Background/Aims: The prognosis of patients with idiopathic pulmonary fibrosis (IPF) and respiratory failure requiring mechanical ventilation is poor. Therefore, mechanical ventilation is not recommended. Recently, outcomes of mechanical ventilation, including those for patients with IPF, have improved. The aim of this study was to investigate changes in the use of mechanical ventilation in patients with IPF and their outcomes over time. Methods: This retrospective, observational cohort study used data from the National Health Insurance Service database. Patients diagnosed with IPF between January 2011 and December 2019 who were placed on mechanical ventilation were included. We analyzed changes in the use of mechanical ventilation in patients with IPF and their mortality using the Cochran- Armitage trend test. Results: Between 2011 and 2019, 1,227 patients with IPF were placed on mechanical ventilation. The annual number of patients with IPF with and without mechanical ventilation increased over time. However, the ratio was relatively stable at approximately 3.5%. The overall hospital mortality rate was 69.4%. There was no improvement in annual hospital mortality rate. The overall 30-day mortality rate was 68.7%, which did not change significantly. The overall 90-day mortality rate was 85.3%. The annual 90-day mortality rate was decreased from 90.9% in 2011 to 83.1% in 2019 (p = 0.028). Conclusions Despite improvements in intensive care and ventilator management, the prognosis of patients with IPF receiving mechanical ventilation has not improved significantly.

BACKGROUND/OBJECTIVES: Chronic or intermittent hyperglycemia is associated with the development of diabetic complications. Oxidative stress and inflammation can be altered by hyperglycemia in diverse tissues, including kidneys and eyes, and play a pivotal role in diabetic complications. Our previous studies showed that the water-insoluble 5,7-dihydroxyflvone chrysin effectively combats diabetic damages incurred in diabetic kidneys and retinas. The current study employed the newly-synthesized 5.7-di-O-acetylchrysin, having higher solubility than chrysin, to compare the effects on diabetes-associated renal fibrosis and abnormal retinal neovascularization.MATERIALS/METHODS: In the in vivo study, db/db mice as animal models of type 2 diabetes were orally administrated 10 mg/kg BW diacetylchrysin, daily for 10 weeks. RESULTS: Unlike chrysin, oral administration of 10 mg/kg diacetylchrysin did not lower the blood glucose level and 24 h urine volume in db/db mice. Nevertheless, the urinary albumin excretion was markedly reduced. The administration of diacetylchrysin also diminished the deposition of collagen fibers in diabetic glomeruli and tubules by suppressing the induction of connective tissue growth factor and collagen IV in diabetic kidneys. Supplying diacetylchrysin enhanced the membrane type-1 matrix metalloproteinase (MMP) expression reduced in diabetic kidneys, while the tissue inhibitor of MMP-2 induction was attenuated in diacetylchrysin-challenged diabetic kidneys. In addition, supplementing diacetylchrysin to diabetic mice ameliorated renal injury due to glomerulosclerosis and tubular interstitial fibrosis. Furthermore, the reduced retinal inductions of Zonula occludens-1 and vascular endothelial cadherin in db/db mice were elevated in the retinal tissues of diacetylchrysintreated animals. Oral administration of diacetylchrysin curtailed the induction of vascular endothelial growth factor (VEGF) and VEGF receptor 2 in db/db mice, ultimately retarding diabetes-associated retinal neovascularization. Additionally, the retinal formation of acellular capillaries with leaky vessels was reduced in diacetylchrysin-treated db/db mice. CONCLUSION Diacetylchrysin may act as a potent pro-health agent for treating renal fibrosisassociated diabetic nephropathy and retinal neovascularization-associated diabetic retinopathy.

Lung cancer is a dismal disease as a leading cause of overall cancer death, but the development of immune checkpoint inhibitors (ICIs) in driver gene mutation negative metastatic non-small cell lung cancer (NSCLC) is changing the paradigm of lung cancer treatment. Recently, ICIs are expanding their treatment area to early-stage NSCLC and ICIs have also changed their treatment strategies of such patients. And it is important to appropriately select patients with resectable early-stage lung cancer through a multidisciplinary team approach and decrease the tumor relapse rate in the ICIs era. In this review article, we discuss the recently released neoadjuvant and adjuvant data of ICIs, their treatment rationale, and unmet needs in the treatment of early-stage NSCLC.

Background: Cardiac dysfunction patients have long been considered at high risk of reintubation. However, it is based on past studies in which only conventional oxygen therapy was applied after extubation. We investigated association between cardiac dysfunction and reintubation rate in situation where high-flow nasal cannula (HFNC) was widely used during post-extubation period. Methods: We conducted a retrospective observational cohort study of patients treated with HFNC after planned extubation in medical intensive care unit of single tertiary center. Patients were divided into normal function group (ejection fraction [EF] ≥45%) and cardiac dysfunction group (EF <45%). The primary outcome was reintubation rate within 72 hours following extubation. Results: Of 270 patients, 35 (13%) had cardiac dysfunction. Baseline characteristics were similar in both groups. There were no differences in the changes in vital signs between the two groups during the first 12 hours after extubation except diastolic blood pressure. The reintubation rates were 20% and 17% for cardiac dysfunction group and normal function group, respectively (p=0.637). In a multivariate Cox regression analysis, cardiac dysfunction was not associated with an increased risk of reintubation within 72 hours following extubation (hazard ratio, 1.56; p=0.292). Conclusion Cardiac dysfunction was not associated with increased reintubation rate within 72 hours when HFNC is immediately applied after planned extubation.

Objective: Coronavirus disease 2019 (COVID-19) has notably altered the emergency department isolation protocol, imposing stricter requirements on probable infectious disease patients that enter the department. This has caused adverse effects, such as an increased rate of leave without being seen (LWBS). This study describes the effect of fever/respiratory symptoms as the main cause of isolation regarding LWBS after the COVID-19 pandemic. Methods: We retrospectively analyzed emergency department visits before (March to July 2019) and after (March to July 2020) the COVID-19 pandemic. Patients were grouped based on existing fever or respiratory symptoms, with the LWBS rate as the primary outcome. Logistic regression analysis was used to identify the risk factors of LWBS. Logistic regression was performed using interaction terminology (fever/respiratory symptom patient [FRP] × post–COVID-19) to determine the interaction between patients with FRPs and the COVID-19 pandemic period. Results: A total of 60,290 patients were included (34,492 in the pre–COVID-19, and 25,298 in the post–COVID-19 group). The proportion of FRPs decreased significantly after the pandemic (P < 0.001), while the LWBS rate in FRPs significantly increased from 2.8% to 19.2% (P < 0.001). Both FRPs (odds ratio, 1.76; 95% confidence interval, 1.59–1.84 (P < 0.001) and the COVID-19 period (odds ratio, 2.29; 95% confidence interval, 2.15–2.44; P < 0.001) were significantly associated with increased LWBS. Additionally, there was a significant interaction between the incidence of LWBS in FRPs and the COVID-19 pandemic period (P < 0.001). Conclusion The LWBS rate has increased in FRPs after the COVID-19 pandemic; additionally, the effect observed was disproportionate compared with that of nonfever/respiratory symptom patients.

Background: Although respiratory tract infection is one of the most important factors triggering acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), limited data are available to suggest an epidemiologic pattern of microbiology in South Korea. Methods: A multicenter observational study was conducted between January 2015 and December 2018 across 28 hospitals in South Korea. Adult patients with moderate-to-severe acute exacerbations of COPD were eligible to participate in the present study. The participants underwent all conventional tests to identify etiology of microbial pathogenesis. The primary outcome was the percentage of different microbiological pathogens causing AE-COPD. A comparative microbiological analysis of the patients with overlapping asthma–COPD (ACO) and pure COPD was performed. Results: We included 1,186 patients with AE-COPD. Patients with pure COPD constituted 87.9% and those with ACO accounted for 12.1%. Nearly half of the patients used an inhaled corticosteroid-containing regimen and one-fifth used systemic corticosteroids. Respiratory pathogens were found in 55.3% of all such patients. Bacteria and viruses were detected in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely to appear in ACO than in pure COPD (8.3% vs. 3.6%, p=0.016). Conclusion Distinct microbiological patterns were identified in patients with moderate-to-severe AE-COPD in South Korea. These findings may improve evidence-based management of patients with AE-COPD and represent the basis for further studies investigating infectious pathogens in patients with COPD.

Purpose: To explore whether panretinal photocoagulation (PRP) improved retinal blood circulation in patients with diabetic retinopathy of various levels of severity based on changes in the retinal circulation time as measured by video fluorescein fundus angiography. Methods: We recruited patients with severe diabetic retinopathy indicated for PRP; we performed video fluorescein fundus angiography before and after PRP. We measured changes in the arterial circulation time (ACT), arteriovenous passage time (APT), and venous filling time (VFT) in patients with diabetic retinopathy of varying severity, and compared the findings. We recorded HbA1c levels and hypertension status. Results: We enrolled 33 patients, 17 with severe nonproliferative diabetic retinopathy (NPDR) and 16 with early proliferative diabetic retinopathy (PDR). After PRP, neither the ACT nor the APT changed significantly in patients with severe NPDR (p = 0.927, p = 0.138) or early PDR (p = 0.137, p = 0.268). After PRP, the VFT was significantly reduced in patients with both severe NPDR (p = 0.000) and early PDR (p = 0.022). The VFT reductions were similar in both groups (p = 0.217). Conclusions In patients with severe NPDR and early PDR, improvements in retinal blood circulation after PRP are reflected by reductions in the VFT evident on video fluorescein fundus angiography. We speculate that the improvements are similar in patients with severe NPDR and early PDR.

Purpose: To explore whether panretinal photocoagulation (PRP) improved retinal blood circulation in patients with diabetic retinopathy of various levels of severity based on changes in the retinal circulation time as measured by video fluorescein fundus angiography. Methods: We recruited patients with severe diabetic retinopathy indicated for PRP; we performed video fluorescein fundus angiography before and after PRP. We measured changes in the arterial circulation time (ACT), arteriovenous passage time (APT), and venous filling time (VFT) in patients with diabetic retinopathy of varying severity, and compared the findings. We recorded HbA1c levels and hypertension status. Results: We enrolled 33 patients, 17 with severe nonproliferative diabetic retinopathy (NPDR) and 16 with early proliferative diabetic retinopathy (PDR). After PRP, neither the ACT nor the APT changed significantly in patients with severe NPDR (p = 0.927, p = 0.138) or early PDR (p = 0.137, p = 0.268). After PRP, the VFT was significantly reduced in patients with both severe NPDR (p = 0.000) and early PDR (p = 0.022). The VFT reductions were similar in both groups (p = 0.217). Conclusions In patients with severe NPDR and early PDR, improvements in retinal blood circulation after PRP are reflected by reductions in the VFT evident on video fluorescein fundus angiography. We speculate that the improvements are similar in patients with severe NPDR and early PDR.

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

Background/Aims: Left ventricular hypertrophy (LVH) on clinical outcomes in patients with acute myocardial infarction (AMI) is not clear. This study was performed to investigate the effect of abnormal left ventricular geometry on clinical outcomes in Korean patients with AMI. Methods: A total of 852 consecutive patients with AMI were divided into two groups: normal left ventricular geometry (n = 470; 389 males) and LVH (n = 382; 214 males) groups. Major adverse cardiac events (MACEs) were defined as cardiac death, recurrent myocardial infarction, and rehospitalization. Results: During the clinical follow-up period of 21 ± 7.8 months, MACEs developed in 173 patients (20.0%), and the rate was higher in the LVH than normal left ventricular geometry groups (25.5% vs. 16.0%, respectively, p = 0.001). According to Kaplan-Meier survival curves, the MACE-free survival rate was significantly lower in the LVH group than in the left ventricular geometry group (p = 0.008). The rates of MACEs and all-cause mortality differed among the AMI with concentric remodeling, concentric hypertrophy, and eccentric hypertrophy subgroups (11.2% vs. 15.5% vs. 22.1%, respectively, p = 0.046). Eccentric hypertrophy was a predictive factor of MACE according to Cox proportional hazards analysis (hazard ratio 1.804, confidence interval 1.034-3.148, p = 0.038). Conclusions LVH is a predictor of poor outcomes in patients with AMI, and eccentric hypertrophy is associated with a worse prognosis compared with concentric remodeling and concentric hypertrophy. Therefore, Korean patients with AMI and LVH, especially eccentric hypertrophy, require more careful observation and intensive treatment.