酶法检测静脉血血浆二氧化碳的临床应用评价

Clinical evaluation of enzymatic assay for the detection of carbon dioxide in venous blood plasma

目的分别比较动脉血血浆总二氧化碳(TCO_(2))和[HCO_(3)^(-)]与酶法测定静脉血浆TCO_(2)的差异性,评价静脉血浆TCO_(2)替代动脉血气分析评价人体酸碱平衡的临床应用价值。方法选取2022年12月至2023年4月宁波大学附属第一医院收治的69例患者作为研究对象,采用浙江金华强盛厂家试剂盒(PEPC酶法)检测其静脉血血浆TCO_(2),采用沃芬GEM Premier 5000全自动血气分析仪检测其动脉血TCO_(2)和[HCO_(3)^(-)]水平,评价血浆TCO_(2)与动脉血TCO_(2)和[HCO_(3)^(-)]的相关性与一致性。同时挑取新鲜抽取静脉血30份,随机分成3组(冰浴组、常温闭盖组、常温开盖组),在即刻、10 min、20 min、30 min、60 min、120 min时间检测分别其血浆TCO_(2)水平,计算各时间的相对偏倚,采用双因素方差分析检验3组实验环境条件下血浆二氧化碳的偏倚的差异性和不同时间的血浆二氧化碳的偏倚的差异性是否显著,采用单因素ANOVA方差分析对每个实验组内的整体差异和两两差异是否显著。挑选新鲜动脉血1份,在常温下对其在即刻、10 min、20 min、30 min、60 min、120 min时间进行血气分析,与3组实验组一起绘制折线图。结果静脉血浆TCO_(2)与血气的[HCO_(3)^(-)](r=0.783,P<0.01)和TCO_(2)(r=0.779,P<0.01)均具有高度正相关性。静脉血浆TCO_(2)与血气[HCO_(3)^(-)]和血气TCO_(2)的一致性良好,但其存在的差异需要改善。不同环境条件下(P<0.01)和不同时间下(P=0.015)血浆二氧化碳偏倚的差异具有显著性,各实验组组内的总体差异均有统计学意义(P<0.01)各实验组内的两两比较分别为:常温开开盖组,10 min与20 min(P=0.322),30 min与60 min(P=0.888),差异无统计学意义;常温闭盖组,10 min、20 min和30 min之间差异无统计学意义,(P=0.8599、0.5922、0.9901);冰浴组:10 min与20 min(P=0.975),10 min与30 min(P=0.085),30 min与60 min(P=0.279),60 min与120 min(P=0.089)差异均无统计学意义,剩余组内的两两比较具有显著性(P<0.05)。折线图显示:冰水浴下可以有效缓解血浆二氧化碳的丢失,而封闭环境并没有缓解血浆二氧化碳的丢失。结论研究人体内的酸碱变化及体内TCO_(2)或[HCO_(3)^(-)]的变化,最佳标本仍旧为动脉血气,若要采用酶法检测系统检测静脉血浆TCO_(2)替代动脉血气样本,需要临床采集到完成检测的最佳时间为30 min,60 min内必须完成检测;若无法及时送检,可以保存于冰箱,有条件的实验室可以采用冰浴送检并在120 min内完成检测。

Objective To compare the differences between arterial blood TCO_(2) and[HCO_(3)^(-)]with enzymatic measurement of venous plasma TCO_(2),and to evaluate the clinical value of using venous plasma TCO_(2) as a substitute for arterial blood gas analysis in assessing human acid-base balance.Methods Sixty nine patients admitted to the first affiliated hospital of Ningbo university from december 2022 to april 2023 were selected as the research subjects.The venous blood plasma TCO_(2) was detected using the Zhejiang Jinhua Qiangsheng manufacturer′s reagent kit(PEPC enzyme method),and the arterial blood TCO_(2) and[HCO_(3)^(-)]levels were measured using the Wofen GEM Premier 5000 automatic blood gas analyzer.The correlation and consistency between plasma TCO_(2) and arterial blood TCO_(2) and[HCO_(3)^(-)]were evaluated.At the same time,30 fresh venous blood samples were selected and randomly divided into 3 groups(ice bath group,normal temperature closure group,and normal temperature opening group).The plasma TCO_(2) levels were measured at immediate,10 minutes,20 minutes,30 minutes,60 minutes,and 120 minutes,and the relative bias at each time was calculated,Two factor analysis of variance was used to test the differences in plasma carbon dioxide bias under three experimental environmental conditions and whether the differences in plasma carbon dioxide bias at different times were significant.One factor ANOVA analysis of variance was used to determine whether the overall and pairwise differences within each experimental group were significant.Select one fresh arterial blood sample and conduct blood gas analysis at room temperature for immediate,10,20,30,60,and 120 minutes.Draw a line graph together with three experimental groups.Results There is a high positive correlation between venous plasma TCO_(2) and blood gas[HCO_(3)^(-)](r=0.783,P=0.00)and TCO_(2)(r=0.779,P=0.00).The consistency between venous plasma TCO_(2) and blood gas[HCO_(3)^(-)]and blood gas TCO_(2) is good,but the differences that exist need to be improved.The difference in plasma carbon dioxide bias under different environmental conditions(P=0.00)and at different times(P=0.015)is significant,and the overall differences within each experimental group are all significant,P=0.00;The pairwise comparisons within each experimental group were as follows:opening the lid at room temperature group,10 minutes and 20 minutes(P=0.3223),30 minutes and 60 minutes(P=0.8879),with no significant differences;There was no significant difference between 10 minutes,20 minutes,and 30 minutes in the normal temperature closure group,with P values of 0.8599,0.5922,and 0.9901,respectively;The ice bath group showed no significant differences between 10 and 20 minutes(P=0.9753),10 and 30 minutes(P=0.0853),30 and 60 minutes(P=0.2790),and 60 and 120 minutes(P=0.0890),while pairwise comparisons within the remaining groups showed significant differences(P<0.05).The line chart shows that ice water bath can effectively alleviate the loss of plasma carbon dioxide,while a closed environment does not alleviate the loss of plasma carbon dioxide.Conclusion Researching acid-base changes in the human body and changes in intracellular TCO_(2) or[HCO_(3)^(-)],the optimal specimen is still arterial blood gas.If an enzyme assay detection system is used to detect venous plasma TCO_(2) instead of arterial blood gas samples,the optimal time for clinical collection to completion of the test is 30 minutes,and the test must be completed within 60 minutes.If it is not possible to send the sample for testing in a timely manner,it can be stored in a refrigerator,and laboratories with conditions can use ice baths to send the samples for testing and complete the test within 120 minutes.