Pulse Oximetry

Pulse oximetry, or pulse ox, is a quick, inexpensive, and needle-free test that measures the amount of oxygen in your blood. It shows whether your heart and lungs supply enough oxygen to meet your body's needs.

Why Would I Need This Test? #

Your doctor will use pulse oximetry whenever they think that your blood-oxygen levels could be too low. The device can help:

• Diagnose symptoms like shortness of breath

• Track your blood oxygen level during surgery

• Test oxygen levels when you use supplemental oxygen

• Show if you need extra oxygen when you exercise

Procedure for Pulse Oximetry #

• You may get this test during a doctor visit or hospital stay.

• Your nurse will put a small, clip-like device called a pulse oximeter on your finger, toe, or ear.

• Or they’ll put a sticky disposable probe on your finger, nose, toe, or forehead.

• The pulse oximeter uses a special type of light to see how much oxygen is in the red blood cells traveling through the blood vessels under your skin.

• The test is painless and quick.

• In just a few seconds, the device will show your heart rate and oxygen saturation level the percentage of your red blood cells carrying oxygen.

• It also measures your heart rate.

• Your nurse will take the clip off if it’s just a one-time check.

• During surgery or a sleep study, it may stay in place to track your blood oxygen.

• You should be able to go home after pulse oximetry, unless you need to stay in the hospital for a procedure or more monitoring.

• Your doctor will let you know what happens next and what to do after the test.

What Do the Results Mean? #

• A blood oxygen level lower than 89% means you may not have enough oxygen in your blood to meet your body’s needs.

• This could be because there’s a problem with your heart or lungs.

• If your levels are low, you may need to breathe in extra oxygen through a tube.

• But a pulse oximeter reading is simply an estimate.

• For example, a reading of 90% oxygen saturation on an FDA-approved prescription machine could mean anything from 86% to 94%.

In addition, a number of other things can affect the accuracy of the reading, including:

• Bad circulation

• Fingernail polish

• Long or dirty fingernails

• Tobacco use

• Different pulse oximeter sensors (finger clip vs. adhesive)

• Skin thickness

• Skin temperature

Risks of Pulse Oximetry #

Pulse oximetry is a safe test. There are no real risks. But:

• Sometimes the sticky material on the probe might irritate your skin.

• If you or your nurse don’t put the sensor on the right way, you may not get an accurate result.