Pulse oximeters, small clip-on devices that measure the level of oxygen in the blood, have been appearing a lot lately, in the news and on social media, and even as flash deals on Amazon.
Find out what it works for and what science says about its use with COVID-19.
What is a pulse oximeter?
Pulse oximetry measures the oxygen saturation of the blood . In other words, check how well oxygen is delivered to your body.
The oxygen saturation level is a percentage of the amount of oxygen your blood is currently carrying compared to the maximum it can actually carry.
A pulse oximeter is a small device that is attached to the finger, earlobe, or toe, and performs painless measurement with a small infrared light. You can tell a doctor if you need oxygen. Not getting enough oxygen into your system, a condition called hypoxia , could damage your heart, brain, and other organs.
What is a normal pulse oximeter reading?
A normal pulse oximeter reading (SpO2) should be at least 95 percent . Some patients with certain medical conditions such as COPD may have low baseline pulse oximeter levels, such as 90 percent.
If you get a low reading for yourself, it is best to speak with a doctor.
Are they accurate?
Oximeters are believed to be reasonably accurate. Most devices will give a reading with an accuracy of 2 percent. So, for example, if your oxygen saturation is 92 percent, you may be in the 90 to 94 percent range.
However, some things can affect the accuracy of the reading, such as:
- Cold hands or poor circulation
- Nail polish or artificial nails.
- Very dark skin
- Of smoking
- Have oxygen saturation levels below 80 percent
- Bright light directly on the pulse oximeter can also affect the readings.
Who needs a pulse oximeter?
This device is necessary for various situations:
- During or after surgery or sedation
- To see if lung medicines work
- To determine if a person can handle increased physical activity
- To see if a fan is needed
- Assess a person with sleep apnea
It is also necessary for home use for those who have suffered from:
- Myocardial infarction
- Heart failure
- Chronic Obstructive Pulmonary Disease (COPD)
- Anemia
- Lung cancer
- Asthma
- Pneumonia
Can they diagnose COVID-19?
Many people with COVID-19 have low oxygen levels, even when they feel fine. So there has been talk that a pulse oximeter could help detect or monitor the virus.
COVID-19 can cause a form of lung disease that interferes with gas exchange. It may feel pretty good, but if you take an X-ray of your lungs or measure your oxygen concentration, there could be many more illnesses than you were experiencing.
This is why doctors began to think that measuring oxygen concentration would be useful for monitoring people with COVID-19. And a pulse oximeter allows it without the person being in a hospital.
You should record what the readings are twice a day, and if they start to drop, then call your doctor. What is contagious is not so much the disease itself, what we want to know is if you are starting to fall.
However, a pulse oximeter is not designed to diagnose COVID-19. If you have symptoms of COVID-19 or exposure to the coronavirus, your best response is to get tested and notify a doctor. If you are diagnosed as positive, a pulse oximeter can be helpful to monitor your blood oxygen level and, based on the number, to determine if you need medical attention.
However, a pulse oximeter level alone is not sufficient to determine your level of disease. For example, some patients have good pulse oximeter readings but feel very ill; on the other hand, there are others who feel good but have very low oxygen levels (happy hypoxia).
How to find the best one?
There are a ton of over-the-counter purchase options, so it can get confusing when it comes to buying a pulse oximeter.
There are many types of oximeters on the market, from very basic to very sophisticated. Some can track your data and even share it with your smartphone and other electronic devices. They also come at very different prices
These are the basic features to look for:
- A clear display that is easy to read and can also be seen in the dark
- The ability to read your pulse, which can provide additional useful data (some devices display a pulse wave, which is useful to ensure that your pulse has been detected)
- The right size for you (many devices can be adjusted to different sizes)
