Does fingernail polish affect pulse oximeter readings?

SummaryIntroductionResults from previous studies evaluating the effect of nail polish on oxygen saturation (SpO2) determined by pulse oximeter monitors are inconsistent. Establishing the effect of nail polish on SpO2 is relevant to clinical practice, since removing nail polish requires clinical time and supplies.ObjectiveThe objective of this study was to determine if fingernail polish affects SpO2 as measured by two different pulse oximeter machines.MethodsAbsorption spectra of 10 nail polish colors were obtained by spectrophotometry. Twenty-seven healthy volunteers with SpO2 ≥ 95% participated. Using the Nellcor N20 and N595 pulse oximeters, the mean SpO2 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.ResultsMean SpO2 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 SpO2 with red nail polish but again this was not clinically significant.ConclusionFingernail polish does not cause a clinically significant change in pulse oximeter readings in healthy people.