Outcomes After Acute Respiratory Failure in Patients With Interstitial Lung Disease

BACKGROUND: Interstitial lung diseases (ILDs) are a heterogeneous group of pulmonary disorders that can result in acute or chronic forms of respiratory failure. Prior studies have shown high mortality among patients with ILD receiving intensive care, but most have focused on idiopathic pulmonary fibrosis (IPF) and have not characterized other ILD subgroups. RESEARCH QUESTION: Does 90-day transplant-free survival differ by ILD subgroup in patients with acute respiratory failure (ARF) requiring respiratory support? STUDY DESIGN AND METHODS: We conducted a retrospective cohort study of adults with ILD admitted to 5 hospitals within our health system (2017-2024) using electronic record health data. We pragmatically defined ARF as receipt of ≥ 24 continuous hours of invasive or noninvasive respiratory support. We identified ILD diagnosis using validated International Classification of Diseases, version 10, Clinical Modification codes categorized into IPF/idiopathic interstitial pneumonia, connective tissue disease-associated ILD (CTD-ILD), exposure-related ILD, sarcoidosis, or other ILD. We evaluated 90-day transplant-free survival with multivariable Cox proportional hazards models adjusted for demographics, comorbidities, hospital type, and acute illness severity. Secondary outcomes included in-hospital death or hospice discharge and hospital length of stay. RESULTS: Among 982 patients with ILD and ARF (median age, 70 years; 50% female), 269 (27%) were categorized as IPF/idiopathic interstitial pneumonia, 74 (8%) were categorized as CTD-ILD, 57 (6%) were categorized as exposure-related ILD, 171 (17%) were categorized as sarcoidosis, and 411 (42%) were categorized as other. By day 90, 466 patients (48%) had died or underwent transplant, with rates ranging from 42% in patients with CTD-ILD to 54% in exposure-related ILD. There were no significant differences in adjusted transplant-free survival or secondary outcomes overall, or when stratified by type of respiratory support. INTERPRETATION: In this multihospital cohort of critically ill patients with ILD and ARF, 90-day transplant-free survival was poor and did not differ by ILD subgroup, even after adjustment for key confounders. These findings underscore the seriousness of ARF among patients with ILD.