1. Dip. Diab.DCA, Dip. Software statistics- Phd
Brain death
Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu),
Dip. Diab.DCA, Dip. Software statistics- Phd
Mahatma Gandhi Medical college and research institute , puducherry , India

2. History
In 1902, Cushing first reported cessation of cerebral circulation when intracranial pressure exceeded arterial blood pressure in monkeys
In 1959, Bertrand and colleagues reported the maintenance of respiration by mechanical means for 3 days after death of a patient with otitis media who underwent circulatory collapse

3. History first heart implantation by Barnard in 1967
Irreversible loss of consciousness
1976
Death is defined as the irreversible loss of the capacity for consciousness, combined with the irreversible loss of the capacity to breathe.”

4. Clinical Diagnosis of Brain Death

5. Diagnostic Criteria for the Clinical Diagnosis of Brain Death
Prerequisites
absence of clinical brain function when the proximate cause is known and demonstrably irreversible.   
1.    Clinical or neuroimaging evidence of an acute central nervous system catastrophe   
2.    Exclusion of complicating medical conditions that may confound clinical assessment (no severe electrolyte, acid-base, or endocrine disturbance)   
3.    No drug intoxication or poisoning   
4.    Core temperature ≥ 32°C (90°F)

6. Brain death The three cardinal findings in brain death are
coma or unresponsiveness,
absence of brainstem reflexes,
apnea.

7. Brain is all omnipotent
Can we test all ??
Immune .
Endocrine etc

8. The first one
Coma or unresponsiveness—no cerebral motor response to pain in all extremities (nail-bed pressure and supraorbital pressure) NO
Drug intoxication, severe electrolyte, acid-base, or endocrine disturbance,

9. Brain stem reflexes
Pupils
4 – 9 mm
No response to bright light

10. Ocular movement  
1. No oculo cephalic reflex (testing only when no fracture or instability of the cervical spine is apparent)   
ii.  No deviation of eyes to irrigation in each ear with 50 mL of cold water
(allow 1 minute after injection and at least 5 minutes between testing on each side)

11. oculocephalic reflex
 reflex eye movement that stabilizes images on the retina during head movement by producing an eye movement in the direction opposite to head movement, thus preserving the image on the center of the visual field.

12. COWS
Ice cold or warm water or air is irrigated into the external auditory canal, usually using a syringe.
The temperature difference between the body and the injected water creates a convective current in the endolymph .
Hot and cold water produce currents in opposite directions and therefore a horizontal nystagmus in opposite directions in patients with an intact brainstem:

13. Facial response I . No corneal reflex to touch with a throat swab
  ii.  No jaw reflex   
iii.  No grimacing to deep pressure on nail bed, supraorbital ridge, or temporo mandibular joint

14. Pharyngeal and tracheal reflexes
i.     No response after stimulation of the posterior pharynx with tongue blade   
ii.  No cough response to bronchial suctioning
Vagus
Failure of the heart rate to increase by more than 5 beats per minute after 1- 2 mg. of atropine intravenously. This indicates absent function of the vagus nerve and nuclei.

15. Clinical testing
Apnea testing

16. Apnea testing Prerequisites i. Core temperature ≥ 36.5°C or 97°F
  ii.  Systolic blood pressure ≥ 90 mm Hg   
iii.  Euvolemia. - +ve fluid balance
iv.  Normal Paco2. Option: Paco2≥ 40 mm Hg   
v. Normal Pao2. Option: preoxygenation to obtain arterial Pao2≥ 200 mm Hg

17. Apnea testing Connect a pulse oximeter disconnect ventilator.
 Deliver 100% O2, 6 L/min, into the trachea
Observe for respiratory movements
8 minutes
Respiratory attempts + means test negative
Motor responses (i.e., the Lazarus sign) may occur spontaneously during apnea testing- spinal origin

18. Apnea testing
Measure arterial Pao2, Pco2, and pH after approximately 8 minutes    
If respiratory movements are absent and arterial Pco2 is ≥ 60 mm Hg
(option: 20 mm Hg increase in Pco2 over a baseline normal Pco2), the apnea test result is positive (i.e., it supports the diagnosis of brain death).

19. Problem in between ???? BP < 90 Desaturation Arrhythmias
Reconnect & ABG
PaCO2 > 60 or increase more than 20 from normal baseline +
but in between results – indeterminate

20. After brain death Patients become poikilothermic Hypothermic No fever
External heat ?? Use
2 – 24 hours hormones continue to secrete
Immune system
Increased immune mediators, cytokines ? Organ transplantation success rates

21. The path Brain injury Progress of ischemia
Sudden hypotension ( vagal )
Brainstem death
Unopposed sympathetic (storm)
Can damage myocardium

22. Young RTA patient with brain death

23. Cerebral Death: Persistent Vegetative State
Stop of the functions of the cerebral cortices.
Brainstem functions governing the respiratory centers, autonomic nervous system, endocrine system, and immune system, which are vital for maintaining life, are preserved
May go for months to years
That is death ?? Controversial

24. Brain dead = dead !! Central Integrator Theory of the Brain
In brain death, the body is no more an integrated organism but a mere and rapidly disintegrating collection of organs that have lost forever the capacity of working as a coordinated whole

25. Infant organs Anencephalics Organ donors
Gernamy OKAYs but still concern about
Dead donor rule
Radionucide blood flow and 2 EEG – children

26. Brain dead mother But fetus Preserve for weeks Tocolytics
Ethical , moral and legal issues to be sorted out

27. Variability in Policies and Practices for Determining Brain Death
Law
Guideline
Apnea test
Number of physicians
Observation time
Confirmatory tests
India !!

28. Confirmatory tests Cerebral Angiography Electroencephalography
Transcranial Doppler Ultrasonography
Cerebral Scintigraphy (99mTc-hexametazime)
Evoked Responses
Positron Emission Tomography

29. Harvard medical school definition
Brain death
unresponsiveness and lack of receptivity, the absence of movement and breathing, the absence of brain-stem reflexes, and coma whose cause has been identified.
Withdraw cardio-respiratory support in accordance with hospital policies, including those for organ donation

30. Organ donation -- anaesthetic concerns
Among the brain dead
4 % of deaths are fit to donate
Out of which 10 % come to our picture

31. Donor
A potential donor is any previously healthy individual who has suffered an irreversible catastrophic brain injury of known aetiology.
Exclusion criteria
old age (greater than yr), untreated systemic sepsis, most extra cranial malignancies, and the presence of transmissible diseases not amenable to antibiotic therapy

32. What organs?? Donor organs may be divided into perfusible organs
(kidneys, liver, heart, lung(s), pancreas, and bowel)
Non perfusable organs and tissues (eyes, skin, bone, heart valves, and dura).
Maintain perfusion

33. Rule of 100 Systolic blood pressure > 100 mmHg
Urine output > 100 ml. hr
PaO2 > 100 mmHg
Haemoglobin > 100 g.
Blood sugar around 100 mg%

34. Anaesthetic problems

35. Other goals CVP 6- 10 mmHg pH – 7.35 to 7.45 Na – 130 – 140
K+ -- , calcium, magnesium kept normal
Temperature - > 35.5 – controversial
PaCo2 – normal
Methylprednisolone 15 mg/kg
T3 ( thyroxine)

36. Anaesthetic concerns
spinal cords are intact and somatic and visceral reflexes remain,
Muscle relaxants are necessary to suppress motor activity mediated by spinal reflexes.
Vasodilators usually are employed to suppress hypertension and tachycardia by noxious stimuli.
Sedation and analgesia ? !!

37. Summary 1. Establishing the cause of disease
2.    Excluding certain potentially reversible syndromes that may produce signs similar to brain death   
3.    Demonstrating clinical signs of brain death: coma, brainstem areflexia, and apnea
Anaesthetic concerns

38. Thank you