The Effect Of Dexmedetomidine On The Stress Response In Patients With Cardiac Valve Replacement And Study Of Lung Protection

Objective:To explore the effect of dexmedetomidine on cardiac valve replacement patients stress response and study of lung protection,to broaden the clinical application of dexmedetomidine with theoretical basis.Methods:select 70 patients taken elective cardiac valve replacement at the Department of Cardiology from 2016.03 to 2017.04 as experiemnt goals.Informed consent of the guardian or patient was obtained and signed.The patients were randomly divided into two groups.60 qualified patients were randomly divided into 2groups,30 patients per group.In the Demei group(group D),intravenously pumped with dexmedetomidine 1.0 ?g·kg-1 for 10 min before anesthesia,maintained with dexmedetomidine 0.5 ?g·kg-1·h-1 during the surgery;control group(C): Pumped with the same volume of saline as group D during the whole program.Two groups patients were routinely monitored and anesthetized after entering the room;the proportion of extracorporeal circulation pre-filled liquid crystal body fluid and colloidal fluid were 1:1,intraoperative Hct was maintained at 21% to 25%,and if necessary,suspended red blood cells were used,and the total amount of preconditioning was approximately 1700 to 2000 ml.The cycle is mainly performed with lower body temperature and medium to high flow.After anesthesia and extracorporeal circulation are prepared,surgical operations such as disinfection,skincare,sawn sternum,thoracotomy,establishment of extracorporeal circulation,ascending aorta and vena cava,and hemostasis are performed.After surgery,patients are sent to ICU after surgery.Fentanyl and midazolam were used to relieve pain and sedation.Collect preoperative general data,observe and record pre-dose(T0),sawn sternum(T1),shutdown(T2),postoperative 24h(T3)HR,MAP,arterial blood gas analysis,record Glu and calculate OI,RI were detected;the Cor concentration in arterial plasma was detected by ELISA;and the concentrations of NE and E in arterial plasma were detected by HPLC.Record intraoperative BIS values,cardiac resuscitation(automatic resuscitation,defibrillation followed by resuscitation),operative time,transit time,blocking time,intraoperative vasoactive drug amount;postoperative insulin use,postoperative vasoactive drug amount,postoperative ICU support time,ventilator support time,lung infections,hospitalization costs,and hospital discharge(discharge,death discharge).Results:1.Comparing two groups' clinical data:the Patient gender,age,weight,ASA,CPB transit time,ascending aortic block time,operative time,cardiac resuscitation situation were indifferent(P ? 0.05).2.Comparing two groups' HR,MAP and BIS values: There was no difference in BIS values between the two groups at the same time(P>0.05).At different time points:MAP at T2 was lower than T0,and in D group HR at D1 was the lowest,but both of them were in the clinical normal range;there was no significant difference of HR and MAP at each time point in the other two groups.The comparison between the two groups at the same time points: T1,D group HR was significantly lower than the C group(P <0.05),MAP changes insignificantly;the rest HR,MAP of the two groups have no significant difference(P> 0.05).3.Changes in oxygenation index(OI)and respiratory index(RI)in the two groups:Comparison between two groups at different time points: Compared with T0,OI decreased significantly in both groups at T1,T2,and T3,while RI increased(P<0.05).Compared with T1,OI decreased and RI increased in T2 group(P<0.05),OI did not change significantly at T3,while RI decreased;compared with T2,OI increased significantly in T3 group,and RI decreased significantly(P<0.05).<0.05).There was no significant difference in OI and RI between the two groups at T0(P>0.05).At T1,T2,and T3,OI in group D was higher than that in group C,while RI was decreased(P<0.05).4.Changes in E,NE,and Cor between the two groups: Comparison between two groups at different time points: Compared with T0,plasma Cor,E,and NE concentrations in both groups showed an upward trend at T1,T2,and T3,and two groups of Cor,The concentration of NE was significantly increased(P<0.05).In group C,plasma E concentration was significantly higher than T0(P<0.05).There was no significant difference in T1,T2 and D group T1,T2,and T3(P>0.05).Compared with T1: plasma concentrations of NE in the two groups increased at T2 and T3(P<0.05).There was no significant difference in plasma E concentrations between the two groups;plasma Cor concentrations at T2 and T3 in C group were significantly higher than those at T1(P<0.05).There was no significant change in the group.At the same time point between the two groups: At T0,there was no significant difference in Cor,E,and NE between the two groups(P>0.05).At T1,T2,and T3,plasma Cor,E,and NE concentrations in group D were lower than those in group C(P<0.05).5.Comparing two groups' blood glucose(Glu)and postoperative insulin use rate :Comparison of two groups at different time points: As the operation time changes,the Glu concentration in the two groups gradually increases,and T1 and T2 are higher than T0(P< 0.05),but all within the clinically normal range.There was no difference in Glu concentrations between the two groups at T0(P>0.05).At T1 and T2,the Glu concentration in D group was lower than that in C group(P<0.05).Patients were followed up for 24 hours after surgery: In Group C,23 cases of insulin were used postoperatively,which accounted for 72% of patients with total insulin use.In Group D,only 9 cases accounting for 28% of total.The use of insulin in Group D was significantly lower than Group C.(P<0.05).6.Postoperative follow-up: Compared with group C,postoperative ICU length of stay and ventilator support time were significantly shorter in group D(P<0.05);clinical diagnosis of pulmonary infection in group C was 14 cases,and the incidence was 47%.Two patients in group D accounted for 7%.The incidence of pulmonary infection in group D was lower than that in group C(P<0.05);postoperative outcomes improved significantly after discharge(P<0.05);There was no significant difference in hospitalization costs,intraoperative and postoperative vasoactive drug dose between the two groups(P>0.05).Conclusion:(1)Dexmedetomidine can reduce the valve replaced patients' plasma concentrations increase of Cor,E,NE,and Glu after CPB,reducing the postoperative insulin use rate,and alleviates the stress response,benefiting the recovery of patients.(2)Dexmedetomidine can improve the valve replaced patients' postoperative pulmonary function under CPB,shorten ICU and ventilator support time,reducing the incidence of postoperative pulmonary infection,and may have a protective effect on the lungs.