Non confirmatory electroencephalography in patients meeting clinical criteria for brain death: scenario and impact on organ donation.

OBJECTIVE

To describe the causes and outcome of adult patients with preserved electroencephalographic activity despite clinical findings suggesting brain death (BD), and its impact on organ donation.

METHODS

Retrospective study of the clinical and electroencephalography (EEG) data of all adult patients admitted to our hospital between January 2001 and December 2011 in whom a comprehensive clinical diagnosis of BD was reached following absence of brainstem reflexes and confirmatory apnea tests, were obtained. All patients with clinical findings suggesting BD and an EEG showing brain activity were selected for the analysis. We calculated the brain death interval (BDI) as the time between the first complete clinical examination and confirmatory ancillary test, or the time between the first and second complete clinical examination for BD, in order to analyze the impact on family consent for organ donation.

RESULTS

A complete clinical examination and EEG were diagnostic in 289 patients. In 279 (96.5%), the first EEG showed electrocerebral inactivity corroborating the clinical findings of BD. The mean BDI in this group was 4.2 ± 5.8h (median; 1.8[1.0-3.5]). This value was significantly lower than in the group in which only two full clinical evaluations were performed (p<0.0001). In 10 out 289 (3.5%), the first EEG showed at least some brain activity. The mean BDI in this group was 27.2 ± 13.8h (median; 22.9 [19.1-31.2]). In two cases, a third EEG was necessary before obtaining electrocerebral inactivity. A BDI>6h, was positively associated with a family refusal for organ donation (p=0.02).

CONCLUSIONS

The rate of EEGs with electrocerebral activity despite clinical findings suggesting BD was only 3.5%. It occurred most frequently with severe brainstem damage. Although in this small percentage of patients, BD diagnosis was notably delayed, in the great majority of cases the use of EEG shortened the BDI. In our series, a BD diagnosis delay >6h negatively affected consent for organ donation.

SIGNIFICANCE

The use of EEG can decrease the time interval for brain death diagnosis.