The Effect Of Dexmedetomidine On Acute Kidney Injury During Perioperative Period Of Heart Valve Replacement

Background Cardiopulmonary bypass(CPB)has become an indispensable technique in heart surgery,but it also brings many complications to patients during the perioperative period,including acute kidney injury(AKI).Due to the potential of dexmedetomidine(DEX)to protect multiple organs during the perioperative period,it may become one of the feasible methods for renal protection after cardiac surgery.Objective To evaluate the effect of DEX on perioperative AKI in patients undergoing cardiac valve replacement under CPB.Methods Approved by the Ethics Committee of Yichang Central People’s Hospital,this study selected 70 patients undergoing elective heart valve replacement surgery.The patients were randomly divided into two groups(n=35)using random numbers generated by SPSS software: dexmedetomidine Group(DEX group)and saline group(NS group).The DEX group was given a loading dose of 1 μg/kg DEX within 10 minutes after induction of anesthesia,followed by a 0.5 μg/kg/h maintenance pump until the end of the operation;the NS group was given equal volume of normal saline and infused until the end of the operation.Venous blood was collected at T0(10min before induction),T1(10min after CPB),T2(after operation),T3(2h after operation),T4(24h after operation),and T5(48h after operation).Concentrations of SCr and NGAL in patients,according to KDIGO standards,record the number of acute kidney injury in each group,and record the patient’s intraoperative HR,MAP,intraoperative vasoactive drug dosage,etc.Follow up the second hospital admissions,the number of deaths,and the number of CKD occurrences within six months after the operation.Results Excluding withdrawal cases(5 cases in the NS group,2 cases in the DEX group),a total of 63 cases were included in the data statistics in this study,including 30 cases in the NS group and 33 cases in the DEX group.(1)Compared with the NS group,the levels of SCr in the DEX group was significantly reduced at T2-T4(P<0.05),and the levels of NGAL in the DEX group was significantly reduced at T1-T3 and T5.(2)Compared with T0,the levels of SCr began to increase significantly at T2(NS group)and T3(NGAL group)(P<0.05),while the levels of NGAL in the two groups increased significantly at T1(P<0.05),suggesting the levels of NGAL In AKI patients after CPB rised earlier than SCr.(3)Compared with the NS group,the incidence of AKI in the DEX group was significantly lower [14/30(46.67%)vs7/33(21.21%)].(4)Intraoperative urine output in the DEX group was significantly higher than that in the NS group(P<0.05),but there was no significant difference in urine output between the two groups at 24 h and 48 h after surgery(P>0.05).There was no significant difference in the number of deaths between the two groups of patients during hospitalization(P>0.05).(5)The dosage of NE intraoperative in the DEX group was significantly lower than that of the NS group(P<0.05).There was no significant difference in the dosage of DA and NTG intraoperative between the two groups(P>0.05).(6)Compared with the NS group,HR and MAP in the DEX Group fluctuated less at T0-T3.(7)The difference between DEX group and NS group in the second hospitalization,the number of deaths,and the development of CKD within half a year,although not statistically significant,DEX decreased The trend of occurrence of CKD and second hospitalization after CPB.(8)SCr,NGAL exceeding the limit and oliguria can be regarded as related risk factors for the occurrence of AKI(P<0.05),and both have a strong correlation: SCr out of limit(OR=10.346,95%CI: 1.891～56.615),NGAL out of limit(OR=11.176,95%CI: 1.190～104.987),oliguria(OR=8.854,95%CI: 1.383～56.675)(9)NGAL combined with SCr has the best diagnostic performance in predicting the occurrence of AKI at 2 hours after surgery,with an AUC of 0.847(95% CI,0.735-0.958).Conclusion(1)The use of DEX can inhibit the increase of SCr and NGAL concentration to a certain extent,reduce the occurrence of AKI in patients undergoing heart valve replacement surgery.SCr,NGAL exceeding the limit and oliguria can be regarded as the occurrence of AKI related risk factors.(2)DEX may protect renal function by stabilizing the patient’s perioperative hemodynamics and reducing the amount of NE.(3)the levels of NGAL rises earlier than SCr in patients after cardiac surgery,and may be used for early prediction of AKI in the future.