6 Tips to Ensure Accuracy in Your Pulse Oximeter Readings

Pulse oximeters serve as essential tools for monitoring oxygen levels. Yet, like any device, they can encounter occasional issues, leading to inaccurate readings. This post aims to simplify the understanding of pulse oximeter use by exploring 6 potential problems and providing practical solutions.

In our community, many use pulse oximeters for at-home oxygen level monitoring. These small devices slip over a finger, using light to measure oxygen saturation – a percentage of inhaled oxygen that reaches hemoglobin. Where I work, oxygen saturations of 90 percent or higher are considered acceptable. Your doctor can help you determine what is acceptable for YOU.¹

Common inaccuracies in pulse oximeter readings and their solutions

Some inaccuracies can arise, leading to lower readings. Below are the 6 most common issues I have observed in the hospital setting, along with potential solutions.

Problem: Inappropriate sensor placement

Incorrect placement of the pulse oximeter sensor on your finger can lead to inaccurate readings.

A practical solution would be more precision in placement. Ensure that the sensor is placed on a clean, dry finger and fits snugly to avoid light leakage.

Problem: Low battery

Low battery levels can lead to inaccurate readings or cause the pulse oximeter to fail to pick up. A practical solution is to energize for accuracy. Of course, the logical solution here is to replace the old battery with a new one.

Problem: Wearing dark nail polish or acrylics

Pulse oximeters use infrared light. This light travels through your finger. And this is how it determines your heart rate and what percentage of oxygen that you inhale is binding with hemoglobin in your arterial blood. If you are wearing dark-colored nail polish or fake nails, the light may not be able to pass through it, making the pulse oximeter unable to pick up a reading.²

A practical solution is to be prepared or go bare. To ensure reliable readings, it's advisable to keep nail polish remover on hand.

If you're about to use a pulse oximeter, taking a moment to remove dark nail polish from the finger you are going to slip the pulse oximeter over can eliminate potential interference. Alternatively, going without nail polish or fake fingernails during measurements allows the infrared light to pass through your finger unobstructed.²

Problem: You often have cold fingers

When your fingers are cold, the vessels tend to constrict. This constriction can affect the blood flow and compromise the precision of the measurements.^1,3,4

A practical solution is to warm your fingers! To ensure reliable results, it is advisable to warm your fingers before using a pulse oximeter, allowing for optimal blood circulation and facilitating more accurate readings of your oxygen saturation levels. One trick we sometimes use to remedy this is to wrap your hand in a warm towel or blanket. Another trick that may work is to rinse your fingers in warm water.³

Problem: You experience tremors or frequent movement

Tremors or excessive movement can pose challenges for accurate pulse oximetry readings. If you find yourself frequently moving your finger, the pulse oximeter may struggle to obtain reliable measurements. Similarly, persistent tremors – constant, uncontrollable hand movement – can interfere with the device's ability to pick up accurate readings.

A practical solution is to steady your hand! Try to keep your hand as still as possible. If you have persistent tremors, consider steadying your hand on a solid surface to reduce movement. This can significantly improve the device's ability to obtain accurate readings.

Problem: Poor perfusion

Certain conditions can limit blood flow to the fingers, affecting the precision of pulse oximeter readings. Vasoconstriction, as previously discussed in the context of cold fingers, is one such condition. Peripheral vascular issues, characterized by reduced blood flow in blood vessels outside the heart and brain, can also impact accuracy. Additionally, conditions like low blood pressure and Raynaud's phenomenon contribute to low perfusion in the fingers, posing challenges for accurate pulse oximetry readings.^{1, 4,5}

A practical solution is to optimize perfusion. Warming your fingers, as mentioned earlier, is a key measure to enhance blood flow and improve perfusion, thus aiding in more reliable pulse oximeter readings.

Additionally, staying hydrated and addressing underlying health conditions like low blood pressure can further contribute to the accuracy of these readings. It's worth noting that using a newer pulse oximeter may also be beneficial, as studies show that advancements in technology have significantly improved the accuracy of modern devices.^4,5

Resolving potential issues in your pulse oximetry readings

These are 6 potential issues that may contribute to low pulse oximetry readings, as these are challenges I've faced as a respiratory therapist. These are problems you should be able to resolve independently.

However, if troubleshooting doesn't improve your pulse oximetry reading, it's important to reach out to your doctor or seek medical consultation for further guidance.