Abstract
Fingertip pulse oximeters were widely used during the COVID-19 pandemic as the main and readily available device (%SpO2). The aim of this study was to determine the extent to which different colours of gel nail polish affect oxygen saturation (%SpO2) measurements. Saturation measurements were taken using the Finger Clip Pulse Oximeter P-01 (China) device, routinely available during the COVID-19 pandemic. The study included 54 healthy female volunteers of undergraduate cosmetology students aged between 24 and 36 years. Each participant was given an individual fingertip pulse oximeter to measure saturation on different fingers painted with different colours of gel nail polish: red, orange, yellow, green – fingers II-V of the right hand; blue, navy, violet, no colour – fingers II-V of the left hand. Increasing wavelength (from violet ~400 nm to red ~680 nm) increased mean saturation levels. Long-wavelength colours (“red”) distorted the measurement results to a lesser degree than short-wavelength colours (“green”). Nail polishes significantly influence the results of oxygen saturation measurements, especially of dark and metallic colour. Interference resulting from long-wavelength colours (e.g. red) is minimal, while short-wavelength colours (e.g. green) cause the most interference. In particular, light-absorbing colours (e.g. green) significantly reduced the %SpO2 (P=0.032), in contrast to longer-wavelength colours (e.g. red).