With oxygen deprivation and lung infections becoming common problems faced by patients during the second wave of Covid-19, many patients have been recommended to use oxygen concentrators and cylinders at home to maintain oxygen levels and avoid fatalities. However, with oxygen therapy, one needs to be doubly careful and be aware of the risks and dangers as well. Here are the answers to some common queries that will help you make the right decision regarding oxygen support.
WHEN SHOULD YOU TAKE OXYGEN SUPPORT?
Oxygenation should be preferred when blood oxygen levels (SpO2) readings drop below 94%. Ideal oxygen levels should be between 95% and 99%. While no oxygen therapy can instantly boost oxygen levels or restore them to normal, Covid-positive patients should aim to achieve a saturation of up to 92%. Experts also advise that achieving 100% saturation shouldn’t be done when the body is sick. More so, this may exhaust your resources quicker, whether it is a concentrator or cylinder that you use.
WHAT IS AN OXYGEN CONCENTRATOR? HOW DOES IT WORK?
An oxygen concentrator is an electronically operated device that separates oxygen from room air. It provides a high concentration of oxygen directly to you through a nasal cannula. These devices work on the principle of ‘rapid pressure swing absorption’ which is where the nitrogen is removed from the air using zeolite minerals which absorb the nitrogen, leaving other gases to pass through and capturing oxygen as the primary gas. The collected oxygen is 92-95% pure.
WHAT IS THE DIFFERENCE BETWEEN OXYGEN CONCENTRATORS AND CYLINDERS?
The difference is that a concentrator purifies the air and makes it available for patients who have low oxygen levels in their blood. It just needs to be pulled into a power source. Cylinders accomplish the same, but the oxygen is already compressed within the tank. That supply is gradually reduced until the tank runs out and needs to be refilled or replaced.
WHAT TO KEEP IN MIND BEFORE BUYING OR RENTING AN OXYGEN CONCENTRATOR?
Normal air will have 21% oxygen. If 1 litre oxygen is provided to the patient through the concentrator, the oxygen percentage (or fraction of inspired air) in the lungs rises to 24%, with 2 litres it rises to 28% and with 10 litres it rises to 60%. Depending on the need, the litres of oxygen per minute must be regulated. There is a need for monitoring this from time to time to ensure that the flow of oxygen is proper and that the patient is not over oxygenated. Seek your doctor’s advice to decide how many litres per minute of oxygen is required for your patient. Keep a pulse oximetre handy to check oxygen levels from time to time. Oxygen concentrators can supply between 0.1 litres per minute (LPM) to 5 to 10 LPM.
WHO IS ELIGIBLE?
Only mild to moderately ill patients, who have an oxygen saturation level between 90% and 94%, should depend on an oxygen concentrator and can use it at home. We must understand that hoarding such life-saving equipment will only worsen the country’s problem. Anyone with oxygen saturation depleting below 80-85% may need a higher flow of oxygen and will have to switch to a cylinder or liquid medical oxygen supply and may eventually need hospitalization.
TYPES OF OXYGEN CONCENTRATORS
There are two types of oxygen concentrators— continuous flow and pulse dose. Continuous flow oxygen will provide the same flow of oxygen every minute unless it is turned off, irrespective of whether the patient is breathing it in or not, while pulse dose oxygen concentrator detects breathing patterns and dispenses oxygen when it detects inhalation. The oxygen dispensed per minute will vary in the second case.
WAYS TO IMPROVE OXYGEN LEVELS FOR COVID PATIENTS
Oxygen delivery can be increased by using prone positioning. Physical position affects the distribution and volume of air in the lungs and can have direct effects on the expansion or collapse of the delicate alveoli that permit the exchange of oxygen and carbon dioxide in the blood. It involves turning a patient with precise, safe motions, from their back onto their abdomen so that the individual is lying face down, to improve breathing and oxygen flow in the body. Having said that, getting the right advice on how proning can be complemented with oxygen supply is significant. Talk to your doctor today to understand when to opt for oxygen support at home, if your patient is eligible for oxygen support at home, and how it can be best utilized.
The author is Consultant, General Physician, Fortis Hospital, Mulund.