What are the criteria for confirming death?

Confirming Death: Clinical Criteria and Procedures

Death is confirmed through either cardiopulmonary criteria (irreversible cessation of circulatory and respiratory functions) or neurological criteria (brain death), with brain death requiring two complete clinical examinations including apnea testing, performed by experienced clinicians. 1

Two Pathways to Death Determination

Cardiopulmonary Death (Traditional Death)

• Irreversible cessation of cardiac and respiratory function confirmed by:
  • Absence of palpable pulse for a minimum observation period 2
  • Absence of heart sounds on auscultation for at least one minute 2
  • Absence of respiratory effort with no chest rise 2
  • Fixed and dilated pupils 2
  • Absence of response to painful stimuli 2

This is the most common pathway and applies when resuscitation is not attempted or has failed. Nurses can verify cardiopulmonary death only if the patient has a DNACPR (Do Not Attempt Cardiopulmonary Resuscitation) order in place. 2

Brain Death (Neurological Death)

Brain death determination requires meeting all of the following criteria in sequence:

Prerequisites Before Testing

The following conditions must be established before proceeding with brain death examination: 1

• Irreversible catastrophic brain injury with known etiology (trauma, hemorrhage, anoxia, etc.) 1
• Core temperature >35°C (normothermia must be maintained) 1
• Absence of CNS depressant drugs or neuromuscular blocking agents (must be below therapeutic levels or completely eliminated) 1, 3
• Normal blood pressure for age (hemodynamic stability achieved) 1
• Correction of metabolic derangements (normal pH, electrolytes) 1
• No confounding factors such as severe hypothermia, shock, or metabolic coma 1

Clinical Examination Components

Two complete neurological examinations must be performed, demonstrating: 1

1. Coma (Unresponsiveness)

• Complete absence of motor responses to noxious stimuli applied to cranial nerve distribution and all extremities 1
• No grimacing, no purposeful movements 1
• Spinal reflexes (withdrawal, myoclonus) may persist and do not preclude brain death 1

2. Absent Brainstem Reflexes

All of the following must be absent: 1

• Pupillary reflex: Pupils fixed (4-9mm), no constriction to bright light in darkened room 1
• Corneal reflex: No eyelid movement when cornea touched with tissue paper, cotton swab, or water squirts 1
• Oculocephalic reflex ("doll's eyes"): Eyes move passively with head rotation without lag (only test if cervical spine cleared) 1
• Oculovestibular reflex (cold caloric): Head elevated 30 degrees, irrigate each ear separately with 10-50mL ice water after confirming patent canal; no eye movement during 1 minute observation 1
• Gag reflex: No response to posterior pharynx stimulation 1
• Cough reflex: No cough with tracheal suctioning to carina level 1

3. Apnea Testing

This is the definitive test for brainstem function and must demonstrate: 1

Prerequisites:

• Core temperature >35°C 1
• Systolic BP appropriate for age 1
• Euvolemia 1
• Normal PaCO₂ at baseline (35-45 mmHg) 1
• Preoxygenation with 100% O₂ for 5-10 minutes 1

Procedure:

• Disconnect ventilator while providing oxygen insufflation via catheter through endotracheal tube OR use T-piece with 100% O₂ 1
• Continuously monitor heart rate, blood pressure, oxygen saturation 1
• Observe for any respiratory effort 1
• Obtain arterial blood gas when patient appears apneic 1

Positive test (consistent with brain death):

• PaCO₂ ≥60 mmHg AND ≥20 mmHg rise above baseline with complete absence of respiratory effort 1

Abort test if:

• Oxygen saturation falls below 85% 1
• Hemodynamic instability occurs 1
• Any respiratory effort observed (inconsistent with brain death) 1

4. Flaccid Tone

• Complete flaccidity on passive range of motion of all extremities (excluding spinal reflexes) 1

Ancillary Studies (When Needed)

Ancillary studies are NOT required for brain death determination if clinical examination and apnea testing can be completed. 1 However, they should be used when: 1

• Components of examination cannot be safely completed 1
• Apnea testing cannot be performed or completed 1
• Uncertainty exists about examination results 1
• Medication effects may interfere with evaluation 1

Available ancillary studies include: 1, 4

• Electroencephalography (EEG) - highest completion rate (98%), good sensitivity (83%) and specificity (97%) 4
• Radionuclide cerebral blood flow study 1
• Transcranial Doppler (TCD) - lower completion rate (54%) 4
• Somatosensory evoked potentials (SEP) - best sensitivity (100%) when combined with EEG 4

If ancillary study is equivocal, the patient cannot be pronounced dead and must be observed for 24 hours before repeat testing. 1

Observation Periods Between Examinations

Two complete examinations are required, separated by an observation period: 1

• Adults and children >1 year: Observation period determined by clinical judgment, typically 6-24 hours 1
• Infants and young children: Longer observation periods required per pediatric guidelines 1

Declaration of Death

Death is declared after confirmation and completion of the second clinical examination and apnea test. 1 The examination must be performed by experienced clinicians familiar with neurocritical care. 1 All findings must be thoroughly documented in the medical record, including both examinations, apnea test results, and any ancillary studies performed. 1

Critical Pitfalls to Avoid

• Never diagnose brain death in the presence of hypothermia (<35°C), drug intoxication, or neuromuscular blockade - these are absolute contraindications 1, 3
• Any respiratory effort during apnea testing is inconsistent with brain death and testing must be terminated 1
• Spinal reflexes can persist after brain death - do not confuse these with brainstem function 1
• Ensure adequate PaCO₂ rise during apnea testing - failure to reach ≥60 mmHg invalidates the test 1
• In patients with chronic respiratory disease, the PaCO₂ must rise ≥20 mmHg above their baseline, as they may only respond to supranormal levels 1
• Ancillary studies are not a substitute for clinical examination - they only supplement when examination cannot be completed 1