Effect Of Dexmedetomidine On Perioperative Adverse Cardiovascular Events In Elderly Patients With Diabetes Mellitus

Objective:The aim of the study was to investigate the effects of dexmedetomidine(Dex)on the preoperative changes in substance P(SP),calcitonin gene-related peptide(CGRP),norepinephrine(NE),troponin I(cTnI)in plasma and the perioperative adverse cardiovascular events(PACE)in elderly patients with diabetes mellitus(DM)undergoing knee and hip replacement surgery.Methods:Forty-eight diabetic patients,aged 65-87 years,and ASA grade II-III,underwent elective total knee arthroplasty and hip replacement operation under spinal anesthesia were enrolled.The patients were randomly divided into two groups,the Dex treatment group(Dex group,n = 22)and the non-Dex treatment group(non-Dex group,n = 26).After fixation of the level of the spinal blockade,the patients in group Dex were given intravenous infusion of dexmedetomidine at 0.4 μg/kg for 10 min,followed by continuous infusion at a rate of 0.4 μg/kg·h.Group non-Dex was given an equal volume of physiological saline.Blood pressures,pulse oxygen saturation,heart rate and cardiac rhythm,electrocardiogram and shift of ST-segment were routinely monitored and analyzed.The perioperative adverse cardiovascular events were monitored and compared between the two groups.Plasma SP,CGRP,NE and cTnI levels were measured by enzyme-linked immunosorbent assay.Results:There was no statistical difference in preoperative blood glucose,plasma cTnI,SP,NE,and CGRP between the two groups(P > 0.05).The total incidence of perioperative adverse cardiovascular events,the increase in the level of the postoperative blood glucose and the magnitude of reduction in plasma CGRP were significantly smaller in Dex group than those in the non-Dex group(P < 0.05).The plasma cTnI was significantly increases in non-Dex group,at 24 h after operation(P < 0.05),when compared to that of Dex group(P < 0.05).However,a non-significant change in plasma SP(P > 0.05)in non-Dex group and a significant reduction in SP in Dex group were observed(P < 0.05).Significantly lower levels of plasma NE at 24 h postoperatively were detected in both of non-Dex and Dex groups(all P < 0.05),but a further lower level of NE was observed in Dex group(P< 0.05)at 24 h postoperatively.The results also revealed significant reductions in SP and CGRP and significantly increased levels of cTnI and NE in the patients with PACE.Conclusion:Dexmedetomidine may stabilize the plasma concentration of CGRP and cTnI in elderly patients with diabetes mellitus,thereby reducing the perioperative adverse cardiovascular events.