This document discusses several historical and modern methods for estimating the postmortem interval (PMI), or time since death, including: - Rigor mortis and livor mortis patterns in the first 24 hours - Algor mortis (body cooling rate) over the first 20 hours - Vitreous potassium levels, which rise linearly for the first 120 hours - Changes in proteins in organs like the liver and kidney that can help estimate PMI over 10 days - Insect colonization and development cycles on decomposing bodies to estimate PMI over months The document reviews several studies analyzing the use of enzymes, electrolytes, and cellular changes in fluids and tissues to correlate with PMI estimation

1. Recent Advances In Determination
Of Duration Of Death i.e. PM
Interval
Dr. Shailendra Patel
Moderator- Dr. Manish Nigam

2. Post Mortem Interval-
• Estimating the time since death, or
postmortem interval (PMI), is an important
component of medicolegal investigations.

3. Historical Background
• Methods for estimating the postmortem interval date
back to the ancient Greeks and Egyptians during the
fourth and third centuries . They understood that dead
bodies cooled and became stiff over a period of time
after death.
• Warm and not stiff: Dead not more than a couple of
hours
• Warm and stiff: Dead between a couple of hours and
a half day
• Cold and stiff: Dead between a half day and two days
• Cold and not stiff: Dead more than two days

4. • Rigor mortis-
Rigor becomes evident approximately two to six
hours after death. Even though rigor mortis
occurs simultaneously in all of the body’s muscle
tissues, it will be noticeable first in the smaller
muscle groups. It begins in the face and hands
and moves progressively throughout the rest of
the body. After approximately eight to twelve
hours, the entire body is rigid. The body will
remain rigid for another twelve to twenty-four
hours. Over the next eight to ten hours, rigor will
begin to disappear . The signs of rigor mortis
disappear in the same order they appeared, from
small muscle groups to larger muscle groups.

5. • Order of appearance and disappearance –
• Heart (left chamber in 1 hour)
• Eye lids ( 3-4 hour)
• Face muscles
• Neck and trunk
• Upper extemities
• Legs
• Small muscle of finger and toes( last to be affected 11-
12 hours)
• It passes off in same order of appearance
• It takes 12 hr to develop from head to foot , persists for
another 12 hr and takes 12 hr to pass off.
• In summer 18- 36 hr and In winter 24- 48 hr.

6. • Livor mortis-
• Suggilation,vabices, hypostasis, staining,
darkening of death.
• Livor mortis can be seen as early as 30
minutes after death. Since lividity results from
the heart stopping, it may begin appearing
antemortem in decedents who die as a result
of cardiac failure. This stains the surrounding
tissue. Lividity usually becomes fixed 6 to 8
hours after death.

7. • Post mortem lividity commences with in an hour
after death.
• Present as mottled patches in dependent parts
with in 1-3 hours
• Patches gradually increase in size and coalesce in
about 2-6 hours .
• Lividity is fully developed and fixed i.e. becomes
unchangeable in about 6-8 hours.
• Finally disappears when putrefaction sets in
• Pressure of thumb- Blanches (Not fix) TSD
<8hours.
• Pressure of thumb- Does not blanches (Fix) TSD
>6hours.

8. • Algor Mortis-
• Cooling of Dead Body.
• Under ideal conditions, the body will have no
drop in temperature for sixty to ninety
minutes after death followed by cooling at the
rate of 0.5 to 0.7 C’ per hour. The most
accurate way to record the body reading is by
inserting the thermometer.

9. • Measurement of body temperature-
• Thanatomenter
• Inserted 8-10 cm in rectum and left for 2-3min
• Other sites auditory meatus , nostrils or under
the liver.
• Rate of cooling-
• For 45 min temperature unchanged.
• Body attains the environmental temperature
in about 16-20 hours after death.
• PMI= 37.2-Rectal tem/0.6

10. • Thumb rules-
• Time since death = 37°C – Rectal temperature
(C) + 3
• Time since death = 98.6°F – Rectal
Temperature (F)/1.5
• Henssge’s nomogram method-

12. • Stomach Emptying as a measure of time since a
death-
• Average meal last for 2-3 hrs.
• Modi –
• Vegitable meal- 4-6 hrs.
• Farinaceous meal- 6-7 hrs.
• Adelson-
• Stomach empting starts within 10 min of swallowing.
• Light meal- 2 hrs.
• Medium meal- 3-4 hrs.
• Heavy meal- 4-6 hrs.
• Meal reaches to ileocaecal valve between 6 and 8 hrs.

13. • Putrefaction and autolysis-
• 1st sign
• External – Greenish discoloration of flank over
cecum appears 12-24 hrs.
• Internal- Greenish discoloration on under
surface of liver.
• Order of putrefaction –
• Larynx and trachea 1st , infant brain, stomach
intestine spleen, liver lung, brain, heart,
Kidney bladder, prostate, uterus (non
gravid),skin muscle tendon, bone.

14. • Marbeling-
• Starts after 24 hrs.
• Most prominent in 36-48 hrs.
• Maggots-
• Flies lay eggs in 18-36 hrs of death
• Maggots or larva appear in 48 hours of death
• Pupae develop in 4-5 days
• Adult flies develop in another 4-5 days
• Skeletonisation- uncoffined bodies 1year

15. • Adipocere/Saponification-
• Shortest recorded period is 3 days 22hrs and
in Summer 3 weeks.
• Time for whole body to be converted into
adipocere is one year.
• Mummification-
• 3 months to 1 year.

16. • Vitreous Humour Chemistry in PMI-Potassium and
Hypoxanthine.
• Stuner-
• PMI=7.14 X Potassium conc.(mEq/l) -39.1
When the body has found in an ambient temperature
of not more than 10’C (50’F).
• PMI=5.26 X Potassium conc.(mEq/l) -30.9
• Rises 0.17 to 0.238 mmol/hr
• Show linear rise up to 120 hrs.
• Rise in infants much faster than in adults .
• Intracellular potassium comes out from the retina .
• Hypoxanthine up to show linear rise up to 120 hrs.
• Cl – Decreases 1mmol/l/hr
• Na- Decreases 0.9 mmol/l/hr

17. • CSF-
• Csf electrolyte are based mainly on the
hypoxic damage of the choroid plexus.
• K+ Increases at a constant rate in relation to
the temperature of the body during the first
20 hrs
• Na, Ca and Mg have no obvious relationship to
PMI.

18. • Blood-
• Lactic acid – 50 -75X in 12 to 24 hrs.
• Aminoacid Nitrogen – less than 14mg /dl up to
10 hrs , Rises to 30 mg/dl by 48 hrs
• Acid phosphates – Increase 20X by 48 hrs.
• Amylase – Increase 3-4X by 2nd day.
• AST4( Glutamate oxalate transaminase )- and
LDH- increase linearly over first 60 hrs.
• Na- Falls by 0.9 m Eq /l/ hr
• Organic phosphorus – 20 mEq/l at 18 hr

19. • Pericardial fluid – Not useful
• Synovial fluid-
• K+ > 2X in first 2 days
• Muscle Enzymes-
• Myofibrillar protease increases linearly
• Creatinine phosphokinase decreases linerly
• Strong +ve correlation b/w the ratio of non
protein nitrogen and total soluble protein and
also creatinine concentration and PMI.

20. • JIFM 2009 Vol 31 Number 3 July Sept.
• Evaluation of cerebrospinal fluid cells in
postmortem period to estimate death interval.
• 60 Cases
• 14-65 Years
• 36 Male 24 Female
• Divided in 4 groups
0-6 Hrs
7-12 Hrs
13-18 Hrs
19-24 Hrs

21. • Alteration in CSF brain barrier
• Up to 12 Hrs – All types of cells can be
counted
• >12 Hrs- Mono, Neutro, can be identified
• Up to 20 Hrs- only lymphocytes can be
identified

22. • JIFM 2005 Vol 27 Number 1 Jan – March
• Study of serum enzymal changes after death and
it’s correlation with time since death.
• AST and ALT, serum acid phosphates
• Definite and marked rise in serum enzymal level
after death was noted from 2 Hrs after death on
words.
• Refrigerated bodies and samples gives
abnormally low values.
• If death is due to trauma to liver show markedly
high levels.
• In burn cases the graph is relatively more linear

23. • JIFM 2012 Vol 34 Number 3 July-Sept.
• K+ and Alkaline phosphates level in vitreous humour
and their role in postmortem interval
• 225 dead bodies
• K+ 12- 100 Hrs
• 6Hrs- 4.64-4.83 mEq/lit
• 6– 12 Hrs- 5.38-5.6 mEq/lit
• 12-24 Hrs- 6.49-6.75 mEq/lit
• 24-36Hrs- 7.41-7.71 mEq/lit
• 36-48Hrs- 10.29-10.71 mEq/lit
• 48-60Hrs- 13.68-14.24 mEq/lit
• Alkaline Phosphates- 0.18-12.32 IU/lit in initial stage up
to 42 Hrs. No significant change in alkaline phosphates.

24. • JIFM 2012 Vol 34 Number 4 Oct-Dec
Preliminary molecular study on protein profile
of vitals organs –A new direction for post
mortem interval determination.
• 20 subjects were taken
• 6 autopsy organ 25 mg of each
Brain
Lungs
Heart
Liver
Pancreas
Kidney
• Based on protein degradation.

25. • Protein collected 0th day to 10th day
• Ice cold homogenate buffer used
• Centrifuged at 10,000 for 15 min
• Procedure was repeated every 2nd day
• Supernatant was collected and kept at 4’ C
• SDS PAGE Analysis of the proteins were done
• Equal volumes 10 micro lit of all the tissue
were taken and proteins were separated using
a SDS-PAGE
• Gel Electrophoresis

26. • Bands of degradation of these protein were
analyzed.
• Transferrin
• Albumin
• Alpha-1 antitrypsin
• Hepatoglobulin
• Glycerldehyde dehydrogenase
• Glutation s- Transferse
• Hb alpha beta

27. • 10th day complete degradation of all proteins
except Albumin and Hb.
• Kidney and liver gives most consistent profile.

28. • JIFM 2012 Vol 34 Number 1 Jan – March
• An Entomological study to determine the
time since death in cases of decomposed
bodies.
• 47 decomposed bodies
• Divided in to 4 stages
• Fresh ( up to 36 Hrs)
• Bloated (36 Hrs to 7 days)
• Decay ( 7 day to 3 month)
• Dry (3 month to 1 year)

29. • Crawling insects were collected with eggs, Pupae
• Species identified mounted they are-
Sarcophagidae
Calliphridae
Muscidae
Silphidae
Dermestidae
• Flash from same body provided as food for
insects
• Developmental stages with time at specific
temperature and humidity were studied.

30. • JIFM 2009 Vol 31 Number 4 Oct-December
• Time passed since death from degenerative change in
liver.
• 45 cases of RTA were taken
• Liver Histopathology--
Grade 0 No change
Grade 1 Mild ( Architecture maintained, mild cloudy
swelling)
Grade 2 Moderate ( Architecture maintained, cloudy
swelling, cords pattern maintained, sinus dilatation)
Grade 3 Sever ( Architecture disturbed , Degenerating
signs are more , Disturbed hepatic lobule)
Grade 4 Very Sever ( Complete disturbance of lobular
architecture)

31. • Degenerative changes in liver
• In portal tried- Hepatic artery , vein , Bile duct
• Cytoplasm – Outline , granularity, hydropic
changes, vacoulation, fatty changes , Glycogen
deposition, Pigment depostion.
• Nucleus- Karyolysis, Degeneration,
fragmentation , vacoulation.
• Hepatic lobules- Central vein, Hepatocytes
,Cords, Sinus

32. • In actual cases-
• Temprature was 20-35 ‘ C
• Humidity was 45- 92%
• Duration was 7 – 34 Hrs
12Hrs G 1,2,3
13-18Hrs G 1,2,3
19-24Hrs G 1,2,3
31-34Hrs G 1,2,3

33. • In experiment at 20’ C
• 24 Hrs- Mild autolytic changes swelling of the
cells
• 36-48Hrs- Moderate autolysis, cytoplasm
granularity, rupture of cell wall with syncytium
• 72 Hrs- Lobular architecture lost.

34. • JIFM 2009 Vol 31 Number 1 Jan-March
• Relationship between the postmortem
interval and the pericardial enzyme activites
in subjects of Chandigarh zone of India.
• 150 Subjects were taken
• Enzymes analysed
Creatinine
Phosphokinase assay (Gamma gltamyle
transferase)
LDH
Amylase

35. Gamma glutamyl transgerase –
<12 Hrs 197
24- 36 Hrs 240
36-48 Hrs 160
48-60 Hrs 158
Creatin phasphokines-
<12 Hrs 2485
24- 36 Hrs 3473
36-48 Hrs 3232
48-60 Hrs 2686

36. Amylase-
<12 Hrs 2546
24- 36 Hrs 3881
36-48 Hrs 3466
48-60 Hrs 1976
LDH-
<12 Hrs 2508
24- 36 Hrs 4030
36-48 Hrs 3691
48-60 Hrs 3242

37. THANK YOU