Hampson N B
Section of Pulmonary and Critical Care Medicine, Virginia Mason Medical Center, Seattle, WA 98111, USA.
Chest. 1998 Oct;114(4):1036-41. doi: 10.1378/chest.114.4.1036.
To evaluate the accuracy and quantitate the error of pulse oximetry measurements of arterial oxygenation in patients with severe carbon monoxide (CO) poisoning.
Retrospective review of patient clinical records.
Regional referral center for hyperbaric oxygen therapy.
Thirty patients referred for treatment of acute severe CO poisoning who demonstrated carboxyhemoglobin (COHb) levels >25%, with simultaneous determinations of arterial hemoglobin oxygen saturation by pulse oximetry (SpO2) and arterial blood gas (ABG) techniques.
COHb levels and measurements of arterial oxygenation from pulse oximetry, ABG analysis, and laboratory CO oximetry were compared. SpO2 did not correlate with COHb levels. SpO2 consistently overestimated the fractional arterial oxygen saturation. The difference between arterial hemoglobin oxygen saturation (SaO2) calculated from ABG analysis and SpO2 increased with increasing COHb level.
Presently available pulse oximeters overestimate arterial oxygenation in patients with severe CO poisoning. An elevated COHb level falsely elevates the SaO2 measurements from pulse oximetry, usually by an amount less than the COHb level, confirming a prior observation in an animal model. Accurate assessment of arterial oxygen content in patients with CO poisoning can currently be performed only by analysis of arterial blood with a laboratory CO-oximetry.
评估重度一氧化碳（CO）中毒患者脉搏血氧饱和度测定动脉氧合的准确性并定量测量误差。
对患者临床记录进行回顾性分析。
高压氧治疗区域转诊中心。
30例因急性重度CO中毒前来治疗的患者，其碳氧血红蛋白（COHb）水平>25%，同时采用脉搏血氧饱和度测定法（SpO2）和动脉血气（ABG）技术测定动脉血红蛋白氧饱和度。
比较COHb水平以及脉搏血氧饱和度测定、ABG分析和实验室CO血氧饱和度测定的动脉氧合测量结果。SpO2与COHb水平无关。SpO2始终高估动脉血氧饱和度分数。根据ABG分析计算的动脉血红蛋白氧饱和度（SaO2）与SpO2之间的差异随COHb水平升高而增大。
目前可用的脉搏血氧仪高估了重度CO中毒患者的动脉氧合情况。升高的COHb水平会错误地提高脉搏血氧饱和度测定法测得的SaO2值，通常升高幅度小于COHb水平，这证实了之前在动物模型中的观察结果。目前，只有通过实验室CO血氧饱和度测定法分析动脉血才能准确评估CO中毒患者的动脉氧含量。
