POST-MORTEM CHANGES 徐智慧/

Normal Postmortem Changes

1. Immediate Changes (somatic death)

2. Early Changes (Cellular death)

3. Late Changes (decomposition and decay)

Immediate Changes (somatic death)

Insensibility and loss of voluntary power

Cessation of respiration

Cessation of circulation

Permanent cessation of brain function

o Loss of sensations: vision, touch, pain, temperature

o Loss of reflexes: corneal reflex, oculo-cephalic reflex, vestibulo-ocular reflexes, gag

reflex

o Total loss of EEG rhythm o Confirmation of brain stem death

Early Changes (Cellular death)

Algor mortis

Rigor mortis

Pallor mortis

Livor mortis

Changes in the eye

Algor mortis

o Cooling of the body after death o Takes place only if the ambient temperature is cooler

than the body temperature at the time of death

(TOD) o Best indicator of TOD in the first 24 hours

o Taken: either rectal or liver o Body cools approx. 1.5 degrees Celsius/hour

Skinny people cool faster No clothes cools faster

In water cools much faster

o (Normal temperature – measured temperature) / 1.5 = number of hours

Rigor mortis

o Stiffening of the muscles due to buildup of salts o Occurs as ATP is depleted, preventing relaxation of

muscle fibers

o Begins 1-2 hours after death (face, arms, abdomen, legs)

o It takes 12 hours to get fully stiffened o Then starts to go away in the same order (face,

arms, abdomen, legs)

o Rigor mortis stops when muscles begin to decompose ~ 36 hours after death

o Infection, terminal seizure, electrocution, strenuous exercise or high body temperature may cause rigor

to develop more rapidly o In hot weather, rigor dissipates more rapidly; in cold

weather, rigor may persist longer

Pallor mortis

o Paleness which happens in those with

light/white skin almost instantly (in the 15-25 minutes after the death) because of a lack of

capillary circulation throughout the body o The blood sinks down into the lower parts

(due to gravity) of the body creating livor

mortis Livor mortis

o Lividity: red/purple coloration of skin

o Due to settling of blood after death o Begins to develop 1-3 hours after death and fully

developed by 10-12 hours o Areas exposed to pressure will not show lividity, as

the blood vessels are mechanically compressed

preventing blood flow o As livor progresses, some bodies show dark purple

Tardieu spots in dependent areas, due to ruptured capillaries

o Tardieu spots are petechiae and purpuric

hemorrhages that develop in areas of dependency secondary to the rupture of degenerating vessels

under the influence of increased pressure from gravity

Changes in the eye

o loss of corneal reflex, opacity of cornea, flaccidity of eyeballs

o pupils: soon after death, pupils are slightly

dilated, because of the relaxation of muscles in the iris. Later they are constricted with the

onset of rigor mortis of the constrictor muscles and evaporation of fluid. As such,

their state after death is not an indication of

their ante-mortem appearance. o retinal vessels: fragmentation or

segmentation (trucking) of the blood columns in the retinal vessels appear within

minutes after death, and persists for an hour. The retina is pale for the first two hours. At

about six hours, the disk outline is hazy and

and becomes blurred in 7-10 hours. o Tache noire is horizontal darkening of the

exposed sclera that occurs secondary to drying when the eyelids are left partially

opened after death. The characteristic

location along the parted eyelids is instrumental in interpreting this finding. It is

a drying artifact that may mimic trauma

Late Changes (decomposition and decay)

Bodies decompose more rapidly in hot environments

and slowly in cold environments 2 days post mortem

o Marbling neck and shoulders

o 1st red then green o From bacteria getting into subcutaneous

tissue

o bloating from gases created by bacteria o Organs decompose in order: Stomach and

intestines, heart and liver, musculature

Autolysis Putrefaction

Adipocere formation Mummification Maceration

Body warm not stiff less than 3 hours

Body warm stiff 3-8 hours

Body cool stiff 8-36 hours

Body cool not stiff more than 36 hours

Autolysis

o aseptic breakdown of tissues due to the release of intracellular enzymes

o Softening & liquefying of the body tissue o Starts 3-4 hrs after death and continues for

2-3 days

Putrefaction

o breakdown of tissue due to bacteria o Green discoloration of the lower abdomen,

due to overgrowth of colonic bacteria o Green-black discoloration and swelling of the

face and neck o Red-brown purge fluid may extrude from

the nose and mouth; this should not be

confused with blood. o Purge fluid is foul smelling, red-brown fluid

that may exude from the oral and nasal passages as decomposition progresses.

o Marbling occurs due to breakdown of

hemoglobin within blood vessels o Brain becomes partially liquefied

o Skeletonization: usually takes several weeks

Adipocere formation

o transformation of body fat to oleic, palmitic, and stearic acids, appears yellow, white, or

brown and waxy

o has a rancid smell o rare and occurs in humid or wet

environments o Bacterial fat splitting enzymes and moisture

are essential – Lecithinase.

o It forms at any site where fatty tissue is present.

o Time required, in summer-3 wks, in tropics-5 to 15 days.

Mummification

o skin turns yellow-brown or black, becomes dry and leathery; occurs in dry environments

o Internal organs get transformed into a thick

brown mass o Mummification occurs in bodies buried in

shallow graves, in dry sandy soils. o Time – 3 months to 1-2 yrs

Maceration is the aseptic autolysis of the fetus that died

in the uterus and remained closed within the amniotic

sac. 徐智慧/

徐智慧/ AUTOPSY: Through the Eyes of Death’s

Detectives

What is an autopsy? Greek autopsia ‘to see with one’s own eyes’ from

autos ‘self’ + opsis ‘view’

The process of taking pieces of tissue (representative

cut sections) from a dead person (cadaver) for the purpose of examination or investigation, in order to

determine the cause of death of the injury leading to the death of the person

Why is an autopsy done? The principal aim of an autopsy is to determine

the cause of death,

the state of health of the person before he or she

died, and whether any medical diagnosis and treatment before

death was appropriate.

An autopsy is frequently performed in cases of sudden death,

where a doctor is not able to write a death certificate, or

when death is believed to result from an unnatural cause.

These examinations are performed under a legal authority (Medical Examiner or Coroner or Procurator Fiscal) and do

not require the consent of relatives of the deceased.

The most extreme example is the examination of murder

victims, especially when medical examiners are looking for signs of death or the murder method, such as bullet wounds

and exit points, signs of strangulation, or traces of poison.

Autopsies are performed to determine 4 specific things:

time of death,

cause of death,

damage to the body, and

type of death (suicide, murder, natural causes)

If autopsy is not required by law, the legal next-of-kin must

sign an autopsy permit.

History

Erasistratus and Herophilus (300) pioneered the

anatomical by dissecting cadavers to study how organs and nerves worked

Galen of Pergamum (late 2nd century) was first to

correlate the patient's symptoms (complaints) and signs (what can be seen and felt) with what was

found upon examining the “affected part of the

deceased” Ibn Zuhr (1131) presented a accurate description of

esophageal and stomach cancers through autopsies

Europeans preserve bodies to make autopsies

easier (1200). Autopsies were done is Europe regularly that they started to preserve bodies better

The first forensic autopsy is performed (1302).

The first forensic autopsies were done in Bologna by a civil officer to determine if a death being

investigated was caused by “fault.”

Antonio Benivieni (1443 – 1502), a Florentine

physician carried out 15 autopsies to determine cause of death

Andreas Vesalius (1543) used autopsies to

distinguished abnormal anatomy in humans

Giovanni Morgagni (1761) writes On the Seats and

causes of Diseases explaining his experiences with Autopsies

Marie F.X Bichat (1771 – 1802) stressed the

importance of the general system and tissues in determining the cause of death

The Standards of Autopsies are written (1880).

Rudolf Virchow wrote the standards of autopsies. The standards are still used today

Richard Cabot (1910), an American physician,

studies 1000 autopsies and finds out that 40% of the

bodies had a incorrect cause of death Toxicology tests are effective (1987) after a

pathologist in Ohio detects cyanide after a autopsy of

a patient John Powell Technology helps solve autopsy mysteries

(2005 – 2007). CT Scan is used to reveal the real

cause of death of King Tut. He died due to a infection

of the leg

TYPES OF AUTOPSY

PURPOSE

Routine hospital autopsy: Done in private hospitals for

the purpose of ascertaining the cause of death of a

person, especially if the

cause cannot be determined clinically.

Medico-legal autopsy:

Done at the NBI or other government institutions for

the purposes of prosecution.

COMPLETENESS OF

PROCEDURE

Partial: Autopsy request

involving only the

examination of a region or regions of the body such as

head only, thorax only, or abdomen only

Complete: Autopsy request

involving the examination of the whole body from head to

foot for complete diagnosis and investigation

MANNER OF INCISION

Y-shaped incision: The

cadaver is opened from both shoulder regions down to the

xiphoid area, then incised

down to the pubis. Commonly done in adult and

female cadavers

Straight cut incision: The

cadaver is opened from the

midline of the body from the suprasternal notch down to

the pubis. Commonly done in children and infants

Phases of an Autopsy

Gross examination: External examination which

includes: o Determination of length and weight

o Observation of symmetry, general nutritional status

o Preservation o Careful scrutiny of structures of the head, neck,

trunk, and extremities for marks or identification and for recent and old injuries

Microscopic examination: Examination of small

representative samples of tissue carefully chosen for their

diagnosis

Prerequisites for Autopsy 徐智慧/

Written consent or permission from the nearest kin or

relative

Type of autopsy procedure must be specified

according to purpose and completeness Common apparatuses or instruments needed during

autopsy procedures.

o Enterotome o Skull chisel

o Hagedorn needle

o Rib cutters o Scalpel

o Toothed forceps o Scissors

o Bone saw o Hammer with hook

o Breadknife

o Vibrating saw

Autopsy Consent A physician cannot order an autopsy on a patient without the

consent of the next-of-kin. However, a medical examiner can

order an autopsy without the consent of the next-of-kin.

Deaths that are investigated by the medical examiner or coroner include all suspicious deaths, and, depending upon

the jurisdiction, may include deaths of persons not being treated by a physician for a known medical condition, deaths

of those who have been under medical care for less than 24

hours, or deaths that occurred during operations or other medical procedures.

In all other cases, consent must be obtained from the next-

of-kin before an autopsy is performed, even at academic

institutions or hospitals. The next-of-kin also has the right to limit the scope of the autopsy (for example, excluding

the brain from evaluation or limiting the procedure to examination of the abdomen) if he/she wishes.

The autopsy consent form typically covers four basic questions:

Who is authorized to give consent for the autopsy? Who is authorized to perform the autopsy?

What limitations (if any) are placed on the autopsy? What is the disposition of the tissues that are

examined?

Who is authorized to give consent for the autopsy?

The permission form must be completed by the deceased's legal next of kin, signed, and witnessed. In some states, if

written permission cannot be obtained in a timely manner, then the next of kin can grant permission by phone or fax,

again, with an appropriate witness.

The next of kin who is authorized to give consent for an

autopsy comes in this order, based on availability. Spouse

Child (must be of legal age and/or married)

Parent

Guardian

Other relatives

Anyone assuming custody

If the deceased has no spouse, or otherwise is also

deceased, the child can give consent, and so on.

Who is authorized to perform the autopsy?

In most cases, medical autopsies are performed in the hospital where the deceased was pronounced dead or

where the individual had received care in the past. The autopsy is usually done by a pathologist on that hospital's

staff.

Occasionally, the family may object to the involvement of the

hospital and its pathologists in the autopsy. In such instances they have the right to arrange for their own autopsy.

What limitations (if any) are placed on the autopsy?

Often, restrictions will result from concerns that the autopsy

will render the body unsuitable for viewing. The family should be reassured that a properly performed standard autopsy will

not leave any visible trace and that funeral arrangements will not be significantly changed.

The next of kin has the right to place any restrictions they wish on the autopsy procedure. Such wishes must not only

be respected (e.g., if an autopsy is limited to the abdomen only, it is not permissible to access the thoracic contents

through the abdominal incision) but also clearly documented in writing on the autopsy permission form.

What is the disposition of the tissues that are examined?

In most cases, the disposition of the tissues removed and examined is left up to the pathologist.

All or some of the tissue may be

returned to the body cavity for burial,

retained for teaching or research purposes, or

disposed of as bio-hazardous material.

However, the next of kin may decide against any of these options.

This becomes particularly important when dealing with

families whose religious beliefs require the burial of the body in as intact and complete a state as possible (eg, Orthodox

Jews, Native Americans).

How is an Autopsy Done? 徐智慧/

At many institutions the person responsible for handling,

cleaning, and moving the body is often called a diener, the German word for servant or helper. The body is received at a medical examiner's office or

hospital in a body bag or evidence sheet. A new body bag is used for each body to ensure that only evidence from that

body is contained within the bag.

Evidence sheets are an alternate way to transport the body.

An evidence sheet is a sterile sheet that the body is covered in when it is moved. If it is believed there may be

any significant residue on the hands, for instance gunpowder,

a separate paper sack is put around each hand and taped shut around the wrist.

Steps

1. Get your pen and paper ready for taking notes, or get a voice recorder and just dictate notes aloud.

2. First, the height, weight, age, and gender of the body

should be noted and recorded. Any distinguishing characteristics like birthmarks, scars, or tattoos should be

noted as well. 3. You should also take fingerprints at this point, as they

may be needed in police investigations.

4. Examine the body very closely, meticulously, under magnification. Check the clothing and skin for any marks

that look out of the ordinary. Fibers that don't seem to belong, droplets of blood, organic materials, and any

residues found on clothing should all be noted. Any bruises, wounds, or marks on the skin should be noted as

well.If foul-play is suspected, carefully check under the

victims fingernails. Oftentimes, you will find blood or skin from the attacker.

5. Check for any dental work. Dental records are often used to identify bodies. Perform an x-ray to find any broken or

fractured bones, or medical devices, like a pace-maker.

These records can also be used to identify the subject. 6. Check the genital area for any signs of rape, bruising and

tearing are common in such cases. This will help determine whether foul-play was involved or not.

7. Now it is time to take a photographic record of the body,

clothed and nude. Take special care when removing the clothing, as it may be needed for police investigation.

Take close-up shots of the marks, bruises, blood flecks, etc., that you noticed earlier.

8. Take a blood sample, it can be used for DNA purposes, or to determine if the victim was on drugs, had been

using alcohol, or whether there was poisoning.

Note: Use a Hypodermic needle and a syringe

9. Now is the time to open the body cavity, but not going into too much detail. Make one large "Y" shaped incision

from each shoulder across the chest to the brisket, then down to the belly button, spread open the skin and check

to see if any ribs are broken.

The pathologist uses a scalpel for these incisions.

There is almost no bleeding, since a dead body has no blood pressure except that produced by

gravity. Prior to cutting, the torso is placed on a rubber

block, extending the body's arch and providing

greater access to the chest and abdomen. If a

brain autopsy is also planned, this block will be moved to support the head once the torso work

is complete. 10. Split the ribcage, open it up, and examine the lungs and

heart, note any abnormalities, and take a second blood

sample directly from the heart. Cut the cartilages that join the ribs to the

breastbone, in order to be able to enter the chest

cavity. This can be done using a scalpel, a saw, or a special knife.

11. Next you should examine each organ in the chest cavity individually. Weigh each organ, record anything notable,

and take a tissue sample in case further examination is

needed. 12. Next, repeat the same process for the organs in the

lower body, like the spleen and intestines, as sometimes partially digested food is used to determine time of

death.

13. A urine sample should also be taken from the bladder using a syringe. Just like blood, the urine can be used in

tests to detect drugs or poisons. 14. Always carefully examine the eyes, as any hemangioma

or petechial rash (tiny, broken blood vessels) can be a sign of choking or strangulation.

15. Next, examine the head. Check for any trauma to the

skull like fractures or bruises. 16. Remove the top of the skull, then remove the

brain. Follow the same procedure as with all other organs, weigh, and take a sample.

To open the skull, use a special vibrating saw

that cuts bone but not soft tissue. This is an

important safety feature. When this is sewed back up, it will be concealed by the pillow on

which the dead person's head rests. 17. Before the autopsy is over, the brain is usually suspended

in fixative for a week so that the later dissection will be clean, neat, and accurate. If no disease of the brain is

suspected, the pathologist may cut it fresh.

18. After the autopsy is completed, finish your notes or your dictated recording. State the cause of death, and the

reasons that brought you to that conclusion. Mention any details, no matter how small, as they may be the final

clues needed to stop a murderer or to put a family

member's mind at ease. 19. Based on your findings (assuming you're a licensed

coroner) The Chief Medical Examiner will issue a Death Certificate.

20. When the internal organs have been examined, the

pathologist may return all but the tiny portions that have been saved to the body cavity. Or the organs may be

cremated without being returned. The appropriate laws and the wishes of the family are obeyed.

21. The breastbone and ribs are usually replaced in the body. The skull and trunk incisions are sewed shut ("baseball

stitch"). The body is washed and returned to surviving

family members for funeral arrangements.