Dr. S. K. Nawaz Ahmed's document discusses death and its causes. It defines death as the irreversible loss of brain function, including brainstem function. It describes the stages of death as somatic/clinical death followed by molecular/cellular death. It discusses the modes of death including asphyxia, coma, and syncope based on which organ system fails first. The document also discusses brainstem death criteria, vegetative and permanent vegetative states, and India's Transplantation of Human Organs and Tissues Act regarding organ donation.

1. Death & its Cause
by
Dr. S. K. Nawaz Ahmed

2. Death & its Cause
2
Competencies in this chapter
FM 2.1 Define, describe death and its types
FM 2.2 Describe and discuss natural and unnatural deaths
FM 2.3 Describe and discuss issues related to sudden
natural deaths
FM 2.4 Describe the salient features of The Human Organ
Transplant (Amendment) Act 2014
FM 2.5 Discuss moment of death, modes of death – coma,
asphyxia and syncope
FM 2.6 Discuss presumption of death and survivorship
FM 2.7 Describe and discuss suspended animation

3. Thanatology
3
Definition of Death
Death is defined as irreversible loss of all functions of
the Brain including the Brainstem.

4. Thantology
4
Stages of Death
1. Somatic or Systemic or Clinical Death
It is defined as the complete and irreversible cessation of
circulation, respiration and brain functions resulting in
complete loss of sensibility and ability to move the body.
(Bichat’s Tripod of Life)
2. Molecular or Cellular Death
 Death of cells and tissues individually
 Occurs one to a few hours after stoppage of vital
functions
 Different tissues die at different rates
 Nervous tissues die rapidly
 Vital centres of the brain die in a few minutes

5. Thantology
5
Bichat’s Tripod of Life:
The Cardiovascular system, Respiratory system and the
Central Nervous System are called Bichat’s Tripod of
life.
Complete cessation of functioning of these systems
results in death (initially somatic death which is
followed by cellular death)

6. Vegetative State
6
Vegetative State
In this condition, the cortical neurons are dead, but the
brain stem neurons are intact.
If cortex alone is damaged, the patient passes into a deep
coma, but brainstem will function and spontaneous
respiration maintained.
Definition: Vegetative state is defined as a clinical
condition of complete unawareness of self and the
environment, accompanied by sleep-wake cycles, with
either complete or partial preservation of hypothalamic &
brain-stem autonomic functions.

7. Vegetative State
7
Vegetative State
Conditions which produce this
1. Cerebral hypoxia following cardiac arrest
2. Toxic conditions
3. Diffuse cerebral injury due to closed head trauma.

8. Persistent & Permanent Vegetative State
8
Persistent Vegetative state(PVS):
Is defined as a vegetative state present at least for 1
month after traumatic or non-traumatic cause
Permanent Vegetative State:
The Persistent Vegetative State is said to be Permanent
after: 12 Months of Traumatic Injury
or
3 months of Non-Traumatic causes

9. Brainstem Death(Cont’d)
9
Brainstem Death
When the brainstem (midbrain, upper pons and medulla)
suffers neuronal damage, the loss of the vital centres
that control respiration and consciousness, the victim:
1. Is irreversibly comatose.
&
2. Incapable of spontaneous breathing.
Conditions which produce this
Increase Intracranial Pressure due to:
1. Intracranial Haemorrhage
2. Cerebral edema

10. 10
Brainstem Death(Cont’d)

11. Normal Brain Anatomy
11
Cerebral Cortex
Brain Stem
Reticular
Activating
System

12. Cerebral Cortex
12
 Cognition
 Voluntary Movement
 Sensation

13. Brainstem(Cont’d)
13

14. Brainstem Death
14
Importance of the Brainstem:
1. Arousal mechanisms – Paramedian areas of the
Mesencephalon & the Rostral Pons.
2. Cardiovascular Centre – Blood Pressure Regulation
3. Respiratory Centres
4. Afferent & Efferent Pathways Conduit
5. Autonomic Nervous System Conduit
6. Cranial Nerve Nuclei
If this portion of the brain is dead, the patient is
irreversibly unconscious and apneic

15. 15

16. Brainstem(Cont’d)
16
Midbrain
Cranial Nerve III
 pupillary function
 eye movement

17. Brainstem(Cont’d)
17
Pons
Cranial Nerves IV, V, VI
 conjugate eye movement
 corneal reflex

18. Brainstem
18
Medulla
Cranial Nerves IX, X
 Pharyngeal (Gag) Reflex
 Tracheal (Cough) Reflex
Respiration

19. Harvard Criteria for Brain-Stem Death (1968)
19
Features as per the Harvard Criteria
1. Unreceptivity and unresponsivity: Total unawareness to
externally applied stimuli and inner need and complete
unresponsiveness to even the most intense painful
stimuli.
2. No movements: No spontaneous muscular moverments in
response to stimuli such as pain. touch, sound or light
for a period of at least one hour.
3. Apnea: Absence of spontaneous breathing for at least
one hour and when patient is on ventilator, the total
absence of spontaneous breathing may be established by
turning off the respirator for 3 minutes and observing
whether there is any effort on the part of the subject to
breathe spontaneously.

20. Harvard Criteria for Brain-Stem Death (1968)
20
Features as per the Harvard Criteria
4. Absence of elicitable reflexes: Irreversible coma with
abolition of central nervous system activity is evidenced
in part by the absence of elicitable reflexes. The pupils
are fixed and dilated and do not respond to a direct
source of bright light. Ocular movement and blinking are
absent. There is no evidence of postural activity. Corneal
and pharyngeal reflexes are also absent. Stretch tendon
reflexes also cannot be elicited.
5. Isoelectric EEG: It has confirmatory value.
All these tests should be repeated within 24 hours with no
change.
The patient should be declared dead before any effort is
made to take him off the ventilator.

21. The diagnosis of brainstem death involves three steps:
1. Comatose Patient
2. Patient on Ventilator
3. Positive diagnosis of cause of coma (structural damage
that cannot be repaired)
Exclusions:
1. Primary Hypothermia
2. Drugs (barbiturates, narcotics etc)
3. Severe metabolic or endocrine disturbances
Brain Death Diagnosis as per latest guidelines
21

22. Tests to be Done
1. Test the Brainstem Reflexes
2. Apnea Test
Brain Death Diagnosis as per latest guidelines
22

23. 1. Pupillary response to light (A: II CN; E: III CN) – making
the pupil constrict.
2. Corneal Reflex (A: V CN; E: VII CN) – blinking response to
corneal stimulation.
3. Vestibulo-ocular reflex (A: VIII CN; E: III & VI CN) - Doll’s
eye movement in response to irrigation of the tympanic
membrane with ice-cold water.
4. Grimace (A: V CN; E: VII CN) - in response to painful
stimulus over face
5. Gag or cough reflex (A: IX CN; E: X CN):
 No Response after stimulation of the posterior pharynx
with a tongue blade.
 No Cough Response to tracheo-bronchial suctioning.
Testing the brainstem reflexes
23

24. Testing the brainstem reflexes(Cont’d)
24

25. Diagnosis of Brainstem Death(Cont’d)
25

26. Apnea test is done to prove that the patient is incapable of
breathing
1. The patient is disconnected from the ventilator
2. Carbon-dioxide concentration increases to a point at
which it will stimulate respiration, if any cells are still
alive in the respiratory centre of the brainstem
3. If respiratory movements are absent despite increase in
arterial partial pressure of carbon dioxide the apnea test
is considered positive.
26
II. Apnea Test

27. 27
The Brainstem Reflexes & the Apnea Test should be
repeated after 6 hours before declaring the patient dead.
The Ventilator should be disconnected after declaring the
patient brain dead.
Declaration of Brain Death

28. 1. The Registered Medical Practitioner in charge of the
hospital where brainstem death has occurred
2. An independent doctor who is a specialist (nominated by
the registered medical practitioner)
3. A Neurologist or Neurosurgeon (nominated by the
Registered Medical Practitioner)
4. The doctor treating the person whose brainstem death
has occurred
Board of Medical Experts to Certify Brainstem Death
28

29. 29
Transplantation of Human Organs & Tissues Act
2014(THOTA)

30. THOTA (Cont’d)
30
It was enacted to provide a system for:
1. Regulation of removal, storage and transplantation of
human organs for therapeutic purposes and
2. Prevention of commercial dealings in human organs

31. THOTA (Cont’d)
31
Regulatory Bodies:
Advisory Committee
1. Regulation of removal, storage and transplantation of
human organs for therapeutic purposes and
2. Prevention of commercial dealings in human organs

32. THOTA (Cont’d)
32
Regulatory Bodies(Cont’d):
Appropriate Authority
1. All other than related transplantation or foreign
transplantations are evaluated by the authorization
committees
2. It regulates living-donor transplantation by reviewing each
case to ensure that the living donor is not exploited by
monetary considerations and to prevent commercial
dealings in transplantation.
3. It also inspects and grants registrations to hospitals for
transplantation, enforces required standards for hospitals,
and conducts inspections of hospitals to examine the
quality of transplantations.

33. THOTA (Cont’d)
33
Regulatory Bodies(Cont’d):
Authorization Committee
1. State level
2. Hospital level (in hospitals which do >25 transplants per
year)
Competent Authority
1. It means the head of the institution or hospital carrying
out transplantation
2. It gives permission for near-related transplants only

34. THOTA (Cont’d)
34
Types of Donors
Living Donors
Near-related donors
Non-related donors
Swap transplantation
Other than related donors
Foreign donors

35. THOTA (Cont’d)
35
Types of Donors
Deceased Donors
1. Deceased donation can be either after brain death (brain
stem death) or after cardiac death
2. The brain death certification is done by a panel of four
doctors

36. THOTA (Cont’d)
36
Authorization for Organ Donation after Brain Death
1. Any donor (>18 years of age) may authorize the removal
before his death.
2. The person lawfully in possession of the dead body can
authorize the removal of any organ including eye/cornea
of the deceased person.

37. THOTA (Cont’d)
37
Transplant Coordinators
1. As per the THOTA 2014 rules, they have been made
mandatory in all organ retrieval and transplanting
centres.
2. Transplant coordinators are being trained by NDO and
MOHAN foundation.
3. In a deceased donor program, the transplant coordinator
coordinate brain death declaration, organ retrieval and
organ donation, help in form filling, and even help with
the last rites of the donor.

38. Tissue & Organ Transplantation after Brain death
38
Beating Heart Donor
After brain stem death has been established, the
retention of the patient on the ventilator facilitates a
fully oxygenated cadaver transplant, the so-called
beating heart donor.
The results of the transplant are much improved.

39. Thanatology
39
I. Cause of Death
II. Mechanism of Death
III.Manner of Death

40. 1. Cause of Death
40
I.Cause of Death
Any Injury or Disease that produces a physiological
derangement in the body that results in the death of the
individual.
The cause of death is the disease or injury responsible
for starting the sequence of events, which are brief or
prolonged and which produce death.
Some examples
1. A gunshot wound to the head
2. A stab wound to the chest
3. Coronary Atherosclerosis
4. Adenocarcinoma of the lung.

41. 1. Cause of Death(Cont’d)
41
I. Cause of Death(Cont’d)
It can be divided into the following
1. Immediate Cause
2. Basic Cause
3. Contributory Cause

42. 1. Cause of Death(Cont’d)
42
1. Immediate Cause: Injury or disease present at the time
of the terminal event. Example: Bronchopeumonia,
peritonitis, trauma etc.
2. Basic Cause: i.e. Pathological process responsible for
the death at the time of the terminal event or prior to
or leading to the terminal event. Example: gunshot
wound of the abdomen complicated by general
peritonitis.
3. Contributory Cause: i.e. The pathological process
involved in or complicating but not causing the
terminal event. e.g. Diabetes Mellitus exacerbating
wound infection.

43. 2. Mechanism of Death
43
II. Mechanism of Death
Physiological or Biochemical Disturbance produced by the
cause of death which is incompatible with life.
e.g.:
1. Shock
2. Sepsis
3. Toxemia
4. Severe metabolic acidosis and alkalosis
5. Ventricular Fibrillation
6. Respiratory Paralysis

44. Cause and Mechanism of Death
44
Injury or Disease (Cause of Death)
Physiological Derangement (Mechanism of Death)
Death of the individual

45. 3. Manner of Death
45
The Manner of Death explains how the cause of death
came about.
Legal or Administrative term that provides circumstantial
evidence about the cause of death.
The Manner may be
1. Natural – Death exclusively by disease.
2. Unnatural – Death exclusively by injury or hastened by
injury. Suicide, Homicide or Accident (Violent Deaths).
3. Undetermined.
-------------------------------------------------------------------
Violent Deaths fall under the jurisdiction of the Medico-
Legal System.

46. Modes of Death
46
Mode of death is an old concept of death based on
Bichat’s concept of tripod of life.
Although now we talk mostly of the cause, mechanism
and manner of death, in earlier times physicians talked
about the mode of death.
Developed mainly by the French physician Bichat, this
concept was based on his tripod of life.
According to this concept if any one of these organs
died, soon all the organs would perish.
Typical PM findings may reveal which organ died first.

47. Modes of Death (Cont’d)
47
It is the physiological abnormality or pathological
condition prevalent at the time of death.
There are three modes of death depending upon
whether death begins in one or other of the three
systems:
1. Asphyxia
2. Coma
3. Syncope

48. Modes of Death (Cont’d)
48
1. If the brain stopped functioning first, the death was
supposed to be due to coma.
2. If the heart stopped functioning first the death was
supposed to be due to syncope,
&
3. If the lungs stopped functioning first, the death was
due to asphyxia.
This concept is not in use anymore today.

49. Modes of Death (Cont’d)
49
Asphyxia
Definition: A condition caused by interference with
respiration or due to lack of O2 in the inspired air due
to which the organs tissue are deprived of O2 causing
unconsciousness or death.
• The term asphyxia refers to a mode of dying and not
a cause of death.
• The neurons of the cerebral cortex will die in 3-7
minutes of Oxygen deprivation.

50. Modes of Death (Cont’d)
50
Asphyxia (Cont’d)
In all forms of asphyxia the heart may continue to beat
for several minutes after stoppage of respiration.
Rules of Thumb:
1. Breathing stops within 20 seconds of cardiac arrest.
2. Heart stops within 20 minutes of stoppage of
Breathing.

51. 51
Vicious Cycle of Asphyxia
Reduction
in O2
tension
Capillary
Dilatation
Capillary
Stasis
Capillary
Engorgement
Stasis of
blood in the
organs
Diminished
venous return to
the heart
Reduced
pulmonary blood
flow
Deficient
Oxygenation in
the lungs
Asphyxia

52. 4. Modes of Death(Cont’d)
52
Asphyxia (Cont’d)
Types & Causes of Asphyxia
1. Mechanical
2. Pathological
3. Toxic
4. Environment
5. Traumatic
6. Postural asphyxia
7. Iatrogenic

53. Modes of Death (Cont’d)
53
Syncope
It is a condition which results from sudden stoppage of
functioning of the heart, which may prove to be fatal.
Mechanism
Sudden stoppage of functioning of the heart
Cerebral Hypoperfusion
Ischemia of the vital centres of the brain
Death

54. Modes of Death (Cont’d)
54
Syncope(Cont’d)
Examples
I. CVS Lesions
1) Rhythm disturbances - Heart Block, Paroxysmal
supraventricular tachycardia (PSVT), Fibrillation
2) Decreased Left Ventricular Output:
A. Due to pump failure - Myocardial Infarction,
Dilated Cardiomyopathy
B. Due to reduced filling – Pulmonary embolism, atrial
myxoma

55. Modes of Death (Cont’d)
55
Syncope(Cont’d):
Examples
I. CVS Lesions
3) Outflow obstruction – Aortic Stenosis, Hypertrophic
Obstructive Cardiomyopathy
4) Reduced Blood volume – Haemorrhage
Vasovagal Attacks

56. Modes of Death (Cont’d)
56
Coma
Definition
It is a state of unarousable unconsciousness
determined by the absence of any psychologically
understandable response to external stimuli or inner
need.
Causes
It involves the central portion of the Brain stem
• Coma is a clinical symptom and not a cause of death.

57. Modes of Death (Cont’d)
57
Causes of Coma:
1. Compression of the brain: Example: effusion of blood
on or in the brain, inflammation, abscess or
neoplasm or both.
2. Infections: Meningitis, encephalitis,
meningoencephalitis
3. Metabolic and Endocrine Disorders: Diabetic
Ketoacidosis, Uremia, Hepatic Encephalopathy,
Hypothermia, Metabolic acidosis, Ecclampsia etc.

58. Modes of Death (Cont’d)
58
Causes of Coma:
4. Drugs: Benzodiazepines, TCAD’s, opiate analgesics,
barbiturates, anticonvulsants, salicylates,
anesthetics, CN-, alcohol, atropine, phenol, cocaine.
5. Other Causes: Embolism and thrombosis in the
cerebral vessels, epilepsy, hysteria etc.

59. Sudden Death
59
Definition of Sudden Death (WHO):
Death is said to be sudden or unexpected when a
person not known to been suffering from any
dangerous disease, injury or poisoning is found dead
or dies within 24 hours after the onset of terminal
illness.
• Incidence: 10% of all deaths
• No period in life is exempt.

60. Causes of Sudden Death
60
Pertaining to a particular system
1. CVS (45-50 %)
2. RS (15-23 %)
3. CNS (10-18 %)
4. GIT(6-8 %)
5. GUT (3-5 %)
6. Miscellaneous (5-10%)

61. Causes of Sudden Death(Cont’d)
61
I. CVS Causes
1. Coronary Artery Disease
A. Occlusion (atherosclerosis, thrombosis, embolus)
i. Coronary atherosclerosis with coronary thrombosis
ii. Coronary artery embolism
iii. Occlusion of the ostium of the coronary artery associated
with atherosclerosis
iv. Coronary Artery Spasm-Coronary vasospasm occurs more
commonly in arteries with underlying atheromatous
disease
B. Coronary artery dissection(SCAD)
C. Coronary artery aneurysm
2. Rupture of fresh myocardial infarct
3. Cardiomyopathies – HOCM, Dilated CM,
Restrictive(Sarcoidosis).

62. Causes of Sudden Death(Cont’d)
62
I. CVS Causes(Cont’d)
4. Hypertensive cardiovascular disease-Arterial Hypertension
with atherosclerosis
5. Aortic Dissection leading to rupture
6. Valvular lesions: Main- Aortic Stenosis, Mitral Valve
Prolapse. Other-A.R. M.S, Rupture of Chordae, Ball-valve
thrombus.
7. Acute Endocarditis & systemic embolism occurring in
bacterial endocarditis.
8. Inflammatory: Acute myocarditis, pericarditis (bacterial,
viral, Dressler syndrome)
9. Cardiac tamponade
10.Pulmonary embolism

63. Causes of Sudden Death(Cont’d)
63
I. CVS Causes(Cont’d)
11. Congenital Heart Disease – Newborn
12. Lesions of the conducting system – fibrosis, necrosis
13. Fatty Degeneration of the Heart
14. Senile Myocardium

64. Causes of Sudden Death(Cont’d)
64
II. CNS Causes
1. Epilepsy
2. Spontaneous Intracranial Haemorrhage – ICH, SAH
3. Infections - Meningitis, Encephalitis, Brain abscess,
Acute polioencephalitis, Cerebral Malaria
4. Vascular Lesions:
Carotid artery thrombosis
Cerebral venous thrombosis and Embolism
Aneurysm
4. Neoplasms: Primary or metastatic
5. Cysts of 3rd and 4th Ventricle

65. Causes of Sudden Death(Cont’d)
65
III. RS Causes
1. Lobar pneumonia
2. Bronchitis and Bronchopneumonia
3. Rupture of Blood vessel in pulmonary TB with
cavitation
4. Pulmonary embolism with infarction
5. Air Embolism
6. Acute edema of glottis
7. Acute edema of lungs
8. Lung abscess
9. Massive lung collapse
10. Pleural effusion

66. Causes of Sudden Death(Cont’d)
66
III. RS Causes(Cont’d)
11. Pneumothorax caused by rupture of emphysematous
bleb
12. Neoplasm of the bronchus
13. Bronchial asthma
14. Impaction of Foreign Body in the larynx
15. Regurgitation of stomach contents into air-passages
and bronchioles

67. Causes of Sudden Death(Cont’d)
67
IV. GIT Causes:
1. Haemorrhage into the G.I.T from peptic ulcer,
esophageal varies, cancer esophagus etc.
2. Perforation of ulcers – peptic, typhoid, amoebic or
malignant.
3. Acute Haemorrhagic pancreatitis
4. Bursting of liver abscess
5. Rupture of enlarged spleen
6. Appendicitis
7. Intestinal obstruction
8. Strangulated Hernia
9. Twisting and intussusceptions of the bowel
10.Paralytic ileus
11.Obstructive Cholecystitis.

68. Causes of Sudden Death(Cont’d)
68
V. Genito-Urinary System Causes:
1. Acute pyelonephritis with sepsis
2. Chronic Nephritis - End-stage renal disease (ESRD) with
uremia
3. Nephrolithiasis
4. Obstructive Hydronephrosis and pyonephrosis
5. Tumors– Kidney/Bladder
6. T.B. Kidney
-------------------------------------------------------------------
7. Rupture of Ectopic Pregnancy
8. Ecclampsia
9. Twisting of ovarian cyst, ovary, fibroid tumour.
10.Uterine Haemorrhage due to fibroids.
11.Cancer vulva eroding femoral vessels

69. Causes of Sudden Death(Cont’d)
69
VI. Miscellaneous Causes
1. Addison’s Disease
2. Diabetes Mellitus
3. Hyperthyroidism
4. Haemochromatosis
5. Reflex Vagal Inhibition
6. Anaphylaxis due to drugs
7. Mismatched Blood Transfusion
8. Cerebral Malaria
7. Blood Dyscrasias
8. Shock due to emotional excitement

70. Suspended Animation
Suspended Animation(Apparent Death)
Definition: Suspended animation is a condition in which
vital signs of life (heart beat and respiration) are not
detected by routine clinical methods, as the functions
are interrupted for some time or are reduced to a
minimum.
Mechanism: The metabolic rate is greatly reduced so
that the requirement of the individual cell for oxygen is
satisfied through the dissolved oxygen in body fluids.
70

71. Suspended Animation (Cont’d)
Conditions where Suspended Animation can be observed
I. Involuntary
1. After Anaesthesia
2. Birth: Newborn infants
3. Cerebral Concussion
4. Drowning
5. Electrocution
6. Hypothermia
7. Heat stroke
8. Shock
II. Voluntary
In practitioners of Yoga
The patient can be resuscitated by cardiac massage or
electric stimulator and artificial respiration.
71

72. Presumption of Death
Presumption of Death:
Explained under Section 107 and 108 of the Indian
Evidence Act
Where there has been no proof of existence of a person
in the society for 7 years, the law presumes him to be
dead.
72

73. Presumption of Survivorship
Presumption of Survivorship:
• It deals with legal rights following death of two persons
where the evidence of the order of their deaths is
unknown.
• Assume a husband and wife die in a single motor vehicle
accident. Their wills specify different beneficiaries.
• The time sequence and order of their deaths is crucial
to determine who is the ultimate beneficiary but that
cannot be factually determined.
• The presumption of survivorship says the younger of the
two is legally presumed to have survived.
• Therefore the younger person’s will shall govern.
73

74. 74
Thank You