An observational study of bispectral index monitoring for out of hospital cardiac arrest.

Cerebral resuscitation is the most important goal of advanced life support. Currently, there are no objective monitoring methods available to gauge the effectiveness of advanced life support on cerebral resuscitation. We assessed the utility of bispectral index (BIS) monitoring during cardiopulmonary resuscitation as a marker of cerebral resuscitation. Twenty one patients with out of hospital cardiac arrest had a BIS monitor applied during the resuscitation, in addition to standard advanced life support. The BIS monitor was also applied to a cadaver to assess the role of artefact. Illustrative data are presented, outlining the process of evaluation undertaken. A major component of the BIS tracing during external chest compressions appears to be due to movement artefact. Our pilot data indicate that with current technology, BIS monitoring is not a clinically reliable marker of the efficacy of external chest compressions.