Perioperative Neuroprotection of Stellate Ganglion Block

Preventive Effect of Stellate Ganglion Block on Cerebral Vasospasm in Patients Undergoing Aneurysm Surgery

To investigate whether stellate ganglion block is helpful to brain protection during cranial aneurysm surgery

The vasospasm after cranial aneurysm surgery have a higher incidence, but not have an ideal treatment method. At present, the medical treatment is very limited effect to prevent the perioperative cerebral ischemia.Stellate ganglion block （SGB）is an effective and well-tolerated approach to the treatment of CVS in various clinical settings.Resent study indicated that SGB has a protective effect on delayed cerebral vasospasm in an experimental rat model of subarachnoid hemorrhage.Therefore,we hypothesized that the preoperative SGB would be a effective treatment for improvement of vasospasm after cranial aneurysm surgery.

Experimental patients will receive a stellate ganglion block with 0.25% ropivacaine 6-8mL on the right side at the level of the sixth cervical vertebrae (C6) before surgery.Then the catheter will be attached to a single use patient-controlled analgesia pump containing 0.2% ropivacaine 150 mL, which will be infused at 2 mL/h.

stellate ganglion block will be administered using either 6-8mL saline (Group 1) or 0.25% ropivacaine 6-8mL (Group 2)

The occurrence of cerebral vasospasm will be diagnosed by using of the transcranial doppler instrument.

Cerebral oxygen metabolism will be monitored through jugular venous oxygen saturation (SjVO2) and cerebral extraction rate of oxygen (CERO2), and measured by blood gas analysis at each time point, the latter will be calculated using the formula: CaO2 = (Hb*1.38*SaO2) + (0.003*PaO2); CvO2 = (Hb*1.38*SjvO2) + (0.003*PjvO2); CERO2 = (CaO2-CvO2)/CaO2 where CaO2 is arterial oxygen content, Hb is arterial hemoglobin concentration, SaO2 is arterial oxygen saturation, PaO2 is the arterial partial pressure of oxygen, CvO2 is mixed venous oxygen content and PjvO2 is the jugular venous partial pressure of oxygen.

The difference of plasma endothelin, melatonin, and S100-β protein level between two groups at each time point

A 5-mL jugular venous blood sample will be taken at each time point, centrifuged at 3,000 rpm for 25 min, and kept in a freezer at -80°C until analysis. the concentrations of plasma endothelin, melatonin, and S100-β protein will be measured using enzyme-linked immunosorbent assays.

The postoperative cognitive function will be measured by using of the mini-mental state examination (MMSE).

The postoperative recovery quality will be evaluated by using of the Post-operative Quality Recovery Scale (PQRS)

Inclusion Criteria: aneurysm subarachnoid hemorrhage patients scheduled for cranial aneurysm surgery， ASA grade：Ⅱ-Ⅲ， Hunt～Hess grade :Ⅰ-Ⅲ, have a informed consent. Exclusion Criteria: history of mental illness， local infection who can't do stellate ganglion block， pregnant or lactating， nausea cancer or diabetes， participated the study or other related research in the last 30 days， unruptured aneurysms patients