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What Clinicians Need to Know About Ambulatory Oxygen Therapy

Posted on November 30, 2022   |   

This post was written by Michael W. Hess, MPH, RRT, RPFT with guest authors David Reynolds, RRT, EMT and Jean Rommes, PhD.

It is well-established that people new to long-term oxygen therapy face many barriers when first learning to use their equipment safely and effectively. Oxygen therapy outside the hospital is far different than using the seemingly endless flow at the bedside. A study published in 2018 found that 35% of new therapy users felt at least somewhat unprepared to operate their oxygen equipment. What is less commonly discussed is that health care professionals are also faced with confusion and misinformation that prevents them from helping their patients adapt. I enlisted two experts in the space to answer some of the most commonly asked questions we see about oxygen therapy. Dave Reynolds, RRT, is a respiratory therapist with over two decades of experience as a durable medical equipment (DME) supplier. Jean Rommes, Ph.D., is a longtime oxygen therapy user and COPD advocate. Together, we hope to help you learn more about optimal care for those who need supplemental oxygen outside the hospital.


When a patient presents with potential hypoxemia, many HCPs know they need to test oxygen levels with a pulse oximeter at rest and during activity. Many describe this as a “six-minute walk test,” but that is something of a misunderstanding. The validated six-minute walk test measures exercise capacity in terms of distance over time. A good oxygen titration has no time limit and looks at saturation. In addition, people should be tested at different levels of activity. According to Jean, it is critical that the person doing the test replicates “the kinds of things you’ll do at home and in your daily routine,” including things like climbing stairs. Only then can a true picture of one’s oxygen demands be seen. Dave also reminds us that tests can also use arterial blood gas (ABG) results, which can be helpful for those prescribing oxygen after an inpatient admission. Either way, remember that the testing cannot be done by the DME supplier, only an HCP or independent testing center.


It is critical to develop relationships with the DME companies in your area. Not only will they determine what equipment is accessible to your patients, but company policies can also affect how much they will pay. Dave says that many suppliers are approved by the Medicare program, but do not accept “assignment.” That means they are not obligated to accept Medicare reimbursement as payment in full and can charge up to 15%. Medicare will still only pay 80% of their approved fee, meaning your patient will be left responsible for the difference (plus the 20% copay). There are also some suppliers that do not participate with Medicare at all; in these cases, patients will have to sign a contract with payment details.

It is also important to remember that many DME companies have been under significant financial strain for many years. Changes in Medicare reimbursement policies have made it much more difficult to provide service at the same level as in previous decades. DME is a business like any other and the financial realities many suppliers face have many impacts, from reducing the kinds of equipment that may be available to the amount of training and education that can be provided. Patients therefore may need to rely heavily upon you (or resources like the COPD Foundation’s Oxygen Therapy Basics publication or the COPDF/American Thoracic Society collaboration website when they have questions.


It is essential to understand the advantages and disadvantages of the different kinds of oxygen equipment out there. Dave and Jean both agree from their perspectives, no device is inherently superior to another, but knowing the potential tradeoffs involved is important. For example, portable oxygen concentrators (POCs) are often lighter and easier to handle than larger cylinders, but also have electronic components that can fail or require service at inconvenient times. Another trade-off with POCs is that in order to save on size and weight, they are not able to generate as much oxygen as their stationary counterparts. That means their ability to provide a continuous flow of oxygen is limited. To overcome this, the devices sense when the user is inhaling and provide a bolus of oxygen at that moment. This is known as “pulse delivery.” Settings on POCs (and some pulse delivery regulators for oxygen tanks) are labeled with numbers from one to five or six, but it is important to note that these settings are NOT equivalent to continuous liter flows. It is also important to remember that settings are not standardized across the industry; in other words, setting 2 on Brand A’s device may not be the same as setting 2 on Brand B’s. That means whenever possible, health care professionals should work with DME suppliers to allow patients to trial devices to ensure they will meet their needs; Jean says, “Try before you buy is really important!”


Communication is critical between prescribers, suppliers, and end users. By working together, each group of stakeholders can work to address gaps in knowledge and care coordination. That will enable patients to get the equipment and service they need and deserve in order to live their best lives. Clinicians are often called upon to be the facilitators of this communication, and the COPD Foundation is proud to offer resources to help you help your patients. By working together, we can help the entire oxygen therapy community breathe a little easier!


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