For COPD patients receiving palliative care, oxygen therapy is provided to relieve hypoxia and dyspnea, improve quality of life, improve the patient’s ability to ambulate and/or exercise, and improve sleep by relieving nocturnal desaturations.

Bill Pruitt, MBA, RRT, CPFT, AE-C, FAARC

Palliative care is a specialized approach for providing care for patients with serious illness (some examples include cancer, heart disease, COPD or other lung diseases, kidney disease, and amyotrophic lateral sclerosis). A team of healthcare professionals is involved to relieve the stress as well as the symptoms of the disease and improve the quality of life for the patient. Relief of the stress addresses both the patient and the caregiver in dealing with anxiety, depression, and lack of resources. Relief of symptoms include pain, dyspnea, fatigue, constipation, nausea loss of appetite and difficulty sleeping.1

Unlike hospice care which is utilized only in terminal illness, does not provide curative care, and has a time limit based on a life expectancy of 6 months (which can be extended in six month intervals), palliative care is not limited in time, can include curative care and can be started in any patient with a serious illness.2 Palliative care provides a holistic approach to help both the patient and the caregiver.3 Some 5 million adults in the US live with chronic lung disease and more than 1 million patients are prescribed to receive long-term oxygen therapy (defined as using oxygen for at least 15 hours/day).4

For COPD patients receiving palliative care, oxygen therapy is provided to relieve hypoxia and dyspnea, improve quality of life, improve the patient’s ability to ambulate and/or exercise, and improve sleep by relieving nocturnal desaturations.

Qualifying for Home Oxygen Therapy

Home oxygen therapy or long-term oxygen therapy (LTOT) is provided for patients who stable, utilizing optimum pharmaceutical support (i.e. bronchodilators, antibiotics, corticosteroids) and demonstrate hypoxemia on at least two arterial blood gas samples obtained while breathing room air. The qualifying levels of hypoxemia fall into three categories. 4,5,6,7

  • Patients with a PaO2 < 55 mmHg (or a SpO2 < 88%) at rest.
  • Patients with a PaO2 56 to 59 mmHg that is linked to a central nervous system dysfunction, cor pulmonale, secondary pulmonary hypertension, polycythemia, edema, hematocrit > 55%,
  • Patients who may have acceptable oxygenation at rest but have a PaO2 < 55 mmHg during exercise and/or sleep (due to sleep-related disorders such as obstructive sleep apnea).

Once home oxygen therapy has been established, the patient should be reassessed for continued need or adjustments in therapy. The 2020 Global Obstructive Lung Disease (GOLD) initiative places this reassessment after 60 to 90 days.4 Moreover, when the severe hypoxemia is the result of an exacerbation, GOLD recommends reassessment at 1 to 4 weeks and again at 12 to 16 weeks. The reassessment should check the SpO2 (or arterial blood gas oxygenation measurements) both at rest and with exertion. Patients should be reassessed at a minimum of every 6 months for prolonged oxygen therapy.4

The reassessments provide justification for continuing the therapy and may involve changes in the supplemental oxygen settings in light of improvement or deterioration in oxygenation. It is estimated that some 50% of patients who started on home oxygen due to an exacerbation may improve. This change in condition may be enough to show that the patient no longer needs supplemental oxygen. On the other hand, some do not achieve this improvement and will continue on home oxygen. Some 40% of patients with moderate to severe COPD have hypoxemia during exertion (defined as a SpO2 < 88% but have normal or acceptable oxygenation at rest. When patients are being reassessed after starting on home oxygen, they should be asked to bring in their portable device to allow the healthcare team to assess its effectiveness and to reinforce self-management. 4

Home Oxygen Delivery Systems: Key Features and Limitations

Home oxygen therapy is supplied by oxygen concentrators, liquid oxygen systems, or by use of cylinders. With the current insurance situation and reimbursement for home oxygen in the US most patients using home oxygen therapy use concentrators and not liquid systems (long-term liquid oxygen systems are about four times more expensive than concentrator systems).6 Durable medical equipment dealers in the US have found that current CMS funds do not fully reimburse costs associated with liquid oxygen systems — in particular the need for a special delivery truck, frequent deliveries, and other special equipment needed for providing liquid oxygen to the home.4  In addition, due to the weight of oxygen cylinders, the limited time a cylinder will provide oxygen, plus the requirement for a cylinder-based system to be refilled periodically; oxygen concentrators are the preferred source for oxygen at home.

Concentrators do not need to be refilled whereas both liquid and cylinder systems must be refilled. Refilling liquid or cylinder systems can be challenging in dealing with patients in rural settings, during significant prolonged weather events or dealing with impassable roadways. In light of these points, the remainder of this article will focus on the use of home oxygen concentrators.

Oxygen concentrators are either portable or stationary systems and provide oxygen based on either by continuous flow or by an intermittent or pulsed flow (usually referred to as an oxygen conservation device or OCD) .6 Oxygen concentrators must have an electrical power supply to run the device, or if battery-powered, must have a power source to recharge the batteries. Patients using a concentrator need to have an emergency back-up oxygen supply in case of a power outage or a problem with the concentrator. The emergency back-up is usually provided by O2 cylinders to provide a few hours of supply to provide time for restoration of power or fixing the concentrator problem. New technology has developed ultra-lightweight concentrators that make ambulation a reality for many who previously could not manage to carry an oxygen source with them. Many of the portable systems allow for the unit to be run from a automobile’s cigarette lighter socket as well as from a standard electrical outlet and many are also approved for carrying on an airplane9 which greatly increases the opportunity for COPD patients to travel close to home or far away.

According to a review of long-term oxygen therapy released by the National Lung Health Education Program (NLHEP), “it can be argued that ambulatory oxygen in functional patients can actually reduce costs even more than initially thought by reducing hospitalizations.”5 The NLHEP document goes on to say; “Portable systems, such as cylinders or strollers, are cumbersome and impede full activity. Ambulatory systems can be carried easily by patients and are designed to allow and encourage full mobility.”5 Finally, NHLEP also states; “The real benefit from oxygen-conserving technology is improved patient care and better compliance with therapy because of smaller, lightweight ambulatory oxygen units that allow greater mobility and improved quality of life.”5

Concentrators produce oxygen by drawing in room air, running it through molecular “sieve” material or semi- permeable membranes to absorb the nitrogen from the air, and release the resulting oxygen to the patient. Oxygen purity is usually around 93% to 96% and as the FIO2 measured at the machine outlet begins to show signs of decreasing over time the device must be serviced (namely changing out the molecular sieve or membrane). Delivered oxygen flow in the continuous flow stationary models is generally 3-5 LPM but newer devices are capable of producing up to 10 LPM.  However, the higher flow devices are bigger, heavier, and have higher electrical costs to run. The pressure generated in the stationary devices is less than the pressure found in the hospital oxygen supply, running at about 10 to 30 PSI compared to 50 PSI, respectively, so oxygen delivery devices requiring the higher pressure would not be suitable for use in the home. Noise, weight, and the heat given off by running the unit can be factors in selecting a stationary device – some machines are quieter, or less heavy, or cooler than others. Some stationary O2 concentrators are able to refill portable cylinders but the cost of these devices may be a factor since they cost up to three times the cost of a machine that is lacking this capability.5

Portable oxygen concentrators are battery-powered (which need periodic recharging), are lighter, and quieter than stationary concentrators, but are usually more expensive. Most portable concentrators use an oxygen-conserving device (OCD) to provide either a pulsed flow, demand flow, or a hybrid approach to delivering flow. OCD helps to eliminate the waste of oxygen that occurs in a continuous flow system that occurs during the normal exhalation and pause prior to the next inspiration. The pulsed dose device provides a short burst of oxygen at the beginning of inspiration but does not continue throughout inspiration. The demand flow device delivers a constant flow throughout inspiration. The hybrid device provides a burst of oxygen at the beginning of inspiration and delivers a lower constant flow during inspiration. All three of these devices provide no during expiration.5 By stopping delivery during exhalation, there is less oxygen wasted compared to the delivery systems that provide constant, non-interrupted flow all the time. The patient’s inspired volume and inspiratory flow determines the FiO2 delivered to the airways. Low inspired volume and low inspiratory flow tends to entrain less room air that mixes with the supplemental oxygen and increases the airway FiO2 and vice-versa. The OCD settings are reference points and should not be considered the same as the flow (LPM) set on a continuous flow concentrator or a standard oxygen flowmeter and system found at the hospital. With an OCD, the setting needs to be titrated to know what setting is best for a patient at rest or sleeping and where it should be set when doing activities such as walking or exercising. The first OCD devices released to the market relied on batteries to run the unit but newer units are now available that use pneumatic power to function. 5

Educational Needs and Safety Issues

Patients receiving home oxygen and their caregivers should have education provided to encourage adherence to the prescribed O2, proper use and troubleshooting the oxygen equipment, safety issues related to the supply system, and self-management, including information on transporting oxygen systems and traveling guidelines. Education regarding safety issues should include how to avoid tripping and falling (in light of the long oxygen supply tubing used with stationary devices), decreasing fire hazards by not smoking (including e-cigarettes or vaping devices) and avoiding any open flame or spark, and not using in petroleum-based nasal products. Finally, education concerning use of the emergency back-up system should be included.4


Palliative care in COPD patients often includes oxygen therapy but it must be justifiable based on measurements of SpO2 by pulse oximetry (or PaO2 and SaO2 values from an ABG). The three overriding issues for ordering home oxygen include relief of dyspnea, treating significant hypoxemia at rest, and/or relief of desaturations occurring when ambulating/exercising. There are several means of providing supplemental oxygen but cost, weight, need to refill, and insurance practices have influenced which means is utilized. OCDs have helped reduce wasted oxygen, extend the time some sources will last (ie liquid and cylinder supply), and help the sources be more efficient. Improved quality of life under palliative care for COPD patients is enhanced as these patients get the opportunity to ambulate and travel. New technology is continuing to make improvements in home oxygen delivery and allow more patients to have a better life while dealing with serious illness.


About the author: Bill Pruitt, MBA, RRT, CPFT, AE-C, FAARC, is a writer, lecturer, and consultant and recently retired from over 20 years teaching at the University of South Alabama in Cardiorespiratory Care. He also volunteers at the Pulmonary Clinic at Victory Health Partners in Mobile, AL.


  1. From the website “Get Palliative Care”: Accessed April 3, 2021.
  2. From the National Hospice and Palliative Care Organization’s pdf “Palliative Care or Hospice? The right service at the right time for seriously ill individuals”: Accessed April 3, 2021.
  3. Baltaji S, Cheronis N, Bajwa O, Cheema T. The Role of Palliative Care in COPD. Critical Care Nursing Quarterly. 2021 Jan 1;44(1):113-20.
  4. Jacobs SS, Krishnan JA, Lederer DJ, Ghazipura M, Hossain T, et al.  Home Oxygen Therapy for Adults with Chronic Lung Disease. An Official American Thoracic Society Clinical Practice Guideline. American Journal of Respiratory and Critical Care Medicine. 2020 Nov 15;202(10):e121-41.
  5. From the National Lung Health Education Program website: Long Term Oxygen Therapy (LTOT) History, Scientific Foundations, and Emerging Technologies. Petty T, McCoy, R, Doherty D. Accessed 4/10/21.
  6. Hardavella G, Karampinis I, Frille A, et al. Oxygen devices and delivery systems. Breathe 2019; 15: e108–e116.
  7. From the CMS National Coverage Determination (NCD) for Home Use of Oxygen (240.2): Accessed 4/15/21.
  8. Federal Aviation Administration (FAA) acceptance criteria for portable oxygen concentrators from the FAA website: Accessed 4/20/21.