOUR CHANGES
 Greenish discoloration of skin over
caecum and flanks after death appears 18-
24 hrs.
 Greenish to black discoloration-
‘Sulphmethahaemoglobin’ formed by
H2S due to microorganisms in the large
intestine.
 Appears early in summer & delayed in
winter.

 Discoloration spreads- front of abdomen,
external genitals, chest, neck, face, arms
and legs – spreads whole body in 24-36
hrs.
 Discoloration of vessel walls due to
pigmentation from decomposed blood
over the shoulder and groin. Arbores-
cent pattern- ‘Marbling’

GASES OF PUTRIFACTION
 Development of gases under the skin and
hollow viscera 18-36 hrs. 24-48 hrs in solid
viscera.
 H2S, ammonia, phosphated hydrogen, CO2 and
methane.
 Causes pseudo rigidity, exerts pressure.
 More gases accumulation, body floats in water.

PRESSURE EFFECTS OF PUTREFACTIVE GASES
 Displaces the diaphragm upwards.
 Discolored fluid and liquefied tissue mixes with gases
producing froth.
 Bloating of the features.
 Shifting of the area of hypostasis.
 Changes in skin, hair and wound.
 Extrusion of fluid from the mouth and nose.
 Emptying of the heart.
 Changes in appearance of genitals.

APPEARANCE OF MAGGOTS
 Flies lay eggs over the
decomposed body- nose,
mouth, vagina and anus in
18-36 hrs.
 After 24-36 hrs eggs hatch
into larvae or maggots,
enter the body and destroy
the tissues.
 After 4-5 days develop into
pupae.
 After 7-8 days into adult
fly.

OTHER SEQULAE
 Fall of teeth
 Separation of skull sutures
 Liquefied brain matter oozes out.
 ‘Colliquative putrifaction’ – this process takes
place between 7-14 days.

INTERNALLY
STOMACH
 Dark red patches over the walls
 Perforation due to autolysis
LIVER
 Softens and flabby
 Becomes spongy ‘Foamy liver’

 Early putrefaction 24-48hrs
Larynx, trachea, brain of infants, stomach,
intestines, spleen, omentum and mesentery,
liver and adult brain.
 Late putrefaction 2-3 weeks
Heart, lungs, kidneys, bladder, esophagus,
pancreas, diaphragm, blood vessels, prostate,
testis and non gravid uterus, ovaries.

FACTORS MODIFYING PUTREFACTION
 EXTERNAL
Warmth and clothing
 Putrefaction begins at 10°C and occurs rapidly at
37°C.
 Freezing point – bacterial growth inhibited and
putrefaction will not occur.
 Clothing hastens putrefaction initially and protects
against flies and insects.

A high environmental humidity will enhance
putrefaction.
The rate of putrefaction is influenced by the
bodily habits of the decedent; obese individuals
putrefy more rapidly than those who are lean.
Putrefaction will be delayed in deaths from
exsanguination (bleeding to death) because blood
provides a channel for the spread of putrefactive
organisms within the body.

Conversely, putrefaction is more rapid in
persons dying with widespread infection,
congestive cardiac failure or retention of
sodium and salts.
It tends to be more rapid in children than in adults,
but the onset is relatively slow in unfed new-born
infants because of the lack of commensal bacteria.
Moisture
 Help in rapid multiplication of organisms.
 Bodies recovered from water if left in air,
decomposes rapidly.

 Heavy clothing and other coverings, by retaining
body heat, will speed up putrefaction.
 Rapid putrefactive changes may been seen in
corpses left in a room which is well heated, or in a
bed with an electric blanket.
 Injuries to the body surface promote putrefaction
by providing portals of entry for bacteria and the
associated blood provides an excellent medium for
bacterial growth.

BODY DECOMPOSES IN AIR
TWICE AS IN WATER
8 TIMES AS IN EARTH
1 week in air = 2 weeks in water = 8 weeks buried
– ‘Casper dictum’
CASPER’S DICTUM

Manner of burial
 In air tight coffins, very little change of body for
long periods.
 Without coffins, putrefaction is very rapid.
 Bodies in deep graves putrefy very slow.
 Bodies buried in lime, decomposition is
retarded.
 Bodies in sandy and porous soils are conducive
to mummification.

adipocere
 What is adipocere?
 Also known as "grave wax," adipocere (from the Latin,
adipo for fat and cera for wax)
 is a grayish-white postmortem matter caused by
fat decomposition, which results
from hydrolysis and hydrogenation of the lipids (fatty
cells) that compose subcutaneous fat tissues.

 Bacterial fat splitting enzymes and moisture are
essential – Lecithinase.
 Composed of saturated fatty acids by palmitic,
stearic, hydroxystearic, olic acids.

It occurs in :
• subcutaneous fat of the
cheeks , breast, buttocks
• may occur in internal organs such as
liver , kidney & heart

Although decomposition of fatty tissues
starts almost immediately after
death,
adipocere formation time may vary from
two weeks to one or two months, on
average, due to several factors, such as
temperature, embalming and burial
conditions, and materials surrounding the
corpse.

 the subcutaneous adipose
tissue of corpses immersed
in cold water or kept in
plastic bags may undergo a
uniform adipocere
formation with the
superficial layers of skin
slipping off.
 Adipocere may be dry,
brittle, & has an odor
mostly smells like
ammonia.

Moistureis necessary.
The optimum
conditions for the
formation of adipocere:
 wet, warm
environment
 bacterial activity
(C. perfiringes).
It is a grayish, greasy
material

Medicolegal Importance of
Adipocrere
• Preserve the body which
can permit identification
after death.
• It may give conclusions about
the cause of death.
• It indicates that the time
interval since death was
at least weeks to several
months.

MUMMIFICATION
 It is a peculiar desiccation
of a dead body where by its
soft parts shrivel up but
retain the natural
appearance and the
features of the body.
 Rusty brown color, dry,
leathery skin adherent to
bones.
 Internal organs get
transformed into a thick
brown mass.

The Optimum Conditions for
Mummification  dry & warm
climate.
Once the changes are complete, the
body will remain in that condition
indefinitely.
No growth of micro
organisms. Mummification is partial
25% of body wt is preserved.

The time required for complete
mummification can’t be precisely stated
but it takes several weeks to months,
depending on the size of the body and
atmospheric conditions.

Medico-legal Importance
of Mummification
 Identification
 Time estimation
 Cause of Death
 Can detect abnormal pathology
inside deep organs

Mummification may occur
naturally or may be achieved
through artificial methods

How does mummification
occur?
The natural mummification process
usually happens in extremely dry
environments that allow the fast
dehydration of tissues,
simultaneously slowing down or
inhibiting the decomposition by
bacteria and other microorganisms.

• The environment is more
important than the time in this process.
• 12-18 months: bone and tendon tags
• after 3 yrs: bare bone.
• In temperate zones the bones will remain solid &
heavy with the preservation of bone marrow in long
bones for a number of years.
• After 40-50 years :
– surface of the bone becomes dry & brittle
– marrow cavity will be empty.

Estimating the Time of Death
1. Core body temperature :
– the best and the most commonly used
– mainly per rectum & by intra/sub-hepatic via an
abdominal stab.
2. Rigor mortis : Rule of 12 hours
3. Hypostasis :
– complete after 6 hrs.
4. Biochemical investigation of the CSF :
– requires the determination of the amino acid content
& lactic acid & non-protein nitrogen content of the
CSF.

4. Eye pressure:
– eye balls become softer, and less fluid pressure in
the first 3 hrs
5. Gastric emptying:
– depend on type of meal and emotional status.
6. The entomology of dead:
– Studying insects & their maggots which infest the
dead body for estimating the probable time of
death.
– Different types of insects infest the dead body at
different stages after death occurs.

7. K level :
– all electrolytes in the body change after death except K.
– Na/K pump stops working.
– There is linear relation b/w K level and time passed after death up
to 120 hrs.
– Measured from vitrous humor
– When there is high urea concentration, there is an electrolyte
imbalance and K can no longer be used as an indicator
– This is the most infrequently used method to determine post
mortem interval.
– Many different opinions exist about its accuracy and ability to
predict post mortem interval.
– Measurement of potassium levels in the eyes can vary greatly from
left to right eyes in the same corpse in ideal conditions.
– From a medico-legal standpoint, this technique is frowned upon.
– This is typically thought of as a “last ditch effort”

Time since death/ post
mortem interval
 Important clue for investigation of time.
 It helps apprehend the person likely to be involved.
 Point to be ascertained are;
-cooling of the body
-post mortem lividity
-rigor mortis
-decomposition changes

- Contents of stomach and bowels
- Contents of urinary bladder
- Biochemical changes
- Circumstantial evidence

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