Titrated oxygen requirement and prognostication in idiopathic pulmonary fibrosis

The supplemental oxygen flow rate is a common bedside measure of gas exchange impairment. We aimed to determine whether a titrated oxygen requirement (TOR) predicted mortality in idiopathic pulmonary fibrosis (IPF). We examined 104 adults with IPF enrolled in a prospective cohort study and a validation cohort of 151 adults with a variety of interstitial lung diseases (ILDs). The TOR was defined as the lowest oxygen flow rate required to maintain an oxyhaemoglobin saturation of 96% while standing. Cox proportional hazards models and time-dependent receiver operating characteristic curves were used to examine survival time. A higher TOR was associated with a greater mortality rate independent of forced vital capacity and 6-min walk test results in IPF (adjusted hazard ratio (per 1 L·min(-1)) 1.16, 95% CI 1.06-1.27). The TOR was at least as accurate as pulmonary function and 6-min walk testing at predicting 1-yr mortality. Findings were similar in other ILDs. The TOR is a simple, inexpensive bedside measurement that aids prognostication in IPF.