Bothma P A, Joynt G M, Lipman J, Hon H, Mathala B, Scribante J, Kromberg J
Intensive Care Unit, Baragwanath Hospital, Johannesburg.
S Afr Med J. 1996 May;86(5 Suppl):594-6.
Prospective assessment of the accuracy of three pulse oximeters and two probe sites in darkly pigmented critically ill patients under clinical conditions.
One hundred consecutive, darkly pigmented critically ill adult patients with arterial lines in situ were studied. Patients were excluded if the haemoglobin concentration was less than 7 g/dl and carboxyhaemoglobin or methaemoglobin levels exceeded 2%. Pigmentation was objectively quantified with a portable EEL reflectance spectrophotometer (Evans Electroselenium Company, Diffusion Systems Limited, London). Reflectance was measured at nine wavelengths.
The degree of pigmentation as measured by percentage reflectance closely matched that of a control group of black Africans from a pigmentation study. The limits of agreement (2.6% to 5.8%), precision and bias values between pulse oximeter and co-oximeter readings fell within a narrow range. The 95% confidence intervals of the limits of agreement reflected a small variation in the difference between pulse oximeter and co-oximeter readings. These small differences were not clinically significant in the pigmented patients who were enrolled in the study.
The accuracy of pulse oximetry is not adversely affected by skin pigmentation, and it remains a useful oxygenation monitoring device in darkly pigmented patients.
在临床条件下对三名患有色素沉着危重症患者的脉搏血氧饱和度仪及两个探头部位的准确性进行前瞻性评估。
对连续100名成年色素沉着危重症患者进行研究，这些患者均已插入动脉导管。若血红蛋白浓度低于7g/dl，且碳氧血红蛋白或高铁血红蛋白水平超过2%，则将患者排除。使用便携式EEL反射分光光度计（伊文斯电子硒公司，扩散系统有限公司，伦敦）对色素沉着进行客观量化。在九个波长下测量反射率。
通过反射率百分比测量的色素沉着程度与色素沉着研究中的一组非洲黑人对照组的色素沉着程度密切匹配。脉搏血氧饱和度仪与血气分析仪读数之间的一致性界限（2.6%至5.8%）、精密度和偏差值均在狭窄范围内。一致性界限的95%置信区间反映了脉搏血氧饱和度仪与血气分析仪读数之间差异的微小变化。在纳入研究的色素沉着患者中，这些微小差异无临床意义。
脉搏血氧饱和度测定的准确性不受皮肤色素沉着的不利影响，它仍然是色素沉着患者有用的氧合监测设备。
