Gehring Hartmut, Duembgen Lutz, Peterlein Mareike, Hagelberg Söhnke, Dibbelt Leif
From the *Department of Anesthesiology, University Clinic of Schleswig-Holstein, Campus Luebeck, Germany; †Institute of Mathematical Statistics and Actuarial Science, University of Bern, Switzerland; ‡Institute of Clinical Chemistry, University Clinic of Schleswig-Holstein, Campus Luebeck, Germany.
Anesth Analg. 2007 Dec;105(6 Suppl):S24-S30. doi: 10.1213/01.ane.0000268713.58174.cc.
The calibration and testing procedures of a pulse oximeter with arterial blood samples from healthy subjects are based on reference values from the hemoximeter. There are no tests to identify the accuracy of the reference devices. Because of this limitation and since the true values of oxygen saturation (sO2 in %) in blood samples were not known, we used the differences between two identical devices, A and B, for error assessment.
Two identical devices, A and B, from five leading manufacturers were investigated. Seventy-two arterial blood samples from 12 healthy volunteers at three different levels of saturation between 100% and 70% sO2 were randomly evaluated by the test systems.
The observed differences (Delta) between Devices A and B, as a measure for the error of the hemoximeters, increased significantly with all manufacturers from level 97 (Deltamin, -0.9%; Deltamax, 2.6%) to 85 (Deltamin, -2.4%; Deltamax, 4.3), this effect was even stronger between levels 97 and 75 (Deltamin, -4.6%; Deltamax, 4.3%). A variance proportion analysis revealed the concentration of the reduced hemoglobin as the main error source for sO2 measurements. Independent from the sO2 levels there were also significant differences for the carboxy hemoglobin concentration in the range of 0%-4% and for the methemoglobin concentration in the range of 0%-1%.
The variance of sO2 measurements between identical devices increased significantly when saturation decreased from the normal level of 97% to the hypoxemic levels of 85% and 75%.
使用健康受试者的动脉血样对脉搏血氧仪进行校准和测试程序是基于血液氧合仪的参考值。目前尚无用于识别参考设备准确性的测试。由于这一局限性，且血液样本中氧饱和度（以%计的sO2）的真实值未知，我们使用两个相同设备A和B之间的差异来进行误差评估。
对来自五个主要制造商的两个相同设备A和B进行了研究。测试系统对12名健康志愿者的72份动脉血样在100%至70% sO2的三个不同饱和度水平下进行了随机评估。
作为血液氧合仪误差的一种度量，设备A和B之间观察到的差异（Δ）在所有制造商中均随着饱和度从97水平（Δ最小值，-0.9%；Δ最大值，2.6%）显著增加到85水平（Δ最小值，-2.4%；Δ最大值，4.3%），在97水平和75水平之间这种效应甚至更强（Δ最小值，-4.6%；Δ最大值，4.3%）。方差比例分析显示还原血红蛋白浓度是sO2测量的主要误差来源。与sO2水平无关，在0% - 4%范围内的碳氧血红蛋白浓度和在0% - 1%范围内的高铁血红蛋白浓度也存在显著差异。
当饱和度从正常的97%降至低氧水平的85%和75%时，相同设备之间sO2测量值的方差显著增加。
