Oxygen has been difficult to find and extremely expensive in countries hit hard by COVID-19.
Medical oxygen has become one of the most important life-saving goods in the fight against COVID-19, which leaves patients with pneumonia and hypoxemia – low blood oxygen levels.
Dozens of COVID-19 patients in India have died as a result of acute oxygen starvation, bringing the production and supply of this critical medical product to the fore worldwide.
When is medical oxygen used? How is it administered? Which countries produce the most of them? And how is it made? We answer these questions in four graphics.
The impact of COVID-19 on the lungs
In many cases, the Sars CoV-2 virus targets the airways and causes inflammation of the lungs. In severe cases, this can lead to hypoxemia, which is the leading cause of death in COVID-19 patients.
Blood oxygen saturation (SpO2) above 95 percent is a healthy range for children and adults. Oxygen saturation values below 90 percent are considered dangerous. According to the World Health Organization (WHO), around 20 percent of COVID patients need oxygen therapy to prevent respiratory failure.
Types of oxygen therapy
Oxygen can be administered in a number of ways. For low to moderate oxygen deprivation, patients can either be placed on a nasal cannula – a medical tube that runs through both nostrils – or on a simple face mask or reservoir face mask. In these cases, one to 15 liters of oxygen per minute are delivered to supplement a patient’s regular breathing.
If higher amounts of oxygen are required, patients can be placed on a high flow nasal cannula, continuous positive airway pressure (CPAP) machine, or a ventilator. In these cases, up to 100 percent of the oxygen a person breathes comes from the oxygen cylinder. In the case of a ventilator, a continuous supply of oxygen may be required to keep a patient alive.
Where does medical oxygen come from?
Some countries, especially those with low to middle incomes, face oxygen starvation. India, which has seen a record number of cases in the past few weeks, requires an estimated 17 million cubic meters of oxygen every day.
According to the Indian Ministry of Health, only about seven million cubic meters of oxygen are produced. This shortage has resulted in thousands of people in dire need of oxygen being turned away and dying as a result.
According to the World Bank, of 102 countries that are part of the export-import trade chain for medical oxygen, 10 countries exported up to 80 percent in 2019. Belgium was the leading net exporter with $ 23.6 million, followed by France with 14 percent and Portugal with 8 percent.
How is medical oxygen created?
The air we breathe is 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases, including carbon dioxide. Medical oxygen consists of at least 82 percent pure oxygen and is produced in industrial plants before it is delivered to hospitals in pressurized gas cylinders or in liquid form in large tanks. In the past 30 years, most of medical oxygen has been produced using the economical pressure swing absorption (PSA) process, which consists of three main phases:
Pressurization: Air from the atmosphere is compressed and stored in a high pressure container.
Adsorption: Air flows through molecular sieves where the nitrogen is absorbed by aluminum and silicon compounds known as zeolite. The remaining air is passed through an air buffer tank.
Pressure relief: Air flows through alternating tanks in a series of cycles to remove unwanted gases. The resulting gas consists of 96 percent pure oxygen. This oxygen is stored in a tank and can then be dispensed into oxygen bottles.