Abstract
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.
- Idiopathic pulmonary fibrosis
- interstitial lung diseases
- outcome prediction
- pulmonary fibrosis
- pulmonary gas exchange
Footnotes
This article has supplementary material available from www.erj.ersjournals.com
Support Statement
This work was supported by National Institutes of Health (NIH) grants HL086714 and RR024156, the Robert Wood Johnson Physician Faculty Scholars Program, and the Herbert and Florence Irving Scholar Award. This publication was made possible by grant number KL2 RR024156 from the National Center for Research Resources (NCRR), a component of the NIH, and the NIH Roadmap for Medical Research. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH. Information on NCRR is available at the NCRR website. Information on Re-Engineering the Clinical Research Enterprise can be obtained from the NIH Roadmap website.
Statement of Interest
Statements of interest for S.M. Kawut and D.J. Lederer can be found at www.erj.ersjournals.com/site/misc/statements.xhtml
- Received June 23, 2011.
- Accepted August 16, 2011.
- ©ERS 2012