As India fights Covid-19 second wave, here's all you need to know about oxygen concentrators
As India battles the second wave of the coronavirus disease (Covid-19), oxygen concentrators have seen a renewed surge in demand, with disease-stricken patients and their relatives scrambling to get hold of one when faced with alarming drops in oxygen levels. Oxygen therapy has also emerged as a leading treatment in severe Covid-19 cases and as a helpful alternative to depleting stocks of liquid oxygen, as evident by the central government announcing on April 28 that it will procure such concentrators in states gravely burdened with coronavirus cases.
However, using an oxygen concentrator correctly is no easy task, and although it is at the forefront of treating Covid-19 patients isolated at home, proper guidance is necessary. Here's a primer on how oxygen concentrators work and when they would be required, if at all:
What is oxygen therapy?
To understand how oxygen concentrators work, one first needs to understand how oxygen is used in the medical treatment of Covid-19.
The coronavirus brings about a respiratory disease, meaning it affects our lungs and subsequently alters the otherwise normal, steady flow of oxygen from the lungs to the various cells within our body. When one contracts the coronavirus disease, it can cause the oxygen to drop to alarming levels, thereby requiring oxygen therapy. This treatment uses an external supply of medical oxygen to artificially enhance our oxygen levels to clinically acceptable levels.
Oxygen level is measured by oxygen saturation, known briefly as SpO2. This is a measure of the amount of oxygen-carrying haemoglobin in the blood. A healthy individual with normal lungs will have an arterial oxygen saturation of 95% – 100%.
The World Health Organization (WHO) mandates that if the oxygen saturation level is 94% or lower, the patient needs to be treated quickly. SpO2 of less than 90% is a clinical emergency. Now, as per the Covid-19-related guidelines issued by the Union health ministry, the patient needs to be admitted to a hospital if the oxygen concentration goes down to 93% or lower, while that below 90% is classified as a severe disease, requiring admission in ICU.
How do oxygen concentrators work?
We know that atmospheric air contains around 78% nitrogen and 21% oxygen. Oxygen concentrators are simple devices that do precisely what their names suggest -- they take in ambient air and increase its oxygen concentration by filtering away the nitrogen.
In a way, these oxygen concentrators function in a similar manner as oxygen tanks or cylinders do, supplying oxygen to the body with the use of a cannula, oxygen masks, or nasal tubes. The only difference is -- while cylinders and canisters need to be refilled, oxygen concentrators can work 24x7.
There is also a difference in quantity. While oxygen concentrators can provide around 5-10 litres per minute and are thus suitable for patients down with a moderate case of Covid-19, critical patients often require up to 40-50 litres of oxygen per minute which these concentrators would not be able to provide. In such cases, one would need liquid medical oxygen (LMO), which is stored in cryogenic tankers, to replenish the body's supply to acceptable clinical levels.
When to use oxygen concentrators?
Does this mean anyone who finds their oxygen level falling below acceptable levels can use a concentrator and help oneself? Absolutely not, says the central government.
Speaking to the Press Information Bureau (PIB) on the appropriate use of concentrators, Professor Sanyogita Naik, the head of the department of anaesthesia at the BJ Medical College in Pune, said: “Oxygen concentrators can be used only in moderate cases of Covid-19 when the patient experiences a drop in oxygen levels, where the oxygen requirement is a maximum of 5 litres per minute.” The professor added that oxygen concentrators are also very useful for patients experiencing post-Covid complications which necessitate oxygen therapy.
Can one use oxygen concentrators on their own?
The answer is a strict no.
Speaking at a webinar organised by the Union health ministry on April 30, Dr Chaitanya H. Balakrishnan, Covid co-ordinator at St. John’s Medical College Hospital in Bangalore, made it abundantly clear that using oxygen concentrators without medical guidance can be very harmful. “Patients with moderate pneumonia induced by Covid-19 -- with oxygen saturations less than 94 -- can benefit from supplemental oxygen given through an oxygen concentrator, but only till they get hospital admission. However, patients using it themselves without suitable medical advice can end up causing more harm.”
According to the doctor, using an oxygen concentrator can prove to be beneficial until a patient finds a bed, but not without guidance from a chest physician or internal medicine specialist. It also depends on a patients' pre-existing lung conditions, he said.
How much do oxygen concentrators cost in India?
Oxygen concentrators can cost upwards of ₹30,000, depending upon the capacity. India has recently seen a big spurt in the manufacture and sale of such O2 concentrators. Besides multi-national brands, several Indian start-ups, funded under the Centre for Augmenting War with Covid 19 Health Crisis (CAWACH) programme of the department of science and technology, have developed efficient and cost-effective oxygen concentrators.
However, both the purchase and the usage of oxygen concentrators have to be done only based on a prescription by a medical doctor. The central government has announced that one lakh oxygen concentrators are being procured through the PM-CARES fund, given how useful these devices have proved in battling the second wave of the coronavirus disease (Covid-19) pandemic.