Elsevier

Respiratory Medicine

Volume 107, Issue 6, June 2013, Pages 789-799
Respiratory Medicine

Review
Pulse oximetry: Understanding its basic principles facilitates appreciation of its limitations

https://doi.org/10.1016/j.rmed.2013.02.004Get rights and content
Under an Elsevier user license
open archive

Summary

Pulse oximetry has revolutionized the ability to monitor oxygenation in a continuous, accurate, and non-invasive fashion. Despite its ubiquitous use, it is our impression and supported by studies that many providers do not know the basic principles behind its mechanism of function. This knowledge is important because it provides the conceptual basis of appreciating its limitations and recognizing when pulse oximeter readings may be erroneous. In this review, we discuss how pulse oximeters are able to distinguish oxygenated hemoglobin from deoxygenated hemoglobin and how they are able to recognize oxygen saturation only from the arterial compartment of blood. Based on these principles, we discuss the various conditions that can cause spurious readings and the mechanisms underlying them.

Keywords

Pulse oximetry
Oxygen saturation
Co-oximetry
Carboxyhemoglobin
Methemoglobin

Cited by (0)