What is Pulse Oximetry?

If you test positive for COVID-19, the Vermont Department of Health may be in touch with you. They will provide information and may offer you a pulse oximeter, if you are at an increased risk of a serious case COVID 19. I know what you’re thinking. A pulse what? People sometimes refuse to accept the device, because they don’t understand how it could help them. I want to explain pulse oximetry and how you can use it to determine whether you need additional care.

A pulse oximeter is a small medical device that clips over a finger. It uses light to painlessly measure how much oxygen your blood is carrying. It might sound like something from Star Trek, but blood with plenty of oxygen in it absorbs light differently than blood that doesn’t have as much oxygen.

For many people, the small relatively inexpensive device provides a very accurate reading, which appears on a small digital screen on top. Medical offices and hospitals use pulse oximeters to determine your current oxygen levels. Many people use them at home to help them monitor their condition or treatment. The device is noninvasive and can, in many cases, detect even small changes in oxygen levels quickly.

An oxygen saturation level of 95 percent or higher is considered typical for most healthy people. A level of 92 percent or lower can indicate potential hypoxemia, which is a low level of oxygen in the blood. People have different baseline oxygen saturations levels, particularly those on chronic oxygen or those with COPD or emphysema.

People with COVID can find that their blood oxygen level drops, even before they feel short of breath. Clipping a pulse oximeter to your finger every few hours and taking a reading is even easier than taking your temperature, and it can help you get treatment when you really need it. Make sure to write down your pulse oximeter readings with the date and time to track if they are getting better, worse, or staying the same.

So, if the Health Department asks you if you would like a pulse oximeter, accept it. It will arrive within a day or two and provide important information you can use to determine if you need more care.  If you are not among those that the Health Department is prioritizing for contact tracing, you can find a pulse oximeter at your local pharmacy or buy one online.

Caitlin Tilley, BSN, RN, director of the Transitions of Care at Southwestern Vermont Medical Center, part of Southwestern Vermont Health Care, in Bennington.