Clinical Characteristics and Outcomes of Interstitial Lung Disease Patients with Acute Respiratory Failure Admitted to the ICU

Abstract Background: Acute respiratory failure is a dreaded complication of interstitial lung disease (ILD) and is the most significant reason for mortality in most forms of ILDs. Knowledge of outcome predictors that can be assessed early after intensive care unit (ICU) admission would help guide the use of specific treatments. The present study attempts to identify the baseline characteristics of ILD patients admitted due to acute respiratory failure to ICU and to evaluate the cause of acute respiratory failure in these patients, management, and the outcomes. Materials and Methods: An observational cohort study was carried out in a tertiary care center in North India on 50 previously diagnosed patients of ILD hospitalized due to acute respiratory failure between January and December 2022. All relevant clinical, investigational, and treatment data were collected from the hospital information system. Results: The baseline mean FVC and 6-min walk distance were lower for non-survivors. The baseline mean DLCO was significantly lower among non-survivors. Comparatively, the radiology pattern of both groups showed that the usual interstitial pneumonia (UIP) pattern was associated with highest mortality. However, this difference was not statistically significant. Mortality was higher in those with lower PaO2/FiO2 ratio than among the survivors. Sputum culture positivity had a statistically significant impact on mortality. The mean hospital stay time was considerably higher in patients with idiopathic pulmonary fibrosis (IPF) and in patients with Type 2 respiratory failure. Conclusion: Baseline lung function tests, comorbidities, and exacerbating factors are invaluable in predicting the clinical outcomes. It is essential to perform all the diagnostic examinations at the earliest to ensure prompt initiation of the most appropriate therapy and lower hospital mortality. Distinguishing those patients who have a known cause for their ILD from those who do not was found to be crucial for deciding the most appropriate management.