Should Patients with IPF Undergo Mechanical Ventilation for Respiratory Failure?

Background

Although most patients with IPF experience a steady, predictable decline in lung function over time, some patients experience a more precipitous course, with periods of relative stability followed by acute deteriorations in respiratory status.¹ These events may be due to acute exacerbations of IPF or a triggering event such as pneumonia or pulmonary embolism.² The role of invasive mechanical ventilation (MV) or non-invasive mechanical ventilation (NIMV) is uncertain in these patients. Numerous small case studies have shown that patients with IPF do poorly with MV.³ Pooled data from these studies have reported high mortality rates, up to 87%.³ Given the poor outcome, the 2011 American Thoracic Society consensus guidelines recommend that the majority of patients with respiratory failure due to IPF should not receive mechanical ventilation.² Because there is a paucity of published data on mortality rates in a large cohort of patients undergoing MV, the investigators sought to characterize mortality rates in patients with IPF who received MV and NIMV in the United States between 2006 and 2012.⁴

What They Did

A retrospective cohort study was conducted using data from the Nationwide Inpatient Sample (NIS), a federal, all-payer database that captures approximately 20% of all US hospital discharges.⁴ Patients older than 18 years of age who had a discharge diagnosis of IPF (N= 17,770) were identified and segregated into patients who received MV (n=1,703) or NIMV (n=778).

What They Found

The overall mortality for the entire cohort of patients with IPF was 11.3%.⁴ Those receiving MV had higher mortality than those receiving NIMV (51.6 vs 30.9%, P< .0001), although these patients were younger and had longer hospital stays. The mortality of IPF patients treated with MV decreased from 58.4% in 2006 to 49.3% in 2012 (P=.03). A similar decrease in mortality for those receiving NIMV was not observed. Patients in the MV group who also used home oxygen therapy (a surrogate for severity [n=149]) experienced an overall mortality of 48.1%, similar to that of patients who did not use home oxygen (P=.35). Similarly, there was no association between home oxygen use and mortality among patients in the NIMV cohort (P=.11). Of note, no difference in mortality between patients who underwent MV for an acute exacerbation of IPF and those who underwent MV for another cause was found.

What It Means

The observed mortality rates in this study were much lower than previously reported.⁴ This may be the result of advances in critical care, specifically lung-protective ventilation strategies, and the use of new pharmacological treatments for IPF. Whether to intubate or non-invasively ventilate an IPF patient with acute respiratory failure is a difficult decision. The results of this study suggest that patients with IPF may fare better than previously reported, particularly those patients receiving NIMV. The mortality rate in patients with a diagnosis of IPF who received MV or NIMV for acute respiratory failure was 51.6% and 30.9%, respectively. Given that these figures are considerably lower than previously reported, a diagnosis of IPF alone should likely not preclude consideration of MV. As such, greater use of MV, particularly NIMV, should be considered. However, further studies are needed to understand the best form of MV to offer.

Link to abstract: http://www.ncbi.nlm.nih.gov/pubmed/26733227

References

1. Collard HR, Moore BB, Flaherty KR, et al. Acute exacerbations of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. 2007;176(7):636-643.
2. Raghu G, Collard HR, Egan JJ, et al. An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management. Am J Respir Crit Care Med. 2011;183(6):788-824.
3. Mallick S. Outcome of patients with idiopathic pulmonary fibrosis (IPF) ventilated in intensive care unit. Respir Med. 2008;102(10):1355-1359.
4. Rush B, Wiskar K, Berger L, Griesdale D. The use of mechanical ventilation in patients with idiopathic pulmonary fibrosis in the United States: a nationwide retrospective cohort analysis. Respir Med. 2016;111:72-76.