The unresolved issue of oxygen therapy in lung fibrosis: Some clues from a Spanish cohort

Abstract

Indication of oxygen therapy in fibrotic interstitial lung diseases is not standardized and its specific requirements are not well defined. The objective of this study was to evaluate ambulatory oxygen therapy features in lung fibrotic patients. Clinical and exploratory data, including 6-minute walking test and pulmonary hypertension, from one hundred and seven patients with fibrotic interstitial lung disease that received ambulatory oxygen treatment were studied. In up to 40% of cases the prescription of oxygen therapy was made after performing a 6-minute walking test. Patients who required ambulatory oxygen only during exercise presented a mild to moderate reduction of the predicted % FVC (62.1 ± 19) and DLCO (49 ± 14.4) while patients who had respiratory failure at rest (mean PaO2 51.9 ± 6.7) presented a moderate reduction of %FVC (56.8 ± 15.6) but a severe decrease of %DLCO (31.67 ± 12). Pulmonary hypertension (PH) was evaluated in 47.7% of patients and occurred in 60.8% of them. In conclusion, there is no pulmonary functional predictor of oxyhaemoglobin desaturation during exercise. PH is frequently associated with interstitial lung diseases, mainly when respiratory failure at rest appears. The heterogeneity of the patients and limitation of retrospective studies could be the cause of the tributes for potential benefits of oxygen treatment in interstitial lung diseases.

Keywords

• Interstitial lung disease, oxygen therapy, 6-minute walking test, pulmonary hypertension