心脏手术患儿6%HES130/0.4急性血液稀释后血钾浓度降低与6%HES130/0.4-HSA复合物的关系

Relationship between decrease in potassium concentrations after acute hemodilution with 6%hydroxyethyl starch 130/0.4 and 6%HES130/0.4-HSA complex in pediatric patients undergoing cardiac surgery

目的评价心脏手术患儿6%羟乙基淀粉(HES)130/0.4急性血液稀释(AHD)后血钾浓度降低与6%HES130/0.4-人血清白蛋白(HSA)复合物的关系。方法择期行室间隔或房间隔缺损修补术的患儿48例,性别不限,年龄2~12岁,体重12~53 kg,ASA分级Ⅱ或Ⅲ级。患儿气管插管术后以0.5 ml·kg^(-1)·min^(-1)的速率静脉输注10%血容量的6%HES130/0.4行AHD。于AHD前即刻和AHD结束后15、30 min时测定全血K^(+)浓度。采用荧光光谱法分析6%HES130/0.4和HSA的结合关系。分别于加入K^(+)前、加入K^(+)后15和30 min时,测定HSA与6%HES130/0.4的结合常数。结果与AHD前即刻比较,AHD结束后各时点K^(+)浓度降低(P<0.05)。荧光光谱分析法显示,6%HES130/0.4和HSA的Trp-214形成1∶1的复合物;与加入K^(+)前比较,加入K^(+)后15和30 min时结合常数降低。结论心脏手术患儿6%HES130/0.4 AHD后血钾浓度一过性降低的机制可能与部分K^(+)与HSA-6%HES130/0.4复合物形成"离子架桥"有关。

Objective To evaluate the relationship between decrease in potassium concentrations after acute hemodilution(AHD)with 6%hydroxyethyl starch(HES)130/0.4 and 6%HES130/0.4 human serum albumin(HSA)complex in the pediatric patients undergoing cardiac surgery.Methods Forty-eight pediatric patients of both sexes,aged 2-12 yr,weighing 12-53 kg,of American Society of Anesthesiologists physical statusⅡ-Ⅲ,undergoing elective surgical repair of ventricular or atrial septal defect,were included in this study.After tracheal intubation,6%HES130/0.4 equivalent to 10%of the blood volume was intravenously infused at 0.5 ml·kg^(-1)·min^(-1) to perform AHD.The K^(+)concentration in whole blood was measured immediately before AHD and at 15 and 30 min after the end of AHD.The binding relationship between 6%HES130/0.4 and HSA was analyzed by fluorescence spectroscopy.The binding constants of HSA and 6%HES130/0.4 were determined before adding K^(+)and 15 and 30 min after adding K^(+).Results The K^(+)concentrations were significantly decreased at each time point after the end of AHD than those immediately before AHD(P<0.05).Fluorescence spectra showed that 1∶1 complexation occurred between the 6%HES130/0.4 and Trp-214 of HSA.The binding constant was significantly decreased at 15 and 30 min after adding K^(+)when compared with that before adding K^(+).Conclusion The mechanism of transient decrease in K^(+)concentrations after 6%HES130/0.4 AHD may be related to the formation of"ion bridge"between partial K^(+)and HSA-6%HES130/0.4 complex in the pediatric patients undergoing cardiac surgery.