Yucha C B, DeAngelo E
School of Nursing, University of Colorado Health Sciences Center, Denver, USA.
J Intraven Nurs. 1996 May-Jun;19(3):141-6.
The purpose of this research is to quantify the minimum amount of blood that must be discarded from an indwelling peripheral intravenous catheter (deadspace 0.5 ml) to obtain an accurate hematocrit reading. Repeat blood sampling from nine subjects is used to develop a mathematical model (Michaelis-Menten curve) describing the mixing of the flush solution and the blood. This model is used to estimate the hematocrit when different volumes are discarded. Differences between the computed hematocrit and true hematocrit were determined for each subject. When 1.5 ml (three times the deadspace volume) is discarded, the 95% confidence interval is within 0.6% of the true hematocrit.
本研究的目的是量化必须从留置外周静脉导管（死腔为0.5毫升）中弃去的最少血量，以获得准确的血细胞比容读数。对九名受试者进行重复采血，以建立一个描述冲洗液与血液混合情况的数学模型（米氏曲线）。该模型用于估计弃去不同体积血液后的血细胞比容。确定了每个受试者计算得到的血细胞比容与真实血细胞比容之间的差异。当弃去1.5毫升（死腔体积的三倍）血液时，95%置信区间在真实血细胞比容的0.6%以内。
