The National Association for Medical Direction of Respiratory Care

December 20, 2016 - Literature Review

Probably all readers of this blog will have already read and thought about the Long-Term Oxygen Therapy Trial (LOTT) study, recently published in the New England Journal (NEJM. 2016; 375:1617–27). This landmark study looked at the role of supplemental oxygen in patients with COPD with either resting or exercise-induced moderate desaturations. This is the first large-scale oxygen study performed since the 1970s when the Nocturnal Oxygen Treatment Trial (NOTT) and Medical Research Council (MRC) studies were performed in the US and UK, respectively. These 2 earlier studies defined the role of supplemental oxygen in COPD patients with severe hypoxemia. The L OTT study looked at a milder group with the hypothesis being that if supplemental oxygen was provided earlier in the course, improvements in survival and quality of life may accrue.

This multicenter trial was funded by the National Institutes of Health and CMS jointly.

The clinical population was defined as an SPO2 of 89% to 93% in addition to having stable COPD. For exercise desaturation the population was characterized as having an SPO2 between 80 and 90% for at least 5 minutes and less than 90% for at least 10 seconds.

738 study participants were recruited from 42 clinical centers. Most of these (75%) were men. Subjects were randomized to receive either supplemental oxygen or usual care without supplemental oxygen. Obviously there was no blinding of the participants to their randomized status. The chief findings of the study was supplemental oxygen did not benefit patients in terms of survival, hospitalizations for a COPD related cause, non-COPD related hospitalizations, quality of life, or functional status. Furthermore there were several adverse events related to oxygen therapy such as tripping over equipment leading to injuries. Five patient’s reported fires or burns related to smoking while on oxygen therapy.

The authors concluded that supplemental oxygen in this milder group of patients is not justified. The results of the study do not take away from the findings of the older NOTT study, now almost 40 years ago. Severe hypoxemia should be treated with supplemental oxygen.

While the study results were disappointing to many in the field who had hoped that a loosening of the oxygen prescribing were guidelines might benefit patients, it is nonetheless useful to know where we stand with respect to this important issue about a very common therapy provided by pulmonary (and primary care) physicians across the country.

There is a lot more to be said about prescribing oxygen than this study addresses. Issues around oxygen prescription development and appropriate dosing related to either liter flow or oxygen saturation endpoints (titrate to saturate!) are still open questions. Oxygen therapy as a clinical and regulatory problem for pulmonologist is always forefront in the mind NAMDRC’s leadership.

We will have an update on Oxygen Therapy at the NAMDRC annual meeting, March 23-25, 2017 in Napa, CA. Please check out the program available at What is your take on this study result?

What oxygen problems do you find most vexing in your practice?

Charles Atwood, MD, FCCP, FAASM - President-Elect

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