Spontaneous Pneumomediastinum is a Predictor of Mortality in Patients with Idiopathic Pulmonary Fibrosis

Rationale: to describe the incidence, radiological & clinical parameters and prognostic impact of pneumomediastinum in idiopathic pulmonary fibrosis (IPF) patients. Methods: records of 182 IPF patients admitted to our tertiary interstitial lung disease (ILD) center between 8/2006 and 7/2013 (who underwent at least 1 chest multidetector computed tomography-MDCT-) were analyzed retrospectively for clinical and functional parameters. Nine patients with pneumomediastinum were identified (M:F, 6:3; median age 63 y, range 43-81 y) and compared to 37 well characterized IPF patients without pneumomediastinum (M:F, 30:7; median age 69 y, range 49-78 y). The presence and location of pneumomediastinum at multidetector computed tomography (MDCT) were assessed by a radiologist for both groups; furthermore, MDCT was evaluated for the overall extent of disease abnormalities (OE), the extent of ground-glass opacity (GGO), reticular opacity (RET), honeycombing (HC), and consolidation (CONS). Overall survival (OS) was calculated from the date of IPF diagnosis to the time of death from any cause. Results: pneumomediastinum occurred in 9 out of 182 patients (5%). Dyspnea and thoracic pain were more frequent in patients with pneumomediastinum as compared to controls (78% vs 40%, p=0.048 and 22% vs 0%, p=0.001, respectively). Moreover, functional limitation was more severe in pneumomediastinum group (median VC% predicted: 48% vs 73%, p=0.001; median TLC%: 52% vs 61%, p =0.007) along with higher extent of the disease at MDCT (median OE: 65% vs 29%, p=0.01). Pneumomediastinum patients demonstrated a significantly shorter OS as compared to the control group (median survival: 30 vs 106 months; p<0.001). The Cox proportional hazards regression analysis confirmed the association between pneumomediastinum and poorer survival (Hazard Ratio: 8.7; 95% CI: 1.8-41.7; p =0.007; Table 1). Conclusions: pneumomediastinum is a rare but severe complication of IPF patients associated with a more advanced disease and a significant shorter overall survival.