Cerebral blood flow monitoring by transcranial Doppler during hypotension induced by epidural block in aged patients

To assess whether the changes in blood pressure during general anesthesia with epidural block affect the cerebral circulation in aged patients, we measured blood flow velocity (MV) in the middle cerebral artery by transcranial Doppler ultrasound method (TCD) in patients without hypertension (H (-) ) group (n=10) (mean age: 75±6 years), patients with hypertension (H (+) ) group (n=10) (mean age: 73±2 years) and control (C) group (n=7) (47±7 years) . The decreasing values of mean blood pressure was 24±8 mmHg (mean±SD) in H (-) group, 25±6 mmHg in H (+) group and 23±8 mmHg in C group respectively, according epidural block. After epidural block, the change of MV was 88±20% in H (-) group, 81±15% in H (+) group and 101±10% in C group, respectively, compared with pre-epidural block. MV decreased significantly in H (+) group compared with control group (P<0.05) .The results suggest that cerebral autoregulation may be impaired in aged patients with hypertension, and careful management must be necessary during anesthesia in aged patients.