Effect of stellate ganglion block on brain injury in patients undergoing cardiac valve replacement under CPB / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of stellate ganglion block (SGB) on brain injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB). Methods Forty ASA Ⅱ or Ⅲ patients of both sexes aged 22-50 yr weighing 40-64 kg undergoing elective cardiac valve replacement were randomly divided into 2 groups (n = 20 each) control group (group C) and SGB group. Radial artery and right internal jugular vein were cannulated for BP and CVP monitoring. A catheter was inserted into left internal jugular vein under local anesthesia and advanced cephalad until resistance was met for blood sampling. Right SGB was performed with 0.25% ropivacaine 10 ml. Successful block was confirmed by ipsilateral Homer's syndrome.ECG, BP, CVP and SpO2 were monitored. Anesthesia was induced with midazolam 0.2 mg/kg, fentanyl 5-8 μg/kg and vecuronium 0.12 mg/kg and maintained with fentanyl infusion at 8-10 μg· kg- 1· h- 1 and intermittent iv boluses of midazolam and vecuronium. Blood samples were collected for determination of plasma NO, ET-1, S100β protein and NSE concentrations and NOS activity immediately after left internal jugular vein was retrogradely catheterized (T0 ), at 30 min of CPB (T1), 10 min after release of aortic cross clamp (T2 ), 6 and 24 h after operation (T3 ,T4 ). The patients' cognitive function was assessed by using mini-mental state examination (MMSE) the day before operation and on 1st and 7th day after operation. Results The plasma ET-1, S100β protein and NSE concentrations were significantly increased during and after operation at T1-3 as compared with baseline values at T0 in both groups and were significantly lower in group SGB than in group C. Plasma NO concentration was significantly increased during CPB at T1 as compared with the baseline at T0 in both groups but was significant higher after CPB at T2 but lower after operation at T3,4 in gToup SGB than in group C. The NOS activity was significantly higher during operation at T1,2 in group SGB than in group C. The cognitive function was significantly better at 1st postoperative day in group SGB than in group C. Compared with the baseline value,NO/ET-1 ratio was significantly decreased during and after operation in group C,but no significant change in NO/ET-1 ratio was found in group SGB. Conclusion SGB can attenuate brain injury induced by CPB by improving cerebral perfusion through maintenance of relative balance of NO/ET-1.