THANATOLOGY
APRIL 2004 / APRIL 1999
Deaths to be reported to the Coroner (Coroners Act 1962)
A public officer whose primary function is to investigate by inquest any death thought to be of other than natural causes
Cause of death unknown
1. Sudden, unexpected or unexplained deaths
2. The doctor cannot sign a medical certificate of the cause of death: the deceased was not seen by the doctor within a month prior to death, cause of death unknown or death cannot readily be certified as being due to natural causes
3. Even if doctor has attended, if death sudden or unexpected or cause unknown
4. If there is any element of suspicious circumstances
5. Death due to drug abuse
Cause of death known (SIDS, accident, drug & alcohol, CJD, violence, unnatural)
6. Sudden infant death
7. If the death may be linked to an accident (whenever it happened), e.g. RTA, fall, any injury
8. If there is any history of violence, homicide or other crime
9. Unnatural deaths; burns, CO poisoning, starvation, hypothermia, drowning, hanging, firearm injuries, poisoning
10. If the death may have been contributed to through the actions of the deceased himself (overdose, self injury, history of drug addiction or solvent abuse)
11. Death which may be due to CJD
12. Acute alcohol poisoning
Death under medical care (invasive investigation, therapeutic, supportive)
13. If the death is linked with abortion
14. Maternal deaths*
15. Hospital deaths if – DOA, die in A&E, die within 24hrs*, if recently in nursing home or other residential institution*
16. If the death was during an operation or before full recovery from the effects of the anaesthetic or was in any way related to the anaesthetic (usually deaths within 24hours of the anaesthetic are referred*)
17. If the death may be due to a medical procedure or treatment whether invasive or not
18. If the death may be due to lack of medical care, medical mismanagement, negligence or malpractice
Death under authority care (garda, nursing home, mental institution, child care)
19. If the death has occurred or the illness arisen during or shortly after detention in prison or police custody (including voluntary attendance at a police station)
20. If the deceased was detained under the Mental Health Act
21. Death of a child in care
22. Death in nursing home
Others
23. Where a body is to be removed from Ireland
24. If the deceased was receiving a pension for industrial accident or disability unless the death can be shown to be wholly unconnected
25. If the death could be due to an industrial disease or related in any way to the deceased’s employment
26. If there is any question of self neglect;
APRIL 2004
Complication of anaesthetia
1. Local anaesthetic.
The risks of complications are 0.05%.
The hazards of local anaesthetics include over-dosage due to rapid absorption of the anaesthetic agent, injection directly into a vessel or hypersensitivity to the anaesthetic agent.
In general there is a maximum therapeutic dose which should not be exceeded. All local anaesthetics are either excitory or depressive to the central nervous system.
2. Regional anaesthetics.
Spinal anaesthetic-the risks are one in 10,000 cases, the most common being permanent nerve damage.
Epidural regional anaesthesia is safer but uses higher doses of the anaesthetic agent.
3. General anaesthetics
The single largest cause of death mainly due to respiratory problems.
(a)Inhalation of anaesthetic gases
The risks are
(i) Due to technique of administration e.g. equipment failure leading to hypoxia or vagal stimulation or pneumo-thorax.
(ii) Direct actions of the anaesthetic agent e.g. may cause respiratory depression, Halothane may cause liver damage, may be collapse of lung tissue, subsequent pneumonia.
(iii) Hazards associated with unconsciousness, e.g. risk of inhalation, as the air passages are vulnerable during this procedure.
(iv) External problems e.g. explosion or fire risks due to use of anaesthetic gases.
(b) Intravenous anaesthetics
Most commonly short acting barbiturates are used and these may be complicated by adverse actions on the blood pressure, heart and respiratory centres.
(c) Relaxant drugs
May be complicated by paralysis of throat muscles, or, inhalation.
APRIL 2004 / AUG 2003 / AUG 1999
Findings established at an inquest
Purpose of an inquest
4 questions must be answered at an inquest & problems in providing them
Def: A systematic investigation or an inquiry into a matter usually held before a jury
Questions answered
1. Who (prob: decomposed bodies)
2. When (prob: time pronounced by doctor, temp at time of death – hypothermia, fever)
3. Where (prob: body moved)
4. How (prob: multicausal, majority natural causes)
MAY 03
The role of forensic pathologist
The objectives of an autopsy are: (who, when, how, what happened)
1. To obtain a positive identification of the deceased.
2. To determine a time of death
3. To provide both a cause and a mode of death
4. To provide a coherent account of the cause of death and any diseases contributing to it on the basis of the above results.
5. To record all internal and external abnormalities
6. To carry out any auxiliary investigations e.g. toxicology, histology, microbiology, virology and serology, necessary to establish the cause of death
7. To collect any trace evidence in suspicious deaths
APRIL 2004 / AUG 2003
Sudden adult death syndrome
Negative authopsy - due to acute onset of a chaotic rhythm in the heart
no signs or symptoms prior to death
postmortem shows no anatomical cause of death
specialised pathology examinations negative e.g. neuropathology
toxicology negative
bacteriology etc. negative
presumed cardiac dysrrhythmia
Risk factors include
A family history of unexplained sudden death in a relative under 40years
Unexplained fainting in young people
Approx 1000 cases/year in UK
Differential Diagnosis
ARVD – abnormal ECG, anatomical changes may not be obvious at postmortem; 30-50% have a family history
Disorders of the Ion Channel – Long QT syndromes, Brugada Syndrome (south east Asia), Catecholaminergic Polymorphic Ventricular Tachycardia (AD; Finland and Italy)
Treatment
Defibrillation
Implantable defibrillator
Sudden death during sporting activities
Males > females
usually underlying, undiagnosed congenital heart disease
cardiomyopathy most common
anomalous coronary circulation
viral myocarditis
> 40 years - coronary artery disease
APRIL 2004 / MAY 2003
Doctor’s role at the scene of death
1. Confirm death (vital signs)
2. Preliminary assessment regarding cause of death
- Natural/ not (position, clothing, etc)
- Unusual or worrying features, particularly injuries
3. Assessment of how long dead (signs of death)
4. Preserving the scene
- not disturbing the scene
- Locard’s principle
AUG 2003
Causes of sudden natural death
Cardiac causes
CORONARY ARTERY DISEASE
ischaemic heart disease, acute MI, cardiac tamponade, stress associated
HYPERTENSIVE HEART DISEASE, acute LVF, arrythmia
CARDIOMYOPATHY, dilated/congestive, hypertrophic
VALVULAR HEART DISEASE, ‘floppy’ mitral valve, aortic valve stenosis
MYOCARDITIS
AORTIC DISSECTIION / RUPTURE
CNS causes
EPILEPSY – SUDEp
SUBARACHNOID HAEMORRHAGE - berry aneurysms
INTRACEREBRAL HAEMORRHAGE- hypertension
tumours,meningitis
PSYCHIATRIC CAUSES
Schizophrenics +/- phenothiazine,
Neuroleptic malignant syndrome
RESPI CAUSES
EPIGLOTTITIS
PULMONARY THROMBOEMBOLISM
ASTHMA
HAEMOPTYSIS - T.B., tumour
SPONTANEOUS PNEUMOTHORAX OF THE NEWBORN
GI CAUSES
HAEMATEMESIS - rupture of oesophageal varices, duodenal ulcer
CHRONIC ALCOHOLICS - acute fatty degeneration of the liver
ADRENAL HAEMORRHAGE - septicaemia
AUG 2003 / MAY 03 / APRIL 1999
The role of expert medical witness
Define the term “expert witness” in a medical context.
APRIL 2004 / APRIL 2000 / SEPT 1998
Identification of the dead
Person X, Suspect X, Unknown X
1. General - broad grouping
Race, stature, age,
Sex - clothing (unisex); hair distribution; skeleton (pelvis-95%accurate-angle under symphisis pubis less than 90% in males; skull-90% accurate-eye sockets rounder in females- mastoid heavier in males; coccyx and pelvis 97% accurate; long bones and sternum- 80%- depends on angles, grooves, protuberances and ridges); external genitalia; internal organs (uterus/prostate remain identifiable in decomposing bodies); sex chromatin(X, Barr bodies)
2. Personal - comparison of remains with antemortem information to establish the identity of a particular individual.
Facial features, Fingerprints, Dental comparison, Blood grouping/serology, DNA, X-RAYS, Personal effects, Personal defects
Premortem films can be matched with postmortem films.
May show individual characteristics.
Frontal sinuses of skull are unique.
Dental films.
Defects (prosthesis, congenital abnormalities, pacemaker, etc)
AUG 03 / APRIL 1999
Changes after death
What are the signs of putrefaction or decomposition?
Immediate signs of death
Cardio-respiratory failure
Absent heart beat, no pulse
No chest movement, no breath sounds
Pupils do not react to light
Retinal vessels show ‘trucking’
Loss of corneal reflexes
Muscle flaccidity
Early postmortem changes
Rigor mortis
Chemical reaction in muscle due to breakdown of ATP, and increase in ADP, lactates and phosphates.
Temperature dependent, more rapid onset in high temperatures, after exercise or if fever..
Starts 1 – 4 hours in face
Limbs stiffen 4 – 6 hours, small muscles of jaw and arms first
Maximal 6 – 12 hours
Secondary flaccidity within 24 – 50 hours
May be instantaneous, cadaveric spasm or rigidity, in violent deaths, drownings.
Hypostasis / lividity
Visible in 2 – 3 hours, gravitational.
Fixed after several hours.
Useful in determining if body position altered within few hours after death.
Bronze – Cl. Perfringens
Pink – carbon monoxide poisoning,
Cold e.g. body in water, hypothermia,
Refrigeration
Deeper pink – cyanide poisoning
DD. bruise – incise tissues as blood in vessels if hypostasis but blood in tissues if bruise.
Cooling of the body
Not immediate, onset when cell death occurs, body temperature will then begin to drop from 37degreesC. Remember temperature at time of death may be less than 37degreesC if hypothermic or greater than 37C in deaths due to asphyxia, other causes of hyperpyrexia e.g. intra cerebral haemorrhage..
After slow start, rapid drop, followed by more gradual decrease when the body is nearing the ambient/environmental temperature.
Body feels cold after about 12hours.
More rapid in cold temperatures, if wet or in water, if thin or if naked.
Take internal/rectal temperature with low reading thermometer.
Newton’s Law of Cooling – rate of cooling is proportional to the difference in temperature between the body and its surroundings - Exponential graph.
Late postmortem changes
Decomposition – due to initial chemical/enzyme reaction, followed by bacteria, fungi, insects and animal activity.
Putrefaction
Liquefaction of the tissues.
First presents as green discoloration of the skin of the anterior abdominal wall three to four days after death, due to intestinal bacteria.
Followed by gaseous distention of the abdominal cavity and the soft tissues,
marbling of the skin, due to haemolysis in the vessels,
and formation of fluid filled blisters.
Bloody fluid from the decomposing lungs is purged from the nose and mouth.
Continues until tissues all liquefy and body skeletalised, within weeks to years, depending on the local conditions.
Accelerated in hot conditions and if ‘attacked’ by flies and other predators.
Retarded if body immersed in water or buried.
Commences in intestines, stomach, liver blood, heart blood and blood in vessels, thereafter air passages, lung and liver,
Followed by brain and cord,
Kidneys, bladder and testis
Voluntary muscles
and lastly uterus and prostate.
Mummification
Dessication or drying of the soft tissues. Occurs in dry conditions, especially if there are air currents. Prevents bacterial decomposition and therefore putrefaction.
May only be partial e.g. fingertips or face, skin leathery and hardened.
Occurs in stillbirths and deaths of newborns as bodies sterile.
Adipocere
Saponification of the body fats, chemical change. Hydrogenation of Oleic acid to opaque Stearic acid.
Occurs in damp or wet conditions e.g. bodies in water or buried in wet ground after many weeks.
Causes stiffening and swelling of body fats and preserves the body fats which remain adherent to bones after the skin has rotted away. Therefore the shape and outline of the body is retained for years.
Skeletalisation
Loss of soft tissues over a period of time (see previous). Tendons, ligaments, uterus, prostate hair and nails survive longest.
Bones disarticulate after a few years. At first bones heavy, surface greasy, marrow in cavities and bones smell.
After 40-50 years bones dry and brittle and may erode. Depends on local environment.
If bones older than 70years of archaeological rather than forensic interest.
Carbon dating useful only in ancient archaeological remains.
For recent bones can use other markers.
Entomology
The use of insects as an indicator of the time since death.
Inthis country Necrophagous species are the first wave of succession, including blue and green bottles and flesh flies. Depends on temperature. Blow flies willnot lay eggs in temperatures less than 6degreesC and do not lay eggs at night.
Eggs layed within 24hours of death.
Develop into 1st. instar maggots within 24hours, 2nd. Instar within the next 24hours and to 3rd. instar stage within the next 24 – 36hours. These develop into pupae and eventually into the fly.
FORENSIC SCIENCE AND MEDICINE
AUG 2003
Forensic significance of diatoms
Microscopic algae. Silica cored, minute organisms
- Found in fresh and salt water, tap water, soil, air Not found in polluted water or quick running streams. Seasonal.
- Found in the lungs of all bodies in water.
- If person alive before entering the water the inhaled diatoms will be absorbed into the bloodstream and circulate to other organs.
- Resistant to putrefaction therefore in badly decomposed bodies can be identified in bone marrow which is protected from contamination when in the water.
- Must compare with potential source i.e. water body recovered from.
- Not legal proof of drowning.
APRIL 2004 / MAY 2003
FORENSIC RADIOLOGY
Identification
· Personal defect
· Dental
· Internal organs or sex id
· Frontal sinus
Data collection for investigation
· Bullet in shooting incident
· Assessment of trauma (fracture, laryngeal injury)
· Foreign body (bomb, explosion, etc)
· Child death
· Traumatic subarachnoid haemorrhage
APRIL 2004 / MAY 2003
DNA IN FORENSIC
1. Paternity / maternity
2. Identify deceased
3. Identify suspect / witness
APRIL 2004
Lockard’s principle
French