What is considered a low pulse ox reading

Your blood oxygen level indicates how much oxygen your red blood cells are carrying. High blood oxygenation plays an essential role in ensuring that your muscles, brain and other organs receive the energy they need to function properly. That’s why it’s so important to understand how to measure your current oxygen level—and determine whether it falls within an acceptable range.

Understanding Oxygen Saturation

Oxygen saturation (SpO2) measures how much oxygen blood carries in comparison to its full capacity. In other words, it’s an estimation of how much oxygen the hemoglobin in your blood contains compared to how much it could contain. Pulse oximetry devices represent this measurement using a simple percentage. So if your red blood cells contain 95% oxygenated and 5% non-oxygenated hemoglobin, your SpO2 would be 95%. Simple, right?

Now, this is where things get more complicated. It’s possible (and perfectly natural) for your SpO2 to change throughout the day, particularly if you’re transitioning from low-energy to high-energy activities. However, as long as your SpO2 stays within a healthy range amidst these fluctuations, there’s no need for concern.
Changes in activity aren’t the only factors that impact oxygen saturation. There are several adverse conditions and diseases that can negatively impact SpO2, including asthma and chronic obstructive pulmonary disease (COPD). People afflicted by these health problems often have a lower SpO2 average, necessitating the use of supplemental oxygen and other treatment methods.

Your “Normal” SpO2 Range

According to the Mayo Clinic, normal pulse oximeter readings usually range from 95 to 100 percent. Values under 90 percent are considered low, and indicate the need for supplemental oxygen. This condition is often referred to as hypoxemia, and its symptoms include severe shortness of breath, increased heart rate and chest pain.

For people with chronic lung conditions and other breathing problems, the “normal” SpO2 range of 95% to 100% doesn’t apply. These individuals should always consult with their doctor for information on acceptable oxygen levels for their unique state of health. That being said, here are a few general guidelines on SpO2 for individuals with acute respiratory issues and chronic diseases:
● In a patient with acute respiratory illness (e.g., influenza) or breathing difficulty (e.g, an asthma attack), an SpO2 of 92% or less may indicate a need for oxygen supplementation.
● In a patient with stable chronic disease (e.g., COPD), an SpO2 of 92% or less should prompt referral for further investigation of the need for long-term oxygen therapy.1

Measuring Your Oxygen Level

Today’s medical experts have access to a wide variety of SpO2 monitoring tools, including finger pulse oximeters. These compact, noninvasive devices attach painlessly to the fingertip and send wavelengths of light through the finger to assess SpO2 and pulse rate. Under the guidance of their physicians, people with heart and breathing problems can use personal finger pulse oximeters to manage their conditions and assess the efficacy of treatment methods. Pulse oximetry can be a useful aid in decision-making, but is not a substitute for a clinical assessment, nor sufficient for diagnosis by itself. Arterial blood gas measurements, obtained by arterial puncture, remain the gold standard for measurement of oxygen saturation.

A personal finger pulse oximeter is designed to be fast, durable and intuitive. All you have to do is place it on any finger and wait a few seconds for it to measure your current SpO2 and heart rate. However, not all pulse oximeters deliver the same level of performance and versatility. Many other brands of finger pulse oximeters are unable to perform with accuracy on patients with low perfusion or dark skin pigmentation, and can’t stand up to repeated daily use. That’s why in-home caretakers and people suffering from respiratory problems count on clinically proven self-monitoring solutions from Nonin.

Nonin Personal Finger Pulse Oximeters

Nonin invented the very first finger pulse oximeter in 1995, making pulse oximetry a viable solution for at-home patient monitoring. Our personal finger pulse oximeters are engineered for daily use in the most demanding monitoring environments, making them suitable for detecting SpO2 and adjusting oxygen flow while exercising, traveling or resting at home. Nonin pulse oximeters provide fast, reliable measurements that empower users and their physicians to make smarter, more confident healthcare decisions.

Count on Nonin for Peerless At-Home Monitoring Solutions

To learn more about Nonin and our award-winning self-monitoring oximetry devices, be sure to contact us today. We can guide you to the perfect at-home monitoring solution for your specific needs.

The COVID-19 pandemic has changed how we live and breathe. While the vaccines give us hope, the emergence of new virus variants is a constant cause for concern. As such, we are encouraged to stay vigilant towards critical COVID-19 symptoms that may need immediate medical attention.

While you may be able to identify the more common symptoms of COVID-19, it has been reported that sometimes oxygen levels may start to drop even before any symptoms would appear. Oximeters are devices that can help track your oxygen levels and detect cases with “silent pneumonia”, one of the most serious consequences of COVID-19.

In this article, we cover the significance of blood oxygen levels and other important facts you need to know about oximeters.

Blood oxygen levels – What’s normal?

As per the World Health Organization’s definition, an oxygen level between 95 – 100% is normal. Levels under 94% should be evaluated by a doctor, while levels below 90% are considered a clinical emergency and require immediate medical attention.

When you’re exposed to COVID-19, your lungs are one of the major organs to be affected. Damage to the lungs can cause the oxygen in your blood to drop to dangerously low levels, even when you feel generally well, or present no other symptoms of the virus. This is known as “silent pneumonia” and if left untreated, can lead to very serious consequences.

Hypoxemia and Hypoxia

Hypoxemia refers to the low level of oxygen in your blood. It can cause hypoxia (low oxygen in your tissues), which means not enough oxygen is making it to the cells in the body that need it.

Fatigue or shortness of breath, bluish colouring in the face and lips, restlessness, chest pain, and a rapid pulse rate are some typical symptoms of low blood oxygen in your body. But in some cases, you may show no symptoms. Silent hypoxia occurs when a pulse oximetry test on a person with no symptoms of low blood oxygen, results in an oximetry reading that is lower than what is considered normal. This occurrence has recently been observed in large number of individuals diagnosed with COVID-19. Hypoxia, if not detected early, can cause serious damage to your major organs and lead to the disease worsening.

Apart from COVID-19, asthma, heart disease, and chronic obstructive pulmonary disease (COPD) are some other conditions that can impact blood oxygen levels.

What is an oximeter?

During COVID-19 times, using an oximeter at home can help you check your blood oxygen levels and indicate when you need prompt medical attention.

How can we use an oximeter at home?

An oximeter is a user-friendly device, with a small clip that can be placed at the end of your finger. In some cases, it is also placed on the toe or earlobe. To achieve the best results, it is recommended to place the oximeter on your right hand’s middle finger.

Before using an oximeter, make sure your hand is warm, relaxed, and held in front of your chest, below the level of your heart. You should avoid movement while conducting the test. You should also remove any fingernail polish as it may interfere with your results.

Keep the oximeter on your finger and wait for the reading to stabilise, which should take 10 – 30 seconds. The blood oxygen level, also known as oxygen saturation (SpO2), will be displayed on the screen.

When using an oximeter at home, you should always keep a record of your oxygen levels in case you need to show it to your doctor. These records can help you easily track changes and highlight any abnormal values. Along with the oximeter readings, it is important to look out for the symptoms of low oxygen levels.

Are oximeters accurate?

Can oximeters be used for babies?

You may be concerned when considering tests on babies, however, oximeters are safe to be used on babies. Oximetry is a non-invasive and painless (needle-free) method. There is also no radiation involved.

Oximeters are a critical tool in determining oxygen needs in newborns, especially those with medical conditions such as congenital heart defects and respiratory abnormalities. However, adult oximeters may not be the right dimensions for use on a baby.

Paediatric pulse oximeters are generally used for children. They work the same way as adult oximeters but the paediatric device is designed to fit smaller fingers. In infants and young children, handheld paediatric oximeters will be used in which probes are placed on the child’s palm or foot. If you have concerns about their oxygen levels, you should always consult your child’s paediatrician. Oximeter readings between 95 – 100% are in the normal range for healthy children.

Smartwatches to check oxygen levels – Is it an option?

Though several smartwatches are equipped to measure blood oxygen levels, readings on smartwatches are not always accurate. Smartwatches cannot check blood oxygen levels to medical levels of accuracy because the sensors are just not designed or tested for medical use and medical-grade oximeters are much more reliable.

Placement or the way you wear the smartwatch can also affect its accuracy. In pulse oximetry, transmission mode is used – oximeters are clipped onto your finger and the blood flow is close to the surface. Light emitted on one side of the oximeter travels to a sensor on the other side. But, in smartwatches, reflectance approach is used – both the light source and sensor are on one side of your wrist and therefore relies on the light that bounces back. The blood vessels in the wrist can also complicate the readings.

Oximeter reading – When to go to the hospital?

Patients with moderate to critical COVID-19 associated pneumonia have a high risk of low oxygen levels. Advanced age, underlying conditions such as diabetes, heart disease and obesity are other risk factors.

If you are managing COVID-19 symptoms at home, always consult a doctor if your blood oxygen level drops below 95% or you notice the typical symptoms of low blood oxygen.

Article reviewed by Dr Joy Lim, acting medical director at IHH Healthcare Singapore

References

Comparison of SpO2 values from different fingers of the hands. Published on 2015 Sep 29. Retrieved on 2 Jul 2021 from https://pubmed.ncbi.nlm.nih.gov/26543696/

Pulse Oximeter Accuracy and Limitations: FDA Safety Communication. Published on 2021 Feb 19. Retrieved on 2 Jul 2021 from https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication

Accuracy and Reliability of Commercial Wrist-Worn Pulse Oximeter During Normobaric Hypoxia Exposure Under Resting Conditions. Published on 2020 Jul 7. Retrieved on 2 Jul 2021 from https://pubmed.ncbi.nlm.nih.gov/32633688/

Oxygen saturation ranges for healthy newborns within 24 hours at 1800m. Published on 2017 Apr 19. Retrieved on 2 Jul 2021 from https://fn.bmj.com/content/102/3/F266

Why can't your fitness tracker tell you if you have coronavirus? Published on 2020 May 6. Retrieved on 2 Jul 2021 from https://www.wired.co.uk/article/blood-oxygen-spo2-covid-wearables

Hypoxia and Hypoxemia. Published on 2020 Jun 14. Retrieved on 2 Jul 2021 from https://www.webmd.com/asthma/guide/hypoxia-hypoxemia.

Answers to Parent Questions about Pulse Oximetry Screening for Newborns. Retrieved on 27 Jul 2021 from https://www.childrenscolorado.org/doctors-and-departments/departments/heart/programs-and-clinics/critical-congenital-heart-disease-screening-program/answers-to-parent-questions/

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