Objective: To provide a concise review of the history, technology, theory, limitations and outcomes of pulse oximetry.
Data sources and selection: Articles published in major medical journals since 1985 critically appraising pulse oximetry were reviewed, as were numerous historical papers.
Result: The pulse oximeter is an imperfect device, with numerous potential limitations.
Conclusion: The pulse oximeter is reasonably accurate under most conditions. However, its reliability diminishes as the clinical situation deviates from the norm, possibly when accuracy is most needed.