effect of nail polish on pulse oximetry findings in healthy volunteers: a randomized clinical trail

background and objectives: pulse oximetry is the most common technique for monitoring hemoglobin oxygen saturation (spo2). different colors and brands of nail polish may cause disturbance in the reading and interpretation of oxygen saturation. the aim of this study was to determine the effect of different colors of nail polish on oxygen saturation measured by pulse oximeter. methods: thirty healthy students with spo2≥95% and without obvious problems in nail bed and peripheral perfusion in ordinary room air, participated in this clinical trial. each volunteer sat in a chair for 10 minutes, maintaining the whole body at rest; then, the spo2 baseline of clean unpolished nail beds of all 10 fingers was measured and recorded. after this phase, the participants were asked to use each of 10 colors of nail polishes randomly and unrepeatedly to polish one of their fingernails. nail polish was applied in two layers. after drying the nail polishes, the spo2 was measured again. data analysis was performed by statistical tests of kolmogorov-smirnov, paired t-, and wilcoxon tests.  results: orange, pink, and purple nail polish had no effect on spo2 (p>0.05), while other colors induced a statistically decrease in spo2 (p<0.05), but this was not clinically significant (<1.2%). conclusion: the results of this study revealed that nail polish has no clinical effect on spo2 measures by pulse oximeter in healthy subjects. therefore, there is no need to spend time and money to clean nail polish from individual’s nails