Home Oxygen Requalification

Abstract

To the Editor: We read with interest the article by Dr. Guyatt and coworkers in a recent issue of CHEST (November 2000)1Guyatt GH McKim DA Austin P et al.Appropriateness of domiciliary oxygen delivery.Chest. 2000; : 1303-1308Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar regarding the appropriateness of domiciliary oxygen delivery. Their study found that 32.1% of patients receiving long-term oxygen therapy (LTOT), all of whom would have had to meet the arterial blood gas criteria outlined in the continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease (NOTT) trial2Kvale PA Cugell DW Athonisen NR et al.Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease.Ann Intern Med. 1980; 93: 391-398Crossref PubMed Scopus (2068) Google Scholar to qualify for funding, did not continue to meet the same criteria when evaluated in their study. Based on these findings, they suggested that these patients should be denied further funding for LTOT to achieve economic savings for the health-care system. We have concerns with respect to their conclusions and recommendations. First, in the NOTT and the long-term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema trials,3Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema: report of the Medical Research Council Working Party.Lancet. 1981; 1: 681-686PubMed Google Scholar hypoxic patients were randomized to their respective study arms, in which they remained for the duration of the trials. Although Pao2 levels were monitored throughout both trials, they were not used to deny or offer patients oxygen therapy. Since these trials provide the strongest evidence of a mortality benefit for patients with hypoxic lung disease who are receiving LTOT, further studies would be needed to determine whether this benefit is maintained if LTOT is stopped in response to an improved Pao2. Second, Guyatt et al dismissed a physiologic argument that we think may have some validity. They dismissed the possibility that oxygen therapy may result in cardiopulmonary vascular changes that improve ventilation/perfusion matching and result in subsequent improvement in blood gas levels while the patient is at rest. While evidence supporting this specific phenomenon is limited,4O'Donohue Jr, WJ Effect of oxygen therapy on increasing arterial tension in hypoxemic patients with stable chronic obstructive pulmonary disease while breathing ambient air.Chest. 1991; 100: 968-972Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar there is convincing evidence demonstrating that cardiovascular parameters in general are substantially improved with oxygen therapy.2Kvale PA Cugell DW Athonisen NR et al.Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease.Ann Intern Med. 1980; 93: 391-398Crossref PubMed Scopus (2068) Google Scholar3Long term domiciliary oxygen therapy in chronic hypoxic cor pulmonale complicating chronic bronchitis and emphysema: report of the Medical Research Council Working Party.Lancet. 1981; 1: 681-686PubMed Google Scholar5Bartels MN Gonzalez JM Kim W et al.Oxygen supplementation and cardiac-autonomic modulation in COPD.Chest. 2000; 188: 691-696Abstract Full Text Full Text PDF Scopus (51) Google Scholar This suggests that more study in this area may reveal that LTOT does lead to an improvement of Pao2 while the patient is breathing room air. Third, in order to determine whether real economic savings will be achieved by discontinuing funding for patients with advanced lung disease who no longer qualify for LTOT, one needs a proper study to assess the health consequences of this action. For example, such patients who have stopped receiving LTOT may have more exacerbations requiring additional medical assessments, therapeutic interventions, and hospitalizations. In the absence of an overall health economic study, the cost savings suggested are purely related to the cost of the LTOT alone. Last, Guyatt et al suggested that the discontinuation of LTOT when patients no longer meet qualifying criteria may improve quality of life. We wonder whether patients' sentiments contributed to this hypothesis. Did they ask the subjects who participated in their study whether they would be willing to stop using LTOT if they were found to have an improved Pao2level? Did they ask them whether they felt that stopping LTOT would improve their quality of life? Based on our experience with similar patients, we think that the majority would be deeply concerned about discontinuing LTOT. Specifically, we think they would be worried about experiencing a reduction in their exercise tolerance and being unable to maintain an optimal level of activity. As recommended by all the published guidelines, we agree that patients being evaluated for LTOT should be required to meet qualifying criteria when they are medically stable. However, we feel it would be wrong to use this recent study to justify the disqualification of recipients who have experienced improvements in their Pao2 levels from receiving LTOT in order to achieve economic savings. Home Oxygen RequalificationCHESTVol. 120Issue 1PreviewDrs. Gershon and Chan make a number of thoughtful andinteresting points about our article (November 2000).1 Full-Text PDF