The impact of microemboli during cardiopulmonary bypass on neuropsychological functioning

Abstract

Background and PurposeMicroemboli have been implicated in the etiology of neuropsychological deficits after cardiopulmonary bypass. This study examined the incidence of high-intensity transcranial signals (microemboli) and their relation to changes in neuropsychological performance after surgery. MethodsTranscranial Doppler ultrasonography was used to measure middle cerebral artery blood flow velocity and detect microemboli. The number of high-intensity transcranial signals was determined and related to a neurological examination and absolute changes in neuropsychological performance as well as the number of patients considered to exhibit a neuropsychological deficit. Data were available on 100 consenting patients undergoing routine cardiopulmonary bypass. Fifty of the patients were randomly assigned to a procedure that included a 40 -μm arterial line filter, and 50 had the procedure without any arterial line filter. ResultsSignificantly more patients were found to have neuropsychological deficits in the group without the arterial line filter at both 8 days (P