Haney M, Tait A R, Tremper K K
Department of Anesthesiology, University of Michigan, Ann Arbor.
Crit Care Med. 1994 Jul;22(7):1181-5. doi: 10.1097/00003246-199407000-00022.
To assess the accuracy of mixed venous hemoglobin oxygen saturation estimated, using in vivo pulmonary artery reflectance oximetry with ranging concentrations of carboxyhemoglobin.
Criterion standard, a comparison of an alternative test to the "gold standard."
Laboratory animal facility of a large university.
Five mongrel dogs.
Anesthetized dogs were mechanically ventilated to normocarbia and instrumented with arterial catheters and pulmonary artery oximetry catheters. The dogs were ventilated with increasing inspired concentrations of carbon monoxide, and blood samples were analyzed for fractional concentrations of oxyhemoglobin and carboxyhemoglobin. Carboxyhemoglobin levels ranged from 0% to 70%. At each level of carboxyhemoglobin, FIO2 was varied from 0.21 to 0.09. Co-oximeter readings were compared with mixed venous oxygen saturation measurements of the pulmonary artery oximetry catheter.
Mixed venous oxygen saturation measurements from the pulmonary artery oximetry catheter system progressively overestimated fractional oxyhemoglobin in the presence of carboxyhemoglobin. This catheter's mixed venous oxygen saturation reading could be corrected for the presence of carboxyhemoglobin by a derived formula. Regression analysis for corrected mixed venous oxygen saturation (calculated) vs. fractional oxyhemoglobin yields a slope and intercept of 0.98 and -1.01, respectively, with a correlation coefficient of .98. The bias and precision values for fractional oxyhemoglobin vs. mixed venous oxygen saturation (calculated) are 1.9 and 2.2 (n = 66), with bias representing the degree of systematic error or deviation from the true measurement, and precision representing the confidence limits (or standard deviation) for individual variations from the true measurement.
Mixed venous oxygen saturation monitoring does not detect the presence of carboxyhemoglobin and progressively overestimates fractional oxyhemoglobin as carboxyhemoglobin increases. Mixed venous oxygen saturation values of the standard pulmonary artery oximetry catheter approximately equal functional hemoglobin saturation. Bench co-oximeter blood analysis is required in patients suspected of having increased carboxyhemoglobin levels.
使用体内肺动脉反射血氧测定法，评估在不同浓度碳氧血红蛋白情况下混合静脉血氧饱和度估计值的准确性。
标准对照，将一种替代检测方法与“金标准”进行比较。
一所大型大学的实验动物设施。
五只杂种狗。
对麻醉后的狗进行机械通气使其达到正常碳酸血症，并插入动脉导管和肺动脉血氧测定导管。用逐渐增加的一氧化碳吸入浓度对狗进行通气，并对血样进行氧合血红蛋白和碳氧血红蛋白分数浓度分析。碳氧血红蛋白水平范围为0%至70%。在每个碳氧血红蛋白水平，吸入氧分数从0.21变化至0.09。将共血氧计读数与肺动脉血氧测定导管的混合静脉血氧饱和度测量值进行比较。
在存在碳氧血红蛋白的情况下，肺动脉血氧测定导管系统的混合静脉血氧饱和度测量值逐渐高估了氧合血红蛋白分数。该导管的混合静脉血氧饱和度读数可通过一个推导公式校正碳氧血红蛋白的存在。校正后的混合静脉血氧饱和度（计算值）与氧合血红蛋白分数的回归分析得出斜率和截距分别为0.98和 -1.01，相关系数为0.98。氧合血红蛋白分数与混合静脉血氧饱和度（计算值）的偏差和精密度值分别为1.9和2.2（n = 66），偏差表示系统误差程度或与真实测量值的偏差，精密度表示个体测量值与真实测量值差异的置信限（或标准差）。
混合静脉血氧饱和度监测无法检测到碳氧血红蛋白的存在，并且随着碳氧血红蛋白增加会逐渐高估氧合血红蛋白分数。标准肺动脉血氧测定导管的混合静脉血氧饱和度值大致等于功能性血红蛋白饱和度。对于怀疑碳氧血红蛋白水平升高的患者，需要进行台式共血氧计血液分析。
