Background

A recent update of the German directive on determining brain death introduced changes regarding the diagnostics in potential donors on extracorporeal membrane oxygenation (ECMO). Physicians familiar with ECMO must accompany apnea testing and cerebral blood flow-based methods are no longer permitted as ancillary tests in potential donors on venoarterial (VA) ECMO because they are considered insufficiently validated.

Objective

The aim was to identify challenges in determining brain death under VA-ECMO in the context of the updated directive.

Methods

We analyzed and compared the complete process of brain death (BD) determination before and after the directive update in all potential donors on VA-ECMO between 2021 and 2024 at the University Hospital Münster.

Results

A total of 8 potential organ donors on VA-ECMO were identified, BD was determined in seven donors and four donations were utilized (15% of all donors during the observation period). Apnea testing was performed safely in all cases, although PaCO₂ varied depending on the sampling site. In three cases before the update, cerebral circulatory arrest was demonstrated. After the update, a flat-line EEG was obtained in four cases. In one case, EEG was inconclusive due to artefacts.

Conclusion

Both apnea tests and cerebral blood flow-based methods were safely performed in donors on VA-ECMO. Electroencephalography (EEG) was only used after the directive update. Future revisions of the directive should provide precise protocols for apnea testing. Further evidence is desirable to reauthorize cerebral blood flow-based methods as ancillary tests. This could support higher organ donation rates in potential donors on VA-ECMO.