Continuous amplitude-integrated electroencephalogram predicts outcome in hypothermia-treated cardiac arrest patients.
OBJECTIVE
To assess the prognostic value of continuous amplitude-integrated electroencephalogram in comatose survivors after cardiac arrest and treated with hypothermia.


METHODS
Prospective observational study.


METHODS
General intensive care unit at a university hospital.


METHODS
Comatose patients after cardiac arrest and treated with hypothermia.


METHODS
Patients were sedated and continuously monitored using an amplitude-integrated electroencephalogram. Monitoring was commenced on arrival in the intensive care unit and continued until recovery of consciousness, death, or 120 hrs after cardiac arrest. The amplitude-integrated electroencephalogram was interpreted together with the original electroencephalogram and analyzed without knowledge of the patient's clinical status. The amplitude-integrated electroencephalogram patterns at start of registration and at normothermia and the transitions of the amplitude-integrated electroencephalogram patterns over time were correlated to outcome.


RESULTS
A total of 111 consecutive patients were assessed; 11 patients were not included because of technical reasons and five were excluded because of death before normothermia. Ninety-five patients remained; 57 (60%) eventually regained consciousness, of whom 49 (52%) lived an independent life at 6 months. Thirty-one patients (33%) at start of registration and 62 patients (65%) at normothermia had a continuous electroencephalogram pattern, and this was strongly associated with recovery of consciousness (29/31 [90%] and 54/62 [87%]). A suppression-burst pattern was always transient and patients with suppression-burst at any time remained in coma until death. An initial flat pattern was registered in 47 patients, but this had no prognostic value. Electrographic status epilepticus was a common finding (26/95 patients [27%]) and two types of electrographic status epilepticus were identified: one developed from suppression-burst and one developed from a continuous background. Two patients from the latter group regained consciousness.


CONCLUSIONS
Continuous amplitude-integrated electroencephalogram adds valuable early positive and negative prognostic information in comatose survivors after cardiac arrest. We identified two types of postanoxic electrographic status epilepticus, which is a novel finding with possible therapeutic implications.
Rundgren
Malin
M
Department of Clinical Sciences, Lund University, Lund, Sweden. malin.rundgren@skane.se
Westhall
Erik
E
Cronberg
Tobias
T
Rosén
Ingmar
I
Friberg
Hans
H
D000368:Aged; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome