Pulse Oximetry: 2023 Year in Review

Pulse oximetry is arguably the most impactful monitor ever introduced into respiratory care practice. Recently there has been increased attention to the problem of occult hypoxemia in which patients are hypoxemic despite an acceptable SpO(2). Although occult hypoxemia might be greater in Black patients than white patients, it is not insignificant in whites. In a given population of patients, the bias between SpO(2) and arterial oxygen saturation (SaO(2)) might be close to zero. However, the limits of agreement can be wide, meaning that SpO(2) might overestimate SaO(2) in many individual patients, which can result in occult hypoxemia in some. Manufactures report accuracy of SpO(2) derived from normal individuals, which might differ from that in the clinical setting. That SpO(2) overestimates SaO(2) in an important number of individuals has caused some to recommend higher SpO(2) targets to avoid occult hypoxemia. There is also evidence that suggests that SpO(2) might not accurately trend SaO(2). Additional research is needed to investigate strategies to mitigate the bias between SpO(2) and SaO(2). Clinicians must be cognizant of the limitations of pulse oximetry when clinically using SpO(2). The aim of this paper is to provide an update on pulse oximetry. Key words: