Supplemental oxygen therapy isn't always helpful

Supplemental oxygen is a safe and readily available therapy for patients who complain of shortness of breath. However, the practice is not based on rigorous scientific study.

Researchers studied 239 patients in the United States, United Kingdom and Australia to see if supplemental oxygen offered a real benefit.

"What we found was (that) delivering a medical gas – either oxygen or air – would improve shortness of breath for about half of people in the study," said Amy Abernethy, an oncologist and director of the Duke Cancer Care Research Program.

"But it didn't matter whether or not oxygen was there," she continued. "It was actually just the process of having something blown past the nose, probably."

The findings don't rule out the use of supplemental oxygen, but doctors should evaluate its use after three days, said Abernethy, who led the study, which was published in the medical journal The Lancet.

"If we prescribe oxygen to try and treat breathlessness and it's not helping, it's important to say, 'OK, it's all right to stop it,''' Abernethy said.

Patients most likely to benefit from supplemental oxygen therapy are those with low blood oxygen levels, often caused by heart failure, lung cancer or chronic pulmonary disease.

Even then, the study shows that for half of those patients, it didn't seem to matter whether they received oxygen or room air. Abernethy said that in that case, a room fan would be cheaper and perhaps just as useful.

The cost for supplemental oxygen therapy varies, but for many patients in palliative care, it could total several hundred dollars a month.