Small airway obstruction in patients with idiopathic interstitial pneumonia (IIP)--comparison between acute and chronic types

Abstract

Small airway obstruction in patients with acute and chronic interstitial pneumonia was studied. Patients with acute interstitial pneumonia (IP, n = 3), and with acute exacerbation of chronic IP (n = 4) were studied as a group, and were compared to patients with chronic idiopathic interstitial pneumonia (IIP, n = 41). Small airway obstruction was defined on a logarithmic %VC-V25/VC plane, because the V25/VC (an index of both small airway obstruction and decreased lung compliance) depended on %VC. Six of seven patients (86%) with acute IP and 8 of 42 patients (19.5%) with chronic IIP had small airway obstruction (p < 0.01). Small airway obstruction was often seen in acute IP, but was not often seen in chronic IIP.