Neurocritical Care
Brain Death Determination
Educational overview of brain death clinical criteria, prerequisites, examination, apnea testing, and ancillary testing. Based on AAN guidelines. Pending institutional review.
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⚠️ Content Status
Guideline-supported example content* — Based on AAN Practice Parameters. This is NOT official local protocol.Section
⚠️ Content Status
Guideline-supported example content* — Based on AAN Practice Parameters. This is NOT official local protocol.- Guideline-supported example content* — Based on AAN Practice Parameters. This is NOT official local protocol.
Brain death determination is a formal medical, ethical, and legal process. Always follow your institution's specific brain death protocol. Consult neurology, neurosurgery, and/or intensivist per your institutional policy. Do not substitute this content for institutional protocol.
Definition
Brain death* (brain death/death by neurological criteria — BD/DNC) is the irreversible cessation of all brain function, including...Section
Definition
Brain death* (brain death/death by neurological criteria — BD/DNC) is the irreversible cessation of all brain function, including...- Brain death* (brain death/death by neurological criteria — BD/DNC) is the irreversible cessation of all brain function, including the brainstem.
Prerequisites (Must Be Established Before Exam)
Known cause of coma — structural or metabolic etiology identified and consistent with brain deathSection
Prerequisites (Must Be Established Before Exam)
Known cause of coma — structural or metabolic etiology identified and consistent with brain death- Known cause of coma — structural or metabolic etiology identified and consistent with brain death
- No reversible causes of coma:
- Significant hypothermia: Core temp must be ≥ 36°C (96.8°F)
- Metabolic disturbances corrected (severe hypoglycemia, hyperosmolarity)
- Drugs: No CNS depressants (benzodiazepines, opioids, barbiturates, antiepileptics), no neuromuscular blocking agents, alcohol ≥ 0
- Sufficient time for drug clearance (depends on drug, dose, duration, organ function)
- Hemodynamic stability — adequate perfusion during exam
Clinical Examination for Brain Death
No purposeful motor response to stimuli • No evidence of consciousness • No sleep-wake cyclingSection
Clinical Examination for Brain Death
No purposeful motor response to stimuli • No evidence of consciousness • No sleep-wake cyclingComa
- No purposeful motor response to stimuli
- No evidence of consciousness
- No sleep-wake cycling
Absence of Brainstem Reflexes
| Reflex | Absent response in brain death |
|---|---|
| Pupillary | Fixed pupils, no response to bright light (mid-position or fully dilated) |
| Corneal | No blink to corneal touch bilaterally |
| Oculocephalic (Doll's eyes) | No eye movement with rapid head rotation (do NOT test if C-spine not cleared) |
| Oculovestibular (cold caloric) | No eye movement after cold water irrigation bilaterally |
| Gag | No gag response to posterior pharynx stimulation |
| Cough | No cough to deep tracheal suctioning |
- Note:* Spinal reflexes (including Babinski, triple flexion) may persist and are not evidence of brainstem function.
Apnea Test
Pre-oxygenate: FiO₂ 1.0 for ≥ 10 minutes; verify PaO₂ ≥ 200 mmHg • Disconnect ventilator • Provide diffusion oxygenation (e. g., 6...Section
Apnea Test
Pre-oxygenate: FiO₂ 1.0 for ≥ 10 minutes; verify PaO₂ ≥ 200 mmHg • Disconnect ventilator • Provide diffusion oxygenation (e. g., 6...- Pre-oxygenate: FiO₂ 1.0 for ≥ 10 minutes; verify PaO₂ ≥ 200 mmHg
- Disconnect ventilator
- Provide diffusion oxygenation (e. g., 6 L/min O₂ via suction catheter in ET tube)
- Observe for spontaneous respiratory effort for 8–10 minutes
- Check ABG at end:
- Positive test (confirms brain death): PaCO₂ ≥ 60 mmHg (or ≥ 20 mmHg above baseline) with no respiratory effort
- Abort if:* hemodynamic instability, SpO₂ < 85% for > 30 seconds, significant arrhythmia.
Number of Examinations Required
Many institutions require 2 examinations by 2 physicians (typically > 6 hours apart) • At least one examination should typically...Section
Number of Examinations Required
Many institutions require 2 examinations by 2 physicians (typically > 6 hours apart) • At least one examination should typically...- Many institutions require 2 examinations by 2 physicians (typically > 6 hours apart)
- At least one examination should typically be by an attending with training in brain death determination
- Follow your institution's specific protocol
Ancillary Testing
Test • What It Shows • EEGSection
Ancillary Testing
Test • What It Shows • EEG| Test | What It Shows |
|---|---|
| EEG | Electrocerebral silence |
| Cerebral angiography | No intracranial circulation |
| Nuclear medicine cerebral perfusion scan | No flow to brain |
| CTA head/neck | No intracranial flow |
| TCD (transcranial Doppler) | No cerebral blood flow |
Documentation
Date and time of declaration • Documentation of clinical exam findings • Apnea test resultsSection
Documentation
Date and time of declaration • Documentation of clinical exam findings • Apnea test results- Date and time of declaration
- Documentation of clinical exam findings
- Apnea test results
- Presence of any ancillary tests
- Attestation by qualified physician(s) per institutional policy
Organ Donation
Once brain death is declared, contact organ procurement organization (OPO) per institutional protocol. OPO will guide referral...Section
Organ Donation
Once brain death is declared, contact organ procurement organization (OPO) per institutional protocol. OPO will guide referral...Once brain death is declared, contact organ procurement organization (OPO) per institutional protocol. OPO will guide referral process and family communication.
- This is guideline-supported example educational content based on AAN Practice Parameters. Always follow your institution's brain death protocol. Brain death determination has specific medical, legal, and ethical requirements that are institution-specific.*