Endobronchial valves for emphysema and persistent air-leak: 10-year experience in an Asian country.

BACKGROUND: Endobronchial valve (EBV) therapy, a validated method for bronchoscopic lung volume reduction (BLVR) in severe emphysema, has been explored for persistent air-leak (PAL) management. However, its effectiveness and safety in the Asian population require further real-world evaluation. In this study, we assessed the outcomes of treatment with EBV within this demographic. METHODS: We conducted a retrospective analysis of medical records from 11 Korean centers. For the emphysema cohort, inclusion criteria were patients diagnosed with emphysema who underwent bronchoscopy intended for BLVR. We assessed these patients for clinical outcomes of chronic obstructive pulmonary disease. All patients with PAL who underwent treatment with EBV were included. We identified the underlying causes of PAL and evaluated clinical outcomes after the procedure. RESULTS: The severe emphysema cohort comprised 192 patients with an average age of 70.3 years, and 95.8% of them were men. Ultimately, 137 underwent treatment with EBV. Three months after the procedure, the BLVR group demonstrated a significant improvement in forced expiratory volume in 1 s (+160 mL vs. +30 mL; P = 0.009). Radiographic evidence of lung volume reduction 6 months after BLVR was significantly associated with improved survival (adjusted hazard ratio 0.020; 95% confidence interval 0.038-0.650; P = 0.010). Although pneumothorax was more common in the BLVR group (18.9% vs. 3.8%; P = 0.018), death was higher in the no-BLVR group (38.5% vs. 54.5%, P = 0.001), whereas other adverse events were comparable between the groups. Within the subset of 18 patients with PAL, the predominant causes of air-leak included spontaneous secondary pneumothorax (44.0%), parapneumonic effusion/empyema (22.2%), and post-lung resection surgery (16.7%). Following the treatment, the majority (77.8%) successfully had their chest tubes removed. Post-procedural complications were minimal, with two incidences of hemoptysis and one of empyema, all of which were effectively managed. CONCLUSIONS: Treatment with EBV provides substantial clinical benefits in the management of emphysema and PAL in the Asian population, suggesting a favorable outcome for this therapeutic approach.

Trends and an Online Survey on the Use of Rigid Bronchoscopy in Korea.

BACKGROUND: Although almost all interventional pulmonologists agree that rigid bronchoscopy is irreplaceable in the field of interventional pulmonology, less is known about the types of diseases that the procedure is used for and what difficulties the operators face during the procedure. The purpose of this study is to evaluate what diseases rigid bronchoscopy is used for, whether it is widely used, and what challenges the operators face in Korea. METHODS: We enrolled 14 hospitals in this retrospective cohort of patients who underwent rigid bronchoscopy between 2003 and 2020. An online survey was conducted with 14 operators to investigate the difficulties associated with the procedure. RESULTS: While the number of new patients at Samsung Medical Center (SMC) increased from 189 in 2003-2005 to 468 in 2018-2020, that of other institutions increased from 0 to 238. The proportion of SMC patients in the total started at 100% and steadily decreased to 59.2%. The proportion of malignancy as the indication for the procedure steadily increased from 29.1% to 43.0%, whereas post-tuberculous stenosis (25.4% to 12.9%) and post-intubation stenosis (19.0% to 10.9%) steadily decreased (all P for trends < 0.001). In the online survey, half of the respondents stated that over the past year they performed less than one procedure per month. The fewer the procedures performed within the last year, the more likely collaboration with other departments was viewed as a recent obstacle (Spearman correlation coefficient, rs = -0.740, P = 0.003) and recent administrative difficulties were encountered (rs = -0.616, P = 0.019). CONCLUSION: This study demonstrated that the number of patients undergoing rigid bronchoscopy has been increasing, especially among cancer patients. For this procedure to be used more widely, it will be important for beginners to systematically learn about the procedure itself as well as to achieve multidisciplinary consultation.

Clinical features and long-term prognosis of acute fibrinous and organizing pneumonia histologically confirmed by surgical lung biopsy.

BACKGROUND: Acute fibrinous and organizing pneumonia (AFOP) is a rare interstitial pneumonia characterized by intra-alveolar fibrin deposition and organizing pneumonia. The clinical manifestations and long-term prognosis of AFOP are unclear. Our objective was to investigate the clinical features and prognosis of AFOP. METHODS: We identified patients diagnosed with AFOP by surgical lung biopsy between January 2011 and May 2018 at Seoul National University Bundang Hospital. We retrospectively reviewed clinical and radiologic findings, treatment, and outcomes of AFOP. RESULTS: Fifteen patients with histologically confirmed lung biopsies were included. The median follow-up duration was 2.4 (range, 0.1-82) months. The median age was 55 (range, 33-75) years, and four patients were immunocompromised. Fever was the most common clinical presentation (86.7%). Patchy ground-glass opacities and/or consolidations were the most predominant findings on chest computed tomography images. Nine patients (60%) received mechanical ventilator care, and eight patients (53.3%) died. The non-survivors tended to have slightly higher body mass index (BMI) and a long interval between symptom onset and diagnosis than the survivors, but these findings were not statistically significant. Among seven survivors, five patients were discharged without dyspnea and oxygen supplement. CONCLUSIONS: The clinical course of AFOP was variable. Although AFOP was fatal, most of the patients who recovered from AFOP maintained normal life without supplemental oxygen therapy and respiratory symptoms.

Evaluation of the synergistic impact of needle and forceps biopsy with electromagnetic navigation bronchoscopy: the CONFIDENT-ENB trial design.

BACKGROUND: Electromagnetic navigation bronchoscopy (ENB) is an emerging advanced imaging-guided bronchoscopy technique for diagnosing peripheral lung lesions. However, the selection strategy for the optimal biopsy device and whether adopting a multi-tool strategy increases the diagnostic yield remains undetermined. The CONFIDENT-ENB trial (NCT05110131) is a prospective randomized study on ENB, performed in a least-invasive setting. The primary aim is to evaluate whether a combination of needle aspiration and forceps biopsy improves the diagnostic performance, and assess the comparative diagnostic value and discordance of the two devices. METHODS: The trial will recruit 142 participants with lung lesions suspected of malignancy who are eligible for an elective ENB procedure under moderate sedation. Participants will undergo ENB-guided needle aspiration and forceps biopsy in a randomized order without the use of any complementary techniques. All participants will be followed up subsequently for up to 12 months to conclude the final diagnosis of the biopsied lesions. Primary outcomes include the diagnostic yield and sensitivity of each biopsy modality and the diagnostic yield of the combined modalities. DISCUSSION: The CONFIDENT-ENB trial will prospectively evaluate the synergistic effectiveness and comparative accuracy of ENB-guided needle aspiration and forceps biopsy in a least-invasive setting. The results are expected to improve our understanding of the optimal tool-selection strategy for ENB. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05110131). Prospectively registered on 5 November 2021.

Lung cancer probability and clinical outcomes of baseline and new subsolid nodules detected on low-dose CT screening.

BACKGROUND: Limited data are available regarding the management of subsolid nodules detected on lung cancer screening with low-dose CT (LDCT). We aimed to determine the characteristics of screen-detected subsolid nodules, and to evaluate the probability of lung cancer and the clinical course of subsolid nodules detected at baseline and during follow-up screening. METHODS: We evaluated 50 132 asymptomatic adults (22 631 never-smokers and 27 501 ever-smokers) who underwent LDCT screening for lung cancer between May 2003 and June 2019 at a tertiary centre in South Korea. The incidence, characteristics and clinical outcomes of the baseline and new screen-detected subsolid nodules were determined. RESULTS: A total of 6725 subsolid nodules (5116 pure ground glass opacity nodules and 1609 part-solid nodules) were detected in 4545 participants (1484 new subsolid nodules detected in 937 (1.9%) participants; the overall incidence of subsolid nodules: 10.7% in never-smokers and 7.7% in ever-smokers, p<0.001). Among 4918 subsolid nodules that underwent follow-up with CT scans (the mean number of CT scans, including the baseline LDCT scan: 4.6), 2116 nodules (30.0% of baseline subsolid nodules and 78.9% of new subsolid nodules) resolved spontaneously. Among 293 biopsied subsolid nodules, 227 (77.5%) nodules were diagnosed as lung cancer, of which 226 (99.6%) were adenocarcinomas. No significant difference was observed in pathological invasiveness or the initial stage between the baseline and new cancerous subsolid nodules. Multivariable analyses revealed that new detection at follow-up screening was significantly associated with a lower probability of lung cancer (OR 0.26, 95% CI 0.14 to 0.49) and overall growth (OR 0.39, 95% CI 0.26 to 0.59), but with a higher probability of resolution (OR 6.30, 95% CI 5.09 to 7.81). CONCLUSIONS: LDCT screening led to a considerably high rate of subsolid nodule detection, particularly in never-smokers. Compared with the baseline subsolid nodules, the new subsolid nodules were associated with a lower probability of lung cancer and higher probability of spontaneous resolution, indicating their more inflammatory nature. Less aggressive follow-up may be allowed for new subsolid nodules, particularly in screening programmes for Asian populations.

Genome-wide association study of non-tuberculous mycobacterial pulmonary disease.

BACKGROUND: The prevalence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) is increasing in South Korea and many parts of the world. However, the genetic factors underlying susceptibility to this disease remain elusive. METHODS: To identify genetic variants in patients with NTM-PD, we performed a genome-wide association study with 403 Korean patients with NTM-PD and 306 healthy controls from the Healthy Twin Study, Korea cohort. Candidate variants from the discovery cohort were subsequently validated in an independent cohort. The Genotype-Tissue Expression (GTEx) database was used to identify expression quantitative trait loci (eQTL) and to conduct Mendelian randomisation (MR). RESULTS: We identified a putatively significant locus on chromosome 7p13, rs849177 (OR, 2.34; 95% CI, 1.71 to 3.21; p=1.36×10-7), as the candidate genetic variant associated with NTM-PD susceptibility. Its association was subsequently replicated and the combined p value was 4.92×10-8. The eQTL analysis showed that a risk allele at rs849177 was associated with lower expression levels of STK17A, a proapoptotic gene. In the MR analysis, a causal effect of STK17A on NTM-PD development was identified (ß, -4.627; 95% CI, -8.768 to -0.486; p=0.029). CONCLUSIONS: The 7p13 genetic variant might be associated with susceptibility to NTM-PD in the Korean population by altering the expression level of STK17A.

Low-dose chest computed tomographic screening and invasive diagnosis of pulmonary nodules for lung cancer in never-smokers.

BACKGROUND: Although lung cancer screening using low-dose computed tomography (LDCT) is now widely used in clinical practice, the characteristics and outcomes of diagnostic procedures related to screen-detected nodules in never-smokers remain unclear. We aimed to determine the incidence of nodules considered for invasive biopsy and evaluate the final diagnoses and procedure-related complications in never-smokers in comparison to ever-smokers who underwent LDCT screening. METHODS: We evaluated 37 436 asymptomatic adults (17 968 never-smokers and 19 468 ever-smokers) who underwent LDCT screening for lung cancer between January 2009 and December 2018 at a tertiary centre in South Korea. The rates of invasive diagnostic procedures for detected nodules and related complications, and the diagnostic outcomes were determined in the never-smoker and ever-smoker groups. RESULTS: Among the never-smokers, 2908 (16.2%) out of 17 968 had positive nodules. Overall, 139 (0.77%) out of 17 968 never-smokers and 194 (1.00%) out of 19 468 ever-smokers underwent invasive biopsy (p=0.022). Lung cancer was diagnosed in 84 (0.47%) out of 17 968 never-smokers and 123 (0.63%) out of 19 468 ever-smokers (p=0.032). The proportions of participants diagnosed with benign disease after invasive biopsy (false-positive) were 50 (0.28%) out of 17 968 and 69 (0.35%) out of 19 468 in the never-smoker and ever-smoker groups, respectively (p=0.191). Multivariate analyses revealed no significant associations of smoking with the risk of a false-positive diagnosis (OR 0.98, 95% CI 0.62-1.57) and complications (OR 1.33, 95% CI 0.65-3.73) after biopsy. Of the 84 never-smokers with lung cancer, 82 (97.6%) had adenocarcinoma, and 75 (89.3%) were in stage I with a favourable prognosis. CONCLUSIONS: LDCT screening in never-smokers resulted in a notable detection rate of lung nodules, which warranted invasive biopsy. The lung cancer detection rate was lower in never-smokers than in ever-smokers. However, no significant differences in the false-positive and complication rates were observed between the two groups. Accordingly, a more specifically tailored management strategy is needed for screen-detected nodules in Asian never-smokers.

Hyperuricemia Is Not Predictive of Long-Term Outcome in Patients with Stable Chronic Obstructive Pulmonary Disease.

BACKGROUND: Although the association of hyperuricemia with an increased risk of mortality has been demonstrated in the context of acute exacerbation of chronic obstructive pulmonary disease (COPD), the long-term outcomes of hyperuricemia have not been studied in the case of stable COPD. METHODS: We retrospectively analyzed baseline data of 240 men with stable COPD enrolled in the Korea Obstructive Lung Disease cohort. We evaluated associations between serum uric acid levels and clinical parameters, risk factors for all-cause mortality, and acute exacerbation of COPD. RESULTS: The mean age of subjects was 66.4 ± 7.7 years, and the median follow-up time was 5.9 years. We identified no significant difference in terms of lung function or laboratory findings between patients with hyperuricemia and those without. Serum uric acid level was negatively associated with systemic inflammation indicated by neutrophil-lymphocyte ratio (r = -0.211, P = 0.001). Univariate Cox regression analysis revealed hyperuricemia to not be associated with an increased risk of all-cause mortality in men with stable COPD (hazard ratio [HR], 0.580; 95% confidence interval [CI], 0.250-1.370; P = 0.213). In the multivariate Cox regression model, hyperuricemia was not an independent predictor of acute exacerbation (HR, 1.383; 95% CI, 0.977-1.959; P = 0.068). CONCLUSION: Among men with stable COPD, hyperuricemia is not an independent predictor of all-cause mortality or future acute exacerbation of COPD. These results differ from those of previous studies on patients with acute exacerbation of COPD.

Factors Associated With Quality of Death in Korean ICUs As Perceived by Medical Staff: A Multicenter Cross-Sectional Survey.

OBJECTIVES: Facilitating a high quality of death is an important aspect of comfort care for patients in ICUs. The quality of death in ICUs has been rarely reported in Asian countries. Although Korea is currently in the early stage after the implementation of the "well-dying" law, this seems to have a considerable effect on practice. In this study, we aimed to understand the status of quality of death in Korean ICUs as perceived by medical staff, and to elucidate factors affecting patient quality of death. DESIGN: A multicenter cross-sectional survey study. SETTING: Medical ICUs of two tertiary-care teaching hospitals and two secondary-care hospitals. PATIENTS: Deceased patients from June 2016 to May 2017. INTERVENTIONS: Relevant medical staff were asked to complete a translated Quality of Dying and Death questionnaire within 48 hours after a patient's death. A higher Quality of Dying and Death score (ranged from 0 to 100) corresponded to a better quality of death. MEASUREMENTS AND MAIN RESULTS: A total of 416 completed questionnaires were obtained from 177 medical staff (66 doctors and 111 nurses) of 255 patients. All 20 items of the Quality of Dying and Death received low scores. Quality of death perceived by nurses was better than that perceived by doctors (33.1 ± 18.4 vs 29.7 ± 15.3; p = 0.042). Performing cardiopulmonary resuscitation and using inotropes within 24 hours before death were associated with poorer quality of death, whereas using analgesics was associated with better quality of death. CONCLUSIONS: The quality of death of patients in Korean ICUs was considerably poorer than reported in other countries. Provision of appropriate comfort care, avoidance of unnecessary life-sustaining care, and permission for more frequent visits from patients' families may correspond to better quality of death in Korean medical ICUs. It is also expected that the new legislation would positively affect the quality of death in Korean ICUs.

Change in inhaled corticosteroid treatment and COPD exacerbations: an analysis of real-world data from the KOLD/KOCOSS cohorts.

BACKGROUND: This cohort study of patients with chronic obstructive pulmonary disease (COPD) was performed to evaluate the status of inhaled corticosteroid (ICS) prescriptions following the 2017 revision of the Global Initiative for Chronic Obstructive Lung Disease guidelines. METHODS: A total of 1144 patients from the Korean Obstructive Lung Disease and Korea Chronic Obstructive Pulmonary Disorders Subgroup Study cohorts, with final follow-up visits completed between 2017 and 2018, were analyzed. Features indicative of ICS usage were as follows: a history of asthma, blood eosinophils of ≥300 cells/µl, or ≥ 2 exacerbations in the year prior to enrollment. Among baseline ICS users, we compared annual total and severe exacerbation rates, based on ICS continuation or withdrawal. RESULTS: ICS-containing regimens were prescribed to 46.3% of the enrolled of patients in 2014; this decreased to 38.8% in 2017, and long-acting dual bronchodilators were used instead. Among ICS users in 2017, 47.5% did not exhibit features indicative of ICS usage; 478 used ICS at baseline, and ICS was withdrawn in 77 (16.1%) during the study period. The proportion of patients with asthma and the baseline annual exacerbation rate were greater in the ICS withdrawal groinup than in the ICS continued group (56.6% vs. 41%, p = 0.01; 0.79 vs. 0.53, p < 0.001). Annual exacerbation rates during the follow-up period were similar between the ICS-withdrawal and ICS -continued groups (0.48 vs. 0.47, p = 0.84); however, former exhibited a significantly higher rate of severe exacerbation (0.22 vs. 0.12, p = 0.03). CONCLUSIONS: Prescriptions of ICS to treat COPD decreased with increased use of long-acting dual bronchodilators. ICS withdrawal might impact severe exacerbation; the potential risks and benefits of withdrawing ICS should therefore be considered based on patients' characteristics.

The Ability of Different Scoring Systems to Predict Mortality in Chronic Obstructive Pulmonary Disease Patients: A Prospective Cohort Study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality, therefore the prediction of mortality in COPD patients is crucial. In the current study, the abilities of different categorization systems to predict mortality in stable COPD patients from a prospective cohort were compared. METHODS: The ability to predict mortality was compared in terms of discrimination by Harrell's C (HC) index and calibration using graphical comparison among the GOLD (Global Initiative for Chronic Obstructive Lung Disease) 2011, GOLD 2017, GOLD grade, BODE (BMI, Airflow Obstruction, Dyspnea, Exercise), updated BODE, BODEx (BMI, Airflow Obstruction, Dyspnea, Exacerbation), e-BODE (Exacerbation and BODE), ADO (Age, Dyspnea, Airflow Obstruction), COPD prognostic index (CPI), and simplified/optimized B-AE-D (BMI, Acute Exacerbation, Dyspnea) indexes. RESULTS: The study included 520 patients, of whom 63 died during a median 40-month follow-up period. Combined prediction systems exhibited higher discrimination properties than single predictors. The CPI exhibited the highest with a HC of 0.768, followed by the simplified B-AE-D (HC 0.761), ADO (HC 0.760), and optimized B-AE-D (HC 0.756). The BODE and its variants other than the ADO exhibited relatively lower HCs (0.656-0.705), and GOLD exhibited the lowest discrimination ability among the combined indices (HCs 0.628-0.637). Subjective symptom questionnaires such as the modified Medical Research Council (mMRC) scale (HC 0.693) and SGRQ (HC 0.679) exhibited the highest ability to predict mortality among the single indices. CONCLUSION: The ADO, simplified B-AE-D, optimized B-AE-D, and GOLD 2017 exhibited good calibration properties, but the CPI did not. The simplified and optimized B-AE-Ds and the ADO index had good discrimination and calibration properties for the prediction of mortality in stable COPD patients.

Combined pulmonary fibrosis and emphysema and idiopathic pulmonary fibrosis in non-small cell lung cancer: impact on survival and acute exacerbation.

BACKGROUND: In non-small cell lung cancer (NSCLC) patients, concomitant idiopathic pulmonary fibrosis (IPF) and emphysema (CPFE) are independently related to poor survival. CPFE is a condition with features of both pulmonary fibrosis and emphysema. Here, we evaluated the effect of CPFE and IPF alone on the outcomes of NSCLC patients. PATIENTS AND METHODS: We retrospectively evaluated 283 patients with CPFE or IPF who were diagnosed with NSCLC between November 2003 and February 2018 at two tertiary care hospitals in South Korea. Patients were classified into CPFE and IPF groups according to chest computed tomography findings. RESULTS: One-hundred-and-seven patients (37.8%; mean age: 70.1 years; men 97.2%) had CPFE. Compared with IPF patients, CPFE patients had a heavier smoking history; lower diffusing capacity of carbon monoxide (78.0% vs 64.8%, p <  0.001), and lower forced expiratory volume in 1 s. Of all patients with NSCLC, 71.7% overall died during the follow-up period; 71.6% died in the CPFE group and 72.0% in the IPF group. Multivariate logistic regression analysis showed that CPFE (odds ratio [OR]: 2.26, 95% confidence interval [CI]: 1.09-4.69; P = 0.029) was significantly correlated with acute exacerbations (AEs). In a Cox proportional hazards analysis, stage > III NSCLC, higher Eastern Cooperative Oncology Group performance status, and higher gender-age-physiology index score was related to higher mortality. However, CPFE was not related to a higher mortality rate in univariate (hazard ratio [HR]: 1.00; 95% CI: 0.75-1.32, P = 0.972) or multivariate analysis (HR: 0.89; 95% CI: 0.66-1.21, P = 0.466). CONCLUSIONS: AE risk, but not all-cause mortality, was higher in patients with CPFE and NSCLC than in those with IPF and NSCLC. Physicians should be aware of the exaggerated risk of AE in patients with concomitant CPFE and NSCLC.

Prognostic Impact of DNA Repair Protein Expression in Non-Small Cell Lung Cancers Treated with Platinum-Based Chemotherapy and Subsequent Curative Lung Resection.

OBJECTIVE: Multimodal treatments that include preoperative platinum-based chemotherapy are fundamental to the treatment of advanced non-small cell lung cancer (NSCLC). This study aimed to investigate the predictive value of DNA repair protein expression in surgically resected NSCLCs in terms of prognosis and responses to platinum-containing chemotherapy. METHODS: This retrospective study included 136 patients with NSCLC who were treated with preoperative platinum-based chemotherapy, followed by curative lung resection. ATM, RAD51, LKB1, H2AX, and SIRT1 expression levels were analyzed in resected tumor specimens via immunostaining and were used to classify patients and compare survival and responses to chemotherapy. RESULTS: SIRT1 expression correlated significantly with improved responses to platinum-based chemotherapy (odds ratio, 2.28; p = 0.024), progression-free survival (hazard ratio [HR], 0.74; p = 0.036), overall survival (HR, 0.63; p = 0.006), and tumor-bearing survival (HR, 0.62; p = 0.014). After adjusting for clinical variables, the HR of SIRT1 expression remained significant for overall survival (HR, 0.59; p = 0.039) but not for progression-free survival (HR, 0.74; p = 0.183). No prognostic stratification was observed for the other 4 markers. CONCLUSION: Patients with SIRT1-expressing NSCLC had superior responses to chemotherapy and longer survival durations than those with SIRT1-negative cancer.

Favorable longitudinal change of lung function in patients with asthma-COPD overlap from a COPD cohort.

BACKGROUND: The recognition of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) as a distinct phenotype of COPD or asthma has increased. Although ACO has worse clinical features than non-ACO COPD, limited information is available on long-term outcomes of lung function decline for ACO and non-ACO COPD. METHODS: COPD patients with at least 3 years of follow-up were selected from the Korean Obstructive Lung Disease cohort. ACO was defined based on 3 major criteria: 1) airflow limitation in individuals 40 years of age and older, 2) ≥10 pack-years of smoking history, and 3) a history of asthma or bronchodilator response of > 400 mL in forced expiratory volume in 1 s (FEV1) at baseline; and at least 1 minor criterion: 1) history of atopy or allergic rhinitis, 2) two separated bronchodilator responses of ≥12% and 200 mL in FEV1, or 3) peripheral blood eosinophils ≥300 cells/µL. Lung function decline was compared using a linear mixed effects model for longitudinal data with random intercept and random slope. RESULTS: Among 239 patients, 47 were diagnosed with ACO (19.7%). During the follow-up period, change in smoking status, use of inhaled corticosteroids (ICS) and long-acting ß2-agonists or ICS and at least 2 exacerbations per year were similar between patients with non-ACO COPD and ACO. Over a median follow-up duration of 5.8 years, patients with non-ACO COPD experienced a faster annual decline in pre-bronchodilator FEV1 than patients with ACO (- 29.3 ml/year vs. -13.9 ml/year, P = 0.042), which was persistent after adjustment for confounders affecting lung function decline. CONCLUSION: Patients with ACO showed favorable longitudinal changes in lung function compared to COPD patients over a median follow-up of 5.8 years.

Activation of Periodate by Freezing for the Degradation of Aqueous Organic Pollutants.

A new strategy (i.e., freezing) for the activation of IO4- for the degradation of aqueous organic pollutants was developed and investigated. Although the degradation of furfuryl alcohol (FFA) by IO4- was negligible in water at 25 °C, it proceeded rapidly during freezing at -20 °C. The rapid degradation of FFA during freezing should be ascribed to the freeze concentration effect that provides a favorable site (i.e., liquid brine) for the proton-coupled degradation process by concentrating IO4-, FFA, and protons. The maximum absorption wavelength of cresol red (CR) was changed from 434 nm (monoprotonated CR) to 518 nm (diprotonated CR) after freezing, which confirms that the pH of the aqueous IO4- solution decreases by freezing. The degradation experiments with varying experimental parameters demonstrate that the degradation rate increases with increasing IO4- concentration and decreasing pH and freezing temperature. The application of the IO4-/freezing system is not restricted to FFA. The degradation of four other organic pollutants (i.e., tryptophan, phenol, 4-chlorophenol, and bisphenol A) by IO4-, which was negligible in water, proceeded during freezing. In addition, freezing significantly enhanced the IO4--mediated degradation of cimetidine. The outdoor experiments performed on a cold winter night show that the IO4-/freezing system for water treatment can be operated without external electrical energy.

Comparison of outcomes between vertical and transverse skin incisions in percutaneous tracheostomy for critically ill patients: a retrospective cohort study.

BACKGROUND: Percutaneous tracheostomy (PT) is a common procedure in critical care medicine. No definite clinical practice guidelines recommended on the choice of the direction of skin incision, vertical or transverse for tracheostomy in critically ill patients. The objective of this retrospective study was to compare the outcomes associated with vertical and transverse skin incisions in patients undergoing PT. METHODS: Patients who underwent PT between March 2011 and December 2015 in the intensive care unit (ICU) of a tertiary hospital were retrospectively included. PTs were performed by pulmonary intensivists at the ICU bedside using the single tapered dilator technique assisted by flexible bronchoscopy. The primary outcome was the incidence of tracheostomy site ulcers at 7 days after PT. RESULTS: Of the 458 patients who underwent PT, a vertical incision was made in 27.1% and a transverse incision was made in 72.9%. There were no tracheostomy-related mortalities, and no significant difference in the incidence of immediate postoperative complications, including bleeding, tracheal ring fracture, and subcutaneous emphysema. Thirty-five patients (7.6%) developed complications within 7 days after PT, in which tracheostomy-related pressure ulcers were the most frequent. Compared with vertical incisions, transverse incisions were associated with significantly lower incidence of complications (14.1% vs. 5.4%, P = 0.001). CONCLUSIONS: This retrospective study showed that transverse skin incisions in PTs for critically ill patients, resulted in a significant decrease in overall complications, particularly ulcers in the tracheostomy site.

Associations between obstructive sleep apnea severity and endoscopically proven gastroesophageal reflux disease.

PURPOSE: Obstructive sleep apnea (OSA) is believed to be an important risk factor for gastroesophageal reflux disease (GERD). However, the association between OSA and GERD is not straightforward and has been incompletely characterized. The aim of this study was to assess the relationship between OSA and GERD by performing both polysomnography (PSG) and esophagogastroduodenoscopy (EGD). METHODS: The enrolled patients underwent both PSG and EGD from October 2003 to July 2015 at Seoul National University Bundang Hospital. All patients were checked for the presence of mucosal injury in the EGD findings and divided into a no-GERD group and a GERD group according to the Los Angeles (LA) classification. In addition, the GERD symptoms of heartburn, acid regurgitation, and reflux-related cough were recorded. RESULTS: A total of 216 patients were enrolled. Ninety-nine patients (45.8%) were in the GERD group, 68 (31.5%) were the minimal-change GERD group, and 49 (22.7%) were in the GERD LA-A/B group. The OSA-related findings were worse in the GERD LA-A/B group than in the no-GERD group: the apnea-hypopnea index was 33.6 ± 25.5 versus 22.0 ± 17.2 (p = 0.01), the longest apnea duration was 50.7 ± 24.0 versus 41.6 ± 23.3 s (p = 0.03), the lowest oxygen saturation was 80.2 ± 7.9 versus 83.2 ± 7.5% (p = 0.02), and the oxygen desaturation index was 25.1 ± 22.4 versus 16.1 ± 15.5 (p = 0.01), respectively. Sleep efficiency was significantly worse in patients with GERD symptoms (81.2 ± 10.8%) than in those without GERD symptoms (85.1 ± 11.4%) (p = 0.03). CONCLUSIONS: Endoscopically proven GERD was associated with more severe OSA. GERD symptoms were also associated with deteriorated sleep quality.

Solid part size is an important predictor of nodal metastasis in lung cancer with a subsolid tumor.

BACKGROUND: Candidates for preoperative or intraoperative nodal assessment among patients with non-small cell lung cancer (NSCLC) manifesting as a subsolid tumor are not established. The present study was conducted to demonstrate the distribution of nodal metastasis rate according to newly proposed T categories for subsolid tumors, and we further aimed to identify radiologic parameters that can be predictive of nodal metastasis. METHODS: We retrospectively reviewed cases of NSCLC manifesting as a subsolid tumor in computed tomography scans in a university-affiliated tertiary hospital between April 2013 and August 2016. All patients underwent mediastinal lymph node dissection during resection surgery. Multivariate analysis was performed among clinical and radiologic parameters. RESULTS: Of the 269 eligible patients, T-categories were classified as cTis (n = 23, 8.6%), cT1 (n = 203, 75.5%), and cT2 (n = 43, 16.0%). Ten patients (3.7%) had nodal metastasis: pN1 (n = 5, 1.9%), pN2 (n = 5, 1.9%). Nodal metastasis was not observed in tumors with a solid part ≤1.0 cm (cT1mi and cT1a) or in nonsolid tumors ≤3.0 cm (cTis). The nodal metastasis rate in cT1b, cT1c, and cT2 tumors was 6.1% (4/65), 8.3% (1/12), and 11.7% (5/43), respectively. Multivariate analysis showed that a solid part size > 1.5 cm [odds ratio, 5.89; 95% confidence interval, 1.25-27.68, p = 0.025] was significantly associated with nodal metastasis. CONCLUSIONS: We observed nodal metastasis from cT1b tumors (solid part size > 1 cm) among proposed T categories for subsolid tumors and a solid part size is an important radiologic parameter predictive of nodal metastasis in NSCLC manifesting as a subsolid tumor. Considering the low rate of nodal metastasis, pathologic nodal assessment may be unnecessary in early T category tumors with a small solid part size.

Association between Pepsin in Bronchoalveolar Lavage Fluid and Prognosis of Chronic Fibrosing Interstitial Lung Disease.

Chronic fibrosing interstitial lung disease (ILD)s are characterized by chronic progressive fibrosis of lung which include idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia (NSIP), and connective tissue disease-associated interstitial lung disease (CTD-ILD). IPF is an irreversible fibrotic lung disease which results in respiratory failure. Although NSIP and CTD-ILD can be improved or stable by treatment with corticosteroid or immunosuppressant, some of them progress to fibrotic lung diseases. Aspiration of gastric contents is suggested as an aggravating factor of ILDs. We measured pepsin, a marker of gastric aspiration, in bronchoalveolar lavage (BAL) fluid of chronic fibrosing ILD patients to evaluate the association between BAL fluid pepsin and prognosis of chronic fibrosing ILDs. Patients with chronic fibrosing ILDs, who underwent bronchoscopy between December 2010 and April 2015 were prospectively enrolled. Pepsin levels were measured using a commercial ELISA kit. Clinical characteristics, lung function data, and mortality were analyzed. Fifty-one patients with chronic fibrosing ILDs were enrolled (26 with IPF, 15 with NSIP, and 10 with CTD-ILD). Pepsin levels in BAL fluid were 69.87 ± 74.16 ng/mL in IPF, 110.68 ± 94.93 ng/mL in NSIP, and 101.87 ± 88.44 ng/mL in CTD-ILDs. There were no statistically significant differences in BAL fluid pepsin levels among patients with the different chronic fibrosing ILDs. In multivariate regression analysis, higher BAL pepsin levels were associated with higher mortality (adjusted odds ratio [aOR] = 1.021, p = 0.025). BAL fluid pepsin may be used as a prognostic marker for predicting mortality in chronic fibrosing ILD patients.

Effectiveness Analysis of a Part-Time Rapid Response System During Operation Versus Nonoperation.

OBJECTIVES: To evaluate the effect of a part-time rapid response system on the occurrence rate of cardiopulmonary arrest by comparing the times of rapid response system operation versus nonoperation. DESIGN: Retrospective cohort study. SETTING: A 1,360-bed tertiary care hospital. PATIENTS: Adult patients admitted to the general ward were screened. Data were collected over 36 months from rapid response system implementation (October 2012 to September 2015) and more than 45 months before rapid response system implementation (January 2009 to September 2012). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The rapid response system operates from 7 AM to 10 PM on weekdays and from 7 AM to 12 PM on Saturdays. Primary outcomes were the difference of cardiopulmonary arrest incidence between pre-rapid response system and post-rapid response system periods and whether the rapid response system operating time affects the cardiopulmonary arrest incidence. The overall cardiopulmonary arrest incidence (per 1,000 admissions) was 1.43. Although the number of admissions per month and case-mix index were increased (3,555.18 vs 4,564.72, p < 0.001; 1.09 vs 1.13, p = 0.001, respectively), the cardiopulmonary arrest incidence was significantly decreased after rapid response system (1.60 vs 1.23; p = 0.021), and mortality (%) was unchanged (1.38 vs 1.33; p = 0.322). After rapid response system implementation, the cardiopulmonary arrest incidence significantly decreased by 40% during rapid response system operating times (0.82 vs 0.49/1,000 admissions; p = 0.001) but remained similar during rapid response system nonoperating times (0.77 vs 0.73/1,000 admissions; p = 0.729). CONCLUSIONS: The implementation of a part-time rapid response system reduced the cardiopulmonary arrest incidence based on the reduction of cardiopulmonary arrest during rapid response system operating times. Further analysis of the cost effectiveness of part-time rapid response system is needed.