不同剂量右美托咪定联合喷他佐辛对老年膝关节置换术病人脑氧代谢平衡与血流动力学影响

Effect of different doses of dexmedetomidine combined with pentazocine on cerebral oxygen metabolism and hemodynamics in the elderly patients undergoing knee arthroplasty

目的采用不同剂量的右美托咪定联合喷他佐辛对病人进行干预,观察不同组老年膝关节置换术病人的脑氧代谢平衡及血流动力学指标变化情况。方法将2014年1月至2016年1月我院收治的120例行老年膝关节置换术年病人随机分为A、B、C 3组,分别采用小剂量右美托咪定+喷他佐辛组(A组),中剂量右美托咪定+喷他佐辛组(B组),大剂量右美托咪定+喷他佐辛组(C组)进行麻醉。3组均采用全身麻醉,在麻醉诱导前均给予负荷剂量右美托咪定0.5μg/kg,输注时间为15 min,喷他佐辛0.25 mg/kg,在气管插管后3组右美托咪定分别以0.3μg/(kg·h)、0.5μg/(kg·h)、0.8μg/(kg·h)持续泵注,手术结束前30 min停止输注,手术结束前约10 min给予喷他佐辛0.25 mg/kg。于手术开始时、手术开始15 min及术后拔除导管时监测3组病人脑氧代谢水平及血流动力学水平,并进行比较。结果 B组及C组病人脑动-静脉血氧含量差(Da-jvO_2)及脑氧摄取率(CERO_2)均显著低于A组(P均<0.05);拔除导管时,3组病人Da-jvO_2及CERO_2水平均显著高于手术开始时(P均<0.05),动脉血氧含量(CaO_2)及颈静脉血氧饱和度(CjvO_2)均显著低于手术开始时(P均<0.05);各时间点B组与C组病人平均动脉压(MAP)及心率(HR)差异均无统计学意义(P均>0.05),但手术15 min及拔除导管时B组和C组MAP与HR水平显著低于A组(P均<0.05),手术15 min及拔除导管时3组病人MAP及HR水平均显著高于手术开始时(P均<0.05),拔除导管时3组病人MAP水平显著高于手术15 min时(P均<0.05)。结论分别采用中、高剂量的右美托咪定与低剂量的右美托咪定联合喷他佐辛应用时,对老年膝关节置换术病人的脑氧代谢平衡与血流动力学的影响存明显差异。

Objective To observe cerebral oxygen metabolism and hemodynamics changes in the elderly patients undergoing knee arthroplasty anaesthetized by using different doses of dexmedetomidine combined with pentazocine. Methods 120 patients undergoing knee arthroplasty from January 2014 to January 2016 in our hospital were divided into three groups randomly. General anesthesia was carried out in all patients,and 0. 5 μg/kg dexmedetomidine was given before the anesthesia induction for 15 min,and 0. 25 mg/kg pentazocine was followed in three groups. After trachea cannula,0. 3 μg/（ kg·h）,0. 5μg/（ kg·h） and 0. 8 μg/（ kg · h） dexmedetomidine was pumped in group A,group B and group C respectively. The indexes of cerebral oxygen metabolism and hemodynamics at the beginning of the operation,15 min after beginning of operation,and at the moment of catheter removed were observed and compared. Results The levels of Da-jv O2 and CERO2in group B and group C were significantly lower than those of group A（ P〈0. 05）. At the moment of removal catheter,the levels of Da-jv O2 and CERO2in three groups were all significantly higher,and the levels of Ca O2 and Cjv O2 were significantly lower than those at the beginning of the operation（ P〈 0. 05）. There were no significant differences in mean arterial pressure（ MAP） and heart rate（ HR） between group B and C group at each time point（ P〉0. 05）,but the levels of MAP and HR in group B and group C 15 min after beginning of operation and at the moment of removal catheter were significantly higher than those in group A（ P〈 0. 05）. Compared to the beginning of the operation,the levels of MAP and HR in three groups 15 min after beginning of operation and at the moment of removal catheter were significantly higher（ P〈 0. 05）. There was significant difference in level of MAP between 15 min after beginning of operation and the moment of removal catheter（ P〈 0. 05）. Conclusions Application of middle or high dose of dexmedetomidine combined with pentazocine in the elderly patients undergoing knee arthroplasty may have difference effect on cerebral oxygen metabolism and hemodynamics.