The effects of gel-based manicure on pulse oximetry

Pulse oximetry is the standard monitoring technique of functional oxygen saturation (SpO₂). As the use of fingernail polish has been described to alter SpO₂ readings, its removal is commonly recommended prior to measurement. Gel-based manicures have gained popularity in recent years due to their attractiveness and longevity. However, the removal of gel nail polish requires a specialised procedure. Valuable time and resources can be saved if removal can be avoided. To our knowledge, there are no available studies on the effect of gel-based manicures on pulse oximetry readings. Hence, we evaluated the effect with two oximeters, using different technology and wavelength combinations.

17 healthy female adult volunteers were recruited for this single-blind randomised controlled trial. Subjects with hypothermia, hypotension, poor plethysmographic waveform and nail pathology were excluded. Colours tested were: black, purple, navy blue, green, light blue, white, yellow, orange, pink and red. Pulse oximetry was measured at 15- and 30-second intervals using two different pulse oximeters, the Philips M1191BL and Masimo SET®. Means were compared using paired t-tests.

Using the Masimo oximeter, light blue (ΔM = 0.97% ± 0.96%; p = 0.001) and orange (ΔM = 0.76 ± 1.17%; p = 0.016) gel nail polish resulted in a statistically significant increase from baseline SpO₂ readings. With the Philips oximeter, the limits of agreement ranged from 2% for pink to 17% for black, indicating imprecision.

Gel-based manicures can result in overestimations of actual readings, delaying detection of hypoxaemia. Gel nail polish should be routinely removed or an alternative monitoring technique sought.