急性等容血液稀释对单肺通气期间组织氧合的影响

摘要

目的 观察急性等容血液稀释(ANHD)对组织氧合的影响.方法 60例ASA Ⅰ或Ⅱ级择期单肺通气(OLV)胸科手术患者随机均分为三个ANHD组:HD_1组,目标Hct为35%;HD_2组,目标Hct为30%;HD_0组不进行ANHD.连续监测ECG、BP、中心静脉压(CVP)及心输出量(CO),于ANHD前(T_1)、ANHD后30 min(T_2)、OLV 15 min(T_3)、OLV 30 min(T_4)测量动静脉血气及血乳酸(Lac),并计算心脏指数(CI),氧供(DO_2)、氧耗(VO_2)、氧摄取率(ERO_2).结果 三组各时点Na~+、K~+、Ca~(2+)、pH及BE无明显改变.ANHD后CI明显增加,OLV后CI继续增加(P<0.05).ANHD后DO_2增加;ERO_2于OLV时均有增加(P<0.05).结论 适度ANHD(Hct>25%)在OLV胸科手术中能保证机体代谢的氧合需要,维持血流动力学及内环境的稳定.%Objective To evaluate the effects of acute norrnovolemic hemodilution(ANHD)on systemic oxygen delivery and consumption during one-lung ventilation(OLV).Methods Sixty ASA Ⅰ or Ⅱ adult patients undergoing elective thoracic surgery under OLV were randomly divided into there groups 20 cases each.ANHD with target Hct of 35%was performed in group HD_1,that of 30%in Group HD_2.ANHD was not used in Group HD_0 as the control ECG,BP,central venous pressure (CVP)and cardiac output(CO)were continuously monitored. Arterial and central venous blood samples were taken for blood gas analysis and determination of lactic acid concentration (Lac) before ANHD (T_1),at 30 min after ANHD (T_2),15 min (T_3) and 30 min after OLV (T_4),cardiac index (CI),oxygen delivery (DO_2),oxygen consumption(VO_2)and oxygen extraction ratio (ERO_2) were calculated as well Results electrolytes, pH and BE were kept stable throughoUt operation.There were no significant changes in HR,BP and CVP,but CI magnified after ANHD. And from OLV,CI could further step up.DO_2 was increased after ANHD.During OLV,DO_2 were decreased compare with that during two lung ventilation.ERO_2 was increased during OLV(P<0.05).Conclusion The stable hemodynamics and balanced oxygenation metabolism can be maintained by moderate degree of ANHD in patients undergoing OLV.