Effect Of Cardiopulmonary Bypass With Different Perfusion Flow On Cerebral Oxygen Metabolism And Sigmoid Sinus Pressure

Objective:To investigate the effect of cardiopulmonary bypass with different perfusion flow on cerebral oxygen metabolism and sigmoid sinus pressure, and to discuss the changes trend of sigmoid sinus pressure and mean arterial pressure and the correlation of them.Methods:Forty-five adult patients scheduled for heart valve replacement were randomly divided into three groups(n=15) according to different perfusion flow (60～80ml/Kg·min) during cardiopulmonary bypass:Groupl perfusion flow(62±2ml/Kg·min)、Group2perfusion flow(72±2ml/Kg-min)、Group3perfusion flow(82±2ml/Kg-min).The left radial artery was punctured for monitoring invasive arterial pressure under local anesthesia while the patient was awake. After anesthesia induction, retrograde catheterization of the right internal jugular vein to the sigmoid sinus was established with ultrasound guidance for measuring the sigmoid sinus pressure (SSP). Group lwere maintained with an average perfusion flow for62±2ml/Kg-min during CPB,Group2with72±2ml/Kg-min,and Group3with82±2ml/Kg-min.The left radial artery and sigmoid sinus venous blood samples were synchronously taken for blood gas analysis and measurement of arteriovenous oxygen partial pressure (PaO2, PsvO2,)、arteriovenous oxygen saturation (SPO2,, SsvO2.)、hemoglobin (HB)、blood glucose、lactic acid and according to the FiCK formula calculating the arteriovenous oxygen content (CaO2,、 CsvO2,), arteriovenous oxygen content difference (Da-vO2,), cerebral oxygen extraction (CERO2,) at the completion of the internal jugular vein retrograde catheter (T1), temperature dropped to the lowest (T2),rewarming to35℃(T3),CPB stopped30min (T4), CPB stop2h (T5), CPB stop6h (T6). The right radial artery and sigmoid sinus blood samples were taken to detect the concentration of S100β protein at T1、T4and T6. MAP and SSP values were recorded at just after retrograde internal jugular vein catherization (P1), CPB started (P2), CPB started5min (P3), CPB started10min (P4), CPB started20min (P5), CPB started30min (P6), rewarming (P7), rewarming10min (P8), aorta open (P9),heart rebeating (P10), heart rebeating10min (P11), CPB ended (P12), CPB ended5min (P13), CPB ended10min (P14), CPB ended20min (P15), CPB ended30min (P16), CPB ended2h (P17), CPB ended6h (P18) and their correlation.Rseult:①There were no significant difference in CaO2、 CsvO2、Da-vO2、CERO2、SPO2、SsvO2、HB、blood glucose and lactic acid at each time point among the three groups(P>0.05).The difference of CaO2、 CsvO2and Da-vO2in T2、T3and T4were statistically significant Comparing in the group (P<0.05). There was statistically significant between T2and T3in CERO2(P<0.05). The difference of PaO2among T2、T4、T5and T6was statistically significant (P<0.05). The difference of PsvO2、SsvO2between T2and T3were statistically significant (P<0.05). Compared to T1to the rest of the each point HB has the statistically significance, HB significantly decreased (P<0.05). Compared to T1to the rest of the each point arterio venous blood sugar had the statistically significance (P<0.05). There was statistically significant in arterio venous lactate among T3、T4、T5and T6(P<0.05).②There were no statistically significance in S100β protein among three groups (P>0.05), in the group there was statistically significant between T1、T4and T1、T6.③The SSP of Group1was lower than Group2and Group3(P<0.05). In the group, the SSP at P9、P10、P11、P12、 P13、P14、P15and P16were higher than P1(P<0.05)④There were no statistically significance in MAP among three groups(P>0.05). In the group, the MAP at P2、P3、P4、P5、P6、P9and P10were lower than P1, the MAP at P17and P18were higher(P<0.05)⑤The SSP had correlation with the MAP, the correlation coefficient was0.452, the regression equation was Y=0.11X+6.717.Conclusion:①There were no statistically significant in different perfusion flow at the range of60～80ml/Kg·min during cardiopulmonary bypass on cerebral oxygen metabolism and S100β protein content. The sigmoid sinus pressure with an average perfusion flow for62±2ml/Kg-min during CPB was lower;②Sigmoid sinus pressure increased significantly from the aorta open during cardiopulmonary bypass,then returned to normal level when the CPB ended2hours;③The cooling and rewarming process under hypothermic anesthesia during cardiopulmonary bypass may result in brain oxygen supply and demand imbalance.