Continuous amplitude-integrated electroencephalography for prognostication of cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation with targeted temperature management

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) has been increasingly used for adult cardiac arrest (CA) patients refractory to conventional CPR. However, data on early prognosticators of neurological outcome are lacking.

Methods: CA patients undergoing ECPR were prospectively monitored via amplitude-integrated EEG (aEEG). Targeted temperature management (TTM) was induced using an extracorporeal membrane oxygenation system. aEEG background patterns were classified into continuous normal voltage (CNV), discontinuous normal voltage (DNV), low voltage (LV), flat trace (FT), burst suppression (BS), and status epilepticus (SE). The Cerebral Performance Category (CPC) scale scores at hospital discharge and at 6 months after discharge were assessed, as was wakefulness after TTM. Good neurological outcome was defined as a CPC score of 1 or 2.

Results: Twenty-two patients were studied. Six patients who showed CNV within 24 hours after arrival, including one with initial FT and two with initial LV, regained consciousness and had good neurological outcome except for one who died of haemorrhagic complication. Patients with persistent FT or BS at any time did not regain consciousness. Regarding 19 patients in whom aEEG data were obtained within 24 hours, CNV background predicted good outcome at 6 months with 100% sensitivity, 93% specificity, 83% positive predictive values, and 100% negative predictive values. All these indices were 100% concerning wakefulness after TTM.

Conclusion: aEEG monitoring was feasible and practical in adult CA patients undergoing ECPR and TTM. Evolution of aEEG background within 24 hours provides early accurate information for neurological prognostication.