Evaluating the Accuracy of Off-Label Placement of Pulse Oximetry Sensors in Comparison to On-Label Placement in the Adult Cardiac Intensive Care Unit Patient Population.

Background: Continuous pulse oximetry (Spo2) is a commonly utilized tool to obtain an indirect, noninvasive measurement of hemoglobin oxygen saturation. Difficulty obtaining measurement with Spo2 sensors can lead nurses to try off-label sites until they find placement that provides a signal. Currently, there is limited evidence to support this application.

Purpose: The purpose of this study was to evaluate the accuracy of off-label placement of pulse oximetry sensors in comparison to on-label placement in adult cardiac intensive care patients.

Methods: Data were collected on 24 participants. At the time of a medically necessary arterial blood gas laboratory draws, 4 Spo2 measurements were gathered from an on-label finger sensor, an off-label finger sensor, an on-label ear sensor, and an off-label ear sensor. Results were analyzed using 4 Pearson correlation coefficients, Bland-Altman plots, and 2 linear mixed-effect models.

Results: Our study found that while both our on-label finger and off-label finger pulse oximetry sensor overestimated when compared to the arterial hemoglobin saturation (gold standard), there was greater overestimation found with the off-label placement. Though there was not a significant difference observed between the ear probe on the nose and the gold standard, figures examining off-label ear probe and gold standard measures show that, in lower ranges of oxygen saturation, the off-site probe substantially overestimates true oxygen saturation, while in higher ranges of oxygen saturation, the off-site ear probe underestimates true oxygen saturation.

Conclusions: No changes should be made to the current practice of using pulse oximetry sensor placement.