Pulse oximetry using a disposable finger sensor placed on the forehead in hypoxic patients.

BACKGROUND

Disposable pulse oximetry sensors designed for the finger are sometimes placed on the forehead. Although finger sensors have not been designed to accurately measure arterial oxygen saturation when placed on other body parts, they are used on the forehead when an oximetry waveform cannot be obtained from the finger.

OBJECTIVES

The purpose of this prospective observational study was to measure the agreement between disposable transmittal sensors placed on the finger and the same sensors placed on the forehead.

METHODS

We used a convenience sample of hypoxic emergency department patients. Patients were attached to three oximeters: 1) a non-disposable finger sensor (reference); 2) a disposable finger sensor placed on the finger; and 3) a disposable finger sensor placed on the forehead. Data were analyzed using the Bland-Altman method. A difference of 5% was considered clinically significant.

RESULTS

Twenty-five patients were approached, and 20 were enrolled. Eleven of the patients had an absolute difference between the disposable finger sensor placed on the finger compared to the forehead > or = 5%.

CONCLUSION

Pulse oximetry measurements taken on the forehead using a disposable finger sensor were inaccurate in over half of the subjects. Therefore, disposable finger oximetry sensors should not be placed on the forehead.