Hypothermia-treated cardiac arrest patients with good neurological outcome differ early in quantitative variables of EEG suppression and epileptiform activity.
OBJECTIVE
To evaluate electroencephalogram-derived quantitative variables after out-of-hospital cardiac arrest.


METHODS
Prospective study.


METHODS
University hospital intensive care unit.


METHODS
Thirty comatose adult patients resuscitated from a witnessed out-of-hospital ventricular fibrillation cardiac arrest and treated with induced hypothermia (33 degrees C) for 24 hrs.


METHODS
None.


RESULTS
Electroencephalography was registered from the arrival at the intensive care unit until the patient was extubated or transferred to the ward, or 5 days had elapsed from cardiac arrest. Burst-suppression ratio, response entropy, state entropy, and wavelet subband entropy were derived. Serum neuron-specific enolase and protein 100B were measured. The Pulsatility Index of Transcranial Doppler Ultrasonography was used to estimate cerebral blood flow velocity. The Glasgow-Pittsburgh Cerebral Performance Categories was used to assess the neurologic outcome during 6 mos after cardiac arrest. Twenty patients had Cerebral Performance Categories of 1 to 2, one patient had a Cerebral Performance Categories of 3, and nine patients had died (Cerebral Performance Categories of 5). Burst-suppression ratio, response entropy, and state entropy already differed between good (Cerebral Performance Categories 1-2) and poor (Cerebral Performance Categories 3-5) outcome groups (p = .011, p = .011, p = .008) during the first 24 hrs after cardiac arrest. Wavelet subband entropy was higher in the good outcome group between 24 and 48 hrs after cardiac arrest (p = .050). All patients with status epilepticus died, and their wavelet subband entropy values were lower (p = .022). Protein 100B was lower in the good outcome group on arrival at ICU (p = .010). After hypothermia treatment, neuron-specific enolase and protein 100B values were lower (p = .002 for both) in the good outcome group. The Pulsatility Index was also lower in the good outcome group (p = .004).


CONCLUSIONS
Quantitative electroencephalographic variables may be used to differentiate patients with good neurologic outcomes from those with poor outcomes after out-of-hospital cardiac arrest. The predictive values need to be determined in a larger, separate group of patients.
Wennervirta
Johanna E
JE
Intensive Care Units, Department of Anesthesiology and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland. johanna.wennervirta@hus.fi
Ermes
Miikka J
MJ
Tiainen
S Marjaana
SM
Salmi
Tapani K
TK
Hynninen
Marja S
MS
Särkelä
Mika O K
MO
Hynynen
Markku J
MJ
Stenman
Ulf-Håkan
UH
Viertiö-Oja
Hanna E
HE
Saastamoinen
Kari-Pekka
KP
Pettilä
Ville Y
VY
Vakkuri
Anne P
AP
D000328:Adult; D000368:Aged; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D005260:Female; D005387:Finland; D006305:Health Status Indicators; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome