With advances in technology it is now possible to conduct surgery that would previously have been considered impossible. Deep Hypothermic Cardiac Arrest (DHCA) is a procedure induced while the patient is anaesthetised. This procedure is used during some intricate cardiovascular and neurosurgical operations. The metabolism and electrical activity in the brain are reduced intentionally by cooling the body to 18°C or lower. Perfusion of oxygen to the brain is enhanced by external techniques. During this state there is no heart beat or breathing – meeting the criteria for clinical death while being monitored under controlled conditions.
There are anecdotal reports from patients who have undergone this procedure that they recalled cognitive, emotional and perceptual awareness during the procedure (see the case of Pam Reynolds reported by Dr Michael Sabom). This procedure is highly important to investigating if consciousness can occur when there is no electrical brain activity.
The COOL study led by Dr Mario Beauregard of Montreal University has retrospectively studied patients who underwent DHCA at Hôpital Sacré-Coeur, a research hospital affiliated with the Université de Montréal, from 2005 – 2010.
With regards to the prospective aspect of this study, Dr Mario Beauregard has informed me by email that the prospective study at present is on hold because the surgeon involved with the study has relocated to another hospital.
However, the retrospective study has revealed the very interesting case of a 31 year old patient who reported some aspects of conscious awareness during the procedure. Dr Beauregard has written up this case and will submit it for publication.
I look forward to reading the full details of the case when it is published.
Let’s hope the prospective aspect of the study will proceed sometime soon because it is cutting edge studies like this that enhance our understanding and knowledge of consciousness.