Liquid Oxygen Recommended for Mobile Patients With Lung Disease

Laird Harrison

November 23, 2020

People with chronic lung disease who need significant amounts of oxygen should be able to take it in liquid form when they are able to leave home, according to a new guideline from the American Thoracic Society (ATS).

"For those patients, often the other types of devices either can't supply enough oxygen or are not portable enough," said Anne Holland, PT, PhD, a

professor of physiotherapy at Monash University and Alfred Hospital in Melbourne, Australia. "They're heavy and cumbersome to use."

Holland and colleagues also gave a more general recommendation to prescribe ambulatory oxygen — though not necessarily in liquid form — for adults with chronic obstructive pulmonary disease (COPD) or interstitial lung disease (ILD) who have severe exertional room air hypoxemia.

They published the recommendations as part of the ATS' first-ever guideline on home oxygen therapy for adults with chronic lung disease in the American Journal of Respiratory and Critical Care Medicine.

The ATS identified the need for an updated guideline because of new research, and because an online survey of almost 2000 US oxygen users showed they were having problems accessing and using oxygen.

For long-term oxygen therapy, the guideline reinforces what most practitioners are already doing, Holland said. It recommends that adults with COPD or ILD who have severe chronic resting room air hypoxemia receive oxygen therapy at least 15 hours per day.

On the other hand, in adults with COPD who have moderate chronic resting room air hypoxemia, the guideline recommends against long-term oxygen therapy.

The recommendation to prescribe ambulatory oxygen for people with severe exertional room air hypoxemia may have more effect on practice, Holland said. Laboratory-based tests have suggested oxygen can improve exercise capacity, but clinical trials used during daily life have had inconsistent results.

The evidence is particularly lacking for patients with ILD, Holland told Medscape Medical News. "It's such an important part of practice to maintain oxygen therapy that it's ethically very difficult to conduct such a trial," she said. "So, we did have to make use of indirect evidence from patients with COPD" for the guidelines.

The portable equipment comes with burdens, including managing its weight and bulk, social stigma, fear of cylinders running out, and equipment noise.

"We tried to clearly set out both the benefits and burdens of that therapy and made a conditional recommendation, and also a really strong call for shared decision-making with patients and health professionals," Holland said.

In addition to looking at the evidence, the panel took into consideration the concerns identified by patients. This included the challenge of figuring out how to use the equipment. "All the oxygen equipment was 'dumped' on me," wrote one oxygen user quoted in the guideline. "I knew nothing and was in a daze. I am sure that the delivery guy gave me some instructions when it was delivered but I retained nothing."

For this reason, the guideline describes as a "best practice" instruction and training on the use and maintenance of the equipment, including smoking cessation, fire prevention, and tripping hazards.

Nothing about the guideline is surprising, said MeiLan K. Han, MD, a spokesperson for the American Lung Association and professor of pulmonary and critical care medicine at the University of Michigan Health System in Ann Arbor. "I don't think they've actually come to any new conclusion," she told Medscape Medical News. "This is pretty much how I practice already."

But the guideline could have an effect on policy, she said. The panel noted research showing that lower Medicare reimbursement to durable medical equipment companies since 2011 has forced many patients to switch from small, easily portable liquid oxygen to home-fill oxygen systems that include heavy cylinders.

"The impact of this decline in the availability and adequacy of portable oxygen devices in the United States has been profound," Holland and colleagues write. "Supplemental oxygen users reported numerous problems, with the overarching theme being restricted mobility and isolation due to inadequate portable options."

For this reason, the guideline recommends liquid oxygen for patients with chronic lung disease who are mobile outside of the home and require continuous oxygen flow rates of >3 L/min during exertion.

Many of Han's patients have struggled with this problem, she said. "The clunkiest, most painful form of 'ambulatory oxygen' are these really large metal cylinders," she said. "They're huge. And you have to carry them on a cart. It's portable, in theory only."

Some of her patients have resorted to buying their own equipment on eBay, she said.

The authors report multiple disclosures including serving as advisory board members to foundations and pharmaceutical companies, and some are company employees or stockholders. Full disclosures are available in the journal.

Am J Respir Crit Care Med. Published November 15, 2020. Full text

Laird Harrison writes about science, health and culture. His work has appeared in national magazines, in newspapers, on public radio and on websites. He is at work on a novel about alternate realities in physics. Visit him at www. or follow him on  Twitter: @LairdH

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