EMBOLI AND NEUROPSYCHOLOGICAL OUTCOME FOLLOWING CARDIOPULMONARY BYPASS

The dramatic decline in mortality related to cardiac surgery has resul ted in over 330,000 surgeries involving cardiopulmonary bypass (CPB) b eing performed yearly in the United States. Although few patients die as a result of cardiac surgery, over two thirds of the patients demons trate evidence of acute neuropsychological dysfunction postoperatively . The potential mechanisms contributing to post-CPB neuropsychological deficits are many, but two major inter-related etiologic factors, po perfusion and emboli, are suggested as the probable culprits. If embol ism is the cause of the deficits, increasing cerebral perfusion would deliver more emboli and increase the amount and severity of injury. Co nversely, if hypoperfusion is the cause of the injury, then decreasing brain blood flow to minimize embolic delivery, would increase the lik elihood of perfusion injury. By, monitoring the carotid arteries of pa tients undergoing coronary artery bypass graft surgery, we have determ ined the frequency and quantity of embolic signals that occur during C PB. Although, we have not been able to determine the nature of the emb olus, gaseous or solid, we have demonstrated a relationship between th e overall embolic load and the probability of having NP dysfunction.