Neurologic prognostication and bispectral index monitoring after resuscitation from cardiac arrest.
OBJECTIVE
While the use of therapeutic hypothermia (TH) has improved outcomes after resuscitation from cardiac arrest, prognostication of survival and neurologic function remains difficult during the post-arrest time period. Bispectral index (BIS) monitoring, a non-invasive measurement of simplified electroencephalographic data, is increasingly being considered for post-arrest neurologic assessment and outcomes prediction, although data supporting the technique are limited. We hypothesized that BIS values within 24 h after resuscitation would correlate with neurologic outcomes at discharge.


METHODS
We prospectively collected BIS data in consecutive patients initially resuscitated from cardiac arrest and treated with TH in one academic medical center. We assessed BIS values in context of cerebral performance category (CPC) assessment on the day of discharge.


RESULTS
Data were collected in 62 post-arrest patients, of whom 26/62 (42%) survived to hospital discharge. Mean BIS values at 24 h post-resuscitation were significantly different in the survivors with CPC 1-2 ("good" outcome) vs those with CPC 3-5 ("poor" outcome) or death during hospitalization (49+/-13 vs 30+/-20; p<0.001). Receiver operator characteristic analysis suggested that 24 h BIS was most predictive of CPC 1-2 outcome compared to the other timepoints; a BIS cutpoint of 45 exhibited a sensitivity of 63% and a specificity of 86%, with a positive likelihood ratio of 4.67. Sixteen patients exhibited a BIS of zero during at least one timepoint; all of these patients died during hospitalization.


CONCLUSIONS
BIS monitoring values at 24 h post-resuscitation are correlated with neurologic outcomes in patients undergoing TH treatment. In 16/62 patients, a BIS of zero at any timepoint was observed, which was uniformly correlated with poor outcome after resuscitation from cardiac arrest; however, a non-zero BIS is insufficient as a sole predictor of good neurologic survival.
Leary
Marion
M
Center for Resuscitation Science and Department of Emergency Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Fried
David A
DA
Gaieski
David F
DF
Merchant
Raina M
RM
Fuchs
Barry D
BD
Kolansky
Daniel M
DM
Edelson
Dana P
DP
Abella
Benjamin S
BS
D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation; D004569:Electroencephalography; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D009420:Nervous System / Q000503:physiopathology*; D010351:Patient Discharge; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome