Introduction Although pirfenidone slows disease progression in patients with idiopathic pulmonary fibrosis (IPF), in clinical practice, patients often cannot tolerate the recommended dose because of several adverse events. This study aimed to investigate adverse events associated with pirfenidone and factors associated with dose reduction. Methods This single-center retrospective cohort study included 156 consecutive patients with IPF who received pirfenidone. Demographic characteristics, pulmonary function, and pirfenidone-related adverse events were investigated. We compared patients who received standard and reduced doses of pirfenidone. Results The mean patient age was 69.7 years. The median follow-up duration was 243 days. The low-dose group (n = 73) included older patients (71.0 years vs. 67.4 years, p = 0.016), fewer smokers (80.8% vs. 96.4%, p = 0.008), and patients with a lower body mass index (BMI; 24.1 kg/m2 vs. 25.7 kg/m2, p = 0.027) than the standard dose group (n = 57). Multivariate logistic regression analysis revealed that older age (odds ratio = 1.066, p = 0.016) was significantly associated with dose reduction of pirfenidone after adjusting for sex, smoking history, emphysema, and BMI. No significant difference was found in the rates of a reduced forced vital capacity and diffusing capacity for carbon monoxide between the two groups. Conclusions Although older patients are more likely to undergo dose reduction of pirfenidone, low-dose pirfenidone might be effective for treating patients with IPF. Low-dose pirfenidone could be considered an effective treatment option for older patients with IPF.

Background Although bronchoscopic cryotherapy (BC) is a pragmatic modality for recanalization of central airway obstruction (CAO), the risk of complications, such as bleeding, remains a concern. This study aimed to present the clinical outcomes of BC and evaluate the factors associated with its complications. Methods In this retrospective study, we reviewed the medical records of patients who underwent BC for CAO at the Asan Medical Center, South Korea. Most sessions were conducted via flexible bronchoscopy under moderate sedation. A multivariate logistic regression analysis was used to identify the factors associated with the success rate and complications. Results BC was performed in 262 sessions in 208 patients between January 2009 and December 2020. The most common cause of cryotherapy was recanalization of the endobronchial tumor related CAO (233/262, 88.9%). More than partial re-establishment of airway patency was achieved in 211 of 233 (90.6%) sessions. The success rate did not differ significantly in the multivariate logistic regression analysis. The most common complication was intrabronchial bleeding (78/233, 35.5%); however, severe bleeding occurred only in one case (0.4%). Univariate and multivariate logistic regression analyses revealed that diabetes mellitus (odds ratio [OR] = 2.820, P = 0.011), respiratory failure before BC (OR = 3.546, P = 0.028), and presence of distal airway atelectasis (OR = 0.417, P = 0.021) were independently associated with moderate to severe intrabronchial bleeding, while the histologic type of tumor was not related to bleeding. BC for CAO caused by blood clot or foreign body was successful in most cases, and there were no complications. Conclusion BC is an efficient and relatively safe intervention for patients with CAO. Our findings suggest that diabetes, respiratory failure before BC, and the absence of distal airway atelectasis may be risk factors of moderate to severe intrabronchial bleeding.