What is an oxygen concentrator?
It’s a medical device that draws in ambient air, passes it through a molecular sieve to concentrate room oxygen to therapeutic levels and deliver it to a patient. It provides the patient supplemental or extra oxygen. These devices can supply a continuous stream of oxygen at flow rates of up to 10 litres per minute. “The core of an oxygen concentrator is what you call a sieve bed. This separates the oxygen from the air and passes it on to the patient at 95% purity,” said Rajiv Mohan, owner, Shakti Technology Enterprises, a New Delhi-based firm that has been dealing in respiratory care equipment.
How do capacity and purity come into play?
The two most common models of oxygen concentrators available in the Indian market currently offer an output of 5 litres and 10 litres per minute. Some of the brands in the market also offer 8 litres per minute, Mohan of Shakti Technology said. However, Dr Mrinal Sircar, director and head, pulmonology and chest and sleep medicine, Fortis Hospital, Noida, said more than the capacity or purity, it is important to understand how much oxygen a patient is able to extract by using such a device. “How much oxygen is getting into the blood is what matters,” he added.
How helpful are they for covid-19 patients?
Sircar said oxygen concentrators were designed to help people suffering from chronic respiratory illness, not acute situations like covid-19. “Oxygen concentrators can be a temporary measure, provided the patients’ oxygen requirement is not very high,” he added. According to the World Health Organization’s (WHO’s) technical specifications on oxygen concentrators, pulse oximeters should be used in conjunction with a concentrator to identify and monitor hypoxaemic (low levels of oxygen in the blood) patients.
What to look for when buying a concentrator?
Beware of fake or ineffective concentrators that are not medical-grade equipment. “You should be getting at least 92-95% purity from these machines at 5 litres per minute,” said Mohan. “Any machine that offers 50% oxygen purity is not fit for use.” Mohan recommended brands such as Phillips, Nidek, OxyBliss, AirSep and DeVilbiss. Noise levels and portability are also key factors. According to the WHO, oxygen concentrators should produce no more than 50 decibels while operating.