血清二氧化碳总量测定结果与放置时间的关系分析

Relationship study between the serum total carbon dioxide and storage time

目的探讨血清标本二氧化碳总量(TCO2)测量结果与开盖放置时间的关系。方法选取该院门诊患者真空采集的静脉血清标本100份,分别于离心开盖后0、2、4、6、8、10、12h测定,将开盖后0h测定结果作为患者血清TCO2基础水平,计算开盖后2、4、6、8、10、12h血清TCO2的留存率,将留存率与开盖放置时间进行曲线拟合。另选取不同天门诊患者真空采集静脉血清标本100份,分别于标本采集当天离心,开盖后0、1.217、2.283、3.267、4.200、5.617、7.100、9.150、11.083h进行测定,计算血清TCO2的实测留存率,比较实测留存率与拟合留存率的差异。结果经曲线拟合,血清中TCO2的留存率与开盖放置时间呈二次或三次函数关系:Y=98.727-5.32X+0.232X^2(r^2=0.983,P<0.05)或Y=99.575-6.734X+0.550X^2-0.018X^3(r^2=0.989,P<0.05),Y为留存率;X为放置时间,0≤X≤12.0。曲线验证表明实测留存率与拟合曲线所得留存率结果差异无统计学意义(P>0.05)。结论血清TCO2水平与开盖放置时间呈二次或三次函数关系,且随着放置时间的延长呈下降趋势,为保证结果的准确性,血清TCO2测定应在开盖后尽快完成。

Objective To investigate the relationship between the serum total carbon dioxide(TCO 2)and storage times.Methods Blood serum samples were collected randomly by venipuncture in vacuum tubes from 100 outpatients.The TCO 2 were tested 0,2,4,6,8,10,12 hours after opening the vacuum tubes respectively.The 0 hour value as a TCO 2 base value,and then the 2,4,6,8,10,12 hours TCO 2 retention rates were calculated.The TCO2 retention rates and storage times were used to fit curve.Other 100 blood serum samples were collected randomly in vacuum tubes from outpatients.The TCO2 were tested at 0,1.217,2.283,3.267,4.200,5.617,7.100,9.150 and 11.083 hours after opening the vacuum tubes respectively.The real retention rates were compared to the calculated retention rates.Results The relationships between TCO2 retention rates and storage times were quadratic or cubic function(Y=98.727-5.32 X+0.232 X^2,r^2=0.983,P<0.05 or Y=99.575-6.734 X+0.550 X^2-0.018 X^3,r^2=0.989,P<0.05),Y was retention rate,X was storage time,0≤X≤12.0.There were no significant difference between the real retention rates and the calculated retention rates(P>0.05).Conclusion The relationships between TCO 2 retention rates and storage times were quadratic or cubic function.The serum TCO 2 value declines with time.In order to ensure the result accuracy,the detection of serum TCO 2 should be completed as soon as possible after opening the vacuum tubes.