| Objective:To investigate the effect of different dexmedetomidine doses on heart rate variability and hemodynamics of patients undergoing retroperitoneal laparoscopy operation.Methods:Ninety elderly patients undergoing retroperitoneal laparoscopy for renal cyst,were randomly divided into 3 groups:low-dose group,high-dose group and control group.Patients in low-dose group and high-dose group respectively infused with dexmedetomidine 0.4 μg/kg and 0.8 μg/kg loading dose before induction,while patients in control group were received infusion of 20 ml normal saline for 15 min.Venous blood samples of patients were taken to measure the plasma epinephrine(E)and acetylcholine(Ach)content before drug infusion(T0),immediately after pneumoperitoneum(T1)and at the end of pneumoperitoneum(T2).The MAP,HR were recorded,and the ECG signal was collected at the same time.HRV frequency domain indexes were obtained by HRV analysis software,including LF,HF.The adverse reactions of patients including bradycardia,hypotension,nausea and vomiting were recorded.Results:1)Compared to T0,MAP,HR between groups decreased obviously at T1,T2,T3(P <0.05).Compared to T1,MAP,HR in group N increased significantly at T2(P < 0.05).At T2,MAP in group N was significantly higher and HR in group N was faster than that inthe group M1 and group M2(P < 0.05).At T3,MAP in group M2 was obviously lower and the HR was significantly slower than that in group M1 and groupN(P < 0.05).2)Compared to T0,the content of E in group M1,group M2 and groupN was decreased significantly at T1、T2、T3(P < 0.05),the Ach in group M2 was significantly increased at T3(P < 0.05).Compared with T1,the content of E in group N were obviously increased at T2(P < 0.05),and the content of Ach in group M2 was increased significantly at T3(P< 0.05).At T2,the content of E in group N was significantly higher than that in group M1 and group M2(P < 0.05).At T3,the content of E in group M2 was significantly less than that in group M1 and group N(P < 0.05),and the content of Ach in the group M2 was more than that in group M1 and group N(P < 0.05).3)LF in the group M2 was significantly less than that in group M1 and group N(P<0.05),while HF in group M2 was significantly higher than that in group M1 and group N.4)the adverse reaction rate in the high-dose group was more than that in group M1 and group N(P<0.05).Conclusion:Dexmedetomidine in elderly patients with retroperitoneal laparoscopy operation can effectively increased heart rate variability and maintain the hemodynamic stability.In addition,0.4 μg/kg load-dose is safer in elderly patients with retroperitoneal laparoscopy operation prefer to 0.8 μg/kg. |
