Portable oxygen concentrators (POCs) are devices developed in response to demand for a lightweight, portable source of supplemental oxygen.[1] Pulse dose delivery allows concentrators to deliver medical grade oxygen all day, every day while remaining convenient to carry.
Is Pulse Dose a More Efficient Form of Oxygen Delivery?
To understand the mechanics of pulse dose therapy, knowing the meaning of a few key terms is helpful.
An oxygen bolus is a single puff of air. The cycling phase is the moment between inhaling and exhaling.
Pulse dose flow oxygen therapy provides earlier delivery of the oxygen bolus into the inspiratory cycle, for more efficient oxygen delivery.[2]
An oxygen bolus delivered late in inspiration may be less effective in improving blood oxygen levels, as portions of the bolus may fall into the anatomical dead space.[3]
Pulse Dose Oxygen Delivery
Pulse dose mechanisms utilize an oxygen conserver and other technology to deliver oxygen to the patient based on breathing rate and other factors. The sensor determines when the patient begins inhaling and delivers the oxygen pulse/bolus at that moment, which is most productive[2], meaning the patient gets the oxygen they need, when they need it.
Pulse dosing is more akin to drinking water from a glass with a straw instead of a fountain. The intake will be based purely on the amount and intensity of sips. The bolus of pulse dose oxygen is measured in milliliters per breath, rather than liters per minute.[3]
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Continuous Oxygen Flow Delivery
The traditional home oxygen therapy is low-flow oxygen, comprising a continuous oxygen flow delivered from a stationary oxygen tank via nasal cannula.[4] Continuous flow (CF) delivers oxygen at a constant adjustable rate, regardless of the user’s breathing, measured in liters per minute.[5]
This method of delivery is simple but inherently inefficient. The oxygen delivered throughout expiration is wasted, with the exception of any oxygen which may ‘pool’ for subsequent inhalation, and may still be potentially wasted. Also wasted is the oxygen flow during late inhalation, which reaches only the conduit airways rather than gas-exchanging lung units.[4]
Think of it like a water fountain: If an individual stands in front of a water fountain flowing at 1 liter per minute, they don’t actually drink one full liter of water in a minute. The amount of water a person drinks is determined by the number of sips and the size of the sip. The rest of the water is not consumed. The same applies to continuous flow oxygen; the net amount of oxygen inhaled is a combination of the flow rate, the number of breaths and the size of the breaths.
If instead, the oxygen is delivered only intermittently, at those times productive for gas exchange, oxygen is conserved[4], and patients get the oxygen they need, when they need it.
The sensor determines when the patient begins inhaling and delivers the oxygen pulse/bolus at that moment, which is most productive[2], meaning the patient gets the oxygen they need, when they need it.
Inogen’s Intelligent Delivery Technology
Inogen® POCs feature proprietary Intelligent Delivery Technology, a reliable pulse-dose based algorithm designed to minimize missed breaths. Inogen’s Intelligent Delivery Technology is designed to deliver oxygen effectively and efficiently whether you are sleeping, at rest, or exerting yourself. With patented conserver technology, an Inogen® portable oxygen concentrator ensures oxygen is delivered within the first 250 milliseconds of inspiration, where oxygen has the most effect on lung gas exchange.
Portability of Pulse Dose Oxygen
Pulse dose oxygen can be delivered using a lightweight, battery powered oxygen concentrator which delivers an oxygen pulse only when an inhalation is detected. These portable devices provide a mobile oxygen source resulting in up to 12 hours of continuous use, depending on the model.[5]
Conclusion
Oxygen use has extended from inpatient to outpatient settings for patients with chronic pulmonary diseases and complications of hypoxemia. Pulse delivery of oxygen, such as that delivered by POCs, can provide prescribed oxygen needs in lightweight systems. Additionally, Inogen® oxygen concentrators may offer the patient one single solution[6] for long term oxygen therapy.
References
McCoy R. Oxygen-conserving techniques and devices. Respir Care. 2000 Jan:45(1):95-103; discussion 104, PMID: 10771785.
Tiep BL, Lewis MI. Oxygen conservation and oxygen-conserving devices in chronic lung disease. A review. Chest. 1987 Aug;92(2):263-72. doi: 10.1378/chest.92.2.263. PMID:3608597.
Questions about Portable Oxygen Concentrators COPD Foundation
This article was reviewed by Senior Director of Community Engagement and COPD360social Community Manager, Bill Clark, as well as certified staff Respiratory Therapists on January 23, 2020. Page accessed Jan 31,
2024. https://www.copdfoundation.org/COPD360social/Community/COPD-Digest/Article/232/Questions-about-Portable-Oxygen-Concentrators.aspx.
Martin DC. Contemporary portable oxygen concentrators and diverse breathing behaviours — a bench comparison. BMC Pulm Med. 2019 Nov
19;19(1):217. doi: 10.1186/s12890-019-0980-x. PMID: 31744499; PMCID: PMC6862795.
Hardavella G, Karampinis I, Frille A, Sreter K, Rousalova I. Oxygen devices and delivery systems. Breathe (Sheff). 2019 Sep;15(3):e108-e116. doi:
10.1183/20734735.0204-2019. PMID: 31777573; PMCID: PMC6876135.
Single solution encompasses both portable and stationary oxygen concentrators provided together
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Getting to Know Blood Oxygen Levels
What Is a Blood Oxygen Level?
When you measure your blood oxygen level, you are measuring how much oxygen your red blood cells are carrying at the time the measurement is taken. Because every cell in your body requires oxygen to function properly, maintaining a normal blood oxygen level is essential to your health. If you struggle with breathing problems or heart problems, it is likely that your health care team will want to carefully monitor your blood oxygen level to ensure that your body is getting the oxygen it needs. [1] If your blood oxygen level is below normal, which is called hypoxemia, you will need to treat the condition quickly. Hypoxia is a condition or state in which the supply of oxygen is insufficient for normal life functions; hypoxemia is a condition or state where there is a low arterial oxygen supply — often these terms are used interchangeably.[2]
Many people with breathing difficulties learn about the benefits of exercise after seeing their doctor or beginning pulmonary rehabilitation. Exercise gets your heart pumping and increases your breathing rate, which means increased circulation of oxygenated blood throughout the body. This can help your body with oxygenation of the tissues and, the better shape your muscles are in, the better they are at using oxygen effectively. With regular exercise, your muscles will require less oxygen and produce less carbon dioxide, reducing how quickly you need to breathe and how quickly you feel out of breath. Regular exercise also strengthens your heart and improves circulation, which continues to help improve your body’s oxygenation. In short: Regular exercise can help improve lung function, symptoms of lung conditions and overall heart health and circulation. All of these combine to create better oxygenation in the body and improved overall health, even for people with lung conditions and breathing difficulties.[1]
So, if you struggle with your breath while exercising, should you consider EWOT?
Acute vs. Chronic Bronchitis: Understanding the Differences
Bronchitis is a respiratory illness that causes inflammation of the tubes that carry air to the lungs—also known as the airways or bronchial tubes. When the airways become irritated, swollen and inflamed, less air is able to travel to and from the lungs and mucus begins to form in them. This generally causes an irritating cough that may be accompanied by shortness of breath, more mucus production and other bothersome symptoms.[1]
There are two types of bronchitis: acute and chronic; the symptoms can be quite different for acute vs. chronic bronchitis. Read on to take a look at how these types of bronchitis differ.[1]
