Study guide
Determination of Death by Neurologic Criteria
ABPN Neurocritical Care Study Guide Exam
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1 Chapter 1: Neurologic Examination & Coma Assessment in the ICU
Current Examination, Blueprint & Preparation Neurologic Examination in Critically Ill Patients Coma Evaluation & Consciousness Alterations Delirium & Toxic-Metabolic Encephalopathy in the ICU
2 Chapter 2: Cerebral Physiology & Intracranial Dynamics
Cerebral Blood Flow, Metabolism & Autoregulation Intracranial Pressure & Compliance Cerebral Edema & Herniation Syndromes
3 Chapter 3: Intracranial Hypertension & Cerebral Perfusion Management
Tiered ICP Management Protocols Hyperosmolar Therapy & Fluid Management Advanced & Refractory ICP Interventions
4 Chapter 4: Airway, Mechanical Ventilation & Pulmonary ICU Management
Emergency Airway Management & Neuro-Intubation Mechanical Ventilation Strategies in Acute Brain Injury Tracheostomy & Ventilator Weaning in Neurocritical Care Pulmonary Complications in the Neuro-ICU Obstructive Lung Disease, Pulmonary Hypertension & Bronchoscopy
5 Chapter 5: Hemodynamics, Shock & Cardiovascular Management
Hemodynamic Monitoring & Blood Pressure Targets Vasoactive Agents: Inotropes, Vasopressors & Antihypertensives Cardiac Complications of Brain Injury
6 Chapter 6: Neuropharmacology, Analgesia & Sedation
ICU Sedation & Analgesia Neuromuscular Blockade & Monitoring Propofol Infusion Syndrome & Drug Toxicities Antiseizure Drug Pharmacology in the ICU
7 Bleeding, Thrombosis & Hematologic Emergencies
Warfarin & Heparin Reversal Direct Oral Anticoagulant (DOAC) Reversal Antiplatelet Management & Platelet Dysfunction Venous Thromboembolism Prophylaxis & Management Transfusion, Coagulopathy, TMA & Cellular-Therapy Neurotoxicity
8 Chapter 8: Systemic ICU Care, Fluids, Electrolytes & Endocrine
Hyponatremia & Osmoregulation: SIADH vs Cerebral Salt Wasting Diabetes Insipidus, Hypernatremia & Endocrine Crises Critical Care Prophylaxis, Nutrition & Infection Prevention
9 Systemic Trauma & Environmental Injury
Polytrauma, Chest Injury & Abdominal Hemorrhage Burns, Electrical Injury & Hanging
10 Cardiac Emergencies & Mechanical Support
IABP, Ventricular Devices & ECMO Acute Coronary, Valvular, Rhythm & Aortic Emergencies
11 Kidney Injury, Acid–Base & Renal Replacement
Acute Kidney Injury & Renal Drug Clearance Acid–Base Disorders, Electrolytes & Renal Replacement
12 Systemic Infection & Endocrine Emergencies
Sepsis, Endocarditis & Antimicrobial Principles Thyroid, Adrenal & Dysglycemic Emergencies
13 Gastrointestinal & Hepatic Emergencies
Acute Abdomen, GI Bleeding & Abdominal Compartment Syndrome Acute Liver Failure, Cirrhosis & Hepatic Drug Effects
14 Chapter 9: Neuroimaging in the Neuro-ICU
Non-Contrast CT & CT Angiography CT Perfusion & Advanced Perfusion Imaging Magnetic Resonance Imaging in Critical Illness
15 Chapter 10: Electrophysiology & Neuromonitoring
Continuous EEG & ACNS Standardized Critical Care Terminology Invasive Neuromonitoring: ICP & External Ventricular Drains Multimodal Monitoring: PbtO2, Microdialysis & Transcranial Doppler
16 Angiography, Electrodiagnosis & CSF Analysis
Conventional Angiography & Cranial–Spinal Shunts EMG, Nerve Conduction & Acute Muscle Disease CSF Analysis: Infection, Inflammation & Hemorrhage
17 Chapter 11: Bedside Procedures, Ultrasound & Death by Neurologic Criteria
Critical Care Procedural Skills Critical Care Ultrasound & Echocardiography Determination of Death by Neurologic Criteria
18 Chapter 12: Acute Ischemic Stroke & Reperfusion Therapies
Acute Ischemic Stroke Management & Thrombolysis Endovascular Thrombectomy & Large Vessel Occlusion Malignant Hemispheric & Cerebellar Infarction
19 Chapter 13: Spontaneous Intracerebral Hemorrhage & Intraventricular Hemorrhage
Acute Intraparenchymal Hemorrhage Management Intraventricular Hemorrhage & Hydrocephalus Surgical Evacuation & Minimally Invasive Surgery in ICH
20 Chapter 14: Aneurysmal Subarachnoid Hemorrhage & Delayed Cerebral Ischemia
Aneurysmal Subarachnoid Hemorrhage: Acute Resuscitation & Securing Delayed Cerebral Ischemia & Cerebral Vasospasm Non-Aneurysmal Subarachnoid Hemorrhage & Vascular Malformations
21 Venous, Spinal & Traumatic Vascular Disease
Cerebral Venous Thrombosis & Spinal Cord Infarction Traumatic Dissection, Carotid–Cavernous Fistula & Penetrating Injury
22 Chapter 15: Traumatic Brain & Spinal Cord Injury
Severe Traumatic Brain Injury & Contusions Acute Traumatic Spinal Cord Injury & Neurogenic Shock Spine Trauma, Fractures & Cord Syndromes
23 Chapter 16: Status Epilepticus, Seizures & Neuromuscular Emergencies
Status Epilepticus: Convulsive & Non-Convulsive Refractory & Super-Refractory Status Epilepticus Acute Neuromuscular Respiratory Failure
24 Chapter 17: Post-Cardiac Arrest Care, CNS Infections & Encephalitis
Targeted Temperature Management & Post-Cardiac Arrest Care Post-Cardiac Arrest Neuroprognostication Acute CNS Infections, Encephalitis & Inflammatory Emergencies
25 Neuroinflammation & Neurooncology
Fulminant Demyelination & Autoimmune Encephalitis Brain, Spinal & Leptomeningeal Cancer Emergencies
26 Pregnancy, Transplantation & Pediatric Care
Pregnancy, Postpartum & Post-Transplant Neurologic Care Pediatric Neurocritical Care
27 Chapter 18: Neurosurgical & Perioperative Emergencies
Postoperative Neurosurgical Complications Device Complications: EVDs, Shunts & ICP Monitors Cerebral Hyperperfusion Syndrome & Post-Interventional Emergencies
28 Chapter 19: Ethics, Palliative Care & Organ Donation in the Neuro-ICU
Communication, Surrogate Decision-Making & Conflict Resolution Neuroprognostication Ethics, Withdrawal of Life Support & Palliative Care Organ Donation & Management of the Deceased Donor
Determination of Death by Neurologic Criteria
Key Takeaways Explain This Topic AI
The 2023 consensus requires core temperature at least 36 °C; if temperature was 35.5 °C or lower, wait at least 24 hours after rewarming to at least 36 °C.
Adult blood pressure must be at least SBP 100 mm Hg and MAP 75 mm Hg; pediatric targets are age-specific.
With no chronic CO2 retention, the apnea endpoint requires no respirations, pH below 7.30, PaCO2 at least 60 mm Hg, and a rise at least 20 mm Hg above baseline.
Ancillary testing is used for specified limitations and does not replace prerequisites or override observed brain-mediated activity.
Children require two independent examinations separated by at least 12 hours and two apnea tests when safely possible.
Last updated: October 2026
Establish Permanence and Exclude Confounders
Brain death/death by neurologic criteria (BD/DNC) is a distinct determination of death, not a prediction of poor functional recovery. Follow applicable law, institutional policy, examiner qualifications, and the 2023 AAN/AAP/CNS/SCCM consensus guideline. Identify a catastrophic permanent brain injury with a known mechanism capable of causing loss of all brain function and compatible neuroimaging. If the injury is primarily infratentorial, confirm that it has also produced catastrophic supratentorial injury before initiating evaluation.
Allow enough observation to establish permanence. The guideline includes age- and injury-specific minimums: in children younger than 24 months, wait at least 48 hours after acute brain injury; in patients aged at least 24 months with hypoxic-ischemic injury, wait at least 24 hours. Other circumstances may require longer observation, including time after interventions intended to reduce ICP. Meeting a minimum interval does not establish permanence by itself.
Core temperature must be at least 36 °C. If it was 35.5 °C or lower, wait at least 24 hours after rewarming to at least 36 °C. This observation period is separate from drug elimination. Sedatives can persist longer with hypothermia, obesity, or renal or hepatic dysfunction. Use appropriate drug levels when available or allow at least five half-lives, extended for those factors and the actual exposure. If pentobarbital was given, the level must be below 5 micrograms/mL or below the laboratory detection limit. A short-lived response to an antagonist does not establish durable absence of drug confounding.
Exclude pharmacologic paralysis with an appropriate peripheral nerve response or preserved deep tendon reflexes under the guideline. Correct severe metabolic, acid–base, and endocrine disturbances. Some uncorrectable metabolic confounders require ancillary testing after the remainder of the examination is performed as fully as possible; high sedative concentrations and hypothermia cannot be bypassed in this way.
Blood Pressure and Clinical Examination
In adults, maintain both SBP at least 100 mm Hg and MAP at least 75 mm Hg, using fluids and vasoactive support if necessary. In children, maintain SBP and MAP at or above the fifth percentile for age. Consider known chronic baseline pressure when applying the guideline. Hypotension can suppress function and invalidate assessment.
Demonstrate coma without brain-mediated response to visual, auditory, tactile, and noxious stimulation. Test pupillary, corneal, oculocephalic when safe, oculovestibular, gag, and cough responses according to the complete protocol. Do not move an unstable cervical spine to test oculocephalic responses. Facial trauma or anatomic limitations may prevent valid assessment and require an ancillary pathway.
Spinal reflexes can persist after BD/DNC and do not themselves exclude it. If a movement cannot confidently be classified as spinal rather than brain-mediated, obtain appropriate expert assessment and ancillary testing as indicated. Any observed brain-mediated activity precludes the determination; a perfusion study cannot override it. Pupils need not have one fixed size, but light responses must be absent bilaterally.
Apnea Testing
Assess the risk of hypoxemia and circulatory instability before testing. Preoxygenate with 100% oxygen for at least ten minutes to achieve PaO2 above 200 mm Hg, establish appropriate baseline PaCO2 and pH, and obtain a baseline gas. Use an accepted oxygenation method that prevents ventilation while maintaining oxygen delivery; CPAP methods can preserve recruitment. Adult catheter insufflation, when used, follows diameter, flow, and position precautions. Pediatric methods differ.
Observe continuously for respiratory effort and obtain gases according to the protocol. The endpoint in a patient without chronic CO2 retention requires all of the following:
No spontaneous respirations.
Arterial pH below 7.30.
PaCO2 at least 60 mm Hg and at least 20 mm Hg above the pretest baseline.
For known chronic hypercarbia, use the known elevated premorbid baseline for the required rise. If chronic retention is suspected but the premorbid baseline is unknown, the guideline requires ancillary testing in addition to an otherwise qualifying apnea assessment. Do not automatically normalize a chronic retainer's baseline and ignore this distinction.
Abort for spontaneous respirations, adult SBP below 100 or MAP below 75 despite support, pediatric pressure below the age-specific threshold despite support, progressive saturation below 85%, or an arrhythmia with hemodynamic instability. Do not wait an invented additional 30 seconds after a dangerous threshold. When instability threatens, obtain an ABG before reconnecting if feasible and safe; subsequent interpretation or repeat testing depends on whether valid endpoints were reached. Stabilize the patient and choose a supported repeat or ancillary strategy rather than persisting through unsafe physiology.
Examinations and Ancillary Tests
Adults require at least one complete examination and one apnea test; policy or law may require more. Children require two independent examinations by two qualified clinicians, at least 12 hours apart, and two apnea tests, one after each examination, when safely possible. This 12-hour inter-examination minimum applies across the pediatric ages covered by the guideline, not the older age-dependent 24/12-hour scheme. Testing does not apply below 37 weeks corrected gestational age.
- Accepted ancillary approach Scope
- Conventional four-vessel catheter angiography Appropriate expert protocol
- Radionuclide cerebral perfusion testing Appropriate tracer, technique, and interpretation
- Transcranial Doppler Adults only; technically adequate assessment
EEG, evoked potentials, CTA, and MRI/MRA are not accepted ancillary tests under this guideline. Perform the clinical examination and apnea testing to the fullest safe extent before ancillary testing. These tests are not standalone alternatives to establishing prerequisites and do not permit declaration when brain-mediated activity is present. Document the examination, testing limitations, results, and determination under the relevant policy.
Source checked October 17, 2026: 2023 consensus guideline and published clarification .