体外循环下瓣膜置换术患者右美托咪定用量及对患者微循环和血流动力学的影响

The Dosage of Dexmetomidine and Its Effect on Microcirculation and Hemodynamics in Patients Undergoing Valve Replacement with Cardiopulmonary Bypass

目的:探讨体外循环(CPB)期间右美托咪定(Dex)用量对瓣膜置换术患者血流动力学的影响。方法:选取2020-06-2022-12于本院接受择期CPB瓣膜置换术患者85例作为研究对象,随机分为低剂量组(n=28)、高剂量组(n=28)和对照组(n=29),在麻醉诱导前10min分别输注0.2μg/kg·h^(-1)Dex、0.4μg/kg·h^(-1)Dex、生理盐水至术毕。比较麻醉诱导后(T1)、CPB转机开始前(T2)、CPB转机后1h(T3)、CPB转机停止时(T4)、术毕4h(T5)、术毕24h(T6)的各组血流动力学指标;分析Dex输注时长对脑电双频谱指数(BIS)的影响及术后恢复情况。结果:低剂量组和高剂量组给药12min、给药15min、插管后1min的BIS值均低于对照组(P<0.05);低剂量组T2-T4时HR、T2-T5时MAP、T2-T6时LA和cTnI、术后心血管不良事件、鼻温肛温复温时间、术后24h N端脑钠肽前体(NT-proBNP)水平低于对照组,而T2-T6时ScvO_(2)和尿量、心脏自动复跳率高于对照组(P<0.05);高剂量组T2时HR和MAP低于低剂量组,而鼻温肛温复温时间、术后24h NT-proBNP高于低剂量组(P<0.05)。结论:低剂量的Dex即可取得良好的麻醉镇静效果,维持血流动力学的相对稳定,在麻醉诱导开始前10min时输注0.2μg/kg·h^(-1)Dex可有效改善CPB下瓣膜置换术对微循环的影响,降低LA和cTnI水平、提高ScvO_(2)和尿量、缩短鼻温肛温的复温时间。

Objective:To investigate the dosage of dexmedetomidine(Dex)and its effect on microcirculation during valve replacement under the guidance of EEG monitoring during cardiopulmonary bypass(CPB).Method:A total of 85 patients who underwent elective CPB valve replacement in our hospital from June 2020 to December 2022 were selected for the study.The patients were randomly divided into three groups:low dose group(n=28),high dose group(n=28)and control group(n=29).Before anesthesia induction,0.2μg/kg·h^(-1) Dex,0.4μg/kg·h^(-1) Dex and normal saline were infused into 10min until the end of operation.The hemodynamics and microcirculation indexes were compared after anesthesia induction(T1),before the start of CPB bypass(T2),1 hour after CPB bypass(T3),when CPB bypass stopped(T4),4 hours after operation(T5)and 24 hours after operation(T6).The effect of Dex infusion time on bispectral index(BIS)and postoperative recovery were analyzed.Results:The BIS values of 12min,15min and 1min after intubation in low dose group and high dose group were lower than those in control group.The levels of HR at T2-T4,MAP at T2-T5,LA and cTnI at T2-T6,postoperative cardio-vascular adverse events,time for nasal and anal warming,and N terminal pro B type natriuretic peptide(NT-proBNP)at 24h post surgery in the low dose group were lower than those in the control group.The ScvO_(2) and urine volume and the rate of automatic cardiac resuscitation at T2-T6 in the low dose group were higher than those in the control group.HR and MAP at T2 in high dose group were lower than those in low dose group.The nasal and anal rewarming time and postoperative 24hNT-proBNP in the high dose group were higher than those in the low dose group.Conclusion:Low dose of Dex can achieve a good sedative effect and maintain hemodynamic stability.Infusion of 0.2μg/kg·h^(-1) Dex at 10min before anesthesia induction can effectively improve the effect of valve replacement under CPB on microcirculation.Low dose of Dex can reduce the levels of LA and cTnI,increase ScvO_(2) and urine volume,and shorten the rewarming time of nasal and anal temperature.