Department of Medicine, University of Calgary, (1403 - 29th Street NW), Calgary, (T2N 2T9), Canada.
BMC Emerg Med. 2010 May 5;10:9. doi: 10.1186/1471-227X-10-9.
Pulse oximetry is routinely used to continuously and noninvasively monitor arterial oxygen saturation (SaO2) in critically ill patients. Although pulse oximeter oxygen saturation (SpO2) has been studied in several patient populations, including the critically ill, its accuracy has never been studied in emergency department (ED) patients with severe sepsis and septic shock. Sepsis results in characteristic microcirculatory derangements that could theoretically affect pulse oximeter accuracy. The purposes of the present study were twofold: 1) to determine the accuracy of pulse oximetry relative to SaO2 obtained from ABG in ED patients with severe sepsis and septic shock, and 2) to assess the impact of specific physiologic factors on this accuracy.
This analysis consisted of a retrospective cohort of 88 consecutive ED patients with severe sepsis who had a simultaneous arterial blood gas and an SpO2 value recorded. Adult ICU patients that were admitted from any Calgary Health Region adult ED with a pre-specified, sepsis-related admission diagnosis between October 1, 2005 and September 30, 2006, were identified. Accuracy (SpO2 - SaO2) was analyzed by the method of Bland and Altman. The effects of hypoxemia, acidosis, hyperlactatemia, anemia, and the use of vasoactive drugs on bias were determined.
The cohort consisted of 88 subjects, with a mean age of 57 years (19 - 89). The mean difference (SpO2 - SaO2) was 2.75% and the standard deviation of the differences was 3.1%. Subgroup analysis demonstrated that hypoxemia (SaO2 < 90) significantly affected pulse oximeter accuracy. The mean difference was 4.9% in hypoxemic patients and 1.89% in non-hypoxemic patients (p < 0.004). In 50% (11/22) of cases in which SpO2 was in the 90-93% range the SaO2 was <90%. Though pulse oximeter accuracy was not affected by acidoisis, hyperlactatementa, anemia or vasoactive drugs, these factors worsened precision.
Pulse oximetry overestimates ABG-determined SaO2 by a mean of 2.75% in emergency department patients with severe sepsis and septic shock. This overestimation is exacerbated by the presence of hypoxemia. When SaO2 needs to be determined with a high degree of accuracy arterial blood gases are recommended.
脉搏血氧饱和度仪常用于连续、无创地监测危重症患者的动脉血氧饱和度 (SaO2)。虽然脉搏血氧饱和度仪的血氧饱和度 (SpO2) 已在多个患者群体中进行了研究，包括危重症患者，但它在急诊科严重脓毒症和感染性休克患者中的准确性从未得到研究。脓毒症会导致特征性的微循环紊乱，理论上会影响脉搏血氧饱和度仪的准确性。本研究的目的有两个：1）确定脉搏血氧饱和度仪相对于严重脓毒症和感染性休克患者 ABG 中 SaO2 的准确性，2）评估特定生理因素对这种准确性的影响。
这是一项回顾性队列研究，共纳入 88 例连续的急诊科严重脓毒症患者，这些患者同时记录了动脉血气和 SpO2 值。2005 年 10 月 1 日至 2006 年 9 月 30 日期间，从卡尔加里卫生区任何成人急诊科入院的成人 ICU 患者中，确定了具有特定、与脓毒症相关的入院诊断的患者。通过 Bland 和 Altman 法分析准确性（SpO2 - SaO2）。确定低氧血症、酸中毒、高乳酸血症、贫血和血管活性药物对偏差的影响。
该队列包括 88 例患者，平均年龄为 57 岁（19-89 岁）。差异的平均值（SpO2 - SaO2）为 2.75%，差异的标准差为 3.1%。亚组分析表明，低氧血症（SaO2 < 90）显著影响脉搏血氧饱和度仪的准确性。低氧血症患者的平均差值为 4.9%，非低氧血症患者为 1.89%（p < 0.004）。在 SpO2 处于 90-93%范围内的 50%（11/22）病例中，SaO2 < 90%。虽然脉搏血氧饱和度仪的准确性不受酸中毒、高乳酸血症、贫血或血管活性药物的影响，但这些因素会降低精度。
在急诊科严重脓毒症和感染性休克患者中，脉搏血氧饱和度仪平均高估 ABG 测定的 SaO2 2.75%。低氧血症会加重这种高估。当需要高度准确地确定 SaO2 时，建议进行动脉血气分析。
Zotero 插件