early signs of death. early signs of death mate Žaja mentor: a. Žmegač horvat early changes rigor...
TRANSCRIPT
Early signs of deathEarly signs of death
EARLY SIGNS OF DEATHEARLY SIGNS OF DEATHMate ŽajaMate ŽajaMentor: A. Žmegač HorvatMentor: A. Žmegač Horvat
early changesrigor mortiscadaveric rigiditypost-mortem hypostasiscooling of the body
Early changesEarly changesno corneal reflexpupils stop reacting to light“trucking” or “shunting” of the
retinal vessels (fragmentation of columns of blood)loss of intraocular tension
Early changesEarly changesprimary flaccidity
◦ complete loss of tone◦ may retain reactivity◦ may respond to touch and other
forms of stimulation hours after cardiac arrest
◦ focal twitching decreases with time (discharges of dying motor neurons)
Early changesEarly changespaleness of the skin, conjuctivae
and mucous membranes◦fall of blood pressure and cessation
of circulation of the blood◦skin of the face and the lips may
remain red or blue in hypoxic/congestive deaths
Early changesEarly changeshair does not continue to grow
after death because hair follicles die at the same time as the rest of the skin
Early changesEarly changesloss of muscle tone in the
sphincters (voiding of urine)emission of semenregurgitation
◦very common feature of terminal collapse
◦common complication of resuscitation
Rigor mortisRigor mortis
O₂ anoxic pathway of energy production
ATP cell acidity
binding of actin and myosin fibres and formation of gel
stiffness of muscles (isometric contraction)
Rigor mortisRigor mortisfirst the smaller muscle groups
◦around the eyes◦around the mouth◦jaw◦fingers
from the head to the legs
Rigor mortisRigor mortisestimation of time of death
◦it should never be used alonevariable processaffected by temperature
◦the colder the temperature the slower the reactions
Rigor mortisRigor mortistemperate conditions
◦face: 1 to 4 hours◦limbs: 4 to 6 hours
strength increases next 6 to 12 hours
secondary flaccidity: 24 to 50 hours
standard conditions for temperature and pressure
(STP)20°C
101,325 kPa
Rigor mortisRigor mortis
◦ warm and flaccid – less than 3 hours◦ warm and stiff – 3 to 8 hours◦ cold and stiff – 8 to 36 hours◦ cold and flaccid – more than 36
hours
Cadaveric rigidityCadaveric rigidityforensic rarityonset immediately at deathhigh levels of emotional or
physical stress immediately before death◦drowning◦battlefield casualties◦suicidal shooting
possibly neurogenic mechanism
Post-mortem hypostasisPost-mortem hypostasispost-mortem lividity or suggilation
passive settling of blood under the influence of gravity
pink or bluish colour change of the lowest areas
Post-mortem hypostasisPost-mortem hypostasiscessation of circulationrelaxation of muscular tone of
the vascular bedsimple fluid movement within the
blood vessels
Post-mortem hypostasisPost-mortem hypostasismay be absent due to:
◦age – very young or very old◦anaemia◦severe blood loss
may be masked due to:◦dark skin colour◦jaundice◦some dermatological conditions
Post-mortem hypostasisPost-mortem hypostasiscompressed areas remain pale
(blanching):◦surface◦clothing◦body areas
position of the body
Post-mortem hypostasisPost-mortem hypostasiscolour of hypostasis:
◦from pink to dark pink to deep purple◦blue - some congestive hypoxic
states◦cherry pink – carbon monoxide
poisoning◦dark red (brick red) – cyanide
poisoning◦bronze - Clostridium perfringens
infection
Post-mortem hypostasisPost-mortem hypostasishypothermia:
◦usual colour can be unusually pink
◦unusual distribution around large joints and over dependent
areas of the body
Post-mortem hypostasisPost-mortem hypostasisno significant role in determining
time of deathaffected by the movement of the
body (even after normal post-mortem coagulation of the blood)
Cooling of the bodyCooling of the bodyindicator of the time of death
based only on three forensic assumptions:◦37°C at the time of death◦extrapolation of temperature and
applying it to the non-uniform body as a whole (more readings are optional)
◦thermally static environment
Cooling of the bodyCooling of the bodyother variables and factors:
◦mass of the body◦mass/surface area◦body temperature at the time of death◦site of reading body temperature◦posture of the body – extended or
curled◦clothing – material, position on the
body, lack of it◦obesity◦emaciation – lack of muscle bulk◦environmental temperature◦winds, draughts, rain, humidity