Background: Pulse oximetry is a noninvasive method to measure the saturation of peripheral oxyhaemoglobin (SpO2). It's usually used in emergency, intensive care and operating room units. Pulse oximeter readings have limited accuracy in the presence of methemoglobin, carboxyhemoglobin, anaemia, peripheral vasoconstriction, nail polish, fluorescent light, and motion. Objectives: To evaluate the interferences of the color of nail polishes and time on SpO2 in healthy individuals. Methods: Sixty-one healthy female volunteers, ages ranging from 18 to 32 years. The nail polish colors used to evaluate SpO2 were: base coat on the little finger, light pink on the ring finger, sparkling light pink on the medium finger and red on the thumb. The index finger was used as control and thus, did not receive nail polish. The time for each color was evaluated every minute until 5 minutes were completed. Results: When the SpO2 measurement was compared with the control, the base coat (p = 0.56), light pink (p = 0.56) and sparkling light pink (p = 0.37) colors didn't present statistically significant differences. Only the red presented a significant variation (p < 0,001), however it was within normal parameters. SpO2 didn't vary significantly with time. Conclusion: Despite the difference found with the red color, all the SpO2 values achieved were inside the normal range for a healthy individual. Pulse oximeter readings are not significantly affected by the color of nail polish in relation to time.

Keywords: Nail polish. Oxygen saturation. Pulse oximetry.