Feiner John R, Severinghaus John W, Bickler Philip E
From the Department of Anesthesia and Perioperative Care, University of California at San Francisco, San Francisco, California.
Anesth Analg. 2007 Dec;105(6 Suppl):S18-S23. doi: 10.1213/01.ane.0000285988.35174.d9.
Pulse oximetry may overestimate arterial oxyhemoglobin saturation (Sao2) at low Sao2 levels in individuals with darkly pigmented skin, but other factors, such as gender and oximeter probe type, remain less studied.
We studied the relationship between skin pigment and oximeter accuracy in 36 subjects (19 males, 17 females) of a range of skin tones. Clip-on type sensors and adhesive/disposable finger probes for the Masimo Radical, Nellcor N-595, and Nonin 9700 were studied. Semisupine subjects breathed air-nitrogen-CO2 mixtures via a mouthpiece to rapidly achieve 2- to 3-min stable plateaus of Sao2. Comparisons of Sao2 measured by pulse oximetry (Spo2) with Sao2 (by Radiometer OSM-3) were used in a multivariate model to assess the source of errors.
The mean bias (Spo2 - Sao2) for the 70%-80% saturation range was 2.61% for the Masimo Radical with clip-on sensor, -1.58% for the Radical with disposable sensor, 2.59% for the Nellcor clip, 3.6% for the Nellcor disposable, -0.60% for the Nonin clip, and 2.43% for the Nonin disposable. Dark skin increased bias at low Sao2; greater bias was seen with adhesive/disposable sensors than with the clip-on types. Up to 10% differences in saturation estimates were found among different instruments in dark-skinned subjects at low Sao2.
Multivariate analysis indicated that Sao2 level, sensor type, skin color, and gender were predictive of errors in Spo2 estimates at low Sao2 levels. The data suggest that clinically important bias should be considered when monitoring patients with saturations below 80%, especially those with darkly pigmented skin; but further study is needed to confirm these observations in the relevant populations.
对于皮肤色素沉着较深的个体，在动脉血氧血红蛋白饱和度（Sao2）较低时，脉搏血氧饱和度测定法可能会高估Sao2，但其他因素，如性别和血氧饱和度测定仪探头类型，研究较少。
我们研究了36名不同肤色受试者（19名男性，17名女性）的皮肤色素与血氧饱和度测定仪准确性之间的关系。研究了用于Masimo Radical、Nellcor N - 595和Nonin 9700的夹式传感器以及粘贴式/一次性手指探头。半仰卧位受试者通过咬嘴呼吸空气 - 氮气 - 二氧化碳混合物，以快速达到2至3分钟的Sao2稳定平台期。在多变量模型中，将脉搏血氧饱和度测定法测得的Sao2（Spo2）与Sao2（通过Radiometer OSM - 3）进行比较，以评估误差来源。
对于饱和度范围为70% - 80%的情况，使用夹式传感器的Masimo Radical的平均偏差（Spo2 - Sao2）为2.61%，使用一次性传感器的Radical为 - 1.58%，Nellcor夹式为2.59%，Nellcor一次性为3.6%，Nonin夹式为 - 0.60%，Nonin一次性为2.43%。深色皮肤在低Sao2时会增加偏差；粘贴式/一次性传感器的偏差比夹式传感器更大。在低Sao2时，深色皮肤受试者中不同仪器的饱和度估计差异高达10%。
多变量分析表明，Sao2水平、传感器类型、肤色和性别可预测低Sao2水平时Spo2估计值的误差。数据表明，在监测饱和度低于80%的患者时，尤其是皮肤色素沉着较深的患者，应考虑具有临床意义的偏差；但需要进一步研究以在相关人群中证实这些观察结果。
