الموت السريري by ketamie2011

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									DEATH & DYING
                               BY
        Prof./ Dina A. Shokry MD.
Prof. and head of the department of forensic
  medicine and toxicology-Cairo University
                     ‫بسم اهلل الرحمن الرحيم‬
‫{ ويسألونك عن الروح قل الروح من أمر ربي وما أوتيتم من العلم إال‬
                                } ‫قليال‬


‫إعداد وإلقاء د/ أيمه حمدان‬
               Objectives

 To Define Death.
 To recall the concept of brain death.
 To view different opinions regarding the
  concept of brain death in attempt to solve
  the confusion arises in such issue.
 Explore common causes of sudden death.
 Death under anaesthesia
       Ethical dilemmas

 Are we dead yet?
 Today, there is no reliable test to tell us
  when precisely a person has died, no set of
  criteria to define that decisive moment
(Jose A. Bufill)
Kirchbaum's device for indicating life in buried
persons, Patent sketch, 1882.
                   The Death
Definitions:
 There is no legal definition of death. The diagnosis
  of death is traditionally made using the Triad of
  Bichat which states that death is "the failure of the
  body as an integrated system associated with the
  irreversible loss of circulation, respiration and
  innervation". This is also known as somatic death
  or clinical death.
 Molecular death may be defined as "the death of
  individual organs and tissues of the body
  consequent upon the cessation of circulation".
     Diagnosis of Clinical Death

                  Brain Death




Cessation of Respiration   Cessation of Circulation
Diagnosis of Clinical Death


     Cessation of Circulation
 Loss of pulsations

No Blood pressure

     Flat ECG
Diagnosis of Clinical Death


     Cessation of Respiration

     Apnea

  Disturbed ABG
Diagnosis of Clinical Death

 Cessation of brain function (brain death)
    Definition : permanent cessation of cerebral
     hemispheres and brain stem functions.
      Incidence of brain death


 Walker stated that brain death occurs in
  approximately 1% of all deaths. ?
 According to Jennett et al, the frequency is ,
  about 4000 cases occurring each year in
  Britain.?????????
  Anatomical consideration
 The brain has three general anatomic divisions: the
  cerebrum; the cerebellum; and the brainstem,
 The cerebrum has been referred to as the
  "higher brain" because it has primary control of
  consciousness and cognition.
 The brainstem          has been called the "lower
  brain," since it controls spontaneous, vegetative
  functions (swallowing, yawning and sleep-wake
  cycles).
Pathophysiology of brain death
                       failure of blood
                             flow

     direct cellular
                                          Hypoxia
    injury




                                          cerebral
    aseptic necrosis
                                          acidosis

                        brain edema,
                         herniation
Pathophysiology of brain death

 The physiological changes following brain death
  are so severe , the progressive somatic
  deterioration and cardiac standstill will inevitably
  occur .
 A number of studies have suggested that brain
  death does not always rapidly lead to somatic
  death & cardiac rhythm could be maintained for
  prolonged periods after the declaration of brain
  death (23.1 ±19.1 days). (Ganapathy ,2006)
Development of the Concept of
       "Brain Death“
 The concept of "brain death" and efforts to refine
  criteria to identify that condition have been
  developing during the last four decades,
  concomitant with the spread of life support
  systems in clinical medicine.
 In 1959, several French neurophysiologists
  published results of research they had conducted
  on patients in extremely deep coma receiving
  respirator assistance, a condition they termed
  “coma dépassé.“ (exceeds a coma) ‫فوق الغيبوبة‬
Development of the Concept of
           "Brain Death“
 Harvard Criteria In 1968 the Ad Hoc
 Committee of the Harvard Medical School
 defined brain death as irreversible coma, with
 the patient being totally unreceptive and
 unresponsive, with absent reflexes and no
 spontaneous respiratory effort during a 3 min
 period of disconnection from the ventilator.
Development of the Concept of
       "Brain Death“

 Another important contribution was the
 memorandum issued by the Conference
 of Royal Medical Colleges (1979) which
 equated brainstem death with death
 itself
 Clinical evaluation of brain
            death
 Exclusions:
 Brain death should not even be thought of until the
  following reversible causes of coma have been
  excluded :
   Intoxication (alcohol)
   Drugs, which depress the central nervous system.
   Muscle relaxants
   Primary hypothermia (by measuring rectal
    temperature)
   Hypovolaemic shock .
   Metabolic and endocrine disorders.
  Clinical evaluation of brain
             death
 Preconditions of diagnosis:
    The patient must be deeply
     comatose.
    The patient must be maintained on a
     ventilator.
    The cause of the coma must be
     known.
    Clinical evaluation of brain
               death
 The patient is unresponsive to any stimulus
  (deep coma).
 No motor responses within the cranial nerve
  distribution can be elicited by painful or other
  sensory stimuli.
 No reflex responses indicative of continued
  brain stem function:
   Clinical evaluation of brain
              death
 Absence of corneal reflex.
 Absence of pupillary response of bright
  light.
 Absence of gag reflex ,spontaneous
  swallowing, tongue or facial
  movements
No oculo-vestibular response
    Technique oculo-vestibular test
   Technique                               Interpretation
     Patient supine with head at 30           Nystagmus both eyes slow
       degrees elevation                         toward cold, fast to midline
        Isolates input of horizontal             Not comatose
         semicircular canals
                                               Both eyes tonically deviate
     Instill 10-20 ml iced saline into          toward cold water
       auditory canal
                                                  Coma with intact brainstem
        Use 20 cc syringe
                                               No eye movement
        Use butterfly tubing with
                                                  Brainstem injury
         needle cut off
                                               Movement only of eye on side of
        Cools mastoid bone and alters
                                                 stimulus
         endolymphatic flow
                                                  Internuclear ophthalmoplegia
        Stimulates vestibular nuclei as
         if head turned
           rapidly to opposite side
Absence of oculo-cephalic
                response




                  Doll’s eye
               phenomenon)




     ‫ظاهرة عيه الدمية‬
   Clinical evaluation of brain
              death
 Apnoea test: Apnoea testing is essential for
  confirmation of brain death.
The following prerequisites have been suggested.
   The core temperature should be ≥ 36.5 ◦C
   The systolic blood pressure should be
    ≥ 90mm Hg;
   Euvolaemia (preferably positive fluid balance in
    the previous (6hour);
   Eucapnoea (arterial pCO2 ≥ 40mmHg).
  Clinical evaluation of brain
             death
Apnoea test:
The three components of the apnoea test are:
 Absence of spontaneous respiratory efforts during
  a period of disconnection from the mechanical
  ventilator (10 min.).
 Arterial carbon dioxide must reach a critical
  point(>60mmHg) during this period.
 Prevention of hypoxemia during this period.
                 Investigations
   Electroencephalography (EEG) to document
    electrocerebral silence should be done over a
    30-minute period, using standardized
    techniques for brain death determinations
       In small children, it may not be possible to meet the
        standard requirement for a I0-cm electrode
        separation.
       The interelectrode distance should be decreased
        proportional to the patient's head size.
       Drug concentrations should be insufficient to
        suppress EEG activity.
                 Investigations
 A cerebral radionuclide angiogram confirms cerebral
  death by demonstrating the lack of visualization of
  the cerebral circulation, even though there may be
  some visualization of the intracranial venous
  sinuses.
   The value of this study in infants under 2 months is under
    investigation.
   Contrast angiography can document lack of effective
    blood flow to the brain.
   While many observers have described this test as nearly
    100% accurate, others have claimed the brain-stem
    circulation, especially in the medulla, is not well
    visualized and absolute absence of blood flow to this
    region cannot be diagnosed with certainty.
 PET: New step forward in the way to look at the brain and
  how it functions.
Cerebral radionuclide
    angiogram
The brain death should be confirmed
  by;
 two medical experts
 each separately
 not including any of the transplant
  team and
 perform examination twice 24 hours
  apart.
                  CRITICS
 Rainer Beckman, who approaches the question from a
  legal perspective, claims that the declaration of the
  World Medical Association on brain death does not
  include any direct reason why brain death should
  indicate the death of a human being.
 Robert Veatch, saw that It’s not an accident to have the
  first heart transplant in 1968, and in 1978 adopting laws
  that change the definition of death had begun.
                 CRITICS
 John Shea who has researched brain death
  extensively claims that “A diagnosis of death by
  neurological criteria is theory, not scientific
  fact...irreversibility of neurological function is a
  prognosis, not a medically observable fact.
 Regarding the criteria itself, according to Dr. Paul
  Byrne, brain death is defined according to many
  disparate sets of criteria. He claims that by 1978
  more than 30 sets of criteria had been
  published...Thus a patient could be determined dead
  by one set, but not by another.
                CRITICS

 Dr. Paul Byrne criticizes the apnea test as a tool
  for determining cessation of respiration since the
  absence of respiration itself causes further
  damage to the brain.
 Byrne raises another interesting point from a
  legal perspective, that it is curious that in brain
  dead victims of homicidal assault, rarely do
  lawyers file charges until the victim is truly and
  certainly dead in the cardiopulmonary sense after
  being taken off life support.
                     CRITICS

 The Catechism of the Catholic Church clearly states
  (2296): “It is morally inadmissible to bring about the
  disabling mutilation or death of a human being, even in
  order to delay the death of other persons.”
 Dr. Vincent was questioned closely about the case of a
  pregnant women, diagnosed as brain-dead, who
  continues her pregnancy while on life-support system,
  even producing breast milk for her unborn child.
                  CRITICS

 A large number of brain-injured patients, even in deep
  coma, can recover to lead a normal daily life; their
  nervous tissue may be only silent, not irreversibly
  damaged, as a consequence of a partial reduction of
  the blood supply to the brain. (This phenomenon,
  called “ischemic penumbra,” was not known when the
  first neurological criteria for brain death were
  established.)
   Meeting of the Pontifical
Academy of Sciences Feb.,2007

 When organs are removed from a "brain dead"
  donor, all the vital signs of the “donors” are still
  present prior to the harvesting of organs, such as:
  normal body temperature and blood pressure; the
  heart is beating; vital organs, like the liver and
  kidneys, are functioning; and the donor is breathing
  with the help of a ventilator.
  Furthermore, vital organs deteriorate very quickly
  after a patient dies. "After true death" unpaired vital
  organs cannot be transplanted.”
Persistent vegetative state
)PVS)
 The term was coined to describe the patient
  who loses the higher cerebral powers of the
  brain but the functions of the brainstem
  remains relatively intact.
 cyclic state of circadian sleep & wake.
 Heads and eyes can follow a moving object or
  move towards a loud sound.
 This condition occur in massive cerebral
  infarcts, hypoxic encephalopathy and head
  trauma.
   Suspended Animation
   “Apparent Death”
 It is the slowing of life processes without termination.
  Breathing, heartbeat, and other involuntary functions
  may still occur, but they can only be detected by artificial
  means.
 It occurs in cases of electrocution, massive doses of CNS
  depressants and yoga practionars.
 Extreme cold is used to precipitate the slowing of an
  individual's functions; use of this process has led to the
  developing science of cryonics. The technique has never
  been applied to humans for more than a few hours.
DEATH UNDER ANESTHESIA
    Death under anesthesia
 Definition : Death occurring after
    administration of anesthesia, either on table or
    before full regain of consciousness.
   the rate is 1 death related to anesthesia for
    every 10,000 progressed to 1:5 million.
   1:1800 died during anesthesia.
   1:730 during the recovery period.
   Most deaths occurred in the elderly (greater
    than or equal to 70 years of age)
Causes :

Death may occur as a result of :
1.The patient :
The injury or disease necessitating
  the operation.

 A pre-existing life threatening
 disease.
  The anesthesia :
overdose  depression of respiratory center
 or myocardial depression.
Light anesthesia  vagal stimulation.
 • during induction due to tracheal intubations
 • during recovery due to aspiration.
Hypoxia  cardiac arrest.
Obstruction of air passages.
Fire and explosions
Allergic reactions


 Anesthetic gases do not produce
 allergic reactions.
 Muscle relaxants , intravenous
 anesthetic drugs, antibiotics and
 latex among causative agents.
  Malignant hyperthermia


 80% of patients who developed this problem died,
  hence the name malignant.



 The rate is one in 10,000 to one in 50,000
  anesthetic administrations.
 Elevated potassium after
 succinylcholine

 patients suffering from muscle
  disease (e.g. muscular dystrophy).
 Burn patients.
 Trauma patients.
 Spinal cord-injured patients.
Local anesthetics

 If the local anesthetic is injected into
  a vessel in large amounts, the
  patient may experience a seizure and
  cardiac arrest.
 In liposuction technique the use of
  large amounts of dilute local
  anesthetics injected under the skin,
  toxicity and death may occur.
  The surgical operation :


 Prolonged or difficult operation precipitate
  surgical shock and exhaustion.

 Surgical accident : unskilled incision of a big
  vessel or aneurysm.
 Take home message

 To recognize reliably that death has occurred, accurate
  criteria must be available for physicians' use.
 Laws and regulations regarding the criteria of death and
  organ donation should be issued and, of course, how to
  guarantee their implementation.
 Alternatives to organ donation should be sought with at
  least the same determination with which we seek organ
  donors.
  “Death is more universal
  than life; everyone dies
  but not everyone lives.”
.‫ الموت هو الحتمية للجميع ؛‬
‫كلنا سنموت ولكن هل كلنا‬
‫حينا؟‬
‫مه عاش لنفسه كان ميتا وهى حي ومه‬
‫عاش لآلخريه فهى حي تحت التراب‬




‫‪THANK YOU‬‬

								
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