Bispectral index monitoring for early detection of brain death.
OBJECTIVE
We sought to determine the utility of the bispectral index (BIS) as a tool for clinical evaluation of the moment of brain death (BD).


METHODS
During a period of 12 months, 54 BDs were registered in our unit, of which 28 were included in the organ donation protocol; 24 fulfilled the requirements of our retrospective observational study. Continuous BIS monitoring was performed using an XP BIS monitor and BIS Quatro sensor evaluating the BIS and the suppression ratio (SR). In almost all cases, sonographic monitoring with transcranial Doppler ultrasound (TCD) was performed every 8 to 12 hours until the diagnosis of BD.


RESULTS
We detected a gradual decrease in BIS and increase in SR when the patients underwent clinical progression to BD. At the moment of BD diagnosis, all cases showed BIS 0 and SR 100. In 9 cases the follow-up TCD showed a BD pattern, moments before a BIS 0 and SR 100 appeared. In 18 cases, at the moment of BIS 0/SR 100, TCD showed BD. In all 24 cases, BD diagnosis was confirmed by means of neurological examination and electroencephalogram (EEG).


CONCLUSIONS
BIS monitoring is a continuous, simple method that is easy to interpret. It can help in clinical evolution and the decision of the BD moment. In our series, cerebral circulatory cessation (TCD) preceded BIS 0 and SR 100 values. The BIS prematurely detected the start of cerebral circulatory cessation, alerting us of BD.
Misis
M
M
Intensive Care Unit, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain. maitemis@yahoo.com
Raxach
J Gener
JG
Molto
H Perez
HP
Vega
S Martinez
SM
Rico
P Sanchez
PS
D001926:Brain Death / Q000175:diagnosis*; D001930:Brain Injuries / Q000175:diagnosis; D002543:Cerebral Hemorrhage; D042241:Early Diagnosis; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D020521:Stroke; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D017585:Ultrasonography, Doppler, Transcranial