What are the techniques for pronouncing death (determination of death)?

Techniques for Determining Death

The determination of death requires a comprehensive clinical examination confirming absence of neurologic function with a known irreversible cause of coma, including absence of all brainstem reflexes and apnea testing, performed by qualified physicians with appropriate observation periods based on patient age. 1, 2

Brain Death Determination

Prerequisites Before Testing

• Ensure reversible conditions are corrected:
  • Normalize body temperature (core temperature >35°C)
  • Correct hypotension
  • Resolve metabolic disturbances that could affect neurological examination
  • Discontinue sedatives, analgesics, neuromuscular blockers, and anticonvulsants for appropriate time periods 1, 2
• Defer assessment for 24-48 hours after cardiopulmonary resuscitation or severe acute brain injuries 1, 2

Clinical Examination Components

1. Coma: Complete unresponsiveness to all stimuli
2. Absence of all brainstem reflexes:
   • Pupillary light reflex
   • Corneal reflex
   • Oculocephalic reflex (doll's eyes)
   • Oculovestibular reflex (cold caloric)
   • Gag reflex
   • Cough reflex 2

Apnea Testing Procedure

1. Preoxygenate with 100% oxygen
2. Disconnect from ventilator while providing oxygen via T-piece, self-inflating bag valve system, or tracheal insufflation
3. Observe for respiratory effort
4. Measure arterial blood gases until PaCO₂ ≥60 mmHg AND ≥20 mmHg above baseline
5. Monitor vital signs continuously throughout testing 1, 2

Number of Examinations and Observation Periods

• Two examinations including apnea testing are required
• Examinations should be performed by different attending physicians
• Recommended observation periods:
  • 24 hours for term newborns (37 weeks gestation to 30 days of age)
  • 12 hours for infants and children (30 days to 18 years) 1, 2

Ancillary Testing

Ancillary tests should be performed when:

• Components of the examination or apnea testing cannot be completed safely
• Uncertainty exists about the clinical examination
• Medication effects may be present
• To reduce the inter-examination observation period 1, 2

Recommended Ancillary Tests

1. Cerebral Blood Flow Studies:

   • Four-vessel cerebral angiography (gold standard)
   • Radionuclide cerebral blood flow studies (sensitivity ~86%)
   • CT angiography (emerging alternative to catheter angiography) 2, 3, 4

2. Electroencephalography (EEG):

   • Demonstrates absence of electrical activity
   • Sensitivity of approximately 76% on first EEG, increasing to 89% with multiple EEGs 2

Circulatory Death Determination

For uncontrolled donation after circulatory death (uDCD), death is determined by:

1. Absence of circulation
2. Absence of spontaneous ventilation
3. Rapid neurologic assessment confirming absence of consciousness, spontaneous motor activity, and brainstem reflexes 1

"No-Touch Period"

• A hands-off interval during which no interventions to the body are allowed
• Required for declaring death
• Varies between protocols, ranging from 5 to 20 minutes 1

Documentation and Declaration

• Death is declared after the second neurologic examination and apnea test confirms an unchanged and irreversible condition
• Documentation must include:
  • Clinical examination criteria
  • Results of apnea testing
  • Results of ancillary testing (if performed)
  • Determination of irreversibility 1, 2

Common Pitfalls to Avoid

1. Misinterpreting spinal reflexes as evidence of brain function
2. Inadequate observation time when etiology is uncertain
3. False detection of respiratory effort during CPAP mode on ventilators
4. Performing testing too early after cardiopulmonary resuscitation or acute brain injury
5. Failing to correct reversible conditions that could confound the examination 1, 2

The American College of Physicians supports maintaining two independent standards for determining death: cardiorespiratory and neurologic (whole brain death), while keeping issues about death determination separate from organ transplantation considerations 5.