Patients With Idiopathic Pulmonary Fibrosis Admitted to the ICU With Acute Respiratory Failure—A Reevaluation of the Risk Factors and Outcomes

Abstract

Introduction: Idiopathic pulmonary fibrosis (IPF) patients admitted to the ICU with acute respiratory failure (ARF) are known to have a poor prognosis. However, the majority of the studies published to date are older and had small sample sizes. Given the advances in ICU care since the publication of these studies, we sought to reevaluate the outcomes and risk factors associated with mortality in these patients. Methods: Retrospective study using a large multi-center ICU database. We identified 411 unique patients with IPF admitted with ARF between 2014-2015. Results: Of all IPF patients admitted to the ICU with ARF, 81.3% required mechanical ventilation (MV): 48.9% invasive and 32.4% non-invasive alone. The hospital mortality rate was 34.5% for all patients; 48.8% in patients requiring invasive MV, 21.8% in those requiring non-invasive MV and 19.5% with no MV. In multiple regression analyses, age, APACHE score, invasive MV, and hyponatremia at admission were associated with increased mortality whereas post-op status was associated with lower mortality. In patients requiring invasive MV, baseline PaO2/FiO2 ratio was also predictive of mortality. Non-pulmonary organ failures were present in less than 20% of the patients. Conclusions: Although the overall mortality rate for IPF patients admitted to the ICU with ARF has improved, the mortality rates for patients requiring invasive MV remains high at approximately 50%. Older age, high APACHE score, and low baseline PaO2/FiO2 ratio are factors predictive of increased mortality in this population.