不同剂量右美托咪定对非体外循环冠状动脉旁路移植术中血流动力学的影响

Effects of different doses of dexmedetomidine on hemodynamics in patients undergoing off-pump coronary artery bypass grafting

目的右美托咪定具有一定的心脏保护作用,但其对非体外循环冠状动脉旁路移植术(off-pump coronary artery bypass grafting surgery,OPCABG)患者血流动力学的影响研究较少。文中旨在观察不同剂量右美托咪定对OPCABG患者术中血流动力学的影响。方法采用随机数字表法将60例择期行OPCABG患者分为4组(n=15):右美托咪定0.2μg/(kg·h)组、0.4μg/(kg·h)组、0.6μg/(kg·h)组和等渗盐水组。右美托咪定0.2μg/(kg·h)组、0.4μg/(kg·h)组、0.6μg/(kg·h)组于麻醉诱导前静脉输注右美托咪定负荷剂量0.5μg/kg,持续时间10 min,随后分别以0.2、0.4、0.6μg/(kg·h)的速率维持至术毕,等渗盐水组以相同速率给予等量等渗盐水。分别于入室后(T_0)、麻醉诱导前(T_1)、气管插管5 min后(T_2)、锯开胸骨时(T_3)、吻合前降支结束(T_4)、吻合右冠状动脉或左旋支结束(T_5)和术毕(T_6)记录各项血流动力学指标,记录术中血管活性药物总量及心脏不良事件发生率情况。结果 T_3至T_6时段,右美托咪定0.4μg/(kg·h)组、0.6μg/(kg·h)组心率、平均动脉压(mean artery pressure,MAP)、中心静脉压(central venous pressure,CVP)、平均肺动脉压(mean pulmonary artery pressure,MPAP)、肺毛细血管楔压(pulmonary capillary wedge pressure,PCWP)较同时段等渗盐水组明显下降(P<0.05)。右美托咪定0.2μg/(kg·h)组、等渗盐水组的体循环阻力指数(systemic vascular resistance index,SVRI)及肺循环阻力指数(pulmonary vascular resistance index,PVRI)在T_3至T_6时段较T_0时刻明显上升(P<0.05)。T_2、T_6时刻与右美托咪定0.6μg/(kg·h)组比较,B组心率及MAP明显上升[T_2:(57±6)次/min vs(52±4)次/min,(72±7)mm Hg vs(63±5)mm Hg;T_0:(72±5)次/min vs(55±6)次/min,(68±5)mm Hg vs(63±5)mm Hg];T_4至T_6时段,右美托咪定0.4μg/(kg·h)组心脏指数、SVRI、PVRI与同时段右美托咪定右美托咪定0.6μg/(kg·h)组比较,差异有统计学意义(P<0.05)。与等渗盐水组相比,右美托咪定0.4μg/(kg·h)组、0.6μg/(kg·h)组高血压、心动过速的发生率及去甲肾上腺素用量、单硝酸异山梨酯用量均明显下降(P<0.05);右美托咪定0.6μg/(kg·h)组低血压、心动过缓发生率明显上升,单硝酸异山梨酯用量明显下降(P<0.05)。结论在OPCABG中,给予右美托咪定0.5μg/kg负荷剂量、继以0.4μg/(kg·h)维持输注有助于维持患者血流动力学的稳定以及心肌的氧供需平衡,从而减少心肌损伤。

Objective Dexmedetomidine posses potential cardiac protective effects,but its effects on cardiovascular alternations in patients undergoing off pump coronary artery bypass grafting（ OPCABG） remain less well studied. The present study was to investigate the effects of dexmedetomidine on postoperative cognitive function in patients undergoing OPCABG. Methods In this randomized double-blind,60 patients scheduled for OPCABG were randomly divided into 4 groups： control group（ group C） and 3 dexmedetomidine group（ group D1、D2、D2）. Patients in each group received saline or dexmedetomidine 0. 2 μg/kg,0. 4 μg/kg,0. 6 μg/kg respectively.Hemodynamic variables such as HR、MAP、CVP、MPAP、PCWP、SVRI and PVRI were recorded after entering into the operationroom（ T_0）,before the anesthesia induction（ T_1）,at 5 minutes after tracheal intubation（ T_2）,during the sternotomy（ T_3）,at the end of anastomosis of left anterior descending（ T_4）,at the end of anastomosis of right coronary artery or 1eft circum flex coronary artery（ T_5） and after operation（ T_6）. Body tempreture and urine volume were recorded during the operation. Total quantity of analgesics consumption and heart adverse reaction（ bradyarrhythmia,tachycardia,hypotension,hypertension etc） were also recorded. Results At T_2- T_6,there was a significant decline in HR,MAP,SVRI,PVRI and CI in group D2 and group D3 compared with group C（ P 0. 05）. SVRI and PVRI in group C and group D2 significantly increased at T_3- T_6 compared with those at at T_0（ P 0. 05）. At T_2 and T_6,HR and MAP in group group D2 signicantly increased compared with group D3（ [57 ± 6]times/min vs [52 ± 4]times/min,[72 ± 7]mm Hg vs[63 ± 5]mm Hg; [72 ± 5]times/min vs [55 ± 6]times/min,[68 ± 5]mm Hg vs [63 ± 5]mm Hg） ]. At T_4- T_6,significant difference was found in CI,SVRI and PVRI between group D2 and group D3（ P 0. 05）. In comparison to group C,hypertension,tachycardia incidence,noradrenaline amount and isosorbide mononitrate amount declined significant in group D2 and group D3（ P 0. 05）; hypotension and bradycardia incidence increased significantly while isosorbide mononitrate amount reduced significantly（ P 0. 05）.Conclusion In OPCABG,dexmedetomidine infused at 0. 4 μg /（ kg·h） after a loading dose of 0. 5 μg /（ kg·10 min） is useful in maintaining stable hemodynamics which contributes to oxygen balance and reduces myocardium injury in patients.