Thanatology Flashcards
Death is defined in the article
46 IPC
It is defined in Declaration of Sydney
Mode of death were given by
What are the modes of death
Bichat 1. Coma 2. Syncope 3. Asphyxia Bishop tripod of life : circulation, respiration and brain function
Atria Mortis
Somatic death
Failure of bishop tripod
Supra vital interval
The period of 2-3 hours between atria mortis and molecular/cellular death
Organ harvesting and Zasko phenomenon (tendon reaction) are related to this period
Philadelphia protocol
Protocol for brain death
The below two criteria should be fulfilled for atleast 2 hours:
1. Hayward criteria-Related with cortical brain death
2. Minnesota criteria-Related with brain stem death
Human organ transplantation act
In 1994
Amended to human organ tissue transplantation act
Any kind of organ trafficking,… is punishment is minimum 10 years and five is 20L- 1Cr
Tissue trafficking 3-5 years and fine is 10 lakh
Changes in the human organ transplantation act
Grandparents and grandchildren are allowed for donation or receiving organs
Switching organs between families is allowed
Organ that is never transplanted
Urinary bladder
Suspended animation
No sign of life but the person is alive
Resuscitation is required
Metabolic activity of body is decreased to low level
Suspended animation examples
Examples: A) anaesthesia B) new born C) cholera, concussion D) drowning E) electrocution FG H) hypothermia and hyperthermia I) insanity (Trance , a yoga posture-voluntary))
Earliest change after death is
Insensibility and loss of voluntary power
Early post mortem changes
Changes of skin Eye Algor mortis Livor mortis Rigor mortis
Delayed post mortem changes
Decomposition and putrefaction
Tests for death
These are not used nowadays Test for circulation: 1. Diaphanus test 2. Magnus test 3. I-CARD dye test
Test for respiration
Winslow test
What are the post mortem changes seen after death
- Length of a person increases by 2-3 cm due to relaxation of intervertebral discs
- Eye changes:
- Algor mortis: decrease in temperature
Kevorkian sign
Rail roading sign
Seen few minutes after death
Earliest sign
Retinal vessels appear segmented
Eye changes after death
- Kevorkian sign
- Potassium ion and hypoxanthine increases in vitreous humour:
Potassium ion is measured using Sturner formula or Madea formula
It can be used to measure time after death - Corneal clouding in 3 hours
- Cornea becomes opaque in 2-4 hours
- Intraocular tension
- Tache-Noire
Changes in intraocular tension after death
It falls from 25 mm Hg (normal)
To 3 mm Hg in 30 minutes
To zero in 2 hours
Tache Noire
A scleral change
A triangular projection due to epithelial cell debris
Generally seen in 3 hours after death
Most accurate site for measuring body temperature
Rectum
Subhepatic region to a lesser extent
What are the changes in temperature following death
It is a inverted sigmoid curve
Initially there is a isothermic plateau phase that lasts for about 3 hours
After 24 hours it becomes stable
Can be used to measure TSD (time since death)
Rate of fall of temperature after death
In summer 0.75•F/hr or 0.5•C/hr In winter 1.5•F/hr or 0.7•C/hr Time since death = (normal BT-rectal temp)/rate of fall If in centigrade: Time =NBT-(RT+3)
Post mortem caloricity
In some cases after death the temperature rises for 2 hours
- Septicaemia, cholera (bacterial activity increases)
- Strychnine poisoning, tetanus (muscle activity increases)
- Sunstroke, pontine haemorrhage (heat regulation fails)
Livor mortis
PM lividity/ PM staining/ vibices/ suggilation / hypostasis
It is the reddish-blue staining of skin (rete mucosum) seen in dependent parts of the body for to accumulation of deoxygenated blood
Glove and stocking pattern
It is the livor mortis seen on a hanging body
Rate mucosum is seen in the hands and feet (the dependent parts)
Time since death and livor mortis
Shortly after death: visible 4 hours: developed 6-12 hours: maximum 7-8 hours: position is fixed persists till putrefaction
Secondary lividity
If the body is moved within 7-8 hours, secondary lividity is observed
Livor mortis and cause of death
- CO poisoning: cherry red
- Cyanide poisoning: bright red/ brick red
- Hypothermia: bright pink
- H2S poisoning: blue-green
- Phosphorus: dark brown
- Opium toxicity: black
- Clostridium perfringes toxicity or septicaemia: bronze
- Oxidising poison (benzene, nitrate, chlorate, aniline): chocolate brown
Rigor mortis/ cadaveric rigidity
Stiffening of muscle
Shortening of muscle
Sommer’s movement
Mechanism was discovered by Shaiparo
Due to ATP depletion or lactic acid accumulation
It follows the primary relaxation phase (which starts immediately after death)
It is followed by secondary relaxation (decomposition)
Rigor mortis starts with which muscle
1st muscle is heart muscle in 0.5-1 hour
In upper eyelid it starts at 2-3 hours
Rigor mortis and climate
In summer it takes about 18-36 hours to develop
In winter it takes 1-2 days
The onset and duration of rigor mortis depends on
- Climate
- Thin/thick muscle
- Rate of ATP depletion
- Muscle activity
Nysten law
Rigor mortis appears and disappears from eyelids to toes
Rule of 12
Rigor mortis
In first 12 hours: appears in all muscles
In next 12 hours it remains in all muscles
In next 12 hours it disappears from all muscles
Therefore rigor mortis exists for about 36-48 hours
Variations of rigor mortis
- In foetuses below 7 months of age, it is absent since actin and myosin are absent
- In children, old people and violent death, the onset is early and duration is short
- In wasting diseases like TB, typhoid, cholera also same situation occurs
- In toxicities like, organophosphorous, strychnine and arsenic
Why in children and old people ,the onset is early and duration is short
In children and old person the muscle mass is less so ATP depleted faster
Why in violent death, the onset is early and duration is short
Muscle activity is more in drowning Heat stroke Throttling Cut throat Fire arm injury ATP depleted faster
In organophosphorous toxicity, what changes occur in rigor mortis
In organophosphorous toxicity, rigor mortis onset is earlier
Strychnine and arsenic poisoning and rigor mortis
In strychnine poisoning: (steal)
Early onset
Long duration
In arsenic poisoning: (all)
Late onset
Long duration
Rigor mortis and ATP
Starts when ATP is 85% of normal and reaches its maximum when ATP is 15% of normal
Specific effects of rigor mortis on muscle
Heart appears as a ventricular hypertrophy
In pregnant uterus it will lead to post mortem delivery
In the erector piles muscle it will lead to goosebumps or cutus anserina
Other post mortem muscle stiffening
- Heat stiffening
- Cold stiffening (-5•C or lower freezing of body fluids)
- Gas stiffening (has formed on decomposition)
- Cadaveric spasm
Heat stiffening
Occurs when temperature is greater than 65•C
Same mechanism causes pugilistic attitude
Coagulation of muscle protein
Cadaveric spasm (how is it different from rigor mortis)
Just after death Instantaneous rigor Involved only in few voluntary muscle like those of hand Gives response to electric stimuli Cannot be broken Gives an idea of mode of death
Situations in which cadaveric spasm occurs
A. Asphyxiation B. Brain injury C. Cerebral injury D. Drowning (clenched hand with grass) and Dinitro-cresol poisoning E. Exhaustion F. Fear and fire-arm injury
Decomposition versus putrefaction 🆚 autolysis
Decomposition is by external bacteria
Putrefaction by gut bacteria
Autolysis own enzymatic activity
First sign is the clouding of cornea
Decomposition changes
- Colour changes
- Gas
- Liquefactive necrosis
Most common bacteria involved in decomposition and its optimum temperature
Clostridium welchi
Its optimum temperature is 21 to 38°C
Main enzymatic activity is lecithinase (a lytic enzyme)
First external change of decomposition
Greenish/ reddish purple discolouration of right iliac fossa (caecum)
Sulfa Hb (Hb degradation product) from H2S
In summer it occurs in 12-18 hours
In winter it occurs in 1-2 days
First internal sign of decomposition
- Brownish discolouration of the intima of the aorta
(then) - Colour change of the undersurface of liver
Second change of decomposition is
Marbelling : Superficial vein becomes prominent Due to sulfa Hb (greenish brown/ reddish purple) Seen from 24-36 hours Common sites are chest, thigh, neck
Third change of decomposition
Maggots:
Blue bottle fly like Musca domestica or M. vicinia
These flies lay eggs in moisture containing areas like nasal/oral or injured parts
Seen 2-3 days (in rainy season:1-2 days)
8 stages of maggots or larva was identified by
Megnin
Number of days taken for a maggot to become a pupae
3-6 days
Number of days taken for pupa to become an adult fly
3-6 days
Forensic entomology
Forensic entomotoxicology
Forensic entomology is the study of insects/ flies on the body
Forensic entomotoxicology is the study of poisons using insects/flies of the body
Gas formation, when and where
2-3 days
Face, abdomen, scrotum
Post mortem purge
Other post mortem changes after decomposition seen within 5 days
After 2-3 days nail, hair become loose
After two days the teeth become loose
After 3-5 days, glove and stocking pattern and skin is peeled off and the sutures of the skull get separated
Post mortem purge
After 2-3 days, due to gas formation, gastric contents come out through oral/ anal orifices (not vomiting)
Respiratory content comes out through nostrils (not frothing)
Colliquative necrosis
Seen after 5-10 days, it is the liquefactive necrosis
Internal organ decomposition
Sequence
- Larynx and trachea (exposed to air)
- Stomach, intestine, spleen (SIS)
- Liver and lung (2L)
- Brain➡️ heart ➡️ kidney (BHK)
…
Last organ
Prostate gland /non gravid nucleus
Then bone
Foamy liver/ honeycomb liver
Liver is the third organ to undergo decomposition
Gas bubbles are formed leading to the appearance
In 24-36 hours after death
Best organ for DNA analysis is
Spleen
Best organ for DNA analysis after decomposition is
Brain
The first and the last amino acid to disappear from bone
First amino acid to disappear is proline and hydroxy proline
Last amino acid is glycine
Less than 7 amino acids suggests the bone is
100 years old
After ___ the cut surface of bone is fluorescent
35 years
Bone decomposition starts at
3-10 years
Nuclear features of the body persists for
2-3 years
Casper Dictum
Given by Taylor Rate of decomposition in different climate Gives idea of time since death Rate: Air> water > soil 1 week > 2 weeks > 8 weeks
Modifications of decomposition
- Adipocere/ saponification/ grave wax
2. Mummification/ desiccation
Adipocere is seen in
Starts in fatty areas like face, abdomen, breast, buttocks,… and then moves other parts
Seen when the body is immersed in water or warm, damp, humid climates
Adipocere mechanism
Fatty acid is hydrogenated and hydroxylated by lipase of Clostridium welchii
And then combines with Ca+2 and Ammonium ion
Pseudosmell
Adipocere when combines with ammonia gives a ammoniacal smell
Which might remain in the clothes of autopsy surgeon called pseudosmell
Adipocere starts at
3 days and continues upto 3 weeks in India
Adipocere appearance
Fresh adipocere:
White, soft, moist
Old adipocere:
Yellow, hard, brittle
Appears like rancid butter
Adipocere is not found in
Foetuses below 7 months of age due to absence of subcutaneous fat
Medico-legal importance of adipocere and mummification
- Climate
- Time since death
- Identification of body and injuries are preserved (lecithinase activity absent)
Mummification
Dry hot like Desert Dehydration Desiccation •Body shrinks •Odourless •Natural appearance is preserved, since no lecithinase activity •seen in IUD (intra uterine death)
Time taken for mummification
3 months to 1-2 years
Elements favouring mummification
Arsenic and antimony favours mummification
Stomach emptying time
Light food: 1-2 hours
Empty: 2 hours
Medium food: 3-4 hours
Heavy meal: 5-8 hours
Growth of hair and nail
Hair: 0.4 mm/day
Nail: 0.1 mm/day
Pink teeth phenomenon
After decomposition, gums are congested which appear like pink teeth
PM luminescence
Dead body may luminescence due to photobacteria, or fungi like:
•Armillaria
•Ramsbottom
Most of viscera should be preserved at
4°C
But ideal temperature we use is -20°C
Time for dead body to be preserved before autopsy
Minimum 72 hours according to police protocol
Human anatomy act: 48 hours
Embalming
Should be done within 6 hours using by fluid
2 types: arterial and cavity
Should be done after post mortem (otherwise 201 IPC-disappearance of evidence)
Embalming fluid composition
Formaldehyde-preservative Glycerin- wetting agent Methanol-preservative Phenol-germicide Na citrate-anti coagulant NaCl-pH control Water
In embalmed body, the samples preserved for toxicology analysis
Buttock muscle
Vitreous, synovial fluid, bile
Artefacts
- Prinslow-Gordon artefact:
Extravasation of blood on neck after asphyxia - Agonal artefact:
PM ‘injury’
Important evidence act wrt post mortem
107 IEA Presumption of life
Any missing person is presumed to be alive for next 30 years.
108 IEA Presumption of death:
If a person is unheard for last 7 or more years, then it is presumed to be dead.
Henssge normogram
To decide time since death via temp-time relation
Commorientes
When two or more people died at the same time and same event, order of death can be difficult to determine
Presumption of survivorship:
Younger person is presumed to survive more than older person
Important in transfer of will
Definition of sudden death
If a person dies within 24 hours of onset of terminal illness with or without known or existing conditions
Most commonly due to CAD (LAD / widow artery)
