Autopsy pathology 1.pptx

Autopsy pathology 1 Dr. Wangari Wambugu Learning areas Introduction Types of autopsy Benefits of autopsy Pathophysiology of death: Definitions Stages of death Signs of death Sudden natural death Postmortem changes Establishment of identity Approach to medicolega...

Autopsy pathology 1 Dr. Wangari Wambugu Learning areas Introduction Types of autopsy Benefits of autopsy Pathophysiology of death: Definitions Stages of death Signs of death Sudden natural death Postmortem changes Establishment of identity Approach to medicolegal autopsy Introduction Autopsy means to see for oneself (from greek word) Auto=self Opis- view Autopsy is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine cause & manner of death & to evaluate any disease or injury that may be present Other commonly used terms: Postmortem examination- examination of body after death Necropsy:- Greek word meaning seeing a dead body Term for pm examination of a dead animal Introduction Purpose/Objectives of an autopsy: Autopsies are performed for either medical or legal purposes. Performed when any of the following information is desired: Cause of death Manner of death Time since death Injury source & extent on deceased To establish identity of deceased To retain relevant organs & tissue as evidence Infants-live birth & viability Introduction Types of autopsy: Clinical/medical Medico-legal (Forensic) Anatomical autopsy Psychological autopsy Postmortem examination Virtual autopsy Minimally invasive autopsy Types of autopsy Medical/ clinical autopsy Carried on a patient who dies in a hospital during course of treatment Objectives: 1. To determine cause of death 2. To confirm or establish the clinical diagnosis 3. To evaluate the effects of treatment given during life 4. Performed by pathologist with consent of relatives Types of autopsy Medicolegal autopsy Special type of scientific examination of dead body carried out under the laws of the state for the protection of its citizens To establish or rule out foul play To assist in identification & prosecution of the guilty Types of autopsy Anatomical autopsy  Performed to study normal structures of human body  Mostly on unclaimed bodies  Performed by anatomists & medical students Post-mortem examination:  Examination of external surfaces of corpse by inspection without giving incision for systemic examination  Some body fluids nay be collected Types of autopsy Psychological autopsy  Undertaken on alleged cases of suicide to evaluate the mental status of deceased at time of death  To learn about:  Background of the person  His habits, mental status, personality, character  Relation to others  Sources of information:  Family members  Professional  Colleagues  Teachers  Physicians Types of autopsy Virtual autopsy  Postmortem examination without compromising the integrity of the body , even without specimen collection  For some reason or disease, an autopsy is not possible  Radiological examination may aid in detecting cause of death- x-rays, U/S, CT scan, MRI Minimally invasive autopsy  In cases of highly contagious diseases  Sample collection done e.g fluids, core biopsies for cultures, histology, molecular tests Benefits of autopsy 1. Benefits to physicians and health care organizations 2. Benefits to the family of deceased 3. Benefits to public health 4. Benefits to medical education 5. Benefits to medical discovery and applied clinical research 6. Benefits to basic biomedical research 7. Benefits to law enforcement and jurisprudence Benefits of autopsy Benefits to physicians & health care organizations  Major objectives of autopsy:  Establishment of final diagnoses  Determination where possible of cause of death  Is the “gold standard” of examining the accuracy of diagnosis & outcome of therapy  Provide critical data for medical quality assurance & ultimately quality improvement Benefits of autopsy  May also reduce hosp & physician ,malpractice risk:  May eliminate suspicion  Provide reassurance to families  Substitute facts for conjecture  Reduce no of claims  Improve quality of care Benefits of autopsy Benefits to the family of the deceased  Therapeutic value  Can identify hereditary or contagious disease  Information that provides basis for  genetic counselling  Preventive care for relatives  Helps families with the grieving process esp by removing guilt Benefits of autopsy  In the setting of a postautopsy conference the clinician or pathologist can console the family by  Reporting cause of death  Provide information about disease process  Answer ant lingering questions about terminal events  Alleviate irrational guilt  Provides accurate data for determination of insurance benefits or workers compensation  Reassurance that the therapy was complete Benefits of autopsy Benefits to public health  Autopsy contributes to public health surveillance thro:  Detection of contagious diseases  Identification of environmental hazards  Contribution to accurate vital stastistics  Population health planning  Disease prevention Benefits of autopsy Benefits to medical education  Aids in education students medicine & other health- related disciplines  Provides teaching materials for anatomy, histology & pathology  Focal point for integration & correlation of basic & clinical medical knowledge  Provides an opportunity for pathologists-in-training to improve their knowledge of normal & abnormal gross & microscopic anatomy Benefits of autopsy Benefits to medical discovery & applied clinical research  Historical perspective- most of the diseases were described thro autopsies  Modern molecular techniques coupled with & supplementing postmortem examinations have identified emerging & reemerging infectious agents  Helps in evaluating toxic effects of the latest drugs, accuracy of imaging techniques & efficacy of new therapies Benefits of autopsy Benefits to basic biomedical research  Autopsy provides investigators with normal & diseased human tissue for research  Very important research in fields of neuropathology & neuroscience as these tissue are not available by other means  Allows examination of pathologic processes at cellular & molecular levels Benefits of autopsy Benefits to law enforcement & jurisprudence  Medicolegal investigation of death is a key component of crime examination  Forensic autopsy is focused on establishing the:  Cause of death  Time of death, is it consistent with proposed time  Manner of death  Circumstance preceding & surrounding death  In anticipation of legal action the forensic pathologist must collect & preserve evidence obtained at the scene & from the autopsy The pathophysiology of death  “Death is not the greatest loss in life. The greatest loss is what dies inside of us while we live” Norman Cousins “Don’t die old, die empty. That’s the goal of life. Go to the cemetery and disappoint the graveyard” Myles Munroe “The graveyard is the richest place on the surface of the earth because there you will see books that were not published, ideas that were not harnessed, songs that were not sung & drama pieces that were not acted” Myles Munroe What is death? Thanatology (Greek thanatos: death, logus :science) is the scientific study of death in all its aspects including its cause phenomenon. It also includes changes that may accompany death & their medico-legal significance. Definition of death- irreversible cessation of all vital functions i. Irreversible cessation of circulatory & respiratory functions ii. Irreversible cessation of all functions of the entire brain including the brain stem  Clinically, death is defined as the irreversible cessation of life. Thus, physician declares death with cessation of all vital functions such as nervous, circulatory and respiratory systems. The advent of human organ transplantation, in 1960s, led to the necessity of scrutinizing the phenomena of death. The heart transplantation studies also raised the medical, ethical and legal questions into critical focus, most specifically concerning when to remove the heart from the donor. The essential thing to be remembered under this is, need of a donor heart which is to be removed at the earliest after death is declared, which is difficult to decide when connected to the artificial means of the modern medical technology. This generated the newer concepts of moments of death. For the purpose of understanding about death and its mechanisms, death is divided into two types: (i) somatic death, and (ii) molecular death. Stages of death Death occurs in two stages: Somatic, systemic/clinical death Molecular/Cellular death Somatic death: cessation in respiratory, circulation & nervous activity. Important in the consideration of resuscitation & organ transplantation Somatic death is declared clinically when the three vital organs namely heart, lungs and brain (the tripod of life) fail to do their function and confirmed by a flat ECG, absence of breath sounds and a flat EEG (often known as the Harvard’s criteria of assessing death). Stages of death Differential diagnosis: Somatic death resembles to certain conditions such as suspended animation, coma following excess dose of sedatives or hypnotic and hypothermia in old age. Somatic death ultimately terminates into molecular death. Stages of death Molecular Death (Cellular Death) Molecular death is defined as ultimate death of all cellular elements. Molecular death occurs piece meal. Initial changes occur due to metabolic dysfunction & later due to structural disintegration After somatic death, various tissues survive till the oxygen supply to them is adequate. When the oxygen reserve in the cells get depleted, cellular death or molecular death sets on. Generally molecular death is complete within 3 to 4 hours of somatic death. Molecular death can be confirmed by absence of any response to an electrical, thermal or chemical stimulus in the tissues. Nervous tissue dies rapidly (i.e. the vital centers of brain dies in about 5 minutes) while the muscle tissue lives up to 3 to 4 hours. CONCEPT OF DEATH (Moment of Death) Reviewing the historical aspects in both medical and legal angles, it is evident that the concept or moment of death was merely comprised of heart and respiration death, i.e. cessation of spontaneous heart and lung functions. However, the bypass machines, mechanical respirators and such other devices of recent invention have helped to maintain the circulation of oxygenated blood to brain stem and thereby prolong existence of life. Thus, life in such cases can only be terminated by withdrawal of these devices. The concept has also become an important issue in relation to organ transplantation. CONCEPT OF DEATH (Moment of Death) This is because the success of organ transplantation mainly depends on rapidity of its removal from the donor body after the stoppage of circulation. Organs like kidneys, lungs, liver etc. need to be removed soon after cessation of circulation, as they deteriorate rapidly. This has lead to the evolution of the concept of brain death (synonyms, moment of death). ORGAN TRANSPLANTATION AND BRAIN STEM DEATH As per this concept and depending on the structures involved, the brain death is classified into three types. 1. Cortical or cerebral death In cortical or cerebral death brain stem is intact, with continuous heart sounds and respiration, but total loss of sentient (sense of perceiving and feeling things) activity. Causes Cerebral hypoxia, toxic conditions, widespread brain injury etc. 2. Brain Stem Death – in brain stem death the cerebrum is intact, but cut off functionally. Causes Cerebral edema increased intracranial pressure etc.. 3. Whole Brain Death Whole brain death comprises combination of both cortical and brain stem death. With this newer concept, clinical definition of death has been now modified as irreversible state of coma consisting of: Deep state of unconsciousness with no response to external stimuli/internal need. No movements, no spontaneous breathing. Cessation of spontaneous cardiac activity without assistance. No reflexes. Bilateral dilated fixed pupils A flat isoelectric EEC No profound abnormalities of serum electrolytes, acid-base balance or blood glucose. This has allowed the feasibility of removal of vital organs such as heart, kidney, liver, etc. from a donor body for the purposes of organ transplantation successfully without any ethical or legal complications. Brain death Brain death is now accepted as brainstem death Respiratory center lies within the brainstem The integrity of the reticular formation within the brainstem is essential for the proper functioning of the cortex Mechanism of brain death: Various causes such as traumatic, cerebrovascular injury or generalized hypoxia, all of which produce oedema Oedema is accompanied by an increase in ICP leading to gradual decrease in cerebral circulation to eventual complete cessation causing asceptic necrosis Within 3-5 days there is widespread brain destruction of pannecrosis of cerebrum & brainstem, the brain becomes a liquefied mass, ‘respirator brain’ Brain death Diagnosing brain death Establishment of cessation of all brain functions Clinical criteria Confirmatory tests Flat isoelectric electroencephalogram (EEG) Somatosensory evoked potentials (SSEP) Tests to measure cerebral blood flow Determination that cessation of these functions is irreversible. Irreversibility determined by: Determination of the cause of loss of brain function Exclusion or reversible conditions Determination that the cessation of brain functions persist for an appropriate amount of time Indications/signs of death Cessation of cardiorespiratory and nervous activity ₋ No audible breath sounds on continuous auscultation of upper part of chest and in front of or on the larynx for minimum of 5 minutes ₋ Continuous auscultation on precordial area of chest for heart sounds for a minimum of 5 minutes. A flat ECG recording for 5 minutes continuously Irreversible unconsciousness- flat or loss of EEG Loss of all reflexes Pain stimuli, corneal, gag & light reflex Muscular flaccidity There may be post-mortem coordinated muscle group activity up to one hour Indications/signs of death Eye signs :loss of corneal & light reflexes leading to insensitive corneas & fixed, unreactive pupils. Light reflex lost as soon as brainstem nuclei suffer ishaemic failure. Corneal haziness, tache noire Retina-provides one of earliest positive signs of death when viewed under ophalmoscope; ‘trucking’ of blood in retinal vessels, loss of blood pressure allows blood to break up into segments, similar to trucks in a railway Definition of terms Definition of death- irreversible cessation of all vital functions i. Irreversible cessation of circulatory & respiratory functions ii. Irreversible cessation of all functions of the entire brain including the brain stem Cause of Death- Anatomical or pathological change(injury or disease) directly leading to death, e.g. stab wound, pressure to the neck, bronchopneumonia Mechanism- the biochemical or physiological process produced by cause of death , e.g. cardiopulmonary arrest, arrhythmias, hypoglycemia, etc Definition of terms Manner- explains how the death came about, the way by which death was produced Natural or Unnatural Accident Suicide Homicide Undetermined Agonal period- is the time between a lethal occurrence & death Mode of death- Refers to an abnormal pathophysiological state pertained at the time of death Cause of death- ICD Classification The International format of certifying the cause of death is certified by the WHO. Cause of death divided into two parts: Part I describes the condition(s) that led directly to death (immediate cause) Further subdivided into 3 subsections. These are disease processes that have led directly to death & are causally related to each other a) Being due to or consequent on b) Which in turn is due to or consequent on c) Antecedent causes Part II is for other conditions, not related to those listed in part I that have also contributed to death (Contributory causes), but should not be used as a basket for all the minor pathologies found at autopsy Cause of death- ICD Classification Its important to note that it is the disease lowest in part I list that is the most important. It is the primary condition & the initiating event leading to death Not necessary to fill parts Ib, Ic or II if there no predisposing factors Cause of death- ICD Classification Examples: Death suddenly due to intracerebral haemorrhage due to hypertension, the cause of death will be: Intracerebral haemorrhage due to Hypertension If same patient survived for few days or weeks and developed pneumonia, the cause of pneumonia will be Ia: Bronchopneumonia Ib: intracerebral haemorrhage II: Hypertension Mode of death(proximate cause of death) Definition: Refers to an abnormal pathophysiological state pertained at the time of death According to Xavier Bichat, a French physician there are three modes of death according to the system affected: i. Syncope-failure of circulatory system Sudden cessation of the action of the heart & failure leading to death ii. Asphyxia- failure of respiratory system Results from interference with respiration or due to lack of oxygen in inspired due to which the tissues are deprived of oxygen causing unconsciousness or death iii. Coma- failure of nervous system State of profound unconsciousness from which a person can not be aroused, with minimal or no detectable responsiveness to stimuli Mode of death-Syncope  Mechanism Sudden stoppage of functioning of the heart can lead to anemia of the brain which in turn results in ischemia of vital centers of the brain and death ultimately. Examples Deaths due to heart diseases, hemorrhage, blood pathological conditions, Exhausting diseases, Poisoning with cardiac poisons, Reflex cardiac inhibition (vagal inhibition of heart) due to sudden fright or emotion or trigger area injuries (e.g.. blow on epigastrium) etc.. Death resulting so is called instantaneous physiologic death, vasovagal shock, vagal inhibition or neurogenic shock. Mode of death-Syncope Clinical features – Pallor or lips, face, dimness of vision, dilated pupils, skin-cold with perspiration, gasping respiration, nausea- vomiting, weak, slow pulse, fall of BP, delirium convulsion and death. Autopsy findings – During the autopsy examination, heart chambers usually show little or no blood, all the viscera appear pale and the capillaries congested. Mode of death-Asphyxia Mechanism Sudden stoppage of or failure of functioning of the lungs can lead to impaired blood oxygenation leading to tissue anoxia. The brain is highly sensitive to oxygen deprivation, which results in failure of vital centers and ultimately death. Gordon’s hypothesis – It emphasizes the fact that tissue anoxia, irrespective of its origin can invariably lead to cessation of vital functions, especially the circulatory failure resulting in death. According to this hypothesis, anoxia is classified into four types namely: i. Anoxic anoxia ii. Anemic anoxia iii. Histotoxic anoxia iv. Stagnant anoxia Mode of death-Asphyxia  Anoxic anoxia – This is mainly due to mechanical asphyxia leading to defective oxygenation in lungs. Here the lungs are normal, blood and blood circulation is normal, but due to the mechanical asphyxia respiration is difficult and entry of oxygen into the lung is impaired, resulting in defective oxygenation of the tissues. Hanging, strangulation, suffocation, choking, drowning, high altitudes, etc. constitute good examples for this type of anoxia.  Anaemic anoxia - This is mainly due to the reduced oxygen carrying capacity of blood. Here though the lungs are normal and blood circulation is normal, the defects are in the circulating blood both in its quantity and in quality result in defective oxygenation. Exsanguination, CO poisoning etc. constitute good example for this type of anoxia. Mode of death-Asphyxia Histotoxic anoxia - This is mainly due to the depression of tissue oxidation. Here the lungs and blood circulation though normal, red blood cells are incapable of functioning normally due to impairment of cytochrome oxidation enzyme resulting in tissue anoxia. Cyanide poisoning is a suitable example for this type of anoxia. Stagnant anoxia – This is mainly due to the inefficient circulation of blood. Here though the lungs are normal and blood in circulation is normal the circulation is inefficient, hence oxygenation is improperly taking place. Congestive cardiac failure, traumatic shock, heat stroke, etc. constitute good examples for this type of anoxia. Mode of death-Asphyxia Clinical features of asphyxia can be described under three stages, which may last for 3 to 5 minutes: Stage of dyspnea Stage of convulsions Stage of exhaustion and respiratory failure Stage of dyspnea: Due to excess accumulation of carbon dioxide, which stimulates respiratory center resulting in increased rate and amplitude of respiratory movements. Mode of death-Asphyxia Stage of convulsions: This is due to lack of oxygen and the victim will show labored respiration, clouding of consciousness, convulsion, sphincteric relaxation, etc.. Face and hands deeply congested and cyanosed. This stage may last for 1 to 2 minutes. Stage of exhaustion and respiratory failure It lasts 2 to 3 minutes. Respiratory and other nervous centers are completely paralyzed. Muscles are flaccid, reflexes are lost, breathing is gasping with long intervals between gasps and then stop, pulse imperceptible, heart may continue to beat for few minutes and then stop, declaring death. Mode of death-Asphyxia Autopsy Findings – Characteristic findings are cyanosis, deep postmortem hypostasis/lividity, petechial hemorrhages (Tardieu’s spots), visceral congestion and cardiac dilatation. – Specific findings depend on actual causes of asphyxia and they could be ligature mark in hanging, fine froth around nostrils and mouth in drowning etc.. Mode of death- Coma Coma results from sudden stoppage of functioning of the brain. Mechanisms – In coma there is a combination of both syncope and asphyxia leading to death. It is due to paralysis or insensibility of vital centers in the brain stem. Causes may include: Compression of brain due to diseases and injuries of brain or its membranes. Acute poisonings with opium, barbiturate, alcohol, carbolic acid, etc. having specific depressor action on brain and nervous system. Metabolic disorders – uraemia, cholemia(bile), acetonemia(ketones)etc.. Mode of death- Coma Autopsy Findings Postmortem findings could reveal all specific pathological findings depending on the actual cause: 1. The brain and meninges are congested. 2. The right side of the heart is usually full, while the left empty. 3. Lungs are congested. Mode of death Mode of death offers no information on underlying pathological condition It should not be used as definitive cause of death unless further qualified by the more fundamental aetiological process Example: Coma due to head injury Syncope due to blow on the epigastrium Asphyxia due to hanging  MEDICOLEGAL IMPORTANCE OF DEATH Death is an important entity in its own way, medicolegally has been enumerated below: Disposal of the Body Rarely, when body is cremated immediately after somatic death spontaneous movements of hand or feet may be observed in funeral pyre, which might create an apprehension that the person was not dead actually but disposed off prematurely. Organ Transplantation Viability of transplantable organs falls sharply after somatic death, a liver must be removed within 15 minutes, kidney within 45 minutes and heart within an hour.  MEDICOLEGAL IMPORTANCE OF DEATH Presumption of Death If a person is unheard of for seven years, the court may on application by the nearest relatives, presume death to have taken place. Presumption of survivorship When two or more related persons perish in a common accident, it may be necessary, in order to decide the question of succession, to determine which of them died first. It is generally accepted that the stronger and more vigorous will survive longest. Issuing of Death Certificate Before issuing this, doctor must confirm that the person is dead. Sudden death (sudden Natural Death) WHO definition of a sudden death is someone who dies within 24 hours of symptoms appearing, but in forensic sense, most of such deaths die even in minutes or even in seconds of onset of symptoms. Those deaths, which are not preceded or only preceded, for a short time by morbid symptoms are called sudden death A sudden death is not necessarily unexpected death and an unexpected death is not necessarily sudden, but very often the two are in combination. To have a systemic view of differential diagnosis of the cause of death and to make a logic choice of most likely cause will help to improve the state of mortality statistics, assist the legal authorities and satisfy the bereaved relatives, perhaps by helping them to obtain insurance and compensation benefits. Sudden death (sudden Natural Death) When sudden and unexpected deaths are concerned, an added dimension appears, as these deaths are usually reportable to the authorities for medicolegal investigation. The vast majority are due to natural causes, but often deceased either has not seen a doctor recently (or at all) or the unexpectedness of their death does not allow their medical practitioner to have any idea of the reason why they suddenly died. Medicolegal importance is usually attached to this type of sudden unexpected natural death. They usually raise a suspicion of foul play and in such cases death certificate must not be issue till an autopsy examination is conducted and cause of death is confirmed. Sudden death (sudden Natural Death) Where a natural death is very rapid, perhaps virtually instantaneous, the cause is invariably cardiovascular. Indeed, if a person collapses and is clinically dead when someone nearly runs to assist him, this can only be a cardiac arrest, as virtually no other mode of death operates so quickly. This type of collapse is the one, which may respond best to cardio-pulmonary resuscitation. Extra-cardiac causes, even still in the cardiovascular system, are rarely so rapidly fatal, though death in minutes is common. Of course, in all such discussion, what is meant by death must be defined, but for our purposes here, irreversible cardiac arrest is taken as the criterion of death. Sudden death may occur from both natural and unnatural causes (such as violence or poisoning) or from a combination of both. However cardiovascular system causes account for the vast majority of sudden deaths. Sudden death (sudden Natural Death)- causes 1. Cardiovascular system A lesion that causes most of the sudden unexpected deaths (SUD) is usually in the cardiovascular system, even if the vessel concerned lie anatomically in the brain or abdomen. the prime cause of SUD lies in the heart itself. The following lesions are most obvious. Coronary artery diseases (atherosclerosis, thrombosis, syphilis, etc.) Congenital heart disease Valvular heart disease (rheumatic, syphilitic etc.) Hypertensive diseases Infections (myocarditis, post infectious myocardial degeneration) Sudden death (sudden Natural Death)- causes Cardiac tamponade constitutes a lesion wherein ruptured myocardial infarct, trauma, etc. resulting in collecting blood in pericardial sac. About 250 to 300 ml blood may act fatal making heart unable to function normally, resulting in cardiac standstill leading to death. Obscure conditions such as cardiomyopathies, Fiedler’s myocarditis etc.. Aortic aneurysms of atherosclerotic or dissecting type. Sudden death (sudden Natural Death)- causes Respiratory causes: – Pulmonary embolisms – Massive hemoptysis (from pulmonary tuberculosis) – Severe infections such as fulminating virus pneumonia (usually influenza) – Chronic asthmatics – Anaphylaxis – Obstruction of respiratory tract Sudden death (sudden Natural Death)- causes Intracranial vascular lesions ₋ Intracranial bleeding due to cerebral atheroma or hypertension ₋ Subarachnoid hemorrhage from ruptured aneurysm ₋ Cerebral thrombosis ₋ Embolisms ₋ Infections of meninges (meningitis) ₋ Brain tumors, which can results in death due to increased intracranial pressure, sudden hemorrhage from tumor mass etc. ₋ Idiopathic epilepsy ₋ Functional inhibition of the vagus nerve Sudden death (sudden Natural Death)- causes Gastrointestinal system the major cause of sudden death within the gastrointestinal system may once again be mentioned to be vascular in origin Severe gastrointestinal bleeding due to gastric or duodenal ulcers. Ulcerative colitis, malignancies, etc. can be fatal in a short time, even though most are moderate enough to allow medical or surgical treatment. Mesenteric thrombosis and embolism leading to infarction of the gut are not sudden, but may be rapid and remain undiagnosed. Perforation of peptic ulcer can be fatal in hours if not treated. Intestinal gangrene due to strangulated hernias and torsion due to peritoneal adhesions can be fulminating and fatal condition. Aortic aneurysmal rupture Diseased viscera undergoing rupture Fulminating hepatic failure Acute hemorrhagic pancreatitis Sudden death (sudden Natural Death)- causes Gynecological conditions A women in child bearing age is found to be dead unexpectedly and suddenly, following may be considered as for cause of death, namely: Complication of pregnancy must be first thought of, just to make a primary exclusion. Haemorrhage in female genital organs could be due to abortion or ruptured ectopic pregnancies, etc. is a grave emergency that can result death from intra-peritoneal bleeding, unless rapidly treated by surgical intervention. Endocrine Sudden natural deaths occur due to any one of the following: Adrenal insufficiency Diabetic coma Myxedemic crisis Parathyroid crisis Sudden death (sudden Natural Death)- causes  Iatrogenic Following may be suspected and may have to be ruled out: - Abuse of drugs - Sudden withdrawal of steroids - Anesthesia - Mismatched blood transfusion  Miscellaneous There is a vast list and comprise of cases of anaphylaxis, bacteremic shock, shock from fright or emotions, malaria, sickle cell crisis, alcoholism, etc.  Special causes in children If the victim happens to be a child following may have to be thought and ruled out, namely SIDS (Sudden infant death syndrome) or cot deaths, Mongol’s and other congenital or mental disorders, concealed puncture wounds, indeterminate – very rarely, causes cannot be determined. Post-mortem changes Post-mortem changes Immediate: Loss of voluntary power loss of EEG rhythm Cessation of respiration & circulation Early: Pallor & loss of skin elasticity Eye changes Primary flaccidity Rigor mortis Post-mortem Lividity/Hypostasis Cooling of the body Late (decomposition) Putrefaction Adipocere Mummification Medico legal importance of Postmortem Changes Postmortem changes are medico legally important as they can help in assessing: Time since death Probable position of the deceased at the time of death Cause of death Motive/manner of death i.e. whether a suicide, homicide, or accident Early post-mortem changes Tache Primary noire flaccidity Rigor Livor mortis mortis Eye changes Loss of corneal reflex- however this is also seen in coma Corneal haziness-hastened when eyes are open after death Flaccidity of the eye ball-due to fall in intraocular tension, eyeballs sink into the orbit Pupillary changes- which usually dilate at death, constrict later thro devt of rigor mortis. Remains constricted in narcotic poisoning Eye changes Retina-provides one of earliest positive signs of death when viewed under ophalmoscope; ‘trucking’ of blood in retinal vessels, loss of blood pressure allows blood to break up into segments which then collide with each other, similar to trucks in a railway Tache noire: When the sclera remains exposed, two yellow triangles of dessicated discolouration appear on each side of the cornea within a few hrs, becoming brown & then sometimes black thus the name ‘tache noire’ Skin changes Loss of elasticity – prevents gaping of the incised wound if caused after death. Color changes – ashy white, pallor, due to draining blood from blood vessels of skin. Lip changes – becomes brownish, and hard due to drying. Cooling of body (Algor Mortis) A complex process. Rate of cooling varies in different bodies Body cools rapidly on the surface, slowly in the interiors Body lose heat via conduction, convection & radiation Measuring cadaveric temp , three methods in practice by use of ordinary clinical thermometer: 1. Introducing the bulb, 8-10cm deep into rectum & recording the rectal temp 2. Placing the bulb in contact with the inferior surface of liver, thro a midline incision 3. Measuring vaginal temp by inserting the bulb8-10cm deep into the vagina Cooling of body (Algor Mortis) Rate of cooling is not uniform. In temperate climate, the cooling rate is: In first 6 hours it is about 1.5oC/hour. In later 6 to 12 hours it is about 0.9oC to 1.2oC/hour. Thus, the whole body surface gets cooled by 10 to 12 hours of death. However, it is well established that the internal organs cool slowly (cools by 18-24 hours of death). An approximate idea of number of hours after death (postmortem interval-PMI) may be calculated by using the formula below: PMI = Normal body temp. (37.2oC) – Rectal Temp. of the cadaver Rate of temperature fall per hour Cooling of body (Algor Mortis) Factors affecting body Factors affecting body cooling cooling Initial body temp Air movement & humidity Body dimension Increased air movement Mass vs surface area increases heat radiation Posture upon death Medium around the body Straight vs curled Water vs air Clothing & coverage Haemorrhage Type of clothing & Blood loss reduces body clothing material mass & heat Ambient temperature Surrounding temp Primary flaccidity Flaccid period starts immediately after death All the muscles begin to relax Lower jaw begins to fall Eyelids loose tension Joints are flexible Extends 3-6hrs after death before stiffening occurs Muscle irritability & response to electrical or mechanical still persists Rigor mortis Stiffening of muscles (voluntary & involuntary), sometimes slight shortening of muscle fibers Stiffening first apparent in small muscles and joints, over the face-around mouth & eyes Followed by hands & upper limbs Finally, large muscles of the lower limbs Onset usually 2hrs after in musckes of face progresses to the limbs over next few hrs Generally onset at 6-12 hrs, may persist 18-36hrs Rigor mortis Mechanism: Depletion of adenosine triphosphate (ATP) from the muscles which is necessary to break down actin-myosin filaments in the muscle fibers In the last phase of rigor mortis, the actin-myosin complex that has formed starts disintegrating due to proteolysis, resulting in the dissolution of the stiffness Change starts appearing in small mm of face, then upper limbs finally lower limbs Generally resolves 36hrs after death, resulting in a phase of secondary flaccidity Various muscles of the body and the time interval of developing rigor mortis Muscle site Time interval after death Eyelids 3-4 hours Face 4-5 hours Neck and trunk 5-7 hours Upper extremities 7-9 hours Legs 9-11 hours Finger and toes 11-12 hours Rigor mortis Factors affecting rigor mortis: Age- occurs rapidly in children & old age Nature of death: Diseases causing exhaustion & wasting (e.g cholera, cancer, TB) or violent deaths (eg electrocution), onset of rigor & duration is shorter Asphyxial death, onset is delayed Widespread bacterial infection (sepsis) onset is very rapid Muscular state Muscle at rest & healthy prior to death, onset is slow & duration long Muscle exhausted eg frm exercise, onset is rapid Atmospheric conditions: Cold weather- onset slow & duration longer Hot weather-onset is rapid due to increased breakdown of ATP Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix Rigor mortis Hot stiffening (pugilistic attitude) When exposed to temperatures >65°C rigidity is produced, more marked than rigor mortis Pugilistic attitude- the PM, boxer-like body posture in defense, flexed elbows & knees & clenched fists caused by shrinkage of body tissues & mm due to dehydration caused by heat Cold stiffening Upon exposure to freezing temperature, tissues are frozen & stiff Once replaced in warm temperature, stiffness is replaced by flaccidity & subsequently rigor mortis occurs Rigor mortis Rigor mortis may be used as the initial crude indicator of post-mortem interval, awaiting more conclusive analysis of time of death Source: 3rd edition KNIGHT S Forensic Pathology Cadaveric spasm Instantaneous form of rigor In midst of intense emotional/ physical activity failure of normal relaxation occurs Affects only small number of group muscle Eg flexor of one arm Ex fall from cliff into cold water, suicidal gunshot to head Source: 3rd edition KNIGHT S Forensic Pathology Postmortem lividity/Hypostasis Lucidity, staining, cogitation Is discolouration of skin & organs after death due to accumulation of blood in dependent areas Occurs when circulation ceases no arterial propulsion or venous return stagnant blood Gravity pulls the blood into its lowest accessible area Visible at skin as a darkened area on black pple & bluish red on white skin Starts 30mis-4hrs after death, & reaches max at 6-12hrs Fixation: Generally, it is said that if pressure applied by a thumb blanches the area, the lividity is not fixed and time since death is less than 8 hours. If the area does not blanch, lividity is fixed and the time since death is more than 8 hours. Fixation is due to the diffusion of haemoglobin through capillary walls and stains the tissues, permanently. Postmortem lividity/Hypostasis Pattern/distribution of hypostasis Depends on posture after death Supine: hypostasis over back area in exception of shoulder, buttocks, calves (pressed against surface compressing vascular channels) Vertical: hypostasis over feet, leg, distal part of hand & arm Hypostasis in organs: Intestine: discontinuous marked discolouration of jejunum & ileum Lung: dark blue in posterior edges, pale over anterior edges Fluid/congestion/oedema will be more apparent at post edge Myocardium: dark patches in posterior wall Oesophagus: haemorrhage post to oesophagus Medicolegal importance of Postmortem Lividity Can assess time since death Can decide the position of the deceased at the time of death Can establish the cause of death It may be mistaken for a contusion Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix Postmortem lividityHypostasis Hypostasis vs bruises(Ecchymosis) Hypostasis Bruises Dependent areas Anywhere Well-defined edges Ill-defined edges Blood is retained in Blood escapes thro intact capillaries ruptured capillaries Superficial Deep into skin Same level on surface Raised Pale over pressure Coloured areas Incision: blood flows Incision: blood from the cut vessel coagulates in tissue (washable) No swelling May be with swelling Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix Decomposition Mixture of processes Autolysis of individual cells by chemical breakdown External process of bacteria/predators/magg ots Divided into: Putrefaction Adipocere Mummification Putrefaction Caused by bacteria mainly originating from intestines & lungs Starts approximately 3dys after death in temperate zones Starts simultaneously, however, visually first observed at abdomen, usu RIF Due to bacteria in caecum that lies superficially The spreads to abd wall (gaseous distension) Face & neck become reddish & swollen Skin fro blisters as upper epidermis is loosened Scrotum & penis may swell Tissue liquefaction, bloody fluid from orifices- nostrils, anus, vagina, mouth Putrefaction After several weeks, reddish green colour will turn black or dark with maggots After several months, soft tissues & visceral progressively disintegrates 12-18 months- skeleton + tendons 3years- skeleton Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix Adipocere Occurs in a cold, wet environment Fat tissue begins to saponify Caused by hydrolysis & hydrogenation of adipose tissues Requires moist environment Mostly occurs in wet graves, damp vaults, cold water Clostridium perfringes thought to assist in hydrolysis & hydrogenation process Importance of adipocere Once formed, it may preserve the body for decades Hence preserving marks of injuries eg bullet holes Total time required-3-12mths Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix Mummification Drying of tissues in place of liquefying putrefaction Can co-exist with other form of decoposition or form at some parts of the body Occurs in hot, dry environments due to evaporation from the body surface Hot desert, closet, cupboards, closed room, beneath floors Skin & tissues are hardened due to drying Source: Colour Atlas of forensic Pathology_3 rd edn-Jay Dix  Decomposition in immersed bodies is slower because: Reduced temperature Protection against insects & maggots Decomposition in buried bodies is slower than body immersed in water or in room air because: Reduced temp No predators Low oxygen level Maceration Asceptic autolysis of a foetus, whisc has died in utero & remained within the closed amniotic sac Occurring as early as 6hrs & most definitely within 12hrs There is slippage of epidermis leaving a red dermis In utero 7-10dys, colour changes to purple to brown Typically within 2 to 3 dys of death in utero, the foetus lose firmness of tissues which manifest as generalized softness on palpation 7-10dys, the skin has a slimy feel, limbs are very loose & easily separatefrom trunk Sometimes putrefaction may override the maceration process: Amniotic membranes rupture Chorioamnionitis Predators Types of predator varies with Geography Season Indoor/outdoor Canine/rodent: Local removal of flesh with evidence of teeth marks No bleeding or inflammation marginal zone Rats/cats-crenated edge with clean cut wounds Most common: maggots(flies) Lay eggs in moist areas such as around wound, eyelis, nostrils, lips Initially explores natural passages, then burrowing under tissues excreting proteolytic enzymes making tunnels & sinuses Time of death (postmortem interval) Postmortem interval can only be estimated: Interval btw time of death & when body was found The longer the time since death the greater the chance of error Numerous individual observations made which together, provide an estimate of time of death Check the following” Rigor mortis Livor mortis Postmortem cooling Decompositional changes Cadaveric entomology Carbon dating (radioactive carbon, C-14) Time of death (postmortem interval) Physical findings compared to witness accounts of when decedent was last seen or heard Environment is the single most important factor in determining the postmortem interval, decomposition occurs faster in warmer environments Type of clothing may indicate what the person was doing & time of day when death occurred Gastric contents used in determining the type of food eaten Not useful in determining time of death coz of individual’s variability Clues from the scene Insects on the body-entomologist to assist Flora beneath the body- botanist to assist Information from the scene: Was mail picked up? Were the lights on or off? Was food prepared? Time on wrist watch Post-mortem chemistry Many natural chemical substances rapidly distorted by postmortem autolysis Serum/creatinine are stable wit little variation upto 100hrs Most reliable sample is vitreous humour Most substance apart from glucose tend to be well preserved in VH than in serum Alcohol levels after 72hrs of death should be analysed in VH ESTABLISHMENT OF IDENTITY OF HUMAN REMAINS Establishment of identity- importance Is an essential part of post-mortem for various reasons: Ethical & humanitarian need to know which individual has died, esp for surviving relatives To establish the fact of death in respect to individual for official, statistical & legal purposes To record the identity for administrative & ceremonial purposes in respect of burial or cremation To discharge legal claims & obligations in relation to property,estate & debts To prove claims for insurance contracts, survivor’s pension & other financial benefits To allow legal investigations to proceed with affirm identity of the decedent To facilitate police enquiries to proceed in criminal or suspicious deaths as the identity of the deceased person is a vital factor in initiating investigations Establishment of identity May be required upon: Intact fresh corpses- visual recognition directly or by photography Decomposed corpses- surface features may be partially or wholly lost, but more information obtained from the skeleton Mutilated & dismembered corpses Skeletalized material- identity will depend on osteological examination Establishment of identity Positive identification: Presumptive identification: Visual Skeletal remains analysed by Numerous injuries & forensic anthropologist decompositional changes may estimating age, gender & race cause disfigurement making Clothing visual identification difficult X-rays may not have enough Fingerprints points foe a positive ID thus Dental presumptive ID made Physical features eg tattoos, X-rays- skull & pelvis scars, birthmarks, absence of Skull has sinues which are some organs frm surgery specific for each individual Circumstances surrounding DNA fingerprinting death Characteristics useful in identification Facial appearance Eye colour Skin pigmentation Hair colour Hair structure Tattoos Finger, palm, foot & lip prints Identifying scars Occupational stigmata Stature of an intact body Characteristics useful in identification Identification by DNA characteristics: uses Establishment of identity Medico-legal purposes Paternity testing Samples: Blood in EDTA, dried blood swab Fresh muscle, spleen Decomposed bodies/ burn cases Tissues where bone is likely have preserved marrow- cartilage, vertebra, sternum Approach to the medico-legal autopsy Authorization Identification Visit of scene of crime History of the case Verification of the injuries noted by the police Examination Notes Preservation of viscera & other tissue List of artefacts Contents of the autopsy report The preamble: Authority Time of arrival of body Date & place of examination Name, age & sex Body identified by The body of the report External & internal examination Wounds/injuries-nature, direction, situation & sizes Conclusions External examination Condition of the body Marks of identification Eyes State of natural orifices, ears, nostrils, mouth anus, urethra & vagina Injuries-nature position & measurements State of limbs Genitals & breasts Collect evidence- hair, nails Internal Examination Body block Approaches: A large and deep Y-incision A T-shaped incision from tips of both shoulders to the sternum A single vertical cut Examination for ascites Removal of the chest plate Pleural fluid/adhesions 114  Autopsy Techniques 1. Virchow Technique – One-by-one organ removal 2. Rokitansky Technique – In situ dissection of organ blocks 3. En bloc Technique (of Ghon) – Cervicothoracic, abdominal and urogenital systems removed as organ blocks 4. En masse Technique (of Letulle) – Cervical, thoracic, abdominal and 115 pelvic organs removed as one organ block Internal examination Thorax  Walls, ribs, 7 cartilages  Pleura & diaphragm  Larynx, trachea & bronchi  Lungs with weight  Pericardium  Heart, cavities, valves & coronary vessels  Large vessels Internal examination Abdomen & pelvis Head  Peritoneal cavity Skull  Stomach & its contents Brain  Intestines, their contents Vessels-circle of Willis  Omentum, mesentery  Liver & gall bladder, Musculoskeletal system spleen, pancreas  Kidneys, urinary bladder  Pelvic organs Poisoning cases Smell of the body Postmortem staining & its colour If froth is present, its nature Colour of sclera ,lips & nails Mouth & its surroundings Injuries Details of GI tract examination Description of stomach & its contents Poisoning cases Viscera to be collected for chemical examination Stomach & its contents Upper part of small intestines 30cms with contents 500g of liver Half of each kidney 5-10ml of blood 30ml of urine Hanging/ligature/ strangulation cases Description of ligature material Description of the ligature mark Marks of salivary dribble Condition of eyes & pupils Colour of lips & nails. Position of tongue Distribution of postmortem staining Presence of injuries on the body Injury to cervical spine & cord Examination of internal organs Preservation of viscera in cases of suspicion of poisoning Burns cases Smell from the body: kerosene, other inflammable substances Nature of burns: Antemortem Postmortem Extent & degree of burns Age of burns Other injuries Colour of postmortem staining Examination of air passages for presence of soot particles Evidence of: Poisoning Pregnancy, abortion, sexual assault References 1. Autopsy Pathology, a Manual and Atlas, 2nd edition, Walter E. F. et al 2. KNIGHTS Forensic Pathology, 3rd edn; Saukko P., Knight B. 3. Colour Atlas of Forensic Pathology; Jay Dix.  'Mortui vivos docent' - the dead teach the living. ₋ The phrase was used repeatedly by physician-theologist, Miguel Servoto (1511-1553) Mors gaudet succurere vita – “Death rejoices in helping life” Anonymous