The Effect of Nail Polish on Pulse Oximetry (Spo2 – Oxygen Saturation) Readings

Q: Why do they not need to remove their nail polish?

A: The pulse oximeter probe light can be taped above the nail bed, not on the nail itself. Or, the reusable probe can be rotated so the light shines on the side of the finger. It can also be placed anywhere there is pulsatile blood flow like the ear, nose, lip-cheek, and toes.

Explanation: Years ago, when we did not have pulse oximeters, we had patients remove nail polish so that we could see the color of their nail bed. A blue nail bed is a clinical sign of hypoxemia.

Note: The anesthesiologist has the final call on this one.

Research:

The mean saturation value for clear nail polish, red nail polish and acrylic nails was not significantly different from the control mean.
Black and brown nail polish resulted in a significant decrease in SpO2. However, the color was also dependent on who conducted the study.
In one study, the SpO2 measurement from the right middle finger and right thumb have statistically significant higher value when compared with the left middle finger in right-hand dominant volunteers.

In summary, many pulse oximetry research studies have been conducted on this subject with varying results. Pulse oximetry is functional when used at different body locations on healthy individuals. However, the most important thing to consider is determining where it produces the most accurate results in low flow states, burn victims, hypothermia, and certain systemic disease. In healthy outpatient patients, it is not routine to ask them to remove their polish.