Oxygen Devices for COPD May not Perform as Expected

Oxygen devices used to provide chronic obstructive pulmonary disease (COPD) patients oxygen therapy on-the-go may not always perform consistently and, in some cases, may provide users with inadequate oxygen when they are active, a new study suggests.

This raises concerns that patients and doctors may interpret resulting activity limitations as a sign of the lung disease worsening, when in reality it is a shortcoming of the oxygen device.

The devices in question, known as oxygen conservers, attach to the portable oxygen cylinders that many COPD patients carry for supplemental oxygen as they walk, climb stairs or perform other daily activities. They are designed to distribute a set oxygen dose each time a person inhales, allowing the cylinders’ oxygen supply to last longer than it would if the oxygen flow were continuous.

In the study, published by the American Journal of Respiratory and Critical Care Medicine in February, researchers at Case Western Reserve University in Cleveland tested four widely used oxygen conservers on the market. Each device was bench tested to gauge performance, and then given to 13 COPD patients in random order at rest and during treadmill walking. Patients were also evaluated while breathing standard room air and while a wall unit supplied the room with two liters of oxygen per minute. The tests were carried out over several weeks.

Overall, the study found that the conservers’ performance varied from product to product, with none of the devices consistently performing at technical expectations. One conserver was no better than breathing standard room air when it came to maintaining patients’ blood oxygen levels during rest or exercise. The other three performed better, but patients’ oxygen levels dipped when they walked on a treadmill compared to with their levels at rest.

The problem, according to researchers, is in the technical aspects of the conservers. Oxygen conservers do not have to go through clinical testing in actual patients before going on the market, but researchers argue that their findings highlight a need for “uniform performance standards” for oxygen conservers set by government regulators, based on advice from professional medical organizations. Click here to access the full story on Medline Plus