Deep hypothermic cardiac arrest (DHCA) is a technique employed during anesthesia in certain cardiovascular and neurovascular surgeries to minimize brain damage, which could be caused by temporary lack of blood flow to the brain. During these surgeries, brain metabolism and electrical activity are intentionally diminished by cooling methods to approximately 18°C or lower. This procedure allows oxygen delivery to the brain to be optimized by applying external perfusion techniques. Because of the rigorously controlled conditions of this procedure, it appears to be an ideal model for determining if mind and consciousness may persist in the absence of measurable electrical brain activity. There have been anecdotal reports of individuals who have reported memories and awareness during this procedure. Therefore, we would like to conduct a retrospective survey in patients who underwent DHCA in order to estimate the prevalence of self reported perceptual, cognitive and emotional processes during DHCA.
A pilot study is being developed by Dr Mario Beauregard at the University of Montreal in Canada.