脉搏 CO-血氧仪在低氧血症时提高亚甲蓝检测的准确性。

Improved accuracy of methemoglobin detection by pulse CO-oximetry during hypoxia.

机构信息

Department of Anesthesia and Perioperative Care, University of California at San Francisco, San Francisco, CA 94143-0648, USA.

出版信息

Anesth Analg. 2010 Nov;111(5):1160-7. doi: 10.1213/ANE.0b013e3181f46da8. Epub 2010 Sep 14.

DOI:10.1213/ANE.0b013e3181f46da8

PMID:20841412

Abstract

BACKGROUND

Methemoglobin in the blood cannot be detected by conventional pulse oximetry and may bias the oximeter's estimate (Spo(2)) of the true arterial functional oxygen saturation (Sao(2)). A recently introduced "pulse CO-oximeter" (Masimo Rainbow SET® Radical-7) that measures SpMet, a noninvasive measurement of the percentage of methemoglobin in arterial blood (%MetHb), was shown to read spuriously high values during hypoxia. In this study we sought to determine whether the manufacturer's modifications have improved the device's ability to detect and accurately measure methemoglobin and deoxyhemoglobin simultaneously.

METHODS

Twelve healthy adult volunteer subjects were fitted with sensors on the middle finger of each hand, and a radial arterial catheter was placed for blood sampling. Intravenous administration of ∼300 mg of sodium nitrite elevated subjects' methemoglobin levels to a 7% to 11% target level, and hypoxia was induced to different levels of Sao(2) (70% to 100%) by varying fractional inspired oxygen. Pulse CO-oximeter readings were compared with arterial blood values measured with a Radiometer ABL800 FLEX multi-wavelength oximeter. Pulse CO-oximeter methemoglobin reading performance was analyzed by the bias (SpMet-%MetHb), and by observing the incidence of meaningful reading errors and predictive value at the various hypoxia levels. Spo(2) bias (Spo(2)--Sao(2)), precision, and root-mean-square error were evaluated during conditions of elevated methemoglobin.

RESULTS

Observations spanned 74% to 100% Sao(2) and 0.4% to 14.4% methemoglobin with 307 blood draws and 602 values from the 2 oximeters. Masimo methemoglobin reading bias and precision over the full Sao(2) span was 0.16% and 0.83%, respectively, and was similar across the span. Masimo Spo(2) readings were biased -1.93% across the 70% to 100% Sao(2) range.

CONCLUSIONS

The Rainbow's methemoglobin readings are acceptably accurate over an oxygen saturation range of 74%-100% and a methemoglobin range of 0%-14%.

摘要

背景

血液中的高铁血红蛋白不能被常规脉搏血氧仪检测到，可能会影响血氧仪对动脉实际功能氧饱和度（Sao(2)）的估计（SpO(2)）。最近推出的“脉搏 CO- 分光光度计”（Masimo Rainbow SET® Radical-7）测量 SpMet，即动脉血中高铁血红蛋白的无创测量值（%MetHb），在缺氧时显示出虚假的高读数。在这项研究中，我们试图确定制造商的改进是否提高了设备检测和准确测量高铁血红蛋白和脱氧血红蛋白的能力。

方法

12 名健康成年志愿者将传感器安装在每只手的中指上，并放置桡动脉导管进行采血。静脉注射约 300 毫克亚硝酸钠将受试者的高铁血红蛋白水平升高到 7%至 11%的目标水平，并通过改变吸入氧的分数来诱导不同水平的 Sao(2)（70%至 100%）缺氧。脉搏 CO- 分光光度计读数与使用 Radiometer ABL800 FLEX 多波长血氧计测量的动脉血值进行比较。通过观察在不同缺氧水平下的有意义的读数错误发生率和预测值，分析脉搏 CO- 分光光度计的高铁血红蛋白读数性能。在高铁血红蛋白升高的情况下，评估 SpO(2)偏差（Spo(2)--Sao(2)）、精度和均方根误差。

结果

观察结果涵盖了 74%至 100%的 Sao(2)和 0.4%至 14.4%的高铁血红蛋白，共进行了 307 次采血和 602 次来自 2 种血氧计的值。Masimo 高铁血红蛋白读数的偏差和精度在整个 Sao(2)范围内分别为 0.16%和 0.83%，且在整个范围内相似。Masimo SpO(2)读数在 70%至 100%的 Sao(2)范围内偏差为-1.93%。