DETERMINATION OF CAUSE, MANNER AND MECHANISM OF.pptx

Important definitions in cause, manner, and mechanisms of death.

1. DETERMINATION OF CAUSE, MANNER AND MECHANISM OF DEATH

2. INTRODUCTION Death MAY be defined as the permanent and irreversible cessation of three vital body systems namely – nervous, cardiac and respiratory systems. Occurs in two stages; Somatic Irreversible loss of perceptive personality, being unconscious, inability to be aware of (or to communicate with) the environment, and the inability to appreciate any sensory stimuli or to initiate any voluntary movement. Molecular/Cellular Tissues and their constituent cells are dead – i.e . , they no longer function or have metabolic activity, primarily aerobic respiration. This follows the ischemia and anoxia unavoidably consequent upon cardiorespiratory failure.

3. GENERAL DEFINITIONS Cause of death (COD): natural disease or injury that leads to physiologic changes resulting in death. Could be either;- Acute event (e.g., motor vehicle collision, gunshot wound to the head, sudden death in previously healthy individuals) Chronic event (e.g., complications related to atherosclerotic cardiovascular disease, malignancy, etc.)

4. Manner of death (MOD): circumstances surrounding death (how the death came about / how the injury or disease leads to death) Mainly based on scene investigation, interviews with next of kin, review of medical history / records, autopsy and ancillary studies (studies (toxicology, histopathology, vitreous chemistry, microbiology, etc.) Mechanism of death: The final physiologic or biochemical derangement, incompatible with continued life, produced by the cause of death, e.g. sepsis, respiratory depression, cardiac dysrhythmia, etc., which is not etiologically specific

5. CAUSE OF DEATH Direct, continuous sequence of events unbroken by any efficient intervening cause that leads to mortality Has an etiologically specific disease or injury. A cause of death is determined by a medical examiner during an autopsy. Cause of death is currently classified and coded based on ICD-10, which is being replaced by ICD-11 on 1 st January 2022.

6. Regarding mortality coding, here’s what to expect in ICD-11 The mortality coding rules of ICD-10 have been adapted for use with ICD-11, with irrelevant rules removed. The international death certificate and the method for selecting a single underlying cause of death, as well as the table recommending additional detail for perinatal mortality, have been maintained from the update of ICD-10 published in 2016. ICD-11 has also incorporated the use of multiple-cause coding and analysis in relation to causes of death.

7. Terminology regarding cause of death that must be distinguished: Immediate cause of death : The disease or injury which initiated the train of morbid events leading directly to death, or the circumstances of the accident or violence which produced the fatal injury (WHO). Underlying cause of death : condition(s) that precede and initiated the train of morbid events that ultimately culminate in the immediate cause of death Intervening cause : any condition that interrupts or exacerbates the chain of proximate causation Contributing factors to death : other conditions that play a role in the death process but are not the primary cause of death.

8. If there is only one step in the chain of events, an entry at line I(a) is sufficient. If there is more than one step, the direct cause is entered at (a) and the originating antecedent cause is entered last, with any intervening cause entered on line (b) or on lines (b) and (c). Part II is for any other significant condition that contributed to the fatal outcome, but was not related to the disease or condition directly causing death.

9. An example of a death certificate with four steps in the chain of events leading directly to death is: I (a) pulmonary embolism (b) pathological fracture (c) secondary carcinoma of femur (d) carcinoma of breast. Example 2; I (a) Bleeding of oesophageal varices (b) Portal hypertension (c)Liver cirrhosis (d) Hepatitis B Example 3: I (a) Bronchopneumonia (b) Chronic bronchitis II Chronic myocarditis

10. QUIZ 1? A 65 year old woman died of acute renal failure. Damage to the kidneys considered to be due to aspirin ingestion for recurrent headaches 3 years prior. Autopsy revealed lesion of renal papillary necrosis.

11. ANSWER TO QUIZ 1 I (a) Acute renal failure…………………………….1 week due to (or as a consequence of) (b) Renal papillary necrosis…………………….1 week due to (or as a consequence of) (c) Aspirin taken for recurrent headaches……….3 years

12. QUIZ 2? A 59 year old woman died of asphyxia following aspiration of vomitus 2 hours after suffering a cerebellar haemorrhage. Three years prior, she had been diagnosed as having an adrenal adenoma with aldosteronism which manifested itself as hypertension. Congestive heart failure was also present.

13. ANSWER TO QUIZ 2 I (a) Asphyxia by vomitus………………………minutes due to (or as a consequence of) (b) Cerebellar hemorrhage…………………….2 hours due to (or as a consequence of) (c) Hypertension……………………………….3 years due to (or as a consequence of) (d) Aldosteronism………………………………3 years due to (or as a consequence of) (e) Adrenal adenoma……………………………3 years II Congestive Heart Failure

14. MANNER OF DEATH Classification / categorization used for how the death came about; a judgment based on the examination and circumstances surrounding the fatal event. Jurisdictions differ in how they categorize and report unnatural deaths, including level of detail and whether they are considered a single category with subcategories. NB - There is no international standard on whether or how to classify a death as natural vs. unnatural. In this presentation – classification according to the US jurisdiction: Natural : due entirely (or nearly so) to natural disease processes; not directly caused by external forces, other than infectious disease. Unnatural manners of death include: Homicide : due to a volitional act of another person with the intent to cause fear, harm or death and some negligent acts, even when a person did not intend to cause harm Suicide: due to injury that occurred with the intent to induce self-harm or cause one's own death

15. Accident : due to injury when there is no evidence of intent to harm Undetermined : inadequate information regarding the circumstances of death to determine manner Example: individual found unconscious with large subdural hemorrhage; in the absence of information on the events leading up to death, it may not be possible to determine if the hemorrhage is due to accidental fall, homicidal violence, etc. In many legal jurisdictions, the manner of death is a determination, typically made by the coroner, medical examiner, police, or similar officials, and recorded as a vital statistic.

16. MECHANISM OF DEATH Defined as the immediate physiologic or biochemical derangement resulting in death. Particular mechanisms of death can be produced by a variety of different causes of death and are never etiological specific Examples: hemorrhage, cardiac arrhythmia, cerebral hypoxia, sepsis, asphyxiation, disseminated intravascular coagulation (DIC) Mechanism of death is usually not specific to the condition that led to death Example: hemorrhage can be associated with natural (e.g., metastatic disease) or traumatic causes (e.g., gunshot wound to the chest).