SESSION TYPE: New Insights into Idiopathic Pulmonary Fibrosis
PRESENTED ON: Sunday, October 21, 2012 at 01:15 PM - 02:45 PM
PURPOSE: To provide a detailed description of the lung function of patients with Idiopathic Pulmonary Fibrosis on initial diagnosis, which to our knowledge has not been previously reported.
METHODS: The pulmonary function tests of patients with IPF when initially diagnosed were obtained from the pulmonary function laboratory at Kingston General Hospital. All patients had the diagnosis of IPF based on chest CT findings compatible with usual interstitial pneumonia, and other causes of pulmonary fibrosis were ruled out. Patients with concomitant obstructive pattern (FEV1/FVC <70%), lung cancer, scoliosis, chest wall deformities and neuromuscular diseases were excluded.
RESULTS: We included 95 patients with an age of 70±9 years, 65% were male and 32% were never smokers. The mean TLC was 71±15% and ranged from 37 to 110% of predicted values. One quarter of the patients had moderate or severe restriction on presentation (TLC<60%). The mean FVC, FEV1 DLco as expected, decreased as the severity of restriction increased. However, the FEV1/FVC ratio increased with increased restriction and the mean FEF25/75 and airway resistance remained normal or high for all degrees of restriction. The DLco decreased as the severity of restriction increased but the DLco/VA remained normal, even in those with the most severe restriction.
CONCLUSIONS: Even though FVC, FEV1 and DLco decrease with increased restriction, the FEV1/FVC, FEF25-75, airway resistance and Dl/VA remain normal or augment with increased restriction.
CLINICAL IMPLICATIONS: The presence of a normal Dlco/VA in patients with restrictive lung disease cannot distinguish intraparenchymal from extraparenchymal disease. Concomitant obstruction should be suspected when the FEV/FVC is <80% in patients with IPF and severe to very severe restrictive lung disease.
DISCLOSURE: The following authors have nothing to disclose: Onofre Moran, Arturo Cortés-Télles, Lutz Forkert
No Product/Research Disclosure InformationQueen's University, Kingston, ON, Canada