Deep learning-based prognostication in idiopathic pulmonary fibrosis using chest radiographs.

OBJECTIVES: To develop and validate a deep learning-based prognostic model in patients with idiopathic pulmonary fibrosis (IPF) using chest radiographs. METHODS: To develop a deep learning-based prognostic model using chest radiographs (DLPM), the patients diagnosed with IPF during 2011-2021 were retrospectively collected and were divided into training (n = 1007), validation (n = 117), and internal test (n = 187) datasets. Up to 10 consecutive radiographs were included for each patient. For external testing, three cohorts from independent institutions were collected (n = 152, 141, and 207). The discrimination performance of DLPM was evaluated using areas under the time-dependent receiver operating characteristic curves (TD-AUCs) for 3-year survival and compared with that of forced vital capacity (FVC). Multivariable Cox regression was performed to investigate whether the DLPM was an independent prognostic factor from FVC. We devised a modified gender-age-physiology (GAP) index (GAP-CR), by replacing DLCO with DLPM. RESULTS: DLPM showed similar-to-higher performance at predicting 3-year survival than FVC in three external test cohorts (TD-AUC: 0.83 [95% CI: 0.76-0.90] vs. 0.68 [0.59-0.77], p < 0.001; 0.76 [0.68-0.85] vs. 0.70 [0.60-0.80], p = 0.21; 0.79 [0.72-0.86] vs. 0.76 [0.69-0.83], p = 0.41). DLPM worked as an independent prognostic factor from FVC in all three cohorts (ps < 0.001). The GAP-CR index showed a higher 3-year TD-AUC than the original GAP index in two of the three external test cohorts (TD-AUC: 0.85 [0.80-0.91] vs. 0.79 [0.72-0.86], p = 0.02; 0.72 [0.64-0.80] vs. 0.69 [0.61-0.78], p = 0.56; 0.76 [0.69-0.83] vs. 0.68 [0.60-0.76], p = 0.01). CONCLUSIONS: A deep learning model successfully predicted survival in patients with IPF from chest radiographs, comparable to and independent of FVC. CLINICAL RELEVANCE STATEMENT: Deep learning-based prognostication from chest radiographs offers comparable-to-higher prognostic performance than forced vital capacity. KEY POINTS: • A deep learning-based prognostic model for idiopathic pulmonary fibrosis was developed using 6063 radiographs. • The prognostic performance of the model was comparable-to-higher than forced vital capacity, and was independent from FVC in all three external test cohorts. • A modified gender-age-physiology index replacing diffusing capacity for carbon monoxide with the deep learning model showed higher performance than the original index in two external test cohorts.

Pulse versus non-pulse corticosteroid therapy in patients with acute exacerbation of idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: Corticosteroids are commonly used for the treatment of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF); however, the optimal initial dose of corticosteroids remains uncertain due to a lack of sufficient evidence. We evaluated whether the administration of a pulse dose of corticosteroids resulted in improved survival outcomes compared with conventional non-pulse dose of corticosteroids. METHODS: We retrospectively analysed 238 patients with AE-IPF treated with corticosteroids at a tertiary referral hospital between January 2013 and December 2021. Based on whether a pulse dose of corticosteroids (methylprednisolone of ≥250 mg/day or equivalent) was administered within 7 days of hospitalization for AE-IPF, the patients were divided into the pulse and non-pulse regimen groups. The survival outcomes were compared between the two groups using multivariable regression and propensity score-matched analyses. RESULTS: Among the 238 patients, 59 patients received pulse dose of corticosteroids, whereas 179 patients received conventional non-pulse dose of corticosteroids. After adjusting for the confounding factors related to the baseline clinical and radiographic severity, compared with the conventional non-pulse regimen, the pulse regimen of corticosteroids did not reduce the risk of mortality at the 3-month (aHR 0.84, 95% CI 0.45-1.38) or 12-month (aHR 0.96, 95% CI 0.60-1.25) follow-ups. Propensity score-matched analysis revealed similar results. CONCLUSION: The survival outcomes of patients with AE-IPF who received a pulse dose of corticosteroids did not differ from those of patients who received conventional non-pulse dose of corticosteroids. Further prospective studies are required to establish the optimal initial dose of corticosteroids for the treatment of AE-IPF.

Classical monocyte-derived macrophages as therapeutic targets of umbilical cord mesenchymal stem cells: comparison of intratracheal and intravenous administration in a mouse model of pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease that has no cure. Although mesenchymal stem cells (MSCs) have been reported to ameliorate lung inflammation and fibrosis in mouse models, their mechanisms of action remain unknown. Therefore, we aimed to determine the changes in various immune cells, especially macrophages and monocytes, involved in the effects of MSC treatment on pulmonary fibrosis. METHODS: We collected and analyzed explanted lung tissues and blood from patients with IPF who underwent lung transplantation. After establishing a pulmonary fibrosis model via the intratracheal administration of bleomycin (BLM) to 8-week-old mice, MSCs derived from human umbilical cords were administered intravenously or intratracheally on day 10 and the lungs were immunologically analyzed on days 14 and 21. Flow cytometry was performed to analyze the immune cell characteristics, and gene expression levels were examined using quantitative reverse transcription-polymerase chain reaction. RESULTS: In the histological analysis of explanted human lung tissues, the terminally fibrotic areas contained a larger number of macrophages and monocytes than the early fibrotic areas of the lungs. When human monocyte-derived macrophages (MoMs) were stimulated with interleukin-13 in vitro, the expression of type 2 macrophage (M2) markers was more prominent in MoMs from the classical monocyte subset than in those from intermediate or non-classical monocyte subsets, and MSCs suppressed M2 marker expression independent of MoM subsets. In the mouse model, the increased number of inflammatory cells in the bronchoalveolar lavage fluid and the degree of lung fibrosis observed in BLM-treated mice were significantly reduced by MSC treatment, which tended to be more prominent with intravenous administration than intratracheal administration. Both M1 and M2 MoMs were upregulated in BLM-treated mice. The M2c subset of M2 MoMs was significantly reduced by MSC treatment. Among M2 MoMs, M2 MoMs derived from Ly6C+ monocytes were most effectively regulated by the intravenous administration, not intratracheal administration, of MSCs. CONCLUSIONS: Inflammatory classical monocytes may play a role in lung fibrosis in human IPF and BLM-induced pulmonary fibrosis. Intravenous rather than intratracheal administration of MSCs may ameliorate pulmonary fibrosis by inhibiting monocyte differentiation into M2 macrophages.

Erratum: Correction of Affiliations in the Article "Outcomes of Patients on the Lung Transplantation Waitlist in Korea: A Korean Network for Organ Sharing Data Analysis".

This corrects the article on p. e294 in vol. 37, PMID: 36281485.

COVID-19 Vaccine-Associated Pneumonitis in the Republic of Korea: A Nationwide Multicenter Survey.

BACKGROUND: Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2. METHODS: In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies. RESULTS: From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients. CONCLUSION: These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

A unique population of neutrophils generated by air pollutant-induced lung damage exacerbates airway inflammation.

BACKGROUND: Diesel exhaust particles (DEPs) are the main component of traffic-related air pollution and have been implicated in the pathogenesis and exacerbation of asthma. However, the mechanism by which DEP exposure aggravates asthma symptoms remains unclear. OBJECTIVE: This study aimed to identify a key cellular player of air pollutant-induced asthma exacerbation and development. METHODS: We examined the distribution of innate immune cells in the murine models of asthma induced by house dust mite and DEP. Changes in immune cell profiles caused by DEP exposure were confirmed by flow cytometry and RNA-Seq analysis. The roles of sialic acid-binding, Ig-like lectin F (SiglecF)-positive neutrophils were further evaluated by adoptive transfer experiment and in vitro functional studies. RESULTS: DEP exposure induced a unique population of lung granulocytes that coexpressed Ly6G and SiglecF. These cells differed phenotypically, morphologically, functionally, and transcriptionally from other SiglecF-expressing cells in the lungs. Our findings with murine models suggest that intratracheal challenge with DEPs induces the local release of adenosine triphosphate, which is a damage-associated molecular pattern signal. Adenosine triphosphate promotes the expression of SiglecF on neutrophils, and these SiglecF+ neutrophils worsen type 2 and 3 airway inflammation by producing high levels of cysteinyl leukotrienes and neutrophil extracellular traps. We also found Siglec8- (which corresponds to murine SiglecF) expressing neutrophils, and we found it in patients with asthma-chronic obstructive pulmonary disease overlap. CONCLUSION: The SiglecF+ neutrophil is a novel and critical player in airway inflammation and targeting this population could reverse or ameliorate asthma.

Expression-based species deconvolution and realignment removes misalignment error in multispecies single-cell data.

BACKGROUND: Although single-cell RNA sequencing of xenograft samples has been widely used, no comprehensive bioinformatics pipeline is available for human and mouse mixed single-cell analyses. Considering the numerous homologous genes across the human and mouse genomes, misalignment errors should be evaluated, and a new algorithm is required. We assessed the extents and effects of misalignment errors and exonic multi-mapping events when using human and mouse combined reference data and developed a new bioinformatics pipeline with expression-based species deconvolution to minimize errors. We also evaluated false-positive signals presumed to originate from ambient RNA of the other species and address the importance to computationally remove them. RESULT: Error when using combined reference account for an average of 0.78% of total reads, but such reads were concentrated to few genes that were greatly affected. Human and mouse mixed single-cell data, analyzed using our pipeline, clustered well with unmixed data and showed higher k-nearest-neighbor batch effect test and Local Inverse Simpson's Index scores than those derived from Cell Ranger (10 × Genomics). We also applied our pipeline to multispecies multisample single-cell library containing breast cancer xenograft tissue and successfully identified all samples using genomic array and expression. Moreover, diverse cell types in the tumor microenvironment were well captured. CONCLUSION: We present our bioinformatics pipeline for mixed human and mouse single-cell data, which can also be applied to pooled libraries to obtain cost-effective single-cell data. We also address misalignment, multi-mapping error, and ambient RNA as a major consideration points when analyzing multispecies single-cell data.

Impact of smoking on the development of idiopathic pulmonary fibrosis: results from a nationwide population-based cohort study.

BACKGROUND: Smoking has been considered an important risk factor for idiopathic pulmonary fibrosis (IPF) incidence. However, there are no population-based large-scale studies demonstrating the effects of smoking on the development of IPF. We aimed to evaluate the effect of smoking on IPF development using a nationwide population-based cohort. METHODS: Using the Korean National Health Information Database, we enrolled individuals who had participated in the health check-up service between 2009 and 2012. Participants having a prior diagnosis of IPF were excluded. The history of smoking status and quantity was collected by a questionnaire. We identified all cases of incident IPF through 2016 on the basis of ICD-10 codes for IPF and medical claims. Cox proportional hazards models were used to calculate the adjusted HR (aHR) of the development of IPF. RESULTS: A total of 25 113 individuals (0.11%) with incident IPF were identified out of 23 242 836 participants registered in the database. The risk of IPF was significantly higher in current and former smokers than in never smokers, with an aHR of 1.66 (95% CI 1.61 to 1.72) and 1.42 (95% CI 1.37 to 1.48), respectively. Current smokers had a higher risk of IPF than former smokers (aHR 1.17, 95% CI 1.13 to 1.21). The risk of IPF development increased as the smoking intensity and duration increased. CONCLUSION: Smoking significantly increased the risk of IPF development. Current smokers had a higher risk of IPF than former smokers. A dose-response relationship was observed between smoking and the development of IPF.

Blood Krebs von den Lungen-6 levels predict treatment response to antifibrotic therapy in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Antifibrotic therapy can slow disease progression (DP) in patients with idiopathic pulmonary fibrosis (IPF). However, the prognostic biomarkers for DP in patients with IPF receiving antifibrotic therapy have not been identified. Therefore, we aimed to evaluate the prognostic efficacy of serum Krebs von den Lungen-6 (KL-6) for DP in patients with IPF receiving antifibrotic therapy. METHODS: The clinical data of 188 patients with IPF who initiated antifibrotic therapy at three tertiary hospitals was retrospectively analyzed. DP was defined as a relative decline in forced vital capacity (FVC) ≥ 10%, diffusing capacity for carbon monoxide ≥ 15%, acute exacerbation, or deaths during 6 months after antifibrotic therapy. RESULTS: The mean age of patients was 68.9 years, 77.7% were male, and DP occurred in 43 patients (22.9%) during follow-up (median, 7.6 months; interquartile range, 6.2-9.8 months). There was no difference in baseline KL-6 levels between the DP and no-DP groups; however, among patients with high baseline KL-6 levels (≥ 500 U/mL), changes in KL-6 levels over 1 month were higher in the DP group than those in the non-DP group, and higher relative changes in KL-6 over 1 month were independently associated with DP (odds ratio, 1.043; 95% confidence interval 1.005-1.084) in the multivariable logistic analysis adjusted for age and FVC. In the receiver operating characteristic curve analysis, the 1-month change in KL-6 was also useful for predicting DP (area under the curve = 0.707; P < 0.012). CONCLUSIONS: Our data suggest that the relative change in KL-6 over 1 month might be useful for predicting DP in patients with IPF receiving antifibrotic therapy when baseline KL6 is high.

Effect of chlorhexidine Mouthrinse on prevention of microbial contamination during EBUS-TBNA: a randomized controlled trial.

BACKGROUND: Although endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure, fatal infectious complications have been reported. However, adequate preventive strategies have not been determined. We aimed to investigate the effect of chlorhexidine mouthrinse on the prevention of microbial contamination during EBUS-TBNA. METHODS: In this single-center, assessor-blinded, parallel-group randomized controlled trial, we randomly assigned adult participants undergoing EBUS-TBNA using a convex probe to gargle for 1 minute with 100 mL of 0.12% chlorhexidine gluconate before EBUS-TBNA or to receive usual care (no chlorhexidine mouthrinse). Aspiration needle wash samples were collected immediately after completion of EBUS-TBNA by instilling sterile saline into the used needle. The primary outcome was colony forming unit (CFU) counts per mL of needle wash samples in aerobic cultures. Secondary outcomes were CFU counts per mL of needle wash samples in anaerobic cultures, fever within 24 hours after EBUS-TBNA, and infectious complications within 4 weeks after EBUS-TBNA. RESULTS: From January 2021 to June 2021, 106 patients received either chlorhexidine mouthrinse (n = 51) or usual care (n = 55). The median CFU counts of needle wash samples in aerobic cultures were not significantly different in the two groups (10 CFU/mL vs 20 CFU/mL; P = 0.70). There were no significant differences between the groups regarding secondary outcomes, including median CFU counts in anaerobic cultures (P = 0.41) and fever within 24 hours after EBUS-TBNA (11.8% vs 5.6%, P = 0.31). There were no infectious complications within 4 weeks in both groups. CONCLUSIONS: Chlorhexidine mouthrinse did not reduce CFU counts in needle wash samples of EBUS-TBNA. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04718922 . Registered on 22/01/2021.

Outcomes of Patients on the Lung Transplantation Waitlist in Korea: A Korean Network for Organ Sharing Data Analysis.

BACKGROUND: The demand for lung transplants continues to increase in Korea, and donor shortages and waitlist mortality are critical issues. This study aimed to evaluate the factors that affect waitlist outcomes from the time of registration for lung transplantation in Korea. METHODS: Data were obtained from the Korean Network for Organ Sharing for lung-only registrations between September 7, 2009, and December 31, 2020. Post-registration outcomes were evaluated according to the lung disease category, blood group, and age. RESULTS: Among the 1,671 registered patients, 49.1% had idiopathic pulmonary fibrosis (group C), 37.0% had acute respiratory distress syndrome and other interstitial lung diseases (group D), 7.2% had chronic obstructive pulmonary disease (group A), and 6.6% had primary pulmonary hypertension (group B). Approximately half of the patients (46.1%) were transplanted within 1 year of registration, while 31.8% died without receiving a lung transplant within 1 year of registration. Data from 1,611 patients were used to analyze 1-year post-registration outcomes, which were classified as transplanted (46.1%, n = 743), still awaiting (21.1%, n = 340), removed (0.9%, n = 15), and death on waitlist (31.8%, n = 513). No significant difference was found in the transplantation rate according to the year of registration. However, significant differences occurred between the waitlist mortality rates (P = 0.008) and the still awaiting rates (P = 0.009). The chance of transplantation after listing varies depending on the disease category, blood type, age, and urgency status. Waitlist mortality within 1 year was significantly associated with non-group A disease (hazard ratio [HR], 2.76, P < 0.001), age ≥ 65 years (HR, 1.48, P < 0.001), and status 0 at registration (HR, 2.10, P < 0.001). CONCLUSION: Waitlist mortality is still higher in Korea than in other countries. Future revisions to the lung allocation system should take into consideration the high waitlist mortality and donor shortages.

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.

Impact of Sleep Duration on Mortality and Quality of Life in Chronic Kidney Disease: Results from the 2007-2015 KNHANES.

INTRODUCTION: In the general population, short and long sleep durations have been associated with adverse health outcomes. However, this association remains unclear in patients with chronic kidney disease (CKD). We examined the relationship of sleep duration to mortality and health-related quality of life (HRQOL) in individuals with CKD. METHODS: A total of 1,783 adults with CKD who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey were analyzed. CKD was defined as an estimated glomerular filtration rate of <60 mL/min per 1.73 m2. Participants were categorized into 3 groups according to self-reported sleep duration: <6 h (short sleepers), 6-8 h, and >8 h (long sleepers). The outcome variables were all-cause mortality and HRQOL. HRQOL was assessed using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.4 years, 481 (27%) deaths occurred. In unadjusted Cox regression analysis, long sleepers with CKD had an increased risk of death (hazard ratio [HR], 1.62; 95% confidence interval [CI]: 1.26-2.09). This significant association remained after adjusting for age, sex, and BMI (HR, 1.36; 95% CI: 1.05-1.75); however, it was lost after adjusting for CKD stage, social and lifestyle factors, and presence of comorbidities (HR, 1.15; 95% CI: 0.89-1.49). Compared with 6- to 8-h sleepers with CKD, long sleepers with CKD had significantly worse HRQOL in multivariable linear regression models. The adjusted means of the EQ-5D index were 0.80 (95% CI: 0.77-0.82) for short sleepers, 0.81 (95% CI: 0.80-0.82) for 6- to 8-h sleepers, and 0.76 (95% CI: 0.73-0.79) for long sleepers (p = 0.01). DISCUSSION/CONCLUSION: Long sleep duration is associated with poor HRQOL in Korean adults with CKD. The weak association between long sleep duration and mortality was attenuated after multivariable adjustment in this study.

Risk of cancer incidence in patients with idiopathic pulmonary fibrosis: A nationwide cohort study.

BACKGROUND AND OBJECTIVE: IPF shares common risk factors and has pathogenic similarities with cancer. However, limited population-based data are available on cancer risk among patients with IPF. Herein, we investigated whether IPF is associated with an increased risk for cancer incidence from a nationwide database in South Korea. METHODS: In this population-based cohort study, patients with IPF were enrolled from 2009 to 2014, and matched controls were randomly selected at a control-to-case ratio of 3:1. In both groups, individuals diagnosed with any malignancy before the index date were excluded. The incidence rates of cancer were measured as the number of events per 1000 person-years. Multivariable Cox regression models were used to assess the cancer incidence risk. RESULTS: This study included 25 241 patients with IPF and 75 723 matched controls. The overall cancer incidence in patients with IPF was 29.0 cases per 1000 person-years, and it was significantly higher in the IPF group than in the non-IPF group (HR, 2.09; 95% CI, 1.96-2.16). Lung cancer showed the highest HR (5.89; 95% CI, 5.40-6.42), followed by lymphoma, skin, uterine cervical, multiple myeloma, thyroid, leukaemia, pancreatic, liver and prostate cancer. Moreover, adjustment for the effects of smoking and other cancer-associated covariates had little effect on the HR of overall and specific cancers. CONCLUSION: The cancer incidence risk was higher in the IPF group than in the non-IPF group. Therefore, healthcare providers should be aware of this risk when treating patients with IPF.

Sleep Duration and Its Associations with Mortality and Quality of Life in Chronic Obstructive Pulmonary Disease: Results from the 2007-2015 KNAHNES.

BACKGROUND: While extreme sleep duration negatively affects mortality and health-related quality of life (HRQOL) in general populations, the relationship remains uncertain in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To evaluate the association between sleep duration and mortality and HRQOL in patients with COPD. METHODS: We analyzed 3,349 participants with COPD enrolled in the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). Participants aged 40 years or older with a smoking history and prebronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.7 were eligible. The participants were categorized as short sleepers (<6 h), 6-8 h, and long sleepers (>8) according to self-reported sleep duration. The outcome variables were all-cause mortality and HRQOL. HRQOL was measured using the European Quality of Life-5 Dimensions (EQ-5D) index. RESULTS: During a median of 6.5 years, 386 (11.5%) participants died. In unadjusted Cox regression analysis, short sleepers with COPD had an increased risk of death (hazard ratio, 1.35; 95% confidence interval [CI]: 1.07-1.71). However, this association was not significant after adjusting for sociodemographic factors, BMI, FEV1, and comorbidities. In unadjusted and adjusted multiple linear regression, short sleepers had significantly worse HRQOL. The adjusted means of the EQ-5D index were 0.88 (95% CI: 0.87-0.89) for short sleepers, 0.90 (95% CI: 0.90-0.91) for 6- to 8-h sleepers, and 0.89 (95% CI: 0.87-0.91) for long sleepers (p = 0.01). CONCLUSIONS: In patients with COPD, sleep duration was not associated with all-cause mortality. However, short sleep duration was significantly associated with worse HRQOL.

Dexmedetomidine versus midazolam for sedation during endobronchial ultrasound-guided transbronchial needle aspiration: A randomised controlled trial.

BACKGROUND: Desaturation is a common complication of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Dexmedetomidine (DEX), a commonly used sedative in intensive care, is associated with less respiratory depression compared with other sedatives. OBJECTIVE: We compared DEX with midazolam (MDZ) when used as a sedative during EBUS-TBNA. DESIGN: A randomised, parallel, double-blinded trial. SETTING: A university-affiliated teaching hospital between June 2014 and July 2015. PATIENTS: A total of 102 patients who underwent EBUS-TBNA were randomly allocated to two groups (48 DEX group, 54 MDZ group). INTERVENTIONS: DEX group received 0.25 to 0.75 µg kg-1 h-1 (start with 0.5 µg kg-1 h-1, modulated in three steps from 0.25 to 0.75 µg kg-1 h-1) of DEX after a loading dose of 0.25 µg kg-1 h-1 for 10 min to maintain a Ramsay Sedation Scale (RSS) of 3 to 5. If the patient was agitated, 1 mg of MDZ bolus was used as a rescue drug. Patients in the MDZ group initially received 0.05 mg kg-1 of MDZ as a bolus. For maintenance and rescue, 1 mg of MDZ bolus was used. MAIN OUTCOME MEASURES: The primary outcome was the presence of oxygen desaturation. Secondary outcomes were level of sedation (Ramsay Sedation Scale score), cough score, sedation and procedure satisfaction score. RESULTS: The baseline characteristics of the patients, duration of EBUS-TBNA procedures and the use of rescue MDZ were not different between the groups. There was no significant difference in desaturation events between the DEX and MDZ groups (56.3 and 68.5%, respectively; P = 0.20). The level of sedation and the sedation satisfaction scores were similar between the two groups. However, cough score was significantly lower in the DEX group (41.9 vs. 53.4; P = 0.02). CONCLUSION: The use of DEX during EBUS-TBNA was not superior to MDZ in terms of oxygen desaturation. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02157818.

Improved Oxygenation After Prone Positioning May Be a Predictor of Survival in Patients With Acute Respiratory Distress Syndrome.

OBJECTIVES: Prone position ventilation improves oxygenation and reduces the mortality of patients with severe acute respiratory distress syndrome. However, there is limited evidence about which patients would gain most survival benefit from prone positioning. Herein, we investigated whether the improvement in oxygenation after prone positioning is associated with survival and aimed to identify patients who will gain most survival benefit from prone positioning in patients with acute respiratory distress syndrome. DESIGN: A retrospective cohort study. SETTING: Medical ICU at a tertiary academic hospital between 2014 and 2020. PATIENTS: Adult patients receiving prone positioning for moderate-to-severe acute respiratory distress syndrome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcomes were ICU and 28-day mortality. A total of 116 patients receiving prone positioning were included, of whom 45 (38.8%) were ICU survivors. Although there was no difference in PaO2:FIO2 ratio before the first prone session between ICU survivors and nonsurvivors, ICU survivors had a higher PaO2:FIO2 ratio after prone positioning than nonsurvivors, with significant between-group difference (p < 0.001). The area under the receiver operating characteristic curve of the percentage change in the PaO2:FIO2 ratio between the baseline and 8-12 hours after the first prone positioning to predict ICU mortality was 0.87 (95% CI, 0.80-0.94), with an optimal cutoff value of 53.5% (sensitivity, 91.5%; specificity, 73.3%). Prone responders were defined as an increase in PaO2:FIO2 ratio of greater than or equal to 53.5%. In the multivariate Cox regression analysis, prone responders (hazard ratio, 0.11; 95% CI, 0.05-0.25), immunocompromised condition (hazard ratio, 2.15; 95% CI, 1.15-4.03), and Sequential Organ Failure Assessment score (hazard ratio, 1.16; 95% CI, 1.06-1.27) were significantly associated with 28-day mortality. CONCLUSIONS: The PaO2:FIO2 ratio after the first prone positioning differed significantly between ICU survivors and nonsurvivors. The improvement in oxygenation after the first prone positioning was a significant predictor of survival in patients with moderate-to-severe acute respiratory distress syndrome.

Validation of age, PaO2/FlO2 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, PaO2/FlO2, 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. METHODS: We retrospectively reviewed the medical records of patients who were diagnosed with ARDS using the Berlin criteria and admitted to the medical ICU at Seoul National University Hospital from January 2015 to December 2016. The validation of the APPS was performed by evaluating its calibration and predictive accuracy. Its calibration was plotted and quantified using the Hosmer-Lemeshow test. Its predictive accuracy was assessed by calculating the area under the receiver operating characteristics (AUC-ROC) curve. RESULTS: A total of 116 patients were analyzed, 32 of whom survived. Of the 116 patients, 11 (9.5%) were classified as APPS grade 1 (score 3-4), 88 (75.9%) as grade 2 (score 5-7) and 17 (14.6%) as grade 3 (score 8-9). In-hospital mortality was 27.3% for grade 1, 73.9% for grade 2 and 94.1% for grade 3 (P for trend < 0.001). The APPS was well calibrated (Hosmer-Lemeshow test, P = 0.578) and its predictive accuracy was acceptable (AUC-ROC 0.704, 95% confidence interval 0.599-0.809). CONCLUSIONS: The APPS predicted in-hospital mortality in Korean patients with ARDS with similar power to its application in a Western population and with acceptable predictive accuracy. TRIAL REGISTRATION: Retrospectively registered.

Extracorporeal membrane oxygenation as a bridge to lung transplantation: analysis of Korean organ transplantation registry (KOTRY) data.

BACKGROUND: The use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation has greatly increased. However, data regarding the clinical outcomes of this approach are lacking. The objective of this multicenter prospective observational cohort study was to evaluate lung transplantation outcomes in Korean Organ Transplantation Registry (KOTRY) patients for whom ECMO was used as a bridge to transplantation. METHODS: Between March 2015 and December 2017, a total of 112 patients received lung transplantation and were registered in the KOTRY, which is a prospective, multicenter cohort registry. The entire cohort was divided into two groups: the control group (n = 85, 75.9%) and bridge-ECMO group (n = 27, 24.1%). RESULTS: There were no significant differences in pre-transplant and intraoperative characteristics except for poorer oxygenation, more ventilator use, and longer operation time in the bridge-ECMO group. The prevalence of primary graft dysfunction at 0, 24, 48, and 72 h after transplantation did not differ between the two groups. Although postoperative hospital stays were longer in the bridge-ECMO group than in the control group, hospital mortality did not differ between the two groups (25.9% vs. 13.3%, P = 0.212). The majority of patients (70.4% of the bridge-ECMO group and 77.6% of the control group) were discharged directly to their homes. Finally, the use of ECMO as a bridge to lung transplantation did not significantly affect overall survival and graft function. CONCLUSIONS: Short- and long-term post-transplant outcomes of bridge-ECMO patients were comparable to recipients who did not receive ECMO.

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 rate of muscle mass change and skeletal muscle index (SMI) were also calculated. Multivariable Cox proportional hazards regression was used to evaluate the association between muscle loss and mortality. RESULTS: Among 125 patients, 113 (90.4%) patients were classified as having sarcopenia. The mean body mass index was 22.6 (3.9) kg/m2. Thirty-nine (31.2%) patients were within the normal range for muscle mass change, while 86 (68.8%) patients demonstrated rapid decline in muscle mass before admission to the ICU. Patients with rapid muscle loss showed high ICU mortality (59.3%) and in-hospital mortality (77.9%). Multivariate Cox analysis showed that ICU mortality and in-hospital mortality were independently associated with malignancy, Acute Physiology and Chronic Health Evaluation (APACHE) II score, SMI, and rapid muscle loss. CONCLUSION: Rapid muscle decline is correlated with increased ICU mortality and in-hospital mortality in critically ill patients with cirrhosis.