CPR First Aid

What is the use of a Pulse Oximeter in Covid-19

What is the use of a Pulse Oximeter in Covid-19?

A pulse oximeter is a medical device used in homes, health care settings, and in situations where first aid response is being applied. It tests if someone’s blood level and pulse rate are average. If not, a person may have serious health conditions. It may be hypoxemia, bradycardia, or tachycardia which must all be treated to prevent further complications. It has also been used by people in Perth to detect Covid-19. But is it effective in doing so? What is the use of a pulse oximeter in Covid-19? Let’s find the answers below.

Using a Pulse Oximeter to Detect Covid-19

One use of a pulse oximeter is to detect if someone’s oxygen level is low. When this happens, a person may be having hypoxemia. According to World Health Organisation, it is one of the danger signs of Covid-19, which must be identified and intervened quickly. Detecting if someone has hypoxemia is possible by using a pulse oximeter. In addition, Covid-19 patients who are isolated at home may also use such devices to monitor if their oxygen levels are low already, so first aid and proper treatment may be applied immediately. However, since a pulse oximeter only detects hypoxemia, many resources claim that going for a test specific for Covid-19 is still the only way of detecting if someone has the virus.

Recognising Hypoxemia with a Pulse Oximeter

One of the danger signs of Covid-19 is hypoxemia, a reduction in oxygen saturation level in the red blood cells. Fortunately, this may be recognised quickly with the help of a pulse oximeter. In doing so, treatment may be done to prevent further damage to the heart and/or the brain.

How does a Pulse Oximeter Reads Oxygen Levels?

The American Lung Association explains that a pulse oximeter uses a cold light source. The source shines a light through a person’s fingertip that makes it look red. The light source that passes through the finger is analysed by a pulse oximeter which is then able to determine the oxygen level in the red blood cells.

Normal Oxygen Levels

To effectively use a pulse oximeter, a common part of first aid management, it is important to be reminded of the normal oxygen levels. According to Healthline, a normal oxygen level is between 80 and 100 millimetres of mercury (mm Hg). It is interpreted by a pulse oximeter in percentage as SpO2.

Understanding the Results in a Pulse Oximeter

One of the results displayed on a pulse oximeter is for the Sp02. According to Healthline, if a person’s oxygen level is within the normal range, a pulse oximeter will display a 95% or higher Sp02. If the results are below 95%, it may mean that a person’s oxygen level is 80 mm Hg or lower, which may indicate hypoxemia.

What is Hypoxemia?

If a person has hypoxemia, he/she may be experiencing a problem related to breathing or circulation. Aside from Covid-19, it is caused mainly by a complication in the heart and/or the respiratory system.

How Hypoxemia Related to Covid-19?

Complications to the respiratory system may be caused by many factors, and one of them is Covid-19. It has effects that are all associated with hypoxemia. According to News-Medical, such effects include the elevation of:

  • White blood cell counts.
  • Neutrophil counts.
  • C-reactive protein levels.

The above may mean an acute inflammation in the respiratory system, which then damages the lungs, and leads to hypoxemia. The same source mentioned that there is no proper documentation on the incidence and prevalence of hypoxemia in Covid-19 patients. Therefore, having hypoxemia may not necessarily mean having Covid-19 too. Especially since there are other causes of hypoxemia.

Other Causes of Hypoxemia

Aside from Covid-19, hypoxemia may also be a result of other factors. Cleveland Clinic lists the following other causes of hypoxemia. These may occur more commonly in people with pre-existing lung or heart disease, an obese status, and those who are active smokers, according to Houston Methodist.

Ventilation-Perfusion (V/Q) Mismatch

This occurs when the airflow and/or blood flow into the lungs do not work properly.

Diffusion Impairment

It occurs when oxygen is not able to pass through or diffuse from the lungs to the blood vessels.


When there is insufficient oxygen in the lungs, it may lead to hypoventilation.

Low Environmental Oxygen

These are areas where there is not enough oxygen in the air around to breathe in. Such places are more common at high altitudes.

Right-to-left shunting

There is a lack of oxygen in the tissues due to the deoxygenated blood being pushed over to the left side of the heart, instead of the right.

Hypoxemia caused by Covid-19

As mentioned above, Covid-19 has effects that may lead to hypoxemia. It may be detected by a pulse oximeter which is easy to use and displays high accuracy. Therefore, using it is advised especially for those Covid-19 patients isolated at home.

Home Isolation for Covid-19 Patients

If a Covid-19 patient is advised to home isolate, he/she must stay home with the other usual household members. The person is not allowed to leave and go to public places, work, school, childcare, or university. The Department of Health has outlined guidance on which Covid-19 patients may home isolate:

  • The Covid-19 patient is well enough to receive care at home.
  • The Covid-19 patient has appropriate caregivers at home.
  • The Covid-19 patient has a separate bedroom where he/she can recover without sharing an immediate space with others.
  • The Covid-19 patient has access to food and other necessities.
  • The Covid-19 patient has access to the recommended personal protective equipment (at a minimum, gloves, and a mask).
  • The Covid-19 patient does not live with household members who may be at increased risk of complications from novel coronavirus infection (e.g. people over the age of 65, young children, pregnant women, people who are immunocompromised, or who have chronic heart, lung, or kidney conditions).

If a Covid-19 is classified to be able to home isolate, monitoring his/her condition must be made so treatment or appropriate first aid practices may be applied immediately. Especially that patients with hypoxemia have a higher mortality risk than those who do not have it according to News-Medical.

Mortality Risk for Covid-19 Patients with Hypoxemia

Multiple research has been made to determine the relationship between COVID-19 and hypoxemia. One of these is posted on PLOS, wherein it was concluded that an oxygen level of below 90% is a strong predictor of in-hospital mortality in patients with COVID-19. It was also mentioned that additional efforts must be done especially for people located in settings with limited resources. One of these may be the people isolated at home since they may not have immediate access to complete hospital equipment. It is one of the reasons why using a pulse oximeter is strongly advised so monitoring blood levels may be done and monitored.

Using a Pulse Oximeter

Using a pulse oximeter is done by the following steps:

  1. Check if an oximeter has batteries.
  2. Turn the oximeter on.
  3. Clipping the oximeter on the end of a finger, making sure that the nail is facing up.

The results will then be displayed on the screen after a few seconds. If the blood levels are normal, then it is advised to check it again after a few hours. If not, then first aid management for hypoxemia may be done while waiting for emergency help. It includes first aid steps that may be learned by enrolling in a first aid course in 123C Colin St West Perth 6005. If a low blood level is detected in a person who is already a confirmed Covid-19 patient who is home isolated, he/she is advised to be brought to a hospital in Perth immediately.


A pulse oximeter may be used to detect hypoxemia, it occurs when the blood levels of a person are lower than normal. It is a serious condition that may affect the heart and/or the respiratory system if left undetected and untreated. It is caused by many factors like Covid-19 and patients who develop hypoxemia have a higher mortality risk than those who do not have it. However, having hypoxemia may not necessarily mean having Covid-19 too. So even though a pulse oximeter is helpful in detecting hypoxemia, which may be a risk factor for Covid-19, going for a test specific for Covid-19 is still the best method of detecting it.

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