This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively.Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques.There has been a decrease in intravenous thrombolysis rates, from 12% in 2017–2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for noncardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.

Objective: Influenza is an acute, respiratory viral disease, and may lead to complications such as pneumonia, which presents with significant morbidity and mortality. Previous studies did not have sufficient data regarding the risk factors and complications of the H1N1 flu caused by the influenza A virus subtype H1N1 during the 2009 pandemic in Korea. Therefore, this study was conducted to analyze the characteristics and risk factors of complicated influenza. Methods: Data were collected from influenza patients who visited a local emergency center in Daegu from January 2017 to December 2019. The study population was divided into three groups: influenza, influenza pneumonia, and influenza with a bacterial infection. The patients’ sex, age, influenza type, comorbidities, vital signs, symptoms, laboratory findings, and clinical outcomes were investigated for the risk analysis of complicated influenza. Results: The total number of patients was 574, of which 393 (68.5%) had influenza only, 135 (23.5%) had influenza pneumonia, and 46 (8%) had influenza with a bacterial infection. The odds ratio of complicated influenza was found using multivariate logistic regression analysis; for influenza pneumonia, it was 2.94 for patients aged over 65-years, 3.47 for those with an elevated procalcitonin level, 2.24 for cough, 6.41 for dyspnea, and 3.11 for renal disease. For influenza with bacterial infection, the odds ratio was 2.31 for males, 2.68 for over 80-year-olds, 3.75 for elevated procalcitonin levels, 7.61 for dyspnea, and 3.65 for nursing home residents. Conclusion The risk factors of complicated influenza were advanced age, elevated procalcitonin level, dyspnea, renal disease, and residing in a nursing home.

Objective: The emergency department (ED) length of stay (LOS) is related to ED overcrowding and emergency practice. This study aimed to investigate the effects of enabling an ED doctor to have the authority to make hospitalization decisions and utilization of the emergency ward on ED LOS. Methods: This retrospective observational study included patients who were admitted through a local emergency medical center. We compared the ED LOS between the periods' March to July 2018 and March to July 2019. In the latter period, ED doctors were authorized to take decisions on patient hospitalizations from the internal medicine department, and the emergency ward was operated under these new conditions. Results: A total of 6,291 patients were included in the study, with 2,934 in 2018 and 3,357 in 2019. In the comparison of ED LOS for internal medicine inpatients by year, there was a significant reduction in the total ED LOS (1,129.0 [491.0-1,618.0] minutes vs. 539.0 [344.0-1,016.25] minutes, P<0.001), LOS before the admission decision (345.0 [198.0-634.0] minutes vs. 280.0 [176.0-442.3] minutes, P<0.001), and LOS after the admission decision (415.0 [147.0-1,089.0] minutes vs. 179.5 [80.0-422.0] minutes, P<0.001). In a subgroup analysis of internal medicine inpatients in 2019, the admission sheets of an ED doctor showed a significant decrease in LOS before the admission decision (268.0 [170.5-424.5] minutes vs. 404.0 [252.0-570.5] minutes, P<0.001). Also, the utilization of the emergency ward showed a significant decrease in LOS after the admission decision (147.0 [75.0-283.0] minutes vs. 187.0 [81.0-460.0] minutes, P<0.001). Conclusion The delegation of hospitalization decisions to the ED doctor and the subsequent utilization of the emergency ward shorten the ED LOS of internal medicine inpatients.

Objective: The purpose of this study was to analyze the characteristics of alcohol-related non-traffic accident trauma patients. Methods: A total of 2,582 non-traffic accident patients, above 16 years old, who visited the emergency department (ED) from July 1, 2016, to June 30, 2017, were retrospectively analyzed. The patients were categorized as alcohol group (A group) and no alcohol group (NA group) after checking their electronic medical records. Their general characteristics, the severity of their injury, and their ED length of stay were compared. Results: The A group included younger patients, a higher percentage of males, and a higher frequency of visits to the ED via the 119 ambulance route than the NA group. The A group had a higher proportion of patients being struck by a person or object in terms of the mechanism of injury, intentional violence, and head injuries, especially in the face as compared to the NA group. In terms of the severity of the injury, the Injury Severity Score was lower in the A group than in the NA group, and the ratio of bone fracture and/or cerebral hemorrhage was also lower. As per the survey, the A group tended to stay in the ED longer than the NA group. Conclusion The characteristics of alcohol-related non-traffic accident trauma patients show that they have a relatively long stay in the ED, a high ratio of facial injury with low trauma severity, and need professional treatment facilities with specialized personnel and equipment.

Objective: The purpose of this study was to analyze the characteristics of alcohol-related non-traffic accident trauma patients. Methods: A total of 2,582 non-traffic accident patients, above 16 years old, who visited the emergency department (ED) from July 1, 2016, to June 30, 2017, were retrospectively analyzed. The patients were categorized as alcohol group (A group) and no alcohol group (NA group) after checking their electronic medical records. Their general characteristics, the severity of their injury, and their ED length of stay were compared. Results: The A group included younger patients, a higher percentage of males, and a higher frequency of visits to the ED via the 119 ambulance route than the NA group. The A group had a higher proportion of patients being struck by a person or object in terms of the mechanism of injury, intentional violence, and head injuries, especially in the face as compared to the NA group. In terms of the severity of the injury, the Injury Severity Score was lower in the A group than in the NA group, and the ratio of bone fracture and/or cerebral hemorrhage was also lower. As per the survey, the A group tended to stay in the ED longer than the NA group. Conclusion The characteristics of alcohol-related non-traffic accident trauma patients show that they have a relatively long stay in the ED, a high ratio of facial injury with low trauma severity, and need professional treatment facilities with specialized personnel and equipment.

Objective: Appropriate triage in emergency rooms is fundamental. This study assessed the appropriateness of the triage results using the Korean Triage and Acuity Scale (KTAS) by emergency medical technicians (EMT) by comparing an emergency physician and a KTAS instructor. Methods: The medical records of patients who presented to a local emergency room for a month were analyzed retrospectively. This study compared the triage results using KTAS among EMTs, an emergency physician, and a KTAS instructor. Results: Among 2,248 patients, consistent KTAS codes of 1,453 patients (64.6%) were obtained between the EMTs and emergency physicians. In addition, a KTAS instructor had agreed with the results of EMT for 1,686 patients (75%). The Kappa value to evaluate the agreement between an emergency physician and a KTAS instructor was 0.72 (95% confidence interval, 0.55-0.89). Conclusion The results of triage using KTAS by EMT was appropriate because substantial agreement existed between an emergency physician and KTAS instructor. On the other hand, there were some inappropriate results of triage, and it is proposed that the results would be reflected in KTAS provider education programs aimed at EMTs. It is expected that qualified KTAS providers will be produced, and the quality of triage can be controlled and improved.

Objective: Air pollutants have attracted increasing interest worldwide, including Korea. Acute and chronic exposure to air pollutants has adverse effects on health. Therefore, this study examined the association of air pollutants with myocardial infarction. Methods: This study included 542 patients who underwent coronary angiography and were diagnosed with acute coronary artery occlusion after visiting a local emergency medical center from January 1, 2016, to December 31, 2018. The days (1,096) were divided into two groups: myocardial infarction days group (the days when symptoms of myocardial infarction developed) and non-myocardial infarction days group (the days when symptoms of myocardial infarction did not develop). This study compared the air pollutants (PM10, PM2.5, O3, SO2, CO, and NO2) and prognosis (survivor, death) from two days ago to the days between the myocardial infarction days and non-myocardial infarction days. Results: The PM10 and PM2.5 of the myocardial infarction days group were 44.332±18.892 and 25.193±12.009 μm/m3, respectively, and those of the non-myocardial infarction days group were 41.906±19.263 and 23.693±12.053 μm/m3, respectively. On day one before symptom development, the PM2.5 of the myocardial infarction days group was 25.316± 11.977 μm/m3, which was higher than that of the non-myocardial infarction days groups (23.642±12.053 μm/m3), and there were no significant differences between the gaseous air pollution and the number of occlusions, except on a 0 day of ozone. The PM2.5 (proximal, middle, and distal according to the vessel size) at day 0 was 25.747±12.361, 22.941± 11.477, and 21.486±10.924 μm/m3, respectively; the proximal group had the highest value. During the study days, the PM10 of the death and survival groups was 51.440 (±20.140)-56.924 (±25.225) μm/m3 and 41.155 (±18.544)-43.002 (±18.858) μm/m3, respectively. PM2.5 of the death and survival groups was 26.968 (±14.140)-30.145 (±12.829) and 23.770 (±11.685)-24.170 (±12.696) μm/m3, respectively. Conclusion Myocardial infarction was found to develop more on the day with the highest PM2.5 and PM10 on day 0 and -1. A high PM2.5 is related to an occlusion of the proximal coronary artery. Therefore, PM2.5 has a stronger association with myocardial infarction than PM10. Furthermore, increased particulate air pollution for three consecutive days is associated with a poor prognosis.

Respiratory syncytial virus (RSV) causes severe pulmonary disease in infants, young children, and the elderly. Formalin inactivated RSV (FI-RSV) vaccine trials failed due to vaccine enhanced respiratory disease, but the underlying immune mechanisms remain not fully understood. In this study, we have used wild type C57BL/6 and CD4 knockout (CD4KO) mouse models to better understand the roles of the CD4 T cells and cellular mechanisms responsible for enhanced respiratory disease after FI-RSV vaccination and RSV infection. Less eosinophil infiltration and lower pro-inflammatory cytokine production were observed in FI-RSV vaccinated CD4KO mice after RSV infection compared to FI-RSV vaccinated C57BL/6 mice. NK cells and cytokine-producing CD8 T cells were recruited at high levels in the airways of CD4KO mice, correlating with reduced respiratory disease. Depletion studies provided evidence that virus control was primarily mediated by NK cells whereas CD8 T cells contributed to IFN-γ production and less eosinophilic lung inflammation. This study demonstrated the differential roles of effector CD4 and CD8 T cells as well as NK cells, in networking with other inflammatory infiltrates in RSV disease in immune competent and CD4-deficient condition.

BACKGROUND: AND PURPOSE: The aim of this study was to determine the diagnostic performance and safety of a new ¹⁸F-labeled amyloid tracer, ¹⁸F-FC119S. METHODS: This study prospectively recruited 105 participants, comprising 53 with Alzheimer's disease (AD) patients, 16 patients with dementia other than AD (non-AD), and 36 healthy controls (HCs). In the first screening visit, the Seoul Neuropsychological Screening Battery cognitive function test was given to the dementia group, while HC subjects completed the Korean version of the Mini Mental State Examination. Individuals underwent ¹⁸F-FC119S PET, ¹⁸F-fluorodeoxyglucose (FDG) PET, and brain MRI. The diagnostic performance of ¹⁸F-FC119S PET for AD was compared to a historical control (comprising previously reported and currently used amyloid-beta PET agents), ¹⁸F-FDG PET, and MRI. The standardized uptake value (SUV) ratio (ratio of the cerebral cortical SUV to the cerebellar SUV) was measured for each PET data set to provide semiquantitative analysis. All adverse effects during the clinical trial periods were monitored. RESULTS: Visual assessments of the ¹⁸F-FC119S PET data revealed a sensitivity of 92% and a specificity of 84% in detecting AD. ¹⁸F-FC119S PET demonstrated equivalent or better diagnostic performance for AD detection than the historical control, ¹⁸F-FDG PET (sensitivity of 80.0% and specificity of 76.0%), and MRI (sensitivity of 98.0% and specificity of 50.0%). The SUV ratios differed significantly between AD patients and the other groups, at 1.44±0.17 (mean±SD) for AD, 1.24±0.09 for non-AD, and 1.21±0.08 for HC. No clinically significant adverse effects occurred during the trial periods. CONCLUSIONS ¹⁸F-FC119S PET provides high sensitivity and specificity in detecting AD and therefore may be considered a useful diagnostic tool for AD.