Neuro - Brain Stem Death Flashcards
Define Death
Simulataneous and irreversible loss of: capacity for conciousness capacity to breathe
Define brain death
Complete and irreversible loss of brain and brainstem functionDue to neurological injuryHeart still beats but resp depends on ventilator
What are the essential components for diagnosis of death by neurological criteria
Academic of Medical Royal Colleges code: 1) fulfil essential preconditions 2) exclude potential reversible causes of coma 3) formally demonstrate apnoea AND coma
What are the pre conditions for brain stem testing
1) patient is deeply unconcious, apneoic and mechnically vented2) there is irreversible brain damage of known aetiology3) none of the exclsuion critera are mett
Exclusion criteria:
1) that coma is not secondary to reversible factors CNS depressant drugs Biochemical/metabolic abnormalities Hypothermia
How do you approach drugs as a cause of coma
1) observe for 2-3 times the half life of the drug2) give antidotes/antagonists3) plasma levels4) alternative tests —> absence of blood flow/perfusions
Levels of: midaz| thio
Midaz : >10ug/LThio: > 5mg/L
Reversible causes (physiology and metabolic)
MAP > 60mmHgResp: pH 7.35 to 7.45 CO2 < 6 pO2>10Temp >34CNa 115-160K - >2Mg >0.5Phos >0.5Glucose 3-20
Who can do tests
Two doctors1 consultant1 more than 5 years GMC registeredClinically competent to do itPaeds - a doctor not associated with the case
When is the legal time of death
Conclusion of the first test
Tests and cranail nerves
Pupillary 2 —> 3. Light in eyesCorneal 5 —> 6. Swab to corneaPain 5 —> 7. Supra orbital pressureVestibulo ocular —> 8 —> 3,4,6 50mls cold water toauditory meatusGag 9–> 10 Pharynx and tonuge depressorCough. 10–> 10 Suction
Describe apnoea test
FiO2 to 1.0ABG —> values for PaCO2 and SaO2 correlate with monitorDecreased MV to get etCO2 > 6(ABG to check CO2>6)Observe for 5 minutesMaintain O2 by 5litres via suction catheterABG - CO2 up by 0.5
When cant you do BSD
1) cannot exclude sedative drugs2) high c-spine injury3) maxfax injruy
If you cant do BSD, what can you do
Auxillary tests:Measure of electrical activity —> EEG SSEPFlow studies: Cerebral angiograph TCD
