Effects Of Stellate Ganglion Block On Circulation And Cerebral Metabolism In Perioperative H-type Hypertension Patients

Objective: The observation was aimed to investigate the effect and possible mechanism of stellate ganglion block(SGB) on circulation and cerebral metabolism in perioperative H-type hypertension patients undergoing laparoscopic cholecystectomy(LC), and to provide clinical and theoretical basis for the prevention of postoperative cognitive dysfunction(POCD). Methods: Sixty H-type hypertension patients were randomly divided into two groups(n=30 each) including group SGB and NSGB(non-SGB). There were no statistical significance between the two groups with age, weight and ASA classification. Thirty minutes before induction of anesthesia, each patient was injected 8 ml of injection at the root position of C6 transverse process. Patients in SGB group were injected with 0.8% lidocaine 8 ml(Horner syndrome of block side prompts success), while patients in NSGB group were injected with 0.9% sodium chloride 8ml. Each anesthetic procedure were given by the same anesthesiologist with no difference in operation and monitoring equipment. Parameters were observed in 5 time points including T0(before induction of the basic state), T1(after tracheal intubation), T2(after pneumoperitoneum onset), T3(after cholecystectomy,BIS=50±5, ETCO2=40±5) and T4(awakening after extubation,BIS>85). Mean arterial pressure(MAP), heart rate(HR), and of the product of heart rate and mean arterial(HR·MAP) at the 5 moments were recorded. Blood sample of radial artery and jugular bulb were taken at T0, T3 and T4. Test indicators included hemoglobin(Hb), jugular bulb oxygen saturation(Sjv O2), jugular venous oxygen partial pressure(Pjv O2), arterial oxygen saturation(Sa O2), arterial partial pressure of oxygen(Pa O2), arterial blood glucose concentration(Glua), jugular bulb blood glucose concentration(Glujv), dynamic blood lactate concentration(Lac) and pulse jugular venousbulb learn lactate concentration(Ljvc). The radial artery- jugular bulb oxygen content difference(Da-jv O2), cerebral oxygen extraction rate(CEO2) in accordance with Fick formula, dynamic blood glucose content in venous difference(Da-jv Glu) and arteriovenous lactate concentration difference(Da-jv Lac) were calculated. Assessment of Postoperative cognitive dysfunction(POCD) were made by mini mental state examination(MMSE) on the day before operations, the 1st and 3rd day after operations. Any postoperative patient with a MMSE score lower than before for 2 or more would be diagnosed of POCD. Results: Hemodynamic parameters of MAP, HR and HR·MAP in each group at T0 showed no significant difference(P>0.05). At T1, T2, T3 and T4 points, SGB group had significant differences in hemodynamic parameters compared with NSGB group(P<0.05). Cerebral oxygen metabolism parameters of Sjv O2, Da-jv O2 and CEO2 in SGB group had significant difference compared with NSGB group(P<0.05) at T3 and T4 points. With time point goes on from T1 to T4, the indications of brain energy metabolism-Glua and Glujv increases in each group and showed significant differences between groups(P<0.05); There were no significant differences between the groups by the value of Lac, Ljvc, Da-jv Glu and Da-jv Lac. Patients in SGB group also had a lower incidence of POCD than those in NSGB group(P<0.05). Conclusion: In H-type hypertension patients undergoing LC, SGB can reduce perioperative stress response, improve cerebral metabolism, and reduce the incidence of POCD.