Differential decline of lung function in COPD patients according to structural abnormality in chest CT.

Background: Different progressions or prognoses of chronic obstructive pulmonary disease (COPD) have been reported according to structural abnormalities based on chest computed tomography (CT). This study aimed to investigate whether different structural abnormalities independently affect annual lung function changes and clinical prognosis in patients with COPD. Methods: This longitudinal multicenter observational study was conducted using the KOCOSS cohort (NCT02800499) database in Korea from January 2012 to December 2019. For COPD patients with chest CT findings at baseline enrolment and longitudinal spirometric data, annual forced expiratory volume in 1 s (FEV1) decline rate (mL/year) and clinical outcomes were compared according to structural abnormalities, including emphysema, bronchiectasis (BE), and tuberculosis-destroyed lung (TDL). We estimated the adjusted annual FEV1 changes using a mixed-effect linear regression model. Results: Among the enrolled 237 patients, 152 showed structural abnormalities. Emphysema, BE, and TDL were observed in 119 (78.3%), 28 (18.4%), and 27 (17.8%) patients, respectively. The annual decline in FEV1 was faster in COPD patients with structural abnormalities than those without (ß = -70.6 mL/year, P-value = 0.039). BE/TDL-dominant or emphysema-dominant structural abnormality contributed to an accelerated annual FEV1 decline compared to no structural abnormality (BE/TDL-dominant, ß = -103.7 mL/year, P-value = 0.043; emphysema-dominant, ß = -84.1 mL/year, P-value = 0.018). Structural abnormalities made no significant differences in acute exacerbation rate and mortality. Conclusion: The lung function decline rate in COPD differed according to structural abnormalities on CT. These findings may suggest that more focus should be placed on earlier intervention or regular follow-up with spirometry in COPD patients with BE or TDL on chest CT.

Multiphase Reset Induced Reliable Dual-Mode Resistance Switching of the Ta/HfO2/RuO2 Memristor.

Higher functionality should be achieved within the device-level switching characteristics to secure the operational possibility of mixed-signal data processing within a memristive crossbar array. This work investigated electroforming-free Ta/HfO2/RuO2 resistive switching devices for digital- and analog-type applications through various structural and electrical analyses. The multiphase reset behavior, induced by the conducting filament modulation and oxygen vacancy generation (annihilation) in the HfO2 layer by interacting with the Ta (RuO2) electrode, was utilized for the switching mode change. Therefore, a single device can manifest stable binary switching between low and high resistance states for the digital mode and the precise 8-bit conductance modulation (256 resistance values) via an optimized pulse application for the analog mode. An in-depth analysis of the operation in different modes and comparing memristors with different electrode structures validate the proposed mechanism. The Ta/HfO2/RuO2 resistive switching device is feasible for a mixed-signal processable memristive array.

Differential response to roflumilast in patients with chronic obstructive pulmonary disease: real-world evidence.

Background: Roflumilast is effective in reducing acute exacerbation in patients with chronic obstructive pulmonary disease (COPD) at high risk of severe exacerbation. Clinical traits related to the benefits of roflumilast need to be evaluated in patients with COPD. Methods: A longitudinal observational study in patients newly diagnosed with COPD was conducted using claims data from the Health Insurance Review and Assessment Service in South Korea from 2012-2020 after a 2-year washout period. The primary outcome was to estimate the ratio of hazard ratio (RHR) of roflumilast for moderate-to-severe exacerbation in prespecified subgroups. A time-dependent Cox regression model was used to estimate the hazard ratio (HR) for moderate-to-severe exacerbations. Results: Among 823,862 patients with COPD, 0.6% used roflumilast. The adjusted HR of roflumilast for moderate-to-severe exacerbations was reduced when treated for ≥3 months (RHR =0.558). Interaction effects of the variables on the HR of roflumilast for moderate-to-severe exacerbation were identified. The adjusted HR of roflumilast for moderate-to-severe exacerbation was significantly reduced in several subgroups: older age (65 years > age ≥50 years, RHR =0.838; age ≥65 years, RHR =0.818), a higher Charlson comorbidity index (1, RHR =0.832; 2, RHR =0.798; ≥3, RHR =0.790), history of exacerbation (RHR =0.886), bronchiectasis (RHR =0.774), chronic bronchitis (RHR =0.793), inhaled therapy [mono-bronchodilator, RHR =0.824; inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA), RHR =0.591; LABA/long-acting muscarinic antagonist (LAMA), RHR =0.822; ICS/LABA/LAMA, RHR =0.570], methylxanthine (RHR =0.853), and statin (RHR =0.888). Conclusions: The benefit of roflumilast in moderate-to-severe exacerbations was estimated to be greater in specific subgroups of patients with COPD. Personalised approaches to roflumilast based on clinical phenotypes would be effective for COPD.

Multifunctional HfAlO thin film: Ferroelectric tunnel junction and resistive random access memory.

This study presents findings indicating that the ferroelectric tunnel junction (FTJ) or resistive random-access memory (RRAM) in one cell can be intentionally selected depending on the application. The HfAlO film annealed at 700 °C shows stable FTJ characteristics and can be converted into RRAM by forming a conductive filament inside the same cell, that is, the process of intentionally forming a conductive filament is the result of defect generation and redistribution, and applying compliance current prior to a hard breakdown event of the dielectric film enables subsequent RRAM operation. The converted RRAM demonstrated good memory performance. Through current-voltage fitting, it was confirmed that the two resistance states of the FTJ and RRAM had different transport mechanisms. In the RRAM, the 1/f noise power of the high-resistance state (HRS) was about ten times higher than that of the low-resistance state (LRS). This is because the noise components increase due to the additional current paths in the HRS. The 1/f noise power according to resistance states in the FTJ was exactly the opposite result from the case of the RRAM. This is because the noise component due to the Poole-Frenkel emission is added to the noise component due to the tunneling current in the LRS. In addition, we confirmed the potentiation and depression characteristics of the two devices and further evaluated the accuracy of pattern recognition through a simulation by considering a dataset from the Modified National Institute of Standards and Technology.

Acute Exacerbation and Longitudinal Lung Function Change of Preserved Ratio Impaired Spirometry.

Background: Preserved ratio impaired spirometry (PRISm) is a heterogeneous disease entity. Limited data are available regarding its prevalence, clinical course, or prognosis. We aimed to evaluate the longitudinal clinical course of patients with PRISm compared with chronic obstructive pulmonary disease (COPD). Methods: A retrospective study enrolled PRISm and COPD patients who underwent chest computed tomography and longitudinal pulmonary function tests between January 2013 and December 2020. We compared the incidence of acute exacerbations and lung function changes between PRISm and COPD patients. Results: Of the 623 patients, 40 and 583 had PRISm and COPD, respectively. Compared to COPD patients, PRISm patients were younger, more likely to be female and have a history of tuberculosis, and less likely to be smokers. They also had less severe comorbidities, lower forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO). The clinical course was not significantly different between the PRISm and COPD patients in terms of the risk of moderate-to-severe acute exacerbations or proportion of frequent exacerbators. During follow-up, PRISm patients had a significantly slower annual decline of forced expiratory volume in 1 second, FVC, and DLCO than COPD patients. Conclusion: PRISm patients had no significant difference in the risk of acute exacerbations, but a significantly slower decline of lung function during longitudinal follow-up, compared with COPD patients.

Clonal hematopoiesis of indeterminate potential is associated with current smoking status and history of exacerbation in patients with COPD.

Background: There is limited data regarding the clinical outcomes of clonal hematopoiesis of indeterminate potential (CHIP) in patients with chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the clinical significance of CHIP as a COPD biomarker. Methods: This retrospective study was conducted on patients with COPD who were enrolled prospectively in the Seoul National University Hospital Airway Registry from January 2013 to December 2019 and underwent pulmonary function and blood tests. We evaluated the CHIP score according to smoking status and severity of airflow obstruction. Results: We analyzed next-generation sequencing data to detect CHIP in 125 patients with COPD. Current smokers had a higher prevalence of CHIP in DTP, DNMT3A, and PPM1D genes than in never- or ex-smokers. CHIP of DTP and DNMT3A genes was significantly associated with current smokers (aOR 2.80, 95% CI 1.01-7.79; aOR 4.03, 95% CI 1.09-14.0). Patients with moderate-to-severe airflow obstruction had a higher prevalence of CHIP in most of the explored genes than those with mild obstruction, although the difference was not statistically significant. CHIP in ASXL1 genes was significantly associated with history of mild, severe, and total acute exacerbation. Conclusion: Given that CHIP in specific genes was significantly associated with current smoking status and acute exacerbation, CHIP can be considered as a candidate biomarker for COPD patients.

Diffusing capacity as an independent predictor of acute exacerbations in chronic obstructive pulmonary disease.

A weak correlation between diffusing capacity of the lung for carbon monoxide (DLCO) and emphysema has been reported. This study investigated whether impaired DLCO in chronic obstructive pulmonary disease (COPD) is associated with increased risk of acute exacerbation independent of the presence or extent of emphysema. This retrospective cohort study included patients with COPD between January 2004 and December 2019. The participants were divided into four groups based on visually detected emphysema and impaired DLCO. Among 597 patients with COPD, 8.5% had no emphysema and impaired DLCO whereas 36.3% had emphysema without impaired DLCO. Among the four groups, patients with impaired DLCO and emphysema showed a higher risk of moderate-to-severe or severe exacerbation than those with normal DLCO. Impaired DLCO was an independent risk factor for severe exacerbation (hazard ratio, 1.524 [95% confidence interval 1.121-2.072]), whereas the presence of emphysema was not. The risk of moderate-to-severe or severe exacerbation increases with the severity of impaired DLCO. After propensity-score matching for the extent of emphysema, impaired DLCO was significantly associated with a higher risk of moderate-to-severe (p = 0.041) or severe exacerbation (p = 0.020). In patients with COPD and heterogeneous parenchymal abnormalities, DLCO can be considered an independent biomarker of acute exacerbation.

Combined effect of changes in NO2, O3, PM2.5, SO2 and CO concentrations on small airway dysfunction.

BACKGROUND AND OBJECTIVE: When multiple complex air pollutants are combined in real-world settings, the reliability of estimating the effect of a single pollutant is questionable. This study aimed to investigate the combined effects of changes in air pollutants on small airway dysfunction (SAD). METHODS: We analysed Korea National Health and Nutrition Examination Survey (KNHANES) V-VIII database from 2010 to 2018 to elucidate the associations between annual changes in air pollutants over a previous 5-year period and small airway function. We estimated the annual concentrations of five air pollutants: NO2, O3, PM2.5, SO2 and CO. Forced expiratory flow between 25% and 75% of vital capacity (FEF25%-75%) <65% was defined as SAD. Using the quantile generalized-Computation (g-Computation) model, the combined effect of the annual changes in different air pollutants was estimated. RESULTS: A total of 29,115 individuals were included. We found significant associations between SAD and the quartiles of annual changes in NO2 (OR = 1.10, 95% CI = 1.08-1.12), O3 (OR = 1.03, 95% CI = 1.00-1.05), PM2.5 (OR = 1.03, 95% CI = 1.00-1.05), SO2 (OR = 1.04, 95% CI = 1.02-1.08) and CO (OR = 1.16, 95% CI = 1.12-1.19). The combined effect of the air pollutant changes was significantly associated with SAD independent of smoking (OR = 1.31, 95% CI = 1.26-1.35, p-value <0.001), and this trend was consistently observed across the entire study population and various subgroup populations. As the estimated risk of SAD, determined by individual-specific combined effect models, increased and the log odds for SAD increased linearly. CONCLUSION: The combined effect of annual changes in multiple air pollutant concentrations were associated with an increased risk of SAD.

Clinical outcomes of long-term inhaled combination therapies in patients with bronchiectasis and airflow obstruction.

BACKGROUND AND OBJECTIVES: Few studies have reported which inhaled combination therapy, either bronchodilators and/or inhaled corticosteroids (ICSs), is beneficial in patients with bronchiectasis and airflow obstruction. Our study compared the efficacy and safety among different inhaled combination therapies in patients with bronchiectasis and airflow obstruction. METHODS: Our retrospective study analyzed the patients with forced expiratory volume in 1 s (FEV1)/forced vital capacity < 0.7 and radiologically confirmed bronchiectasis in chest computed tomography between January 2005 and December 2021. The eligible patients underwent baseline and follow-up spirometric assessments. The primary endpoint was the development of a moderate-to-severe exacerbation. The secondary endpoints were the change in the annual FEV1 and the adverse events. Subgroup analyses were performed according to the blood eosinophil count (BEC). RESULTS: Among 179 patients, the ICS/long-acting beta-agonist (LABA)/long-acting muscarinic antagonist (LAMA), ICS/LABA, and LABA/LAMA groups were comprised of 58 (32.4%), 52 (29.1%), and 69 (38.5%) patients, respectively. ICS/LABA/LAMA group had a higher severity of bronchiectasis and airflow obstruction, than other groups. In the subgroup with BEC ≥ 300/uL, the risk of moderate-to-severe exacerbation was lower in the ICS/LABA/LAMA group (adjusted HR = 0.137 [95% CI = 0.034-0.553]) and the ICS/LABA group (adjusted HR = 0.196 [95% CI = 0.045-0.861]) compared with the LABA/LAMA group. The annual FEV1 decline rate was significantly worsened in the ICS/LABA group compared to the LABA/LAMA group (adjusted ß-coefficient=-197 [95% CI=-307--87]) in the subgroup with BEC < 200/uL. CONCLUSION: In patients with bronchiectasis and airflow obstruction, the use of ICS/LABA/LAMA and ICS/LABA demonstrated a reduced risk of exacerbation compared to LABA/LAMA therapy in those with BEC ≥ 300/uL. Conversely, for those with BEC < 200/uL, the use of ICS/LABA was associated with an accelerated decline in FEV1 in comparison to LABA/LAMA therapy. Further assessment of BEC is necessary as a potential biomarker for the use of ICS in patients with bronchiectasis and airflow obstruction.

Spirometric Interpretation and Clinical Relevance According to Different Reference Equations.

BACKGROUND: Global Lung Function Initiative (GLI)-2012 reference equation is currently suggested for interpretation of spirometry results and a new local reference equation has been developed in South Korea. However, lung function profiles according to the different reference equations and their clinical relevance have not been identified in chronic obstructive pulmonary disease (COPD) patients. METHODS: Our cross-sectional study evaluated Choi's, Korean National Health and National Examination Survey (KNHANES)-VI, and GLI-2012 reference equations. We estimated the percentages of predictive forced expiratory volume in one second (FEV1) and airflow limitation severity according to reference equations and analyzed their associations with patient reported outcomes (PROs): COPD assessment test (CAT) score, St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) score, and six minute walk distance (6MWD). RESULTS: In the eligible 2,180 COPD patients, lower predicted values of FEV1 and forced vital capacity (FVC) were found in GLI-2012 compared to Choi's and KNHANES-VI equations. GLI-2012 equation resulted in a lower proportion of patients being classified as FEV1 < 80% or FVC < 80% compared to the other equations. However, the Z-scores of FEV1 and FVC were similar between the KNHANES-VI and GLI-2012 equations. Three reference equations exhibited significant associations between FEV1 (%) and patient-reported outcomes (CAT score, SGRQ-C score, and 6MWD). CONCLUSION: GLI-2012 reference equation may not accurately reflect FEV1 (%) in the Korean population, but the Z-score using GLI-2012 equation can be a viable option for assessing FEV1 and airflow limitation in COPD patients. Similar to the other two equations, the GLI-2012 equation demonstrated significant associations with PROs.

Association between timed up-and-go test and subsequent pneumonia: A cohort study.

BACKGROUND: Sarcopenia is a risk factor for pneumonia in the elderly, and the timed up-and-go test (TUG) can be used as a screening tool for sarcopenia in this population. This study aimed to evaluate the association between TUG test results and future pneumonia or ventilator care. MATERIALS AND METHODS: From the National Health Insurance Service-Senior Cohort database, we identified 19,804 people without neurological diseases who underwent the TUG test in the National Screening Program for Transitional Ages at the age of 66 years during 2007-2008. Gait abnormality was defined as taking 10 s or longer to perform the TUG test. Pneumonia occurrence was defined using the International Classification of Diseases 10th Revision (ICD-10) code for pneumonia (J12-J18, J69), and ventilator care was defined by procedure codes (M5830, M5850, M5867, M5858, M5860, M5859) according to the Healthcare Common Procedure Coding system codes from 2007 to 2015. RESULTS: The mean follow-up period was 7.4 years (standard error, SE 0.02). The incidence rates of pneumonia in the normal and slow TUG groups were 38 and 39.5/1000 person-years, respectively. The slow TUG group did not show a higher risk of pneumonia (adjusted hazard ratio [aHR], 1.042; 95% confidence interval [95% CI], 0.988-1.107]). Regarding ventilator care, the incidence was 4.7 and 5.2 cases per 1,000 person-years in the normal and slow TUG groups, respectively. Slow TUG groups also did not show an increased risk of ventilator occurrence (aHR, 1.136, [95% CI = 0.947-1.363]). CONCLUSION: The TUG test result was not associated with future pneumonia or ventilator care and may not be useful for predicting pneumonia in community-dwelling elderly individuals. Further studies are needed to identify additional functional tools for sarcopenia associated with future pneumonia occurrences.

Preliminary investigation on the implementation of an artificial synapse using TaOx-based memristor with thermally oxidized active layer.

This study presents a preliminary exploration of thermally oxidized TaOx-based memristors and their potential as artificial synapses. Unlike the 10-min annealed devices, which display instability due to current overshoots, the 5-min annealed device exhibits stable resistive switching, retention, and endurance characteristics. Moreover, our memristor showcases synaptic behaviors encompassing potentiation, depression, spike-timing-dependent plasticity, and excitatory postsynaptic currents. This synaptic emulation holds tremendous promise for applications in neuromorphic computing, offering the opportunity to replicate the adaptive learning principles observed in biological synapses. In addition, we evaluate the device's suitability for pattern recognition within a neural network using the modified National Institute of Standards and Technology dataset. Our assessment reveals that the Pt/TaOx/Ta memristor with an oxidized insulator achieves outstanding potential manifested by an accuracy of 93.25% for the identical pulse scheme and an impressive accuracy of 95.42% for the incremental pulse scheme.

Associations between depression and anxiety index and frequency of acute exacerbation in chronic obstructive pulmonary disease.

BACKGROUND: Comorbidities of chronic obstructive pulmonary disease (COPD) influence clinical characteristics and prognosis. OBJECTIVES: This study compared the clinical characteristics and exacerbation rate of COPD according to the presence of depression or anxiety. DESIGN: This study used data from The Korea COPD Subgroup Study (KOCOSS) cohort, a nationwide prospective cohort from 54 medical centers, between April 2012 and 2019. METHODS: Depression and anxiety were diagnosed with the Beck Depression Inventory and Beck Anxiety Inventory. Negative binomial regression analysis was performed to analyze the frequency of exacerbations in depressed patients and anxiety. Differences in lung function trajectory according to presence of depression/anxiety were analyzed using a linear mixed model. RESULTS: In all, 2147 patients were enrolled. Depressed patients or anxiety had lower lung function, higher modified Medical Research Council (mMRC) grade, St. George Respiratory Questionnaire (SGRQ) score, and COPD assessment test score, and higher rates of exacerbation in the past year than those without depression/anxiety. Depressed patients had a higher frequency of moderate to severe exacerbations [Incidence Rate Ratio (IRR): 1.57, CI: 1.17-2.11, p = 0.002] and those with anxiety had higher frequencies of moderate to severe (IRR: 1.52, CI: 1.03-2.27, p = 0.038) and severe exacerbations (IRR: 2.13, CI: 1.09-4.15, p = 0.025) during 1-year follow-up compared to those without these comorbidities. The differences in the change in annual forced expiratory volume in 1 seconds (FEV1) over 3 years according to the presence of depression or anxiety were not statistically significant. CONCLUSION: Depressed and anxious patients showed increased respiratory symptoms and exacerbation rate as well as reduced health-related quality of life, whereas there were no significant differences in changes in lung function between groups with and without depression/anxiety.

Correction: Synaptic plasticity and non-volatile memory characteristics in TiN-nanocrystal-embedded 3D vertical memristor-based synapses for neuromorphic systems.

Correction for 'Synaptic plasticity and non-volatile memory characteristics in TiN-nanocrystal-embedded 3D vertical memristor-based synapses for neuromorphic systems' by Seyeong Yang et al., Nanoscale, 2023, https://doi.org/10.1039/D3NR01930F.

Synaptic plasticity and non-volatile memory characteristics in TiN-nanocrystal-embedded 3D vertical memristor-based synapses for neuromorphic systems.

Although vertical configurations for high-density storage require challenging process steps, such as etching high aspect ratios and atomic layer deposition (ALD), they are more affordable with a relatively simple lithography process and have been employed in many studies. Herein, the potential of memristors with CMOS-compatible 3D vertical stacked structures of Pt/Ti/HfOx/TiN-NCs/HfOx/TiN is examined for use in neuromorphic systems. The electrical characteristics (including I-V properties, retention, and endurance) were investigated for both planar single cells and vertical resistive random-access memory (VRRAM) cells at each layer, demonstrating their outstanding non-volatile memory capabilities. In addition, various synaptic functions (including potentiation and depression) under different pulse schemes, excitatory postsynaptic current (EPSC), and spike-timing-dependent plasticity (STDP) were investigated. In pattern recognition simulations, an improved recognition rate was achieved by the linearly changing conductance, which was enhanced by the incremental pulse scheme. The achieved results demonstrated the feasibility of employing VRRAM with TiN nanocrystals in neuromorphic systems that resemble the human brain.

Association between successful weaning from nasogastric tube feeding and thoracic muscle mass in patients with aspiration pneumonia.

Nasogastric tube feeding is often used to provide optimal nutrition and hydration in patients with aspiration pneumonia. However, evidence regarding radiologic indicators for successful nasogastric tube weaning is lacking. We investigated whether thoracic skeletal muscle assessment can be useful for predicting successful weaning from nasogastric tube feeding in patients with aspiration pneumonia. This longitudinal, observational study included subjects with aspiration pneumonia who underwent a videofluoroscopic swallowing study (VFSS) and chest computed tomography (CT) in Boramae Medical Center, from January 2012 to December 2019. We estimated the area under the receiver operating characteristics curve (AUC) to evaluate the predictive performance of skeletal muscle and visceral fat parameters and VFSS results for successful weaning from nasogastric tube feeding. A board-certified radiologist measured muscle and fat areas. Muscle and fat volumes were segmented and measured using an externally validated convolutional neural network model. Among the 146 included patients, nasogastric tube feeding was successfully transitioned to oral feeding in 46.6%. After adjusting for covariables related to successful weaning, skeletal muscle areas, indices, and volume indices were positively associated with successful nasogastric tube weaning. Although VFSS results and skeletal muscle parameters alone showed suboptimal performance for predicting successful weaning, a prediction model combining skeletal muscle index at the T4 level and VFSS results improved the prediction performance to an acceptable level (AUC ≥ 0.7). Skeletal muscle index measured at the T4 level may be a useful supplementary indicator for predicting successful weaning from nasogastric tube feeding in patients with aspiration pneumonia.

Validation of the Rome proposal for severity of acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: The Rome proposal provides an objective assessment tool for severity of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) but requires validation. OBJECTIVES: We aimed to evaluate the predictive performance of the Rome proposal in patients with AE-COPD. DESIGN: This observational study assessed the patients who visited the emergency room (ER) or were hospitalized due to AE-COPD between January 2010 and December 2020. METHODS: We compared the performance of the Rome Proposal with that of the DECAF score or GesEPOC 2021 criteria in predicting intensive care unit (ICU) admission, need for non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV), and in-hospital mortality. RESULTS: A total of 740 events of ER visit or hospitalization due to AE-COPD were reviewed and classified into mild (30.9%), moderate (58.6%), or severe (10.4%) group according to the Rome proposal. The severe group had a higher rate of ICU admission, required more NIV or IMV, and had a higher in-hospital mortality than the mild and moderate groups. The predictive performance of the Rome proposal was significantly better for ICU admission [area under the receiver operating characteristic curve (AU-ROC) = 0.850 versus 0.736, p = 0.004] and need for NIV or IMV (AU-ROC = 0.870 versus 0.770, p = 0.004) than that of the GesEPOC 2021 criteria but better than that of the DECAF score only in female patients. There was no significant difference in predicting the in-hospital mortality between the Rome proposal and DECAF score or GesEPOC 2021 criteria. CONCLUSION: External validation of the Rome Proposal in Korean patients demonstrated excellent performance for ICU admission and need for NIV or IMV and an acceptable performance for in-hospital mortality.

The Incidence of Brain-Dead Donors Based on Screening and Management Led by Intensivists.

BACKGROUND This study aimed to compare the incidence of brain-dead (BD) donors and potential brain-dead (PBD) donors before vs after the introduction of intensivists. MATERIAL AND METHODS This longitudinal retrospective study was performed between January 2012 and December 2020 at Seoul Metropolitan Government-Seoul National University Boramae Medical Center. Four dedicated intensivists were introduced in January 2016. The periods before and after introduction of the intensivists were defined as the pre-introduction period (2012-2015) and post-introduction period (2016-2020), respectively. RESULTS During the study period, there were 2872 discharges in the Intensive Care Unit, of which there were a total of 113 PBD (3.93%) and 36 BD (1.25%) donors. The number of PBD and BD donors increased in the post-introduction period compared in the pre-introduction period (PBD, 47.84 vs 27.14 per 1000 discharges; BD, 13.59 vs 11.03 per 1000 discharges). Poisson regression analysis showed the annual incidence rate of PBD donors significantly increased post-introduction (PBD, 27.53% vs 48.11%, P=0.044), while those of BD donors were similar between the 2 groups (BD, 11.41% vs 13.9%; P=0.743). The annual incidence rate of the total number of organ donations, multi-organ donations (>3 organs), and donation of organs (heart, lung, and kidney) increased in the post-introduction period compared to that in the pre-introduction period. CONCLUSIONS Our findings suggest a beneficial role of a dedicated intensivist, not only in improving actual organ donation and discovering PBD donors, but also in affecting the yield of the heart and lung transplantation in actual organ donation compared to donors without a dedicated intensivist.

The factors associated with mortality and progressive disease of nontuberculous mycobacterial lung disease: a systematic review and meta-analysis.

This systematic review and meta-analysis aimed to comprehensively evaluate the factors associated with mortality and progressive disease in NTM-LD patients. We conducted a literature search to identify the eligible studies, dated between January 1, 2007, and April 12, 2021. Forty-one studies with total 10,452 patients were included. The overall all-cause mortality rate was 20% (95% CI 17-24%). The overall rates of clinical and radiographic progressive disease were 46% (95% CI 39-53%) and 43% (95% CI 31-55%), respectively. Older age, male sex, history of TB, diabetes, chronic heart disease, malignancy, systemic immunosuppression, chronic liver disease, presence of cavity, consolidative radiologic features, acid-fast bacillus (AFB) smear positivity, hypoalbuminemia, anemia, increasing platelet count, high CRP, and high ESR were significantly associated with increased all-cause mortality, whereas increasing body mass index (BMI), hemoptysis, and treatment with rifamycin regimen (in M. xenopi) were significantly associated with decreased all-cause mortality in multivariable analysis. History of TB, Aspergillus co-infection, cough, increased sputum, weight loss, presence of cavity, and AFB smear positivity were significantly associated with increased clinical progression with treatment, while older age and low BMI were significantly associated with decreased clinical progression in multivariable analysis. Older age, interstitial lung disease, presence of cavity, consolidative radiologic feature, anemia, high CRP, and leukocytosis were significantly associated with increased radiographic progression after adjusting for covariates. Older age, history of tuberculosis, presence of cavity, consolidative radiologic features, AFB smear positivity, anemia, and high C-reactive protein were common significant factors associated with the all-cause mortality and clinical or radiographic progressive disease of NTM-LD. These factors are thought to directly affect NTM-LD related mortality. The future prediction models for the prognosis of NTM-LD should be established considering these factors.

Summary of Korean Asthma Guideline.

Asthma is a chronic inflammatory airway disease that is characterized by variable airflow obstruction. The Korean Asthma Study Group of the Korean Academy of Tuberculosis and Respiratory Diseases has recently updated the Korean Asthma Guideline. This review summarizes the updated Korean Asthma Guideline. Asthma prevalence is increasing worldwide, and in Korea. Variable airflow obstruction can be confirmed by bronchodilator response or other tests, and should be established prior to the controller medication. A low-dose inhaled corticosteroid-formoterol is used to alleviate symptoms in all treatment step, and it can be used as a controller as well as reliever in steps 3-5. This approach is preferred, because it reduces the risk of severe exacerbations, compared to the use of short-acting ß2-agonist as reliever. In severe asthma, phenotype/endotype based on the underlying inflammation should be evaluated. For type 2 severe asthma, the biologics should be considered.