Lasts <3months, usually progresses one way or another within 2 weeks
Anoxic brain injury, Alzheimer’s, CJD
Brain Death: Absent, Absent, Positive, Negative
Clinical
Lack of spontaneous respirations
CT Scan/MRI with devastating CNS event with known cause
Absence of confounding factors
No confirmed confounding drug intoxication or poisoning
Core temperature >36, SBP >100
Neurological
Comatose patient
Absent CN reflexes & motor responses (including flexor/extensor posturing)
Absent oculovestibular reflex (caloric response)
Absent cough with tracheal suctioning
Absent sucking or rooting reflexes
Apnea by apnea test
Hemodynamically stable, temp >36, normal pH, normal PaCO2/PaO2
Pre-oxygenate with 100% oxygen for 10 minutes
Discontinue MV, continue 100% O2 passively for 10 minutes
Get ABG to confirm PaCO2 >60 or that it increased >20 from baseline ABG
Objectively confirms brainstem failure if pt cannot generate spontaneous breaths or trigger the vent in response to elevated PaCO2 levels >10 minutes after disabling control mode
Positive
Repeat clinical exam
Suggestive of brain death: Brain dead
Inconclusive or unreliable: Testing below
Inconclusive or unable to tolerate
Consider testing below
Negative
Not brain dead, no further testing
Further Testing if:
Unable to examine CN
Patients with neuromuscular paralysis or heavy sedation
Unable to complete apnea test or inconclusive results