老年病人术中不同容量急性高容量血液稀释的可行性

目的　评估对老年病人输注不同负荷容量的6%羟乙基淀粉(HES)实施急性高容量血液稀释(AHH)的安全性和有效性。方法　选择ASA I~II 级、择期全髋置换术病人24 例,随机分为A组和B组,每组12 例,分别输注6% HES15 ml/kg和20 ml/kg。两组病人均在硬膜外阻滞复合全身麻醉下实施AHH,全麻诱导后,经中心静脉分别将15 ml/kg和20 ml/kg的6%HES以50 ml/min输注完毕。术中采用无创心功能监护仪连续监测心排血量(CO)、心脏指数(CI)、每搏量(SV)、外周血管阻力(SVR)、肺血流量(PCBF), 同时监测CVP 、MAP、HR。分别在AHH前、AHH完毕即刻和术毕记录上述数据。上述各时点和术后1天采集动、静脉血,进行动脉血气分析。记录术中失血量和输液量。结果　两组病人的CI、CVP、CO、PCBF及SV在AHH完毕即刻和术毕较AHH前明显升高(P<0.05);其变化幅度无显著性差异。两组病人的Hb、Hct及Pt在AHH完毕即刻、术毕和术后1天与AHH前相比均降低(P<0.05);两组病人之间的比较均无显著性差异(P>0.05)。A和B组病人的ACT和血乳酸浓度在AHH前后均无显著性差异(P>0.05)。结论　在硬膜外复合全麻下,对无严重心肺疾病的老年人采用6%HES按15 ml/kg和20 ml/kg以50 ml/min快速扩容实施AHH是安全有效的。

Feasibility of acute hypervolemic hemodilution with different volume during operation in the elderly patients

Objective To evaluate the effect and the safety of acute hypervolemic hemodilution(AHH) with 6% hetastarch(HES) in the elderly patients during operation under combined general-epidural anesthesia.Methods Twenty-four ASAI~II patients undergoing elective total hip replacement were enrolled in this study.The patients were randomly divided into two groups according to loading volume with 12 patients each.The operations were performed under combuned general-epidural anesthesia.After induction of anesthesia,AHH was performed with 6% hetastarch 15 ml /kg (group a) or 20 ml /kg (group B) at a rate of 50 ml /min by skin incision. Radial artery was cannulated for direct BP monitoring and internal jugular vein was cannulated for CVP monitoring.Cardiac output(CO),stroke volume(SV),pulmonary caplillary blood flow(PCBF), cardiac index(CI),SVR and HR were continuously monitored using noninvasive measurement of cardiac output (NICO). Arterial and venous blood samples were taken for blood gas analysis and determination of lactic acid(Lac), after AHH and at the end of operation.Routine blood test was checked one day after operation.The volume of solution infusion and blood loss was recored during the operation.Results There was no significant changes in MAP and HR after AHH(P> 0.05 )but CO,SV,CVP,PCBF and CI were increased and SVR decreased significantly after AHH in both groups as compared with those before AHH. Hct,Hb and Pt were reduced after AHH ,at the end of operation and one day after operation.ACT and Lac did not change significantly after AHH. There was no significant difference in the volume of solution infused ,blood loss,CO,CI,SV,SVR,CVP and PCBF between the two groups.Conclusion Under combined general-epidural anesthesia AHH with 6% hetastarch 15 ml /kg or 20 ml /kg at a rate of 50 ml /min can be well tolerated by the elderly patients.