Brain Protective Effect Of Dexmetomidine Combined With Ulinastatin On Patients Undergoing Valve Replacement Under Cardiopulmonary Bypass

Objective:To investigate the protective action of dexmedetomidine combined with ulinastatin on brain injury in elderly patients undergoing cardiac valve surgery under.extracorporeal circulation.Methods:According to the random number table method,Eighty patients were grouped into dexmedetomidine（D）group,ulinastatin（U）group,normal saline（N）group and ulinastatin+dexmedetomidine（U+D）group。group D was pumped1.0μg/kg for 15 minutes before induction,and then 0.4μg/kg/h until the end of the operation。Group U was given 20000 UI/kg intravenously immediately after induction。The usage of dexmetomidine and ulinastatin in group（U+D）is the same as above,and Group N has the same amount of normal saline。Sjv O₂,Da-jv O₂,CERO₂ and r SO₂were detected immediately before cardiopulmonary bypass（T1）,opening of aorta（T2）,end of CPB（T3）and 6 hours after operation（T4）。At the same time,the concentrations of S100β,NSE,IL-6 and TNF-αwere measured at T1 to T4 and 24hours after operation（T5）。Finally,the postoperative neurocognition was evaluated 1 day before operation（T0）and 7 days after operation（T6）,and the incidence of delirium within one week after operation was calculated。Results:At T2-T3,compared with group N,the levels of Sjv O₂ were remarkably raised,but the leves of Da-jv O₂ and CERO₂ were remarkably descend in other three groups;compared with group D+U,the levels of Sjv O₂ were remarkably descend,but the levels of Da-jvO₂ and CERO₂was remarkably raised in Group D and Group U（all P（27）0.05）。At T2,compared with group N,the levels of r SO2 was remarkably raised in other three groups;compared with group D+U,the levels of r SO2 were remarkably descend in Group D amd Group U（all P（27）0.05）。At T3,there was no obvious difference of r SO2 in four groups。At T2–T4,compared with group N,the concentration of NSE、S100β、IL-6、TNF-a was lower in Group D,Group U and Group D+U;compared with group D+U,the concentration of NSE、S100β、IL-6、TNF-a was higher in Group D and Group U（all P（27）0.05）。At T6,compared with group N,the MMSE score of others three groups raised;Compared with group D+U,the MMSE score of group D and group U descend（all p（27）0.05）。Compared with group N,the incidence of delirium in others three groups decreased within one week after operation,while compared with group D+U,the incidence of delirium in group D and group U increased（all P<0.05）.Conclusion:Dexmetomidine combined with ulinastatin can further inhibit the sympathetic activity and inflammatory reaction of patients with rheumatic valvular disease during CPB,significantly improve perioperative cerebral oxygen metabolism,reduce brain injury,and have a certain brain protective effect.