EVALUATION OF INCIDENCE NEUROCOGNITIVE IMPAIRMENT AFTER CARDIAC SURGERY: ROLE OF CPB

Objectives: Neurocognitive decline has been described as an important possible complication following cardiac surgery, especially when cardiopulmonary bypass (CPB) is applied. Symptoms consist in defects of attention, concentration, short term memory and speed of mental responses. Aim of present study was to evaluate the specific role of CPB on the onset of cognitive deficits. For this reason, we evaluated prospectively the incidence of cognitive impairments in our population using a standardized battery of neuropsychologic tests. Methods: Between May 2007 and May 2008 we analysed 121 patients, 63,5 % on- pump, 36,5% off-pump, mean age 63±12,9 years undergoing elective cardiac surgery . Patients with previous history of stroke, cognitive impairment or major psychiatric disorder, or who had neurological injury (stroke) after surgery were excluded. Two equivalent batteries of neuropsychologic tests (10 tests) were administered preoperatively and 1 month after surgery. Results: No difference in cognitive impairments between groups was detected after surgery. Conclusions: At variance with some previous reports, this prospective, randomized study shows no difference in post-operative cognitive functions between the two groups of patients up to 1 moth post-operatively. This lack of difference might be due to different causes, including criteria of inclusion/exclusion of patients and different sensitivity of the tests. However, in most previous studies post-surgical testing occurs after a shorter delay from surgery. Our data suggest, therefore, that cognitive decline is just temporary.