Stellate Ganglion Block and Cerebral Vasospasm

"After the patient entered the operating room, early SGB will be performed by a designated experienced anesthesiologist using the B-ultrasound visualization technique. The intervention site is the ipsilateral side of the planned craniotomy site. After routine disinfection, 0.5% ropivacaine 8-10 mL will be injected into the surface of the longus colli muscle on the medial side of the prevertebral fascia at the level of the C6 anterior tubercle, and then the puncture point will be covered with sterile dressings. The success criteria of e-SGB are Horner's syndrome, which is characterized by a miosis, ptosis, enophthalmos, conjunctival hyperemia and facial reddishness without sweating. For the camouflaging arm, the anesthesiologist only covered the corresponding part of the patient with sterile dressings to confuse the follow-up, without any puncture. All patients will be admitted to the ICU after the operation and then receive the standard of care."