A score without diffusion capacity of the lung for carbon monoxide for estimating survival in idiopathic pulmonary fibrosis. Issue 25 (19th June 2020) - Fukuda, Cesar Yoshito
Abstract : Abstract: Prediction models for survival at baseline evaluation have been proposed in idiopathic pulmonary fibrosis (IPF) but include diffusion capacity of the lung for carbon monoxide, a test not available in many places. The aim of the present study was to develop a simple new mortality risk scoring system for patients with IPF at initial evaluation without diffusion capacity of the lung for carbon monoxide measurement. A total of 173 patients, 72% males, mean age 70 years, 64% smokers/ex-smokers, were included in a retrospective study. The diagnosis was made by surgical lung biopsy in 40 (23%); in the remaining patients, a usual interstitial pneumonia pattern was present in high-resolution computed tomography. Patients with forced expiratory volume in 1 second/forced vital capacity ratio (FEV1 /FVC) <0.70 were excluded. Dyspnea was evaluated by magnitude of task on the Mahler scale (Chest 1984). Peripheral oxygen saturation was measured by oximetry at rest and at the end of a 4 minutes step test or a 6-minute walk test. At the end of the follow-up period, 154 (89%) of the patients had died. Based on the univariate Cox proportional-hazards model, survival ( P ⩽ .10) was related directly to the dyspnea score, presence of cough, lower values of FVC% and FEV1 %, lower rest and oxygen desaturation during exercise, and greater FEV1 /FVC. By Cox multivariate analysis, the results remained correlated to the survival dyspnea score, FVC%, and exercise peripheral oxygen saturation. A score, using these variables, was developed and was able to discriminate among 3 groups, with high, low, and intermediate survival curves. A prognostic score, taking into account dyspnea, FVC%, and oxygen desaturation during exercise, can estimate survival in IPF.