内源性干扰物质对酶法测定钾钠氯结果的影响

目的评价黄疸、溶血、脂血、尿毒症等异常标本中内源性干扰物质对酶法测定血清中钾钠氯结果的影响。方法依据美国国家临床实验室标准化委员会(NCCLS)的EP 7-P文件,分别用间接离子选择性电极(ISE)和酶法测定正常对照组(非黄疸、溶血、脂血)、黄疸组、溶血组、脂血组、尿毒症组标本中钾钠氯,对结果进行统计学分析。结果正常对照组,酶法钠氯均高于ISE(P<0.05),钾在两种方法间无差异;溶血、黄疸对酶法测定钾钠氯均无干扰(P>0.05);脂血(TG<15mm o l/L)对酶法测定钾氯无干扰,钠呈负偏差,但酶法不能测定严重脂血标本(TG>15 mm o l/L)中钾钠氯,脂血标本中钠偏倚与甘油三酯、胆固醇浓度不相关(r=0.06,r=0.10);尿毒症组样品中钾与对照组呈负偏差(P<0.05),与CREA、BUN的浓度间弱相关(r=0.31,r=0.26),而尿毒症组标本中钠氯较正常对照组呈正偏差(P<0.05),与CREA、BUN浓度间无相关性(r=0.07,r=0.05)。结论溶血、黄疸、轻中度脂血对酶法测定钾钠氯无干扰,但不能用于分析严重脂血标本、尿毒症标本的钾钠氯测定。

Evaluating the Effect of Endogenous Interferential Substances on Enzymatic Methods for Determining Potassium ,Sodium ,Chloride

Objective To evaluate the effect of endogenous substances in hemolyzed,icteric,lipemic and uremic samples on enzymatic methods for determining potassium(K~ ),sodium(Na~ ),chloride(Cl~-).Methods According to the National Committee for Clinical Laboratory Standards EP7-P,the K~ ,Na~ and Cl~-in normal serum,hemolyzed,icteric,lipemic and uremic samples were analyzed by indirect ion-selective electrodes(ISE) and enzymatic methods.The all results were statistically analyzed.Results In normal samples,the Na~ and Cl~-of enzymatic methods were higher than those of ISE(P<0.05),while K~ had no significant bias between two methods.The hemolysis and icterus had no interferences on the results of K~ ,Na~ and Cl~-analyzed by enzymatic methods(P>0.05).The enzymatic values of K~ and Cl~-were not affected by lipemia(TG<15mmol/L),while Na~ had negative bias in lipemic samples,there was no correlation of the negative bias with the serum concentration of triglyceride(r=0.06) and cholesterol(r=0.10).The enzymatic methods could not be used in determining K~ ,Na~ and Cl~-in grossly lipemic samples(TG>15mmol/L).In uremic samples,enzymatic K~ values showed negative bias(P<0.05),the deviations correlated only weakly with urea nitrogen and creatinine(r=0.26,r=0.31).Whereas enzymatic Na~ and Cl~-values showed positive bias which had no correlation with urea nitrogen and creatinine(r=0.05,r=0,07).Conclusion The hemolysis,icterus,middle or lightly lipemia have no significant effects on enzymatic methods for determining K~ ,Na~ and Cl~-.However the enzymatic methods can not be used in determining K~ ,Na~ and Cl~-in grossly lipemic and uremic samples.