Consciousness in deep hypothermic circulatory arrest: a feasibility study.
Journal of cardiothoracic surgery May 27, 2025 Joshua Ross, Thomas Jan, Deane Smith et al. 1 citation
A spectrum of consciousness and awareness, including signs of implicit learning and electrocortical biomarkers, may be present during deep hypothermic circulatory arrest (DHCA), despite the absence of visible signs of consciousness. In a prospective study across 10 hospitals with 36 DHCA patients, 29 had a tablet set up to deliver audiovisual stimuli. All had EEG and NIRS monitoring, but only 9 had usable EEG data. Delta EEG waves were observed during circulatory arrest in 3 of those 9 patients. None had explicit recall of the three fruit names, but 3 of 36 correctly guessed them, suggesting implicit learning, and 3 recalled other memories, including themes of a death experience. This may help explain negative psychological outcomes in cardiac arrest survivors.