术前预先静脉输注右美托咪定对老年患者围术期心肌肌钙蛋白Ⅰ的影响

Influence of preoperation dexmedetomidine infusion on serum concentration of troponin Ⅰ in aged patients

目的观察术前预先静脉持续注射右美托咪定对老年患者围术期心肌肌钙蛋白I（cTnⅠ）表达的影响。方法选择在全身麻醉下择期行普外科腹部手术的老年患者80例,年龄60~75岁,随机分入右美托咪定组（右美组）和对照组,每组40例。麻醉诱导前40min,右美组患者予右美托咪定负荷剂量1μg/kg,10min静脉输注完毕,随后以0.8μg·kg^-1·h^-1的速度维持静脉输注30min;对照组患者恒速静脉输注0.9%氯化钠溶液。分别于患者入手术室后（T0）、麻醉诱导前（T1）、气管插管后即刻（T2）、气管插管后1min（T3）、切皮前（T4）、切皮后1min（T5）、手术结束时（T6）、拔除气管导管前（T7）、拔除气管导管后1min（T8）、拔除气管导管后5min（T9）各时间点,记录患者的心率和平均动脉压（MAP）。采用化学发光法检测患者在术前、拔除气管导管后、术后24h的血清cTnⅠ水平。结果对照组在T2、T3时间点的心率显著快于同组其余时间点（P值均〈0.05）,T5时间点的心率显著慢于同组其余时间点（P值均〈0.05）;T2、T3时间点的MAP显著高于同组其余时间点（P值均〈0.05）。右美组组内各时间点间心率和MAP的差异均无统计学意义（P值均〉0.05）。术前两组间血清cTnⅠ水平的差异无统计学意义（P〉0.05）,右美组拔除气管导管后、术后24h的血清cTnⅠ水平显著低于对照组同时间点（P值均〈0.05）,对照组术后24h的血清cTnⅠ水平显著高于同组术前和拔除气管导管后（P值均〈0.05）。两组各时间点的血清cTnⅠ水平均在正常范围内（0~0.040ng/mL）。结论老年患者术前预先静脉输注右美托咪定有助于维持血流动力学稳定,减轻气管插管等手术刺激时的心血管反应,也可能在一定程度上减少老年患者围术期的心肌损害。

Objective To observe the effect of dexmedetomidine administered before anesthesia induction on the serum concentration of cardiac troponin Ⅰ （cTnⅠ） in elderly patients. Methods Eighty elderly patients （60 - 75 years old） scheduled for abdominal surgery were randomly divided into two groups （n = 40）. The patients in dexmedetomidine group received bolus dose dexmedetomidine 1 μg · kg^-1·10 min^-1, followed by 0.8μg· kg^-1· h^-1 for 30 min before anesthesia induction. The patients in control group received normal saline by constant speed. Heart rate （HR） and mean artery pressure （MAP） were recorded at the time points as follows. baseline （T0）, before induction （T1）, immediately after intubation （T2）, 1 min after intubetion （T3）, before incision （T4）, 1 min after incision （T5）, the end of the surgery （T6）, before extubation （T7）, 1 min （T8） and 5 min after extubation （T9）. The concentration of serum cTnⅠ was determined before surgery, after extubation and 24 h after surgery. Results In the control group, HR at T2 and T3 were significantly faster than those at other time points （all P〈0.05）, while HR at T5 was significantly slower than those at other time points （all P〈0.05） ; MAP at T2 and T3 were significantly higher than those at other time points （all P〈0.05）. There were no significant differences in HR or MAP at each time point in the dextromethorphan group （all P 〉 0.05）. There was no significant difference in the level of cTnⅠ between two groups before surgery （P〉0.05）. The levels of cTnⅠ afterextubation and 24 h after surgery in the dextromethorphan group were significantly lower than those in the control group （all P〈0.05）. The level of cTnⅠ at 24 h after surgery was significantly higher than baseline and that after extubatien （both P〈0.05）. However, the level of cTnⅠ was within normal limits （0-0. 040 ng/mL） at each time point in all patients. Conclusion For aged patients, dexmedetomidine infusion before anesthesia induction is helpful for myocardial protection and hemodynamic stability and can reduce cardiovascular responses to noxious stimulation.