by David Douglas

Last Updated: 2007-08-24 11:45:01 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Although home use of short burst oxygen therapy (SBOT) is widely prescribed in the UK for patients with COPD, it may be helpful only in a small minority of patients, researchers report in the August issue of Thorax.

"SBOT is used extensively despite little evidence of benefit," lead investigator Dr. Simon J. Quantrill told Reuters Health. As he noted, "18 million pounds per year are spent on oxygen cylinders used for SBOT in the UK. No guidelines exist on how and when to use SBOT."

To investigate whether SBOT helps COPD patients with daily activities, Dr. Quantrill and colleagues at Whipps Cross University Hospital, London, studied 39 such patients. All claimed that SBOT was helpful.

They were asked to choose two routine activities, such as walking upstairs or vacuuming, for which they used SBOT to relieve breathlessness. The patients were then given two cylinders, one of which contained oxygen and the other, compressed air.

Using nasal prongs, the participants inhaled from one cylinder to recover from breathlessness after performing one of the tasks, and then, at least 15 minutes later, they used the other cylinder after repeating the task. The subjects then went on to use the same two-cylinder procedure for their other chosen activity.

Based on pulse oximetry, the mean recovery time over two activities was 38 seconds less when oxygen rather than compressed air was inhaled. Rating by patients put this figure at 34 seconds.

Five of the patients were able to correctly identify when oxygen was employed, and there was an indication that their difference in recovery times with oxygen versus air was greater than was the case in the other patients — indicating a greater benefit of oxygen therapy.

On objective measures, recovery was hastened by 91 seconds with oxygen compared with air in the "correct identifiers," but by only 20 seconds among the "incorrect identifiers."

This difference was not significant, continued Dr. Quantrill, "but there may be a small group of patients with severe COPD who do in fact benefit."

Nevertheless, he noted, "this needs further research with bigger numbers of patients." Moreover, Dr. Quantrill concluded, "further research is needed to be able to produce guidelines on SBOT usage."

Thorax 2007;62:702-705.