Transcript WELCOME TO THE WORLD OF FORENSIC MEDICINE

WELCOME TO THE WORLD
OF FORENSIC MEDICINE
Marie Cassidy
Professor of Forensic Medicine and
State pathologist
FORENSIC MEDICINE
THE BRANCH OF MEDICINE THAT APPLIES
THE PRINCIPLES AND KNOWLEDGE OF THE
MEDICAL SCIENCES TO PROBLEMS IN THE
FIELD OF LAW
FORENSIC
MEDICINE/PATHOLOGY
‘Scientific’ investigation of the cause of
injury and death in unexplained
circumstances particularly when
criminal activity is suspected
FORENSIC SPECIALISTS
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Forensic pathologist
‘forensic’ pathologist/neuropathologist
G.P.
Police surgeon
Accident and emergency doctor
Forensic physician
Paediatricians
Forensic Psychiatrist
FORENSIC SPECIALISTS
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Forensic pathologist - suspicious deaths
‘forensic’ pathologist- nonsuspicious deaths
Neuropathologist – head injuries, brain damage
G.P.- injured or deceased patients
Police surgeon-prisoner, drink driver, victim
Accident and emergency doctor - injured
Forensic physician - a/a, sexual crimes
Paediatricians- any abnormality in children
Forensic Psychiatrist- prisoners
FORENSIC EXAMINATIONS
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WOUNDS AND INJURIES
SEXUAL ASSAULTS
CHILDREN
SCENE OF DEATH
DETERMINATION OF DEATH
CAUSE OF DEATH
POSTMORTEM EXAMINATIONS
COURT TESTIMONY AND REPORTS
INVESTIGATION OF DEATHS
• To determine the cause and the manner of
death
• To identify the deceased if unknown
• To determine the time of death and injury
• To collect evidence from the body that can
be used to prove or disprove an
individual’s guilt or innocence and to
confirm or deny the account of how the
death occurred
INVESTIGATION OF DEATHS
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To document injuries or lack of them
To deduce how the injuries occurred
To document any natural disease present
To determine or exclude other contributory
or causative factors to the death
• To provide expert testimony if the case
goes to trial
‘Forensic pathology, DiMaio’
DEALING WITH DEATH
The doctor and death
The dead patient
• History
• Examination
• Diagnosis of death
Definition of DEATH
CESSATION OF LIFE IN A PREVIOUSLY
VIABLE ORGANISM
DEATH
A DOCTOR MUST DECLARE DEATH
?duty of care to determine death
DEATH
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Somatic death
Molecular death
Brain death
Brain stem death
• NO law defines death
SOMATIC DEATH
• Failure of the body as an integrated
system
• loss of circulation, respiration and
innervation
• for such a time impossible for life to return
• irreversible unconsciousness
Somatic death
• Heart stops
no pulse, no heart sounds, flat ECG,
segmentation of blood in retinal vessels
• Lungs stop
no breathing, no chest movement
• Brain activity stops
• muscles floppy
• metabolism stops, body cools down
Somatic death
• Auscultate for 4 to 5 minutes
• D.D. shock, hypothermia,
electrocution, depressant
drugs
MOLECULAR DEATH
• Depends on susceptibility to oxygen
deprivation
• varies - important in organ harvesting
• brain most susceptible, 3 to 7 minutes
• wbcs may remain motile for up to 12hours
• muscles respond to stimuli for few hours
• skin viable for several days
• importance - transplants
BRAIN DEATH
• CORTEX
• BRAIN STEM
• WHOLE BRAIN
BRAIN DEATH
CORTICAL brain death
• deep coma
• brain stem functioning
BRAIN DEATH
PERSISTANT VEGETATIVE STATE
• functioning brain stem but non
functioning higher centres
• respiratory centres functioning do not
require permanent assisted ventilation
• require parenteral feeding
• if heart protected from hypoxic damage
and nutrition sustained, may survive for
years
BRAIN DEATH
BRAINSTEM INJURY
• COMA due to damage to the ascending
reticular activating system
• require assisted ventilation due to
failure of the respiratory motor system
• beating heart
BRAIN DEATH
Severe irreversible cortical damage
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Brain stem damage
WHOLE BRAIN DEATH
Beating heart donor
Brain stem death tests
1. Absent pupillary response to light
2. Absent corneal reflex
3. No motor response within the cranial
nerve distribution and the limbs
4. Absent gag reflex
5. Doll’s eye phenomenon
6. No vestibulo-ocular reflexes
7. Persistent apnoea when ventilator
disconnected
Cause of Death
Cause of death
“The pathologist is bound to rely in part on
what he/she is told of the events leading
up to death for functional lapses like fall in
blood pressure, cardiac arrythmia, spasm
of the glottis or vagal inhibition which leave
no trace at autopsy.”
Simpson
THANATOLOGY
SUDDEN NATURAL DEATH
Sudden Death
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Deaths at home
Deaths in hospital
Death outside
Death in unusual circumstances:
place, position, appearance of body
Sudden Death
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G.P. or Hospital doctor
Medical history
Treatment for recent illness
Other information
Sudden Death
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Natural death
Accident
Suicide
Homicide
Sudden Death
Age
• Children
• Teenager/young adult
• Adult
• Elderly
Sudden Death
Children
• Stillbirths
• Congenital abnormalities
• Sudden infant death
syndrome
• Tumours
Sudden Death
Young adults
• Suicide
• Accidents - RTAs
• Homicides
• Natural
Sudden Death
Adults
• Natural
• Accidents - RTAs
• Homicides
• Suicides
Sudden Natural Death
In the developing world sudden cardiac
death remains the major cause of
death
Adults and elderly
• Cardiovascular disease
• Cancer
SUDDEN NATURAL DEATHcardiac causes
• CORONARY ARTERY DISEASE, ischaemic
heart disease, atheroma, thrombosis, dissection,
‘bridging’, acute MI, cardiac tamponade, stress
associated
• HYPERTENSIVE HEART DISEASE, acute LVF,
arrythmia
• CARDIOMYOPATHY, dilated/congestive,
hypertrophic (commonest genetic cause of
sudden death), genetic
• VALVULAR HEART DISEASE, ‘floppy’ mitral
valve, aortic valve stenosis
SUDDEN NATURAL DEATH
• MYOCARDITIS
• AORTIC DISSECTION hypertension/heredity/inflammation,
Marfan’s
• Arrhythmogenic Right Ventricular
Dysplasia –genetic – MRI – 20% sudden
cardiac deaths – cardioverter/defibrillator
• RUPTURE OF AORTIC ANEURYSM
SUDDEN NATURAL DEATH
PHYSIOLOGICAL –
• Wolff-Parkinson-White,
• long QT syndrome, ion channelopathy–
congenital (inherited as a dominant gene)
or acquired
(antipsychotic/antiarrhythmic/allergy drugs,
electrolytes, toxins, hypothermia, anorexia
nervosa, dieting with liquid protein diets)
SUDDEN NATURAL DEATHCNS causes
• EPILEPSY - SUDEp
• SUBARACHNOID HAEMORRHAGE berry aneurysms
• INTRACEREBRAL HAEMORRHAGEhypertension
• INTRACRANIAL PATHOLOGY
ASSOCIATED WITH ACUTE
HYDROCEPHALUS OR EPILEPSY tumours,meningitis
SUDDEN NATURAL DEATH
PSYCHIATRIC PATIENTS,
Schizophrenics +/- phenothiazine,
Neuroleptic malignant syndrome
SUDDEN NATURAL DEATH
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EPIGLOTTITIS
PULMONARY THROMBOEMBOLISM
ASTHMA
HAEMOPTYSIS, T.B., tumour
SPONTANEOUS PNEUMOTHORAX OF
THE NEWBORN
SUDDEN NATURAL DEATH
• HAEMATEMESIS, rupture of oesophageal
varices, duodenal ulcer
• CHRONIC ALCOHOLICS, acute fatty
degeneration of the liver
• ADRENAL HAEMORRHAGE, septicaemia
SUDDEN NATURAL DEATH –
other causes
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AIR EMBOLISM
FAT EMBOLISM
AMNIOTIC FLUID EMBOLISM
Ruptured ectopic pregnancy
Toxic shock syndrome
Sudden death in Diabetes – IHD, CM, hypo or
hyperglycaemia
• Sudden death in alcohol
• Commotio cordis
Sudden death
Sudden adult death syndrome
‘SADS’
Sudden
Arrhythmic
Disease Syndrome
Sudden Death
The negative autopsy
SADS
• Sudden unexpected death in an adult
• 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
SADS
Now agreed to be due to
acute onset of a chaotic
rhythm in the heart
SADS
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
SADS
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)
SADS
Treatment
• Defibrillation
• Implantable defibrillator
Sudden adult death
Sudden death during sporting
activities
Sudden death in sport
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Males > females
USA - 1 : 133,000 males
USA - 1 : 800,000 females
usually underlying, undiagnosed
congenital heart disease
cardiomyopathy most common
anomalous coronary circulation
viral myocarditis
> 40 years - coronary artery disease
Child Deaths
50% due to Natural causes
Genetic or congenital disorder
Cot death - SIDS
Infections
Neoplasms
CNS disorders
U.K - risk of abnormal baby = 1:40
Child Deaths
50% of Neonatal deaths occur in first
2 days
Prematurity
Hypoxia
Congenital Abnormality
Birth Injury
Still Birth
S.I.D.S
(Cot Death)
The sudden death of any infant or young child,
which, from the case history, is unexpected, and
in which a thorough postmortem examination
fails to demonstrate an adequate cause for the
death.
It is a diagnosis of exclusion
S.I.D.S
Features
Age - 2 weeks to 2 years
few after 9 months
male>female
Time - during sleep
80% found dead by 6am
weekends>weekdays
COLDER months
S.I.D.S
Features
Prematurity
low birth weight
twins
urban>country
Lower social classes
Poor social classes
Young mothers/single parent/smoker
Theories
Sleeping position
Over heating
pvc mattresses
sleep apnoea
viruses-cause or incidental
small size of larynx
trace metal deficiency
allergy to cow’s milk
abnormal nervous conducting system to heart
excess Na in feeds
overhead electric cables
nuclear power stations
Theories
Autopsy Findings
1. Nothing
2. Non- specific findings
froth at mouth
petechial haemorrhages
congestion of lungs
3. Manifest illness- NOT SIDS