Clinical Characteristics Based on the New Criteria of Acute Exacerbation in Patients with Idiopathic Pulmonary Fibrosis.

Objective: Idiopathic pulmonary fibrosis (IPF) is the most common parenchymal lung disease. Patients with IPF sometimes develop acute exacerbation (AE), which predicts a poor prognosis. To evaluate the predictors of 90-day mortality of AE in patients with IPF based on the new 2016 criteria.
Materials and Methods: Sixty-five patients with AE were studied retrospectively between January 2001 and December 2016 at Okinawa Chubu Hospital.
Results: The mean age of the patients was 74 years, with 40 (61.5%) men and 25 (38.5%) women. Among our cohort, 37 were current or ex-smokers, with a mean exposure of 32.4 pack-years. The mean grade of the modified Medical Research Council breathlessness scale was 2.8, and the mean duration of dyspnea prior to admission was 6.5 days. Clubbed fingernails were present in 29% of patients. Triggered AE occurred in 12 (18%) of patients. Patients with triggered AE had more extensive ground-glass opacity and higher consolidation scores than the idiopathic AE group (7.3 vs. 4.2, p=0.01). The triggered group had shorter survival than the idiopathic group (1.4 vs. 11.4 months, p=0.094). Serum lactate dehydrogenase (LDH), ΔLDH, and the ratio of partial pressure of oxygen to the fraction of inspiratory oxygen ratio were strong predictors of 90-day mortality. Hazard ratios were 1.003 (p=0.004), 1.004 (p=0.02), and 0.994 (p=0.010), respectively.
Conclusion: Compared with idiopathic AE, triggered AE in patients with IPF had more extensive infiltration and tended toward shorter survival. Serial trends of serum LDH >2 weeks can help predict prognosis of AE in patients with IPF.
Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors