肝素对两种血氨测定方法干扰的研究

目的研究不同浓度肝素对干化学法和酶动力学法测定血氨的影响。方法参照美国临床实验室标准委员会（NCCLS）EP7-P文件,将不同浓度肝素分别加入低、中、高血氨浓度的样本中,用干化学法和酶动力学法测定各样本中血氨的浓度,与未加肝素的基础样本比较,观察肝素对两种方法测定血氨的影响,确定采用肝素抗凝样本的最佳浓度。结果对于干化学法测定血氨,低、中血氨浓度时要求肝素浓度≤40U/ml,高血氨浓度时要求肝素浓度≤60U/ml,对血氨测定影响较小。对于酶动力学测定血氨,低浓度样本要求肝素浓度≤40U/ml,中、高浓度样本,肝素浓度≤60U/ml时,对血氨测定影响较小。结论采用肝素抗凝血样本测定血氨浓度,肝素浓度需控制在10～40U/ml以内为宜。

Effects of Heparin on the Measurement of Blood Ammonia

Objective To determine the effect of different concentrations of heparin on the measurement of blood ammonia by chemical and enzymatic methods. Method According to the procedures as described by NCCLS, different concentrations of heparin were added into the blood samples with a low, medium and high concentrations of ammonia. The concentrations of ammonia were determined using chemical and enzymatic methods. Result The maximum concentration of heparin used in the chemical analysis of a low to medium and a high concentration of ammonia is 40 U/ml and 60 U/ml, respectively. The maximum concentration of heparin used in the enzymatic analysis of a low and a medium to high concentration of ammonia is 40 U/ml and 60 U/ml, respectively. Conclusion The appropriate concentration of heparin used in the determination of blood ammonia should be in the range of 10- 40 U/ml.