右美托咪啶对老年胸腔镜下食管癌手术患者心肌氧供需平衡的平衡影响

Effects of dexmedetomidine on oxygen supply-demand balance in elderly patients with esophageal cancer under thoracoscopy surgery

目的对照研究不同剂量右美托咪啶(DEX)对老年胸腔镜下食管癌手术患者心肌氧供需平衡的影响。方法 60例符合研究条件的65岁以上老年患者,随机平均分成低剂量DEX(L组)组(0.5μg/kg,15min内泵入),高剂量DEX(H组)组(1.0μg/kg,15min内泵入)以及生理盐水(N组)对照组(与研究组同等速率泵入),实验组维持量均为0.5μg/(kg.h)。所有患者输注前均静脉补充5mL/(kg.h)乳酸钠林格注射液,同时完成桡动脉监测与右颈内静脉放置漂浮导管。记录有创监测稳定后10min(T1)、DEX负荷量输注开始5min(T2)、DEX负荷量输注开始10min(T3)、DEX负荷量输注开始15min(T4)、DEX维持输注30min(T5)5个时间点的血流动力学指标,计算心率与收缩压乘积(RPP),抽取桡动脉和肺动脉血进行动脉血气分析,计算氧供(DO2)和氧耗(VO2)。结果各组患者一般情况比较差异无显著性(P>0.05)。与对照组比较,L、H组内HR变化呈现降低趋势,T3、T4、T5时点较T1均出现HR显著降低(P<0.05),L、H两组间比较差异无显著性;L组患者MAP组内变化差异无显著性,与L组相比,H组T3、T4、T5时点MAP显著降低(P<0.05),T5时点较其他时点以及其他组显著降低(P<0.05)。L组内DO2比较差异均无显著性,两组VO2在T3、T4、T5时点均较T1显著降低,与L组相比较,H组T5时点DO2显著降低(P<0.05)。结论小剂量右美托咪啶输注可显著降低老年胸腔镜下食管癌手术患者心肌氧耗量,对血液动力学影响小,改善心肌氧供。大剂量右美托咪啶显著降低心肌氧耗量,降低平均动脉压,对血液动力学有一定影响,可能降低心肌氧供。

[Objective] To investigate the effects of dexmedetomidine of two different dose infusing by pump on oxygen supply-demand balance in elderly patients with esophageal cancer under thoracoscopy surgery.[Methods] Sixty patients were enrolled in the study.These patients were randomly divided into three groups：low dose dexmedetomidine（L Group）,High dose dexmedetomidine（H Group）,and normal saline（N Group）.Loading dose dexmedetomidine was infusing by pump with 0.5μg/kg in Group L and 1.0μg/kg in Group H accordingly and the same maintenance dose 0.5μg/（kg·h） in both of them,same infusing speed of saline in Group N as a control study.All groups were given the same medication,and radial arterial blood pressure monitoring and right jugular vein with Swan-Ganz catheter were performed.Hemadynamics,HR × pressure product（RPP）,arterial and pulmonary blood gas analysis,oxygen supply（DO2） and oxygen consumption（VO2） at 5 time points interval were recorded：invasive administrated 10 minutes later（T1）,5,10,15 minutes（T2,T3,T4） after loading dose dexmedetomidine infusion,30 minutes after dexmedetomidine maintaining infusion（T5）.[Results] Comparing with N Group,heart rate depression trend was significantly found in L and H groups after the infusion,and there were significant reducing on HR in L and H group at T3,T4 and T5 time points（P 0.05）.No significant changes in DO2 in L group（P 0.05）,while there were significant decrease in VO2 in L and H Group during T3,T4 and T5 time points than that in T1 time point（P 0.05）.And there was significantly reducing in DO2 in H group than that in L and N group at the T5 time point（P 0.05）.[Conclusion] Low dose dexmedetomidine infusion exhibits slight influence on Hemadynamics,and can promote the oxygen supply-demand balance with depressing oxygen consumption while maintaining the oxygen supply.High dose dexmedetomidine infusion may cause uncertain risk on oxygen supply-demand balance in elderly patients.