Abstract
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(pO(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 S(pO(2)) and arterial oxygen saturation (S(aO(2)) ) might be close to zero. However, the limits of agreement can be wide, meaning that S(pO(2)) might overestimate S(aO(2)) in many individual patients, which can result in occult hypoxemia in some. Manufactures report accuracy of S(pO(2)) derived from normal individuals, which might differ from that in the clinical setting. That S(pO(2)) overestimates S(aO(2)) in an important number of individuals has caused some to recommend higher S(pO(2)) targets to avoid occult hypoxemia. There is also evidence that suggests that S(pO(2)) might not accurately trend S(aO(2)) Additional research is needed to investigate strategies to mitigate the bias between S(pO(2)) and S(aO(2)) Clinicians must be cognizant of the limitations of pulse oximetry when clinically using S(pO(2)) The aim of this paper is to provide an update on pulse oximetry.