Does fingernail polish affect pulse oximeter readings?

Abstract

Results from previous studies evaluating the effect of nail polish on oxygen saturation (SpO(2)) determined by pulse oximeter monitors are inconsistent. Establishing the effect of nail polish on SpO(2) is relevant to clinical practice, since removing nail polish requires clinical time and supplies. The objective of this study was to determine if fingernail polish affects SpO(2) as measured by two different pulse oximeter machines. Absorption spectra of 10 nail polish colors were obtained by spectrophotometry. Twenty-seven healthy volunteers with SpO(2)> or =95% participated. Using the Nellcor N20 and N595 pulse oximeters, the mean SpO(2) was measured on each of 10 nails with and without nail polish and using a side-to-side configuration. Means were compared using paired t-tests. Mean SpO(2) had a statistically significant decrease with brown and blue nail polish using both machines (p<0.05) but this was not clinically significant (<1% difference). Using the side-to-side configuration, the N595 oximeter had a statistically significant decrease in mean SpO(2) with red nail polish but again this was not clinically significant. Fingernail polish does not cause a clinically significant change in pulse oximeter readings in healthy people.