[FEATURES OF CEREBRAL BLOOD FLOW DYNAMICS IN PATIENTS WITH ARTERIAL HYPERTENSION DURING CARDIAC SURGERY]

Cognitive dysfunctions (CD) is the most common postoperative neurological complication in cardiac surgery, which is detected in 30%-65% of patients within 1 month after myocardial revascularization and 20%-40% of the examined, during the next five postoperative months. This problem is especially relevant for patients with arterial hypertension (AH). Goal - to study of the correlation relationship between the mean arterial pressure (MAP) and the velocity of blood flow in the middle cerebral artery (MCA) in patients with AH during coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). The study included 128 patients with coronary artery disease, which was performed by the CABG with CPB. The average age - 62.1±4.8 years. All subjects were divided into 2 groups: 1-st group - 83 patients with AH (II-III degree); 2-nd group - 45 patients without AH. Patients were operated under sevoflurane-based endotracheal anesthesia. Registration of cerebral blood flow was carried out by the method of transcranial doplerography. For neuropsychological testing MMSE-test, FAB-test, clock drawing test and SAGE-test were used. Reduced blood flow in the MCA in patients of both groups was observed at the following stages: induction into anesthesia (by 46.7 ± 2.5% relative to the initial value, p=0.0139), the onset of hypothermia during CPB (64.2±3, 9% of the initial value, p=0.0024). There was no significant difference in the levels of the average blood flow velocity in the MCA during the non-pulsative and pulsative CPB modes (p=0.758). Correlation analysis of the assoсiation between MAP and average velocity of cerebral blood flow in MCA in patients with AH revealed a significant correlation weak strength (r=0.099, p=0.004). According to the results of the neuropsychological tests, on the 6-th day after the operation, in patients of 1-st group, there was a significant decrease in the results of the MMSE test (p=0.046) and the SAGE test (p 0.041) compared to the baseline values. Patients in 2-nd group had no significant difference in the results of all four tests. Determination of the level of MAP does not allow to fully and properly evaluate the cerebral blood flow. In view of this, we recommend intraoperative monitoring of cerebral blood flow to prevent the development of CD for all patients with AH.