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 S_pO2 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 S_pO2 and arterial oxygen saturation (S_aO2 ) might be close to zero. However, the limits of agreement can be wide, meaning that S_pO2 might overestimate S_aO2 in many individual patients, which can result in occult hypoxemia in some. Manufactures report accuracy of S_pO2 derived from normal individuals, which might differ from that in the clinical setting. That S_pO2 overestimates S_aO2 in an important number of individuals has caused some to recommend higher S_pO2 targets to avoid occult hypoxemia. There is also evidence that suggests that S_pO2 might not accurately trend S_aO2 Additional research is needed to investigate strategies to mitigate the bias between S_pO2 and S_aO2 Clinicians must be cognizant of the limitations of pulse oximetry when clinically using S_pO2 The aim of this paper is to provide an update on pulse oximetry.