Background: Hypercapnia can cause a disturbance of consciousness and adversely affect a patient's general condition. Patients with interstitial lung disease seldom experience hypercapnia. Hypercapnia is a typical phenomenon in patients with pleuroparenchymal fibroelastosis (PPFE), especially in advanced stages. However, the clinical significance of hypercapnia in patients with idiopathic PPFE (iPPFE) has not been studied in detail.
Methods: We retrospectively selected patients with iPPFE who had undergone blood gas analysis. The first blood gas data obtained after iPPFE diagnosis were examined. The partial pressure of carbon dioxide (PCO2) levels and their association with characteristic iPPFE parameters, including the flat chest index (the ratio of the anteroposterior diameter of the thoracic cage to the transverse diameter of the thoracic cage), were investigated.
Results: A total of 47 patients with iPPFE were included in this study. The PCO2 level was moderately and inversely correlated with the forced vital capacity. (r = -0.431, P = 0.014), flat chest index (r = -0.497, P < 0.001), and body mass index (r = -0.313, P = 0.038) and was positively correlated with residual volume/total lung capacity. (r = 0.514, P < 0.01). A higher PCO2 level was also significantly associated with poorer prognosis in patients with iPPFE.
Conclusions: PCO2 levels could be used as an indicator of disease severity in patients with iPPFE.
Keywords: Hypercapnia; Non-invasive positive pressure ventilation; Pleuroparenchymal fibroelastosis; Prognosis.
Copyright © 2023 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.