Prevalence and impact of airway diseases on clinical outcomes in idiopathic pulmonary fibrosis.

Background/aims: The prevalence and effects of airway diseases, including asthma, eosinophilic bronchitis (EB), chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) have not been thoroughly studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to evaluate the prevalence of airway diseases in patients with IPF and to identify the differences in symptoms based on the presence of airway diseases.

Methods: This single-institution prospective cohort study was conducted from June 2017 to September 2018, at the Seoul National University Hospital.

Validation of age, PaO/FlO and plateau pressure score in Korean patients with acute respiratory distress syndrome: a retrospective cohort study.

Background: A predictive scoring system for acute respiratory distress syndrome (ARDS) patients, which incorporates age, PaO/FlO, and plateau pressure, APPS, was developed recently. It was validated externally in a Caucasian population but has not been studied in Asian populations. The aim of this study was to validate APPS in Korean ARDS patients.

Mortality risk and causes of death in patients with non-cystic fibrosis bronchiectasis.

Background: All-cause mortality risk and causes of death in bronchiectasis patients have not been fully investigated. The aim of this study was to compare the mortality risk and causes of death between individuals with bronchiectasis and those without bronchiectasis.

Methods: Patients with or without bronchiectasis determined based on chest computed tomography (CT) at one centre between 2005 and 2016 were enrolled.

Sleep duration and health-related quality of life in Korean adults: 2007-2015 Korea National Health and Nutrition Examination Survey.

Purpose: To evaluate the association of sleep duration with health-related quality of life (HRQOL) and examine the influence of age, sex, and common comorbidities on this association.

Methods: Using appropriate survey design, we analyzed 50,181 adults who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey. Participants were categorized into five groups according to self-reported sleep duration ≤ 5 (short sleeper), 6, 7, 8, and ≥ 9 h (long sleeper).

Reduction of PaCO by high-flow nasal cannula in acute hypercapnic respiratory failure patients receiving conventional oxygen therapy.

Background: It has been suggested that a high-flow nasal cannula (HFNC) could help to remove carbon dioxide (CO) from anatomical dead spaces, but evidence to support that is lacking. The objective of this study was to elucidate whether use of an HFNC could reduce the arterial partial pressure of CO (PaCO) in patients with acute hypercapnic respiratory failure who are receiving conventional oxygen (O) therapy.

Methods: A propensity score-matched observational study was conducted to evaluate patients treated with an HFNC for acute hypercapnic respiratory failure from 2015 to 2016.

Role of ethambutol and rifampicin in the treatment of Mycobacterium avium complex pulmonary disease.

Background: A three-drug regimen (macrolide, ethambutol, and rifampicin) is recommended for the treatment of Mycobacterium avium complex pulmonary disease (MAC-PD). Although macrolide has proven efficacy, the role of ethambutol and rifampicin in patients without acquired immune deficiency syndrome is not proven with clinical studies. We aimed to clarify the roles of ethambutol and rifampicin in the treatment of MAC-PD.

Diagnostic and prognostic values of serum activin-a levels in patients with acute respiratory distress syndrome.

Background: We aimed to evaluate whether serum activin-A levels are elevated and have any value in predicting severity and prognosis in acute respiratory distress syndrome (ARDS).

Methods: Retrospective cohort study was performed with patients who were admitted to MICU with diagnosis of ARDS and have serum samples stored within 48 h of Intensive care unit (ICU) admission between March 2013 and December 2016 at a single tertiary referral hospital. Serum activin-A levels were measured with ELISA kit, and were compared with those of normal healthy control and non-ARDS sepsis patients.

Nontuberculous mycobacterial pulmonary disease diagnosed by two methods: a prospective cohort study.

Background: Microbiological criteria for diagnosing nontuberculous mycobacterial pulmonary disease (NTM-PD) include positive culture results from at least two separately expectorated sputum specimens or one bronchial washing or lavage. However, the clinical similarities and differences between patients diagnosed by these two methods remain unclear. We compared clinical features and prognoses of patients with NTM-PD diagnosed from both specimen types.

Improved oxygenation 48 hours after high-flow nasal cannula oxygen therapy is associated with good outcome in immunocompromised patients with acute respiratory failure.

Background: Respiratory failure requiring intubation is a risk factor for mortality in immunocompromised patients, therefore, noninvasive methods to avoid intubation are preferred in such patients. A high-flow nasal cannula (HFNC) is an alternative noninvasive technique for oxygen delivery but can be potentially harmful in cases of delayed intubation. We sought to identify the physiological predictors of outcome to assess the responsiveness to HFNC of immunocompromised patients with acute respiratory failure.

Respiratory virus of severe pneumonia in South Korea: Prevalence and clinical implications.

Background: Severe viral pneumonia is associated with a high mortality rate. However, due to the vulnerability of critically ill patients, invasive diagnostic methods should be performed with caution in the intensive care unit (ICU). It would be helpful if the prevalence, risk factors, and clinical impact of virus detection are elucidated.

Rapid Muscle Loss Negatively Impacts Survival in Critically Ill Patients With Cirrhosis.

Purpose: To assess the impact of rapid muscle loss before admission to intensive care unit (ICU) in critically ill patients with cirrhosis.

Materials And Methods: Patients with cirrhosis who had undergone 2 or more recent computed tomography scans before admission to the medical ICU were included. Muscle cross-sectional area at the level of the third lumbar vertebra was quantified using OsiriX software.

The effect of metformin on culture conversion in tuberculosis patients with diabetes mellitus.

Background/aims: Patients with diabetes mellitus (DM) and tuberculosis (TB) have increased morbidity and a high risk of treatment failure or recurrence. It is important to manage both diseases simultaneously. Among anti-diabetic drugs, metformin inhibits intracellular growth of mycobacteria.

Clinical Outcome of Eosinophilic Airway Inflammation in Chronic Airway Diseases Including Nonasthmatic Eosinophilic Bronchitis.

We enrolled patients with confirmed sputum eosinophilia who had visited our tertiary referral hospital between 2012 and 2015. We evaluated the incidence and predictors of exacerbations in patients with nonasthmatic eosinophilic bronchitis (NAEB), and investigated predictors of improvement in eosinophilic inflammation in chronic airway diseases with or without persistent airflow limitation. In total, 398 patients with sputum eosinophilia were enrolled.

Implication of species change of Nontuberculous Mycobacteria during or after treatment.

Background: Co-existence or subsequent isolation of multiple nontuberculous mycobacteria (NTM) species in same patient has been reported. However, clinical significance of these observations is unclear. The aim of this study was to determine clinical implications of changes of NTM species during or after treatment in patients with NTM lung disease.

Histopathologic heterogeneity of acute respiratory distress syndrome revealed by surgical lung biopsy and its clinical implications.

Background/aims: Diffuse alveolar damage (DAD) is the histopathologic hallmark of acute respiratory distress syndrome (ARDS). However, there are several non-DAD conditions mimicking ARDS. The purpose of this study was to investigate the histopathologic heterogeneity of ARDS revealed by surgical lung biopsy and its clinical relevance.

Utility of the National Lung Screening Trial Criteria for Estimation of Lung Cancer in the Korean Population.

Purpose: Screening forlung cancerin high-risk patients using theNational Lung Screening Trial (NLST) criteria resulted in a decreased lung cancer-related mortality rate. However, whether these criteria are applicable to the Korean has not been investigated thus far. Therefore, we estimated the utility of the NLST criteria as a screening tool for lung cancer in the Korean population.

Effect of Preadmission Metformin Use on Clinical Outcome of Acute Respiratory Distress Syndrome among Critically Ill Patients with Diabetes.

Background: Acute respiratory distress syndrome (ARDS) is related to high mortality and morbidity. There are no proven therapeutic measures however, to improve the clinical course of ARDS, except using low tidal volume ventilation. Metformin is known to have pleiotropic effects including anti-inflammatory activity.

Treatment Outcomes of Mycobacterium avium Complex Lung Disease: A Systematic Review and Meta-analysis.

Background: The advent of macrolides has led to therapeutic advances in the treatment of Mycobacterium avium complex lung disease (MAC-LD). The aim of this study was to elucidate the treatment outcomes of macrolide-containing regimens.

Methods: We performed a systematic review and meta-analysis of published studies reporting treatment outcomes of macrolide-containing regimens for MAC-LD using the Medline, Embase, and Cochrane Library databases through 31 July 2016.

Effect of Renin-Angiotensin System Blockage in Patients with Acute Respiratory Distress Syndrome: A Retrospective Case Control Study.

Background: Acute respiratory distress syndrome (ARDS) remains a life-threatening disease. Many patients with ARDS do not recover fully, and progress to terminal lung fibrosis. Angiotensin-converting enzyme (ACE) inhibitor is known to modulate the neurohormonal system to reduce inflammation and to prevent tissue fibrosis.

Medical Thoracoscopy in Pleural Disease: Experience from a One-Center Study.

Background: Medical thoracoscopy (MT) is a minimally invasive, endoscopic procedure for exploration of the pleural cavity under conscious sedation and local anesthesia. MT has been performed at the Seoul National University Hospital since February 2014. This paper summarizes the findings and outcomes of MT cases at this hospital.

The additional role of Xpert MTB/RIF in the diagnosis of intrathoracic tuberculous lymphadenitis.

Background: Diagnosis of intrathoracic tuberculosis (TB) lymphadenitis remains a challenge because of difficulties in obtaining adequate tissue and the lack of a sensitive test. Recently, Xpert MTB/RIF assay is being used for rapid diagnosis of pulmonary TB, but it has not yet been widely validated in intrathoracic TB lymphadenitis. The aim of this study was to assess the additional role of Xpert MTB/RIF in diagnosing intrathoracic TB lymphadenitis using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) specimen.

Serum Uric Acid Level as a Prognostic Marker in Patients With Acute Respiratory Distress Syndrome.

Purpose:: Uric acid acts as both a pathogenic inflammatory mediator and an antioxidative agent. Several studies have shown that uric acid level correlates with the incidence, severity, and prognosis of pulmonary diseases. However, the association between uric acid level and acute respiratory distress syndrome (ARDS) has not been studied.

Efficacy of Treatment for Latent Tuberculosis in Patients Undergoing Treatment with a Tumor Necrosis Factor Antagonist.

Rationale: Current guidelines recommend that all patients undergoing treatment with a tumor necrosis factor-α antagonist should receive screening for latent tuberculosis and appropriate treatment before initiating the inhibitor. However, no well-designed study has shown the efficacy of treating these patients for latent tuberculosis.

Objectives: To compare the risk of active tuberculosis between tumor necrosis factor antagonist users who have received treatment for latent tuberculosis with those who have not.

Proportion and clinical features of never-smokers with non-small cell lung cancer.

Background: The proportion of never-smokers with non-small cell lung cancer (NSCLC) is increasing, but that in Korea has not been well addressed in a large population. We aimed to evaluate the proportion and clinical features of never-smokers with NSCLC in a large single institution.

Methods: We analyzed clinical data of 1860 consecutive patients who were newly diagnosed with NSCLC between June 2011 and December 2014.

Analysis of Fifty Hotspot Mutations of Lung Squamous Cell Carcinoma in Never-smokers.

Smoking is the major risk factor for lung squamous cell carcinoma (SCC), although a small number of lung SCCs occurs in never-smokers. The purpose of this study was to compare 50 hotspot mutations of lung SCCs between never-smokers and smokers. We retrospectively reviewed the medical records of patients newly diagnosed with lung SCC between January 1, 2011 and December 31, 2013 in the Seoul National University Hospital.