| Objective: To compare the protective effect of DEX pretreatment and whole procedure pump injection on ischemic myocardium in CPB patients undergoing rheumatic heart valve replacement surgery,in other words,their effects on myocardial injury markers,inflammatory factors,oxidative stress and stress response in order to find the best method of administration and provide reference for clinical application.Methods: 90 patients with rheumatic heart disease undergoing valve replacement were selected and randomly divided into three groups,namely,the control group(group C),dexmedetomidine(DEX)with whole procedure pump group(D)and DEX pretreatment group(P group),30 cases in each group(n = 30).Anesthesia monitoring was performed routinely after the patients entered the room.Group D was injected intravenously with DEX loading dose 1.0μg/kg(10min)before anesthesia induction,and the maintenance dose was 0.5μg/kg·h until the completion of operation.Group P was infused with DEX 1.0μg/kg(10 min)before anesthesia induction,and maintained the same dose of saline as the group D;group C was injected with the same amount of saline as the group D before anesthesia induction and during the maintenance of the operation.First,hemodynamic parameters including mean artery pressure(MAP)and heart rate(heart rate,HR)were recorded at the time of before medication,medication after 10 min,immediately after intubation,skin incision,sawing sternum,at the moment of stopping cardio-pulmonary bypass,at the end of operation,and 24 hours after operation.The pump rate of epinephrine,dopamine and nitroglycerin at the end of 24 hours after surgery and at the moment of stop of the cardio-pulmonary bypass were recorded;Second,blood samples were collected immediately before medication,at the time of stoping the extracorporeal circulation machine,at the end of operation,and at the end of 24 hours after operation.The supernatants were centrifuged(4000 rpm)to detect troponin I(c Tn I),creatine kinase isoenzyme(CK-MB),tumor necrosis factor alpha(TNF-α),interleukin-8(IL-8),interleukin-10(IL-10),malondialdehyde(MDA),superoxide dismutase(SOD)activity and norepinephrine(NE),blood glucose concentration;finally,record the general information of patients,perioperative duration of aortic clamping time,cardiac self-rejuvenation rate,the incidence of ventricular fibrillation after reperfusion.Postoperative extubation time,ICU retention time and postoperative hospitalization time were followed-up.Results: 1.There was no significant difference between the three groups in general information,ascending aorta blocking time,transit time,ventricular fibrillation after cardioversion,cardiac self-rejuvenation rate and operation time(P>0.05).2.Hemodynamics manifested as HR and MAP,the HR of DEX pretreatment group and the whole procedure pump infusion group at 10 minutes after medication,intubation immediately,skin incision and sawing the sternum were lower than before administration medicine(P<0.05).However,the HR of the three groups were significantly higher at the moment of stopping cardio-pulmonary bypass,at the end of surgery and 24 hours after surgery than before administration medicine,10 minutes after administration medicine and at the moment of intubation(P<0.05).Compared with the control group,the HR of DEX pretreatment group and DEX whole procedure pump infusion group were significantly decreased at 10 minutes after administration medicine,at the moment of intubation,cutting the skin and sawing the sternum(P<0.05).The MAP of DEX pretreatment group and DEX whole procedure pump infusion increased at the 24 hours after operation compared with that of the control group(P<0.05).The pumping rates of adrenaline and dopamine in the DEX pretreatment group and the DEX whole procedure pump infusion group were lower than those in the control group at the moment of stopping cardio-pulmonary bypass and 24 hours after operation,and the rate of nitroglycerin infusion increased 24 hours after operation than that in the control group(P<0.05).The postoperative extubation time and ICU retention time in DEX pretreatment group and whole procedure infusion pump group decreased compared with that in control group,and the whole procedure infusion of DEX could shorten the time from postoperation to discharge(P<0.05).3.The myocardial injury markers CK-MB and c Tn I in the DEX pretreatment group and the whole procedure pump infusion group were lower than those in the control group at the moment of stopping cardio-pulmonary bypass,at the end of operation and 24 hours after operation(P<0.05).Compared with the DEX whole procedure pump infusion group,the CK-MB in the DEX pretreatment group increased at the end of the operation and 24 hours after the operation(P<0.05).4.The levels of TNF-α and IL-8 in DEX pretreatment group and whole procedure pump infusion group were lower than those in control group at the moment of stopping cardio-pulmonary bypass,at the end of operation and 24 hours after operation(P<0.05).The levels of IL-10 in DEX pretreatment group and whole procedure pump infusion group were higher than those in control group at the moment of stopping cardio-pulmonary bypass and at the end of surgery,but decreased at 24 hours after operation(P<0.05).Compared with DEX whole procedure pump infusion group,the levels of TNF-α and IL-8 in DEX pretreatment group increased at the moment of stopping cardio-pulmonary bypass,at the end of surgery and 24 hours after surgery,and IL-10 decreased at the moment of stopping cardio-pulmonary bypass and at the end of surgery,but decreased at 24 hours after operation(P<0.05).5.The level of MDA in DEX pretreatment group and whole procedure pump infusion group were significantly lower at the moment of stopping cardio-pulmonary bypass,at the end of surgery,and 24 hours after surgery compared with the control group(P<0.05).The activity of SOD in DEX pretreatment group and whole procedure pump infusion group was significantly higher than the control group at the moment of stopping cardio-pulmonary bypass and the end of surgery,but decreased at 24 hours after operation compared with the control group(P<0.05).In the DEX pretreatment group,MDA was higher than the whole pump infusion group at the moment of stopping cardio-pulmonary bypass(P<0.05).There was no significant difference between the remaining time points(P>0.05).6.The level of blood glucose in the DEX pretreatment group and the DEX whole procedure pump infusion group was lower than that in the control group at the time of sawing the sternum,at the moment of stopping cardio-pulmonary bypass and the end of operation,and the level of NE also decreased at the moment of stopping cardio-pulmonary bypass and the end of operation,and the level of NE in the DEX whole procedure pump infusion group was lower than that in the control group at the 24 hours after operation(P<0.05).Compared with the DEX whole procedure pump infusion group,the NE in the DEX pretreatment group increased at the end of the operation and 24 hours after the operation(P<0.05).Conclusion: DEX preconditioning and whole procedure pump infusion have protective effects on patients with rheumatic heart disease undergoing CPB valve replacement.However,the method of whole procedure pump infusion is superior to pretreatment,and its mechanism may be related to the reduction of inflammatory reaction,oxidative stress and stress reaction. |
