Continuous Oxygen Use in Non-Hypoxemic Emphysema Patients Identifies a High-Risk Subset of Patients: Retrospective Analysis of the National Emphysema Treatment Trial.
Chest. 2008 Jul 18;
Authors: Drummond MB, Blackford AL, Benditt JO, Make BJ, Sciurba FC, McCormack MC, Martinez FJ, Fessler HE, Fishman AP, Wise RA
BACKGROUND Continuous oxygen therapy is not recommended for emphysema patients who are non-hypoxemic at rest, although it is often prescribed(1). Little is known regarding the clinical characteristics and survival of non-hypoxemic emphysema patients using continuous oxygen. Analysis of data from the National Emphysema Treatment Trial (NETT) offers insight into this population. METHODS We analyzed demographic and clinical characteristics of 1215 participants of NETT, stratifying by resting Pa(O2) and reported oxygen use. Eight year survival was evaluated in individuals randomized to medical therapy. RESULTS At enrollment, 33.8% (n=260) of participants non-hypoxemic at rest reported continuous oxygen use. When compared to non-hypoxemic individuals not using oxygen (n=226), those using continuous oxygen had worse dyspnea, lower quality of life, more frequent exercise desaturation and higher case fatality rate. After adjusting for age, BMI, and FEV(1) % predicted, the presence of exercise desaturation accounted for the differential mortality seen between these groups. CONCLUSIONS In NETT, the use of continuous oxygen in resting non-hypoxemic emphysema patients was associated with worse disease severity and survival. The differential survival observed could nearly all be accounted for by the higher prevalence of exercise desaturation in those using continuous oxygen, suggesting that it is not a harmful effect of oxygen therapy contributing to mortality. It remains unclear whether continuous oxygen therapy improves survival in normoxic patients with exercise desaturation.
PMID: 18641094 [PubMed - as supplied by publisher]