Explained | Covid-19, breathlessness and oxygen shortage across India

The second wave of Covid-19 has put an unprecedented amount of pressure on India's healthcare infrastructure. Beds and medicines are scarce in almost every state, even as the country continues to post record rises in cases and deaths with each passing day.

Read | Covid-19 leaves India breathless as Centre, states scramble to meet growing demand for medical oxygen

However, the most disheartening impact on the health infrastructure is the severe lack of oxygen for hospitals. Across the country, hospitals are trying to get their hands on as much oxygen as they can for Covid-19 patients, while state governments are begging the Centre to do something about the oxygen supply.

But why does a Covid-19 patient need oxygen? How does SARS-CoV-2 affect the respiratory system? Read on to find out

One of the most common symptoms of a Covid-19 infection is shortness of breath in a patient. It can range from mild trouble in breathing to severe pain and inability to breathe.

A typical healthy person's lungs enable the body to absorb oxygen and dispel carbon dioxide through the lungs. The process works by the function of alveoli - the so-called air sacs that line the inside of the lungs.

Read | What medicines should you take if you have Covid-19? Here is what an expert has to say

Lining the lungs and the respiratory tract are the respiratory epithelial cells, whose purpose is to defend the respiratory system from pathogens and infections. Since SARS-Cov-2 affects the lower respiratory tract, the body's immune system triggers an inflammatory reaction to prevent damage to the lungs - and this, combined with subsequent fluid buildup in lungs, is what causes shortness of breath.

Why does a patient need oxygen?

The inflammatory reaction and the fluid buildup in the lungs can impact the body's ability to efficiently absorb oxygen into the blood. A healthy person typically has a SpO2 (oxygen saturation) level of 95-96 per cent. Respiratory infections, such as pneumonia and Covid-19, can cause that number to fall.

While a fall in oxygen levels due to Covid-19 is expected, doctors recommend rushing a patient to a hospital if the oxygen levels fall below 90 per cent, as the resulting condition, called hypoxemia, can lead to multiple issues like organ failure and cardiac arrest if not treated early.

Why is oxygen in high demand?

According to data from hospitalised patients during the first and second wave, the requirement of oxygen is higher in the second wave at 54.5 per cent as compared to the first wave at 41.1 per cent, while the demand for mechanical ventilation is lower in the second wave at 27.8 per cent in comparison to the first at 37.3 per cent.

On why oxygen requirement is higher this time, ICMR Director General Balram Bhargava said, "It could be explained by the fact that there has been a sudden surge in Covid-19 cases, creating panic among people to get admitted to hospitals and therefore, the oxygen requirement suddenly shot up, which is one reason. But this is limited data from hospital settings and more will have to be looked at."

What is being done to alleviate the oxygen shortage?

The Centre has banned the supply of oxygen for industrial purposes except in nine specified industries in view of the shortage of the essential public health commodity in several states, with a total of 6,600 metric tonnes out of 7,500 metric tonnes produced in India being supplied to states for medical use.

It also plans to increase supplies of medical oxygen in the coming days, Health Secretary Rajesh Bhushan said on Wednesday. Some state governments have set up 'war rooms' to monitor the supply of oxygen to hospitals.

Private companies such as JSW and Tata have also pitched in to help relieve the supply issues surrounding the life-saving gas.

With agency and DHNS inputs