Brain Death on ECMO — Summary

1. Introduction & Objectives

• Objectives:

  • Understand why brain death assessment on ECMO is important.

  • Review the technical process of declaring brain death by neurological criteria.

• Relevance:

  • Many ECMO patients originate from out-of-hospital cardiac arrest (OHCA).

  • Despite ECMO’s life-saving role, many patients do not survive.

  • ECMO can preserve organs and expand the donor pool, offering collateral benefits through organ donation.

2. ECMO and Organ Donation

• Organ Shortage: Global demand for organs is rising sharply.

• ECMO Contribution:

  • Maintains organ perfusion and function, improving graft outcomes.

  • Applicable to ECPR, cardiogenic shock, and ARDS cases.

• Studies Highlight:

  • ECMO patients show significant potential for organ donation (brain death and circulatory death donors).

  • Emphasizes ethical, humane handling and institutional preparedness.

3. Prerequisites for Brain Death Evaluation

• Institutional Protocols: Each ECMO center should have internal criteria with neurologist involvement.

• Preconditions:

  • Confirm catastrophic brain injury via history, imaging, and examination.

  • Exclude confounders: drug effects, hypothermia, intoxication, or hemodynamic instability (MAP >75 mmHg).

  • Consider ECMO’s altered pharmacodynamics — allow sufficient time for drug clearance.

4. Diagnostic Criteria

• Absence of Cerebral Function: No movement or response to pain; spinal reflexes may persist.

• Absence of Brainstem Function:

   

  • No pupillary, corneal, vestibular, gag, or cough reflexes.

  • No spontaneous breathing.

   

• Irreversibility: Condition must be non-recoverable.

5. Apnea Test on ECMO

• Principle: Elevated CO₂ should trigger breathing in a non–brain-dead patient.

• Procedure:

  • Reduce sweep gas (0.5–1 L/min) to retain CO₂.

  • Preoxygenate and disconnect from the ventilator (CPAP or oxygen supplement).

  • Obtain baseline and follow-up blood gases (multiple sites for VA/VVA).

  • Positive test: PaCO₂ > 55 mmHg or ≥ 20 mmHg rise with no respiratory effort.

  • Terminate if instability or desaturation occurs.

6. Ancillary Tests

• • EEG: Absence of electrical activity indicates brain death.

  • Cerebral Angiography or Perfusion Scan: No blood flow signifies absent cerebral perfusion.

  • Somatosensory Evoked Potentials: Absence of N20 wave suggests cortical inactivity.

    If Apnea Test Not Feasible:

7. Key Recommendations

• Establish brain death on ECMO protocols involving neuro experts.

• Allow 24–48 hours stabilization before testing post–acute phase.

• Exclude all reversible causes.

• Perform apnea test ideally twice or with two independent providers.

• Use ancillary tests when apnea test cannot be safely performed.

Conclusion:

ECMO offers life-saving potential and opportunities for organ donation, but brain death diagnosis requires structured, ethical, and multidisciplinary protocols to ensure accuracy and respect for patients and families