Adler J N, Hughes L A, Vivilecchia R, Camargo C A
Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
Acad Emerg Med. 1998 Oct;5(10):965-70. doi: 10.1111/j.1553-2712.1998.tb02772.x.
To determine whether pulse oximeter (PO) accuracy and signal quality are affected by level of skin pigmentation.
Observational study in a community hospital ED. Consecutive adult patients undergoing arterial blood gas determination were enrolled into the study. Skin pigmentation was determined by comparison with standardized color swatches under controlled lighting; assigned values were used to stratify patients into 3 groups (light, intermediate, and dark) using predetermined criteria. Simultaneous with arterial blood sampling, staff recorded PO reading of O2 saturation using the Nellcor D-25 oximeter. PO values were compared with criterion standard values measured using a 4-wavelength spectrophotometer or co-oximeter. PO signal quality also was recorded. Bias (the mean difference between PO and co-oximeter-measured values of hemoglobin saturation) and precision (the standard deviation of the bias) were calculated. Groups were compared using one-way ANOVA, Bartlett's test for variances, and chi2 test.
O2 saturation data were obtained for 284 patients. Bias values did not differ between the 3 skin pigment groups (p = 0.79). Precision was of borderline significance (p = 0.05), but there was no dose-response relation between skin pigmentation and precision. Study personnel reported suboptimal PO function most often among patients in the dark group (p = 0.003), but this finding was of no clinical significance. PO signal failure was rare (<1% of all patients).
Although several prior studies suggest the contrary, this study found that skin pigmentation does not affect the bias or precision of pulse oximetry. Furthermore, skin pigmentation has no clinically significant effect on PO signal quality.
确定脉搏血氧仪（PO）的准确性和信号质量是否受皮肤色素沉着水平的影响。
在一家社区医院急诊科进行观察性研究。纳入连续接受动脉血气测定的成年患者。在可控照明条件下，通过与标准化色卡比较确定皮肤色素沉着情况；根据预定标准，将指定值用于将患者分为3组（浅色、中间色和深色）。在采集动脉血样的同时，工作人员使用Nellcor D - 25血氧仪记录PO的氧饱和度读数。将PO值与使用四波长分光光度计或血气分析仪测量的标准值进行比较。还记录了PO信号质量。计算偏差（PO与血气分析仪测量的血红蛋白饱和度值之间的平均差异）和精密度（偏差的标准差）。使用单因素方差分析、Bartlett方差检验和卡方检验对各组进行比较。
获得了284例患者的氧饱和度数据。3个皮肤色素组之间的偏差值无差异（p = 0.79）。精密度具有临界显著性（p = 0.05），但皮肤色素沉着与精密度之间无剂量反应关系。研究人员报告，深色组患者中PO功能欠佳的情况最为常见（p = 0.003），但这一发现无临床意义。PO信号失败很少见（<所有患者的1%）。
尽管此前有多项研究得出相反结论，但本研究发现皮肤色素沉着并不影响脉搏血氧测定的偏差或精密度。此外，皮肤色素沉着对PO信号质量无临床显著影响。
