Post Mortem Interval
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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
Post Mortem Interval
- 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