I- Introduction and Definition of Death :
A- La thanatologie :
This is the science that studies death in all its aspects, especially forensic perspective. It describes death and research to know its mechanisms and causes.
B- The death :
This is a mandatory step that must undergo every living, characterized by the complete and permanent cessation of vital functions , with disappearance of its functional consistency and in particular the electrical activity of brain ( tracé E.E.G plats ) , and progressive destruction of its tissue and cell units until its dust transformation .
II- pathophysiology :
- among the mechanisms that can cause death, there is :
- Because heart => circulatory failure => drop flow => anoxie.
- Cause respiratory => mechanical or other => asphyxiation => anoxie.
- Cause Neurological => regulatory disorders of central origin => anoxie, etc….
- The cardiac arrest causes ischemia (blood supply failure) that causes cell anoxia (lack of oxygen supply ..).
- Cell consequences :
– lysis of the nucleus.
– cytoplasmic vacuolation.
- The biochemical consequences :
– enzymatic release.
– rapid consumption of the remaining oxygen.
– stimulation of anaerobic metabolism and energy depletion.
– ion accumulator acids.
- A terme, it leads to an irreversible oxygen debt, to acidosis and decreased ATP stock cathécholaminergique causing a discharge resulting in an increase of collapse.
- By type of cell function, time maxima anoxia allowing recovery is the following :
– intellectual functions : 4 7 '
– brain and spinal cord centers : 8 10 '
– vasomotor centers and cardiac : 20 30 '
– respiratory centers : 30 50 '
The ability of tolerance is higher in children.
III- Diagnosis of death :
This diagnosis is based on two categories of signs , to know :
1- negative signs of life :
This is an early diagnosis of death based on an external examination of the body and laboratory tests.
a- external review :
This examination shows a large stop life support :
These judgments will be confirmed by auscultation of both devices and palpation of the arterial routes .
- abolition of conscience, any sensitivity, areflexia
- loss of muscle tone and bilateral mydriasis
This abolition and its losses are confirmed by a neurological examination and
b- laboratory examinations :
- brain or cerebral angiography scanner ;
- the ECG and EEG are replaced by a isoelectric line
- It is also possible to note the absence of respiratory flow by placing a mirror in front of the mouth (presence or absence of steam).
- cardiopincture at the 4th intercostal space left : needle into the heart does not move => no cardiac motion
- the arteriotomy at the radial artery (more blood flow)
- test d’ICARD : fluorescein test (non-staining connective l / 2heure after intravenous injection of fluorescein)
- the test with ether (subcutaneous injection ether which spring the needle hole when the subject died).
2- Positive signs of death :
Also called the late signs of death or cadaveric phenomena.
Ces phénomènes cadavériques if GOINFRENT en :
a- physical phenomena :
The tunnel cadavérique :
The result of the fall of the central body of the T ° in relation to several factors, inter alia, the room T °, the applicant's health before his death.
Les lividités cadavériques :
They correspond to transudations blood through the vessels as passive phenomena driven by gravity.
They become perceptible ( from the 5th hours after death and become unchangeable from I8th hours after death) level dependent regions of the body. They are absent at pressure points applied to the body .
their coloring, can move towards the cause of death.
For exemple :
– the carmine red color : =>CO poisoning
=>poisoning cyanide -the dark red color : asphyxia
The déshydratation cadavérique :
It results from the loss of body water is responsible :
- the corneal opacification (sailing glairy corneal)
- sclera black spot at the outer corner of the eye.
- sagging eyeballs.
- by tracking the skin.
- hypotonia fontanelle in neonates.
b- chemical phenomena :
The rigidity cadavérique :
It is the result of the attachment of molecules of actin with myosin molecules (in relation to the absence intracellular ATP).
It affects all the muscles of the body and begins .
It begins about 05 hours after death, it peaked at 18 hours.
If it is broken before the 18 th hour, it can recover.
c- active phenomenon :
Putrefaction is the decomposition of organic tissues under the predominant influence of the bacteria hosted by the individual, especially those of the intestinal flora, Then fungi that invade the body.
It begins with the appearance of the abdominal patch of green rot at the right iliac fossa, 48 hours after death sometimes more in winter, it results from the transformation by the action of bacteria, hemoglobin (rouge) a sulfhémoglobine (vert).
Putrefaction greatly complicates the task of the pathologist, through :
- alteration of identification characters,
- the transformation of traumatic injuries,
- brings up the fake bruises,
- manufacturing cadaveric alkaloids : addict because of error
IV- Dating Death :
There are no methods to date the time of death. On the other hand, there are multitudes of methods currently used for estimating the time of death.
This time can not be calculated after calculating the postmortem period ( D.P.M) is subtracted from the time of collection of the parameter used for this purpose , examples :
- D.P.M = 06h calculated from a thermometric methods
- the time of collection of T ° and ambient qu'ellel body would be 16 h The time of death would be = 16h- 06h = lOh (the time of death)
- D.P.M = 15h calculated from methods that use the potatium rate in the vitreous humor
- time sampling the vitreous humor of a corpse she would 14 h in the afternoon
The time of death would be = 15h – 14h = 01 am
calculated time between the time of the discovery of the body and that of the time of death
The dating of death may be from :
- des phénomènes cadavériques.
- temperature measurements (nomograms the Hensge)
- potassium determination in vitreous humor.
- Artificial neural networks of -entomologie
No assurance can be drawn from these .a simple assessment methods can be advanced with caution.
DIAGNOSIS OF BRAIN DEATH (COMA EXCEED) :
The concept of brain death has emerged since the onset of resuscitation, allowing maintains cardiac function, in respiratory and renal a subject vital functions are completely and definitively abolished.
- The death of the brain result of various brain injury, either primitive (trauma, encephalitis, hemorrhagic stroke) or secondary (anoxia circulatory or respiratory origin, intoxication).
- The forensic criteria are irreversible coma :
- Total loss of consciousness and spontaneous activity of all.
- Abolition of all responsiveness in the field of cranial nerves :
– Abolition of the corneal reflex
– mydriase aréflexique
– disappearance of swallowing
– no blinking the threat, no reactions to noises or to nociceptive stimuli in the territory of the trigeminal.
- Abolition of spontaneous breathing.
- Electro-zero plot encephalographic :
Each record must be at least 10 minute normal range, double, and maximum.
2 EEG tracings thou hurt 6 hour intervals provide brain-dead graphics certainty and more forensic paper unimpeachable.
- Other clinical signs : core temperature between 32 ° -34 ° c, sinus heart rhythm 40 at 60 beats / min.
- Other tests : cerebral angiography, Early auditory evoked potentials.
V- Forms forensic death :
A- NATURAL DEATH :
Often, it is the fatal outcome of disease, the deceased was followed and his death does not surprise also measure.
B- VIOLENT DEATH :
accidental : death related to accidental trauma. The causal link is evident .if the accident circumstances are not suspicious, there is no need to check < Forensic obstacle>.
Suicidal : suicidal character can be established only after investigation and careful examination of the dead body. The investigation should be interested in the psychiatric history and treatment.
Differential diagnosis with a criminal act must always be analyzed, in doubt, you must check the box : obstacle.
criminal : if the criminal action is obvious. Example : wound firearm weapon nearby.
C- LA suspicious deaths :
- linked to the deceased's personality (States from mafia, politician, etc….)
- presence of lesions not to explain the etiology of death.
- survey does not prove depressive character of the deceased.
- Death of a young person, without obvious cause such as sudden death of an athlete such.
WE- The Attestation of Death and Medical Certificate of Death :
The death certificate is an obligation of the physician with respect to one who has died, family and society.
Au plan social, death interests the advertising department is always informed of all the dead who are not natural.
It also looks vital that fits in every town the list of citizens.
Writing of the death certificate within the competence of any doctor.
The death certificate certificate is written on paper, in accordance with the general rules of writing this document.IL two parts :
The 1time said portion nominative, is for the office of civil status; it includes the identity of the deceased (last name, first name, age, sex, and the time, the data and place of death), the doctor will certify that death is real, constant and of natural causes or unnatural causes (violent or suspicious death).
The 2th part is the medical certificate of cause of death itself, this part is anonymous, he asked the doctor to identify the direct cause of death (condition, homicide, suicide or accident).this part is for the Ministry of Public Health. It will allow epidemiologists to statistics on causes of death.
In case of natural death, the officer of civil status will keep the registered party, and send the anonymous party to the Ministry of Public Health, to issue the burial permit unobstructed by forensic.
In case of unnatural death, of the registrar will notify the appropriate authorities to investigate and burial will be allowed until after investigations Forensic.
VII – The legislation :
Art 49 code civil :
The declaration of death must be submitted within 24 hours of death.
Art 78 code civil :
No burial can be made without authorization on paper Officer Vital.
The death certificate will be drawn up by the officer of civil status in the city or the death occurred after the declaration of a relative of the deceased or that of a person with accurate information on marital status.
Art 82 code civil :
In case of suspicious or violent death, burial can not be done when a police officer assisted by a medical doctor has drawn an official report on the state of the body and the circumstances surrounding the death.
Courses of Prof. B. Bensmail – Faculty of Constantine