know about Oxygen in these Covid times

How does Covid impact the respiratory system? How is an Oxygen Concentrator different from an Oxygen Cylinder? In which cases should we get an Oxygen Concentrator? How to measure SpO2 correctly?

We get these kinds of questions every day. So in this post we’ll provide information about Oxygen as relevant in the context of Covid. If you have a question about Oxygen that is not addressed in this article, chat with us and we’ll be happy to advise you.

1. How does Covid impact the respiratory system and Oxygen use in our body?

The lungs enable the body to absorb oxygen from the air and expel carbon dioxide. When a person inhales and takes in air, tiny air sacs (Medical term: alveoli) in the lungs expand to capture Oxygen. This Oxygen is then transferred to blood vessels and transported throughout the body.

There are cells that line the respiratory tract (Medical term: epithelial cells), whose main job is to protect the tract from pathogens and also help in gas exchange. The Coronavirus can infect these cells. The virus starts to replicate and spread by infecting surrounding good cells and tries to spread throughout the respiratory tract and in some cases it also infects the air sacs in the lungs.

To counter the infection, the immune system releases cells that trigger inflammation. When the inflammatory immune response increases, it affects the regular transfer of oxygen in the lungs. At the same time such response may also lead to fluid buildup in the lungs. These reactions may lead to shortness of breath (Medical term: Dyspnea). When the air sacs in the lungs are also inflamed, it can lead to pneumonia.

One of the reasons your doctor may have told you to do a test for inflammatory markers (such as elevated white blood cell count or neutrophil count) is that these are signs of the inflammatory response in the body’s fight against Covid.

When the body is deprived of adequate Oxygen at the tissue level (Medical term: Hypoxia) several symptoms show up and other organs (not just the lungs) may also be impacted.

However, it is important to remember that only a small percentage of Covid patients need Oxygen support.

2. What is Medical Oxygen?

When a patient has a severe Covid-19 infection, his or her Oxygen levels may fall. In order to keep the Oxygen levels at the normal range, Medical Oxygen needs to be given.

The air we normally breathe has only around 21% Oxygen (Nitrogen forms the highest percentage of air). Medical Oxygen is created by taking the Oxygen from the air and compressing it. As a result, the Medical Oxygen you take in, for instance, from a cylinder, is highly concentrated Oxygen (as close to 100% as possible).

3. What is the difference between an Oxygen Cylinder and an Oxygen Concentrator?

An Oxygen Cylinder has a finite amount of Oxygen compressed within it that can be inhaled by the user until it runs out. By contrast, Oxygen Concentrators filter and generate medical grade Oxygen infinitively so long as the battery that powers this mechanism is working. Think of an Oxygen Concentrator like an air conditioner with an air purifier. It takes in air, purifies it, modifies it and delivers it in a new form.

All Oxygen Cylinders deliver oxygen at a continuous rate (Continuous Flow). With Oxygen Concentrators, it tends to vary by device, as some of the more portable options operate on delivering Oxygen based on the breathing rate (Pulse-Dose delivery).

With an Oxygen Concentrator, there are no Oxygen leakage issues, no problem of running out of compressed Oxygen and the cost is mostly upfront — no need to replenish cylinders.

However, Oxygen Concentrators can only supply 5–10 litres of Oxygen per minute and are best suited for moderately ill patients. For critically ill patients, 40–50 litres of Oxygen per minute might be needed and Oxygen Concentrators don’t suffice.

Oxygen Concentrators provide 90%–95% pure Oxygen which is adequate in treating mild and moderate levels of Covid-19 infection (at home or at Covid Care Centres), but for critical cases, over 99% pure Oxygen is required and Oxygen Concentrators are not recommended for critical cases.

4. In which cases should we get an Oxygen Concentrator?

Let your doctor make this decision. If any family members have shown symptoms or your Oxygen saturation level is falling (below 94), please consult your doctor immediately. Let your doctor decide whether an Oxygen Concentrator can help, whether it is ok to treat you at home or you need hospitalization. Oxygen is only a supportive measure and is not a treatment for COVID virus. Don’t prioritize getting a Concentrator over consulting your doctor or other treatments/measures your doctor suggests.

If you have been diagnosed with Covid and your doctor has advised you to get an Oxygen bed in a hospital, but you can’t get one in spite of all efforts because they’re all full or if your doctor has advised you to be in home treatment with Oxygen Concentrator, then in such cases get one.

Oxygen levels in some patients could fall rapidly or other conditions could show up. Hence it’s very important that you get a hospital bed with Oxygen, under a doctor’s care, if your doctor has prescribed it.

5. What is Sp02 and how often should it be measured?

A Pulse Oximeter measures the amount of oxygen being carried in your blood, as a percentage. This measurement is known as the Sp02 — the saturation of peripheral oxygen — and it is an estimate of the Sa02 — the saturation of arterial oxygen.

The Haemoglobin in your red blood cells carries the Oxygen (with a small amount being dissolved in the blood). Each Haemoglobin molecule can carry 4 oxygen molecules. If all of your Haemoglobin molecules have four oxygen molecules bound to them, your blood would be ‘saturated’ with oxygen and you would have an SpO2 of 100%.

Most people don’t have oxygen saturations of 100% so a range of 95–99% is considered normal.

SpO2 levels below 95 mean there is less Oxygen being delivered from the blood to the tissues in the body.

For Covid-19 patients with mild symptoms we recommend measuring SpO2 levels every 4–5 hours using a Pulse Oximeter. For critically ill patients, appropriate monitoring and treatment is done by the treating physician.

6. What is the right way to use a Pulse Oximeter?

There are many good youtube videos on this. Please watch one of them from a credible organization/doctor.

The short answer on how to use a pulse oximeter is —

  1. Rest for five minutes and relax your body
  2. Place the pulse oximeter on your index or middle finger and place your hand (which has the oximeter) on your chest. Our recommendation is if you’re right handed use the right middle finger and if you’re left handed use the left middle finger.
  3. Keep the oximeter on your finger for at-least a minute, till the reading stabilizes.
  4. Note down the highest reading that flashes on the oximeter once it has stabilized (remains constant for 5 seconds).

Originally published in Medium:

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