Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
J Appl Lab Med. 2023 May 4;8(3):583-597. doi: 10.1093/jalm/jfac096.
As hypoxemia and hypoxia are central elements of disease pathophysiology and disease-related morbidity and mortality in individuals affected by sickle cell disease (SCD), clinical management aims to optimize oxygenation.
Hypoxemia is primarily screened for with pulse oximetry. However, in SCD pulse oximetry can inaccurately reflect arterial saturation, posing the risk of undetected (occult) hypoxemia. Solely relying on pulse oximetry might therefore lead to misdiagnosis or mismanagement, with devastating effects on tissue oxygenation. The interpretation of oxygenation status is multifaceted, and "oxygen saturation" is often used as an umbrella term to refer to distinctly different measured quantities-estimated oxygen saturation (O2Sat), hemoglobin oxygen saturation (SO2) by either pulse oximetry or co-oximetry, and fractional oxyhemoglobin (FO2Hb). While in many clinical situations this ambiguous use is of little consequence, O2Sat, SO2, and FO2Hb cannot be used interchangeably in the setting of SCD, as dyshemoglobins, anemia, cardiopulmonary comorbidities, concomitant medications, and frequent transfusions need to be accounted for. This article describes the parameters that determine blood and tissue oxygen concentration, discusses laboratory method performance characteristics and the correct interpretation of currently available clinical laboratory testing, and reviews the literature on noninvasive vs invasive oxygenation measurements in SCD.
By correctly establishing and interpreting oxygenation parameters, clinical and laboratory teams can ensure high-quality, equitable healthcare, counteracting systemic exacerbations of health disparities frequently experienced by individuals with SCD.
低氧血症和缺氧是镰状细胞病（SCD）患者疾病病理生理学和与疾病相关的发病率和死亡率的核心要素，因此临床管理旨在优化氧合。
低氧血症主要通过脉搏血氧饱和度仪进行筛查。然而，在 SCD 中，脉搏血氧饱和度仪可能无法准确反映动脉饱和度，从而存在未被发现（隐匿性）的低氧血症的风险。因此，仅依赖脉搏血氧饱和度仪可能会导致误诊或管理不当，对组织氧合造成毁灭性影响。氧合状态的解读是多方面的，“氧饱和度”通常用作一个总称，指的是截然不同的测量量——估计氧饱和度（O2Sat）、脉搏血氧饱和度仪或比色法测量的血红蛋白氧饱和度（SO2），以及氧合血红蛋白分数（FO2Hb）。虽然在许多临床情况下，这种模糊的用法没有什么影响，但在 SCD 中，O2Sat、SO2 和 FO2Hb 不能互换使用，因为需要考虑异常血红蛋白、贫血、心肺合并症、同时使用的药物以及频繁输血等因素。本文描述了决定血液和组织氧浓度的参数，讨论了实验室方法的性能特征和当前可用的临床实验室检测的正确解读，并回顾了 SCD 中非侵入性与侵入性氧合测量的文献。
通过正确建立和解释氧合参数，临床和实验室团队可以确保高质量、公平的医疗保健，从而对抗 SCD 患者经常经历的系统性健康差异加剧。
