Death

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Death Post-Mortem changes

• Mohammed Bader
• 5th year medical school
• University of Jordan

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Death

• Death is divided into two stages
• Clinical death
• its the Cessation of the function of 3
  systems
• CVS, RS, CNS.
• Cellular death
• cells no longer functioning or have metabolic
  activities or aerobic respiration.
• Its follow the clinical death stage.
• Its depend on the blood perfusion to the tissue.
• Different tissue die at different rate cerebral
  cortex tolerate only few minutes of anoxia while
  connective tissue and muscles may survive longer
  (for hours).

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Somatic Death (Brain death)

• the person is irreversibly unconscious, not aware
  of surrounding environment and he is unable to
  appreciate sensory stimuli or initiate any
  voluntary movement
• Reflex nervous activity may persist and
  circulatory and respiratory function continue
  either spontaneously or with artificial support.
• Somatic death brain death vegetative state
• (all tissue and cells of the body are alive and
  functioning except for those damaged in the CNS)
  

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Indications of Death

• Indications of death
• Unconsciousness
• Loss of all reflexes
• No reaction to painful stimuli
• Muscular flaccidity
• Cessation of heart beat and respiratory movement
• Eye signs
• loss of corneal and light reflexes
• Mid dilated position of the pupils
• Irregular size and shape of the pupils
• Eyelids usually closed incompletely
• Tache noire where the sclera remains exposed,
  two triangles of discoloration appear at each
  side of the cornea, either brown or black.

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Tache Noire
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Apparent Death

• a state that mimics death, occurs in
• Electrocution
• Hypothermia
• Sun stroke
• Drowning
• Drug over dose (barbiturates)
• Head injury

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Rigor Mortis

• One of the recognizable signs of death that is
  caused by a chemical change in the muscles after
  death, causing the limbs of the corpse to become
  stiff and difficult to move or manipulate.
• Death ?cessation of respiration ?depletion of
  oxygen used in the making of ATP? ATP no longer
  provided to operate the SERCA pumps in the
  membrane of the sarcoplasmic reticulum, which
  pump calcium ions into the terminal cisternae?
  Calcium ions diffuse from the terminal cisternae
  and extracellular fluid to the sarcomere ? Ca
  binds with troponin ? crossbridging between
  myosin and actin proteins.
• Unlike normal muscle contractions, the body is
  unable to complete the cycle and release the
  coupling between the myosin and actin, creating a
  perpetual state of muscular contraction, until
  the breakdown of muscle tissue by digestive
  enzymes during decomposition.
• Causes of rigors mortis are ATP depletion
  (glycogen store depletion), actin-myosin
  interaction and lactic acid accumulation.

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Rigor Mortis (contd)

• Sequence
• Primary muscular flaccidity
• Generalized muscular stiffness
• Secondary muscular flaccidity
• RM starts to develop about 2-3 hrs after death
• Usually its first detected in smaller muscle
  groups such as those around the eyes, mouth, jaw
  fingers.
• It resolves in the same order in which it
  develops.
• It concludes around 36-48 hrs after death

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Factors affecting timing of RM

•  
• Environmental temperature
• Cold and wet ? onset slow, duration longer
• Hot and dry ? onset fast, duration shorter
• Muscular activity before death
• muscles healthy and robust, at rest before death
  ? slow onset, duration longer
• muscles exhausted/ fatigued ? onset rapid, esp in
  those limbs being used (eg in someone running at
  time of death, lower limbs develop RM faster than
  upper limbs)
• increase activity (convulsions, electrocution,
  lightning) ? rapid onset short duration
• Age
• extremes of age ? rapid onset
• Health
• Cause of death
• asphyxia, pneumonia, nervous des with muscle
  paralysis dehydration ? slow onset
• septicemia poisoning ? rapid onset, may even be
  absent, esp in limbs affected by septicimia
• emaciated or died of wasting disease ? rapid
  onset, short duration
•  

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RM time estimation
Warm Flaccid Death lt 3 hrs
Warm Stiff 3-8 hrs
Cold Stiff 8-36 hrs
Cold Flaccid Death gt 36 hrs
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Rigor Mortis (contd)

• RM in Iris
• Antemortem constriction or dilation modified
• May affect the eyes unequal, making the pupils
  unequal
• RM in the Heart
• Contracted, stiff LV may be mistaken for LV
  hypertrophy
• RM in Dartos muscle of scrotum
• Rigor in Dartos? constricts testes and epididymis
  expulsion of semen
• Contraction of seminal vesicles and prostate
• Postmortem expulsion of semen
• RM in Erector Pilli muscles attached to hair
  follicles
• Goose bumps, hair stands up

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Cadaveric Spasm

• Cadaveric spasm
• also known as instantaneous rigor, cataleptic
  rigidity, or instantaneous rigidity
• rare form of muscular stiffening that occurs at
  the moment of death, persists into the period of
  rigor mortis and can be mistaken for rigor mortis
• the cause is unknown, but usually associated with
  violent deaths happening with intense emotion
• may affect all muscles in the body, but typically
  only groups, such as the forearms, or hands
• seen in cases of drowning victims when grass,
  weeds, roots or other materials are clutched, and
  provides proof of life at the time of entry into
  the water.
• often demonstrates the last activity one did
  prior to death and is therefore significant in
  forensic investigations, e.g. clinging on a knife
  tightly

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Rigor Mortis vs. Cadaveric Spasm
Rigor mortis Cadaveric spasm
Onset delayed after death (2-3 hrs) Duration approx 12-24 hrs Onset is instantaneous Duration is a few hours, until it is replaced by rigor mortis
Intensity comparatively moderate Intensity comparatively very strong
All muscles of the body are affected gradually. Selected muscles, which were in a state of contraction at the time of death, are affected.
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Cadaveric spasm in a drowning victim had grass
from the river bank firmly clutched in the hand
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Conditions Mistaken as RM

• Heat stiffness
• Exposure of a body to intense heat (burning, high
  voltage electrocution, etc) ?coagulation of
  muscular proteins ? muscular shortening, with
  flexion in the upper limb, giving the apperance
  of pugilistic attitude.
• Cold stiffness
• Exposure of the body to extreme cold (lt-5C)
  ?solidification of subcutaneous fat and muscles,
  freezing of synovial fluid in joints
• Rigor mortis is only postponded, and after
  warming the body, the rigor mortis will
  supervene.

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Medicolegal Importance of RM

• Time estimation
• Cause of death
• Know position
• Sure sign of death

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Hypostasis/Livor Mortis

• 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 ?discoloration will be pale.
• starts immediately after death.
• apparent after 0.5-1 hr and fixed after 8 hrs.
• may not appear at all especially in infants, old
  ppl and anemic ppl.

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Hypostasis (contd)

• 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

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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.

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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.
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Color of Hypostasis

• The color of hypostasis is variable and depends
  on the state of oxygenation at death.
• Usual color is blue-pink
• Its 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)

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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

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Body Cooling/ Algor Mortis

• the most useful indicator of time of death during
  the first 24 hours post-mortem.
• after death all metabolic activity ceases rapidly
  (muscles, liver) circulation stops ? heat
  production ceases soon after death
• The body surface begins cooling immediately after
  death, followed by delay in deep organs cooling,
  until a heat gradient is set up between the core
  of the body and the surface.
• Delay ? temperature plateau
• Plateau variable from minutes to 2-3 hours.
• In practice the temperature is either measured
  per rectum or intra-hepatic via an abdominal
  stab.
• The rate of body cooling
• 1C/hr in summer
• 1.5C/hr in winter.
•  

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Factors affecting Rate of Cooling

• Surface area of the body
• larger surface area ? speeds up cooling rate.
• Children increase surface area gives rapid heat
  loss.
• Body weight
• Larger bw slower cooling
• Smaller bw faster cooling
• Edema
• slower cooling rate.
• Clothing, posture and.
• Environmental Temperature
• Higher humidity rapid cooling rate
• Rapid air velocity rapid cooling rate
• Water
• rapid cooling rate
• More rapid in flowing water than still water
• If there is a fulminating infection, e.g.
  septicaemia, the body temperature may continue to
  rise for some hours after death.

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Post-Mortem Decomposition

• Turning the tissue of the body into fluids and
  gases by the effect of bacteria and enzymes
• starts immediately after death at the cellular
  level
• becomes visible in 48-72 hrs.
• Two phenomena for putrefaction
• Autolysis occurs by digestive enzymes released
  from the cells after death.
• Bacterial action most of them come from the
  bowel and Clostridium welchii predominates (same
  bacteria that causes gas gangrene)

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• The speed of decomposition depend on
• amount of bacteria in the body.
• Temperature Rapid putrefactive changes may been
  seen in corpses left in a room which is well
  heated.
• Humidity A high environmental humidity will
  enhance putrefaction.
• 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.

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Mummification

• Occurs as a result of exposure of the body to
  high temperatures and dry air currents, to a
  degree that decomposition will stop.
• The body will be Dry, Shriveled up and brown in
  color.
• 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.
• The time required for complete mummification
  cant be precisely stated but it takes several
  weeks to months, depending on the size of the
  body and atmospheric conditions.

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Medico-legal Importance of Mummification

• Identification
• Time estimation
• Cause of Death
• Can detect abnormal pathology inside deep organs

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Adipocere

• 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.
• The optimum conditions for the formation of
  adipocere
• Moisture
• Warm environment

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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.

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• The End.