[Association of postoperative brain dysfunction and atherosclerosis, intraoperative rSO2 and CO2 reaction in open heart surgery].

We studied the relationship between postoperative brain dysfunction and the state of atherosclerosis in the patients of open heart surgery, by analyzing the intraoperative cerebral oxygen saturation (rSO2) and the CO2 reaction. The subjects were 143 patients with average age of 64 years. The patients with low postoperative Hasegawa's Dementia Score were categorized as brain dysfunction group. rSO2 was utilized to monitor cerebral blood flow, and AI and stiffness parameter beta were used for evaluation of systemic atherosclerosis. Postoperative brain dysfunction was confirmed in 12%. There were significantly high values of AI and beta as well as low rSO2, in elder age with low cardiac index and no correlation was observed between rSO2 and PaCO2 in the brain dysfunction group. The results suggested that a higher level of atherosclerosis is associated with the postoperative brain dysfunction with resultant decreased cerebral blood flow and disturbed reaction to CO2 of cerebral blood vessels.