The second wave of the coronavirus has hit the country badly, every minute records at least 1-3 persons being diagnosed with COVID-19.  Medical experts are urging people to safeguard themselves and seek prompt medical assistance in case they exhibit any COVID-19 symptoms. One of the most common symptoms is a fall in oxygen levels, where a delay in attending the patient can put them at increased risk of complications. Health care experts stress the need to maintain oxygen saturation in COVID-19 patients. One small medical gadget that has gained a lot of attention for its potential and efficiency in monitoring coronavirus symptoms is the pulse oximeter, which is alerting the person about the drop in oxygen levels.

Every single cell and organ in the body need oxygen to live on, without which cells begin to break down and eventually die. The body carries oxygen to the organs by filtering it through the lungs. The lungs supply oxygen into the blood and the rest of the system via haemoglobin in red blood cells. Pulse oximeter determines the percentage of oxygen in the haemoglobin called oxygen saturation, which indicates the level of oxygen getting to the organs. It is a very small device that clasps onto a person’s finger.
Pulse Oximeter

It is mainly used for evaluating patients in hospitals, including those who underwent surgeries and at homes for people suffering from respiratory issues. As per medical experts, this tiny device may assist the physician to decide whether the patient needs extra oxygen support. The use of finger pulse oximeter at home by patients with COVID-19 can anticipate the oxygen desaturation that leads to emergency intensive care attention.

The normal oxygen saturation (Spo2 or Sao2) levels are between 95 and 100 percent, oxygen saturation levels below 90 percent are considered abnormally low and need immediate medical care.

The cut-off for COVID-19 patients is 94 %, dipping oxygen levels may lead to hypoxemia. This condition develops when the oxygen levels in the body are consistently low and can lead to organ damage or death of the affected individual, if not treated on time.

Also Read: Happy Hypoxia: Decoding The Mystery Behind Why Oxygen Levels Decline In COVID-19 Patients

What Is A Pulse Oximeter?

Pulse oximeter is a rapid, non-invasive test that measures the oxygen saturation level in the blood. It is an easy, painless method to determine how efficiently oxygen is carried to parts of the body furthest from the heart including the arms and legs. The device is attached to the finger or earlobe, where it uses light to measure how much oxygen is in the blood. It helps to identify if a person needs extra oxygen and also shows whether the heart and lungs are supplying adequate oxygen throughout the body.

Oxygen saturation can drop for several reasons, including:



Infections, such as pneumonia


Lung diseases, such as emphysema, lung cancer, and lung infections

Inhaling poisonous chemicals

Heart failure

Allergic reactions

General anaesthesia

Sleep apnea

Pulse Oximeter Benefits

The main purpose of pulse oximeter is to monitor how well your heart is pumping oxygen through the body. It is used to check the health status of individuals with any other conditions that can affect blood oxygen levels, especially while they are in the hospital. These conditions include:

Chronic obstructive pulmonary disease (COPD)




Lung Anaemia

Heart attack or heart failure

Congenital heart defects

Some of the other common uses of pulse oximeter include:

  • To evaluate how well a new medication for lung problem is working
  • To monitor if a person needs breathing aid
  • To assess how beneficial a ventilator
  • To check oxygen levels during or after surgical procedures that need sedation
  • To evaluate how effective supplemental oxygen therapy, when they have newly started
  • To check a person’s ability to endure increased physical activity
  • To determine if a person temporarily stops breathing while sleeping- in case of sleep apnea or during a sleep study

How It Is Measured?

Pulse oximeter may be used for patients in both hospitals and at-home settings. The pulse oximeter process is as follows:

A clip-like device will be placed on your finger, earlobe, or toe. You may feel a little pressure, and however, there is no pain or pinching. You will need to keep the probe on for as long as needed to check pulse and oxygen saturation. When determining physical activity abilities, this will be placed during the entire exercise and the recovery period. While during surgery, the probe will be attached beforehand and removed once the patient regains consciousness. Once the readings are measured, the clip will be removed.

Also Read: COVID-19: Watch Out For Critical Symptoms That May Require Hospitalization

Pulse Oximeter Readings

It is a fairly accurate test when using high-quality equipment. The pulse oximeter reliably provides results within 2% difference, for instance, if you're reading was 82 %, the right oxygen saturation level may be anywhere from 80-84%. Furthermore, other factors such as movement, temperature, or nail polish can impact the accuracy of the result.

Generally, more than 89% of blood should be transporting oxygen. This is the oxygen saturation level required to keep the cells and body function in good health. While having an oxygen saturation below this for a short period does not cause any damage, but repeat or consistent incidences of low oxygen saturation levels may be damaging vital organs.

An oxygen saturation level of 95% is considered normal for most healthy persons. A level of 92% indicates potential hypoxemia or deficiency in oxygen reaching the cells and tissues in the body.


Some factors can lower the accuracy of a pulse oximeter reading including:

Change in the pulse.

Carbon monoxide poisoning, which may show an alert in a pulse oximeter.

High bilirubin levels.

Lipids in blood plasma.

Interference from external light or colour including nail polish.

Having cold hands or poor circulation.

Furthermore, individuals having breathing difficulty, shortness of breath, dizziness, or any other signs of oxygen deficiency should seek immediate medical attention.