Stellate Ganglion Block in Preventing Cerebral Vasospasm Secondary to Subarachnoid Hemorrhage

Inclusion Criteria: * 1.Emergency patients with subarachnoid hemorrhage caused by ruptured aneurysm, aged 18-65 years; 2. ASA : II-IV grade, Hunt-Hess : I-III grade 3. For the first case, the operation time is within 24 hours. 4.After signing informed consent, underwent interventional intravascular embolization Exclusion Criteria: * 1\. Patients with severe bleeding disorders; 2. Patients with trauma and local infection risk in the nerve block area; 3. Patients with previous aneurysm surgery and unruptured aneurysm; 4. Aneurysm located in middle cerebral artery; 5. Patients with unconsciousness cannot cooperate with the block operation; 6. Those with a history of mental illness and epilepsy; 7. Those who have a history of severe cardiovascular and cerebrovascular diseases and severe organ diseases;