Objective: To examine the association of inferior vena cava (IVC) diameter ratio measured using computed tomography with outcomes in patients with gastrointestinal bleeding (GIB). Methods: A single-center retrospective observational study was conducted on consecutive patients with GIB who presented to the emergency department. The IVC diameter ratio was calculated by dividing the maximum transverse and anteroposterior diameters perpendicular to it. The association of the IVC diameter ratio with outcomes was examined using multivariable logistic regression analysis. The primary outcome was in-hospital mortality. The area under the receiver operator characteristic curve (AUC) of the IVC diameter ratio was calculated, and the sensitivity and specificity, including the cutoff values, were computed. Results: In total, 585 patients were included in the final analysis. The in-hospital mortality rate was 4.6% (n=27). The IVC diameter ratio was significantly associated with higher in-hospital mortality in multivariable logistic regression analysis (odds ratio, 1.793; 95% confidence interval [CI], 1.239–2.597; P=0.002). The AUC of the IVC diameter ratio for in-hospital mortality was 0.616 (95% CI, 0.498–0.735). With a cutoff of the IVC diameter ratio (≥2.1), the sensitivity and specificity for predicting in-hospital mortality were 44% (95% CI, 26%–65%) and 71% (95% CI, 67%–75%), respectively. Conclusion The IVC diameter ratio was independently associated with in-hospital mortality in patients with GIB. However, the AUC of the IVC diameter ratio for in-hospital mortality was low.

Objective: Lactate clearance is reportedly associated with the outcomes of various critical illnesses. However, few studies have examined the association between lactate clearance and outcomes in patients with gastrointestinal bleeding (GIB). Methods: A single-center retrospective observational study between 2016 and 2020 was conducted. Consecutive adult patients with GIB symptoms (melena, hematemesis, and hematochezia) presenting to the emergency department were included. Lactate clearance was calculated as ([initial lactate-subsequent lactate]/initial lactate)×100. The association between lactate clearance and outcomes was examined by multivariable logistic regression analysis. The primary outcome was the in-hospital mortality. The area under the curve (AUC) of lactate clearance for in-hospital mortality was calculated. The sensitivity and specificity with optimal cutoff values were computed. The AUC of lactate clearance was compared with the Glasgow-Blatchford score and AIMS65 for predicting in-hospital mortality. Results: Three hundred and fifty-one patients were included in the final analysis, and the in-hospital mortality rate was 12%. Lactate clearance was significantly associated with lower in-hospital mortality (odds ratio, 0.991; P=0.016). The AUC of lactate clearance for in-hospital mortality was 0.64. The AUC of Glasgow-Blatchford score and AIMS65 for inhospital mortality was not significantly different from lactate clearance (P=0.759 and P=0.442, respectively). A cutoff lactate clearance of less than 10% had 45.2% sensitivity, 30.7% specificity, 8.2% positive predictive value, and 80.5% negative predictive value for predicting in-hospital mortality. Conclusion Lactate clearance was independently associated with in-hospital mortality in GIB patients. Further prospective studies will be needed to address the prognostic value of lactate clearance in GIB.

Purpose: This study investigates the characteristics and prognosis of acute poisoning patients visiting nationwide emergency departments before and after the Coronavirus disease 2019 (COVID-19) pandemic. Data were obtained from the National Emergency Department Information System (NEDIS). Methods: This nationwide retrospective observational study included acute poisoning patients who visited the emergency departments between February 1 to December 31, 2020, which has been determined as the pandemic period. The same periods in 2018 and 2019 were designated as the control periods. The primary outcome assessed was the length of stay in emergency departments (EDLOS). The secondary outcomes examined were intensive care unit admission rate and in-hospital mortality rate before and after the pandemic. A subgroup analysis was performed for inpatients and intentional poisoning patients. Results: A total of 163,560 patients were included in the study. During the pandemic, the proportion of women increased from 50.0% in 2018 and 50.3% in 2019 to 52.5% in 2020. Patients aged 20-29 years increased from 13.4% in 2018 and 13.9% in 2019 to 16.6% in 2020. A rise in cases of intentional poisoning was also noted - from 33.9% in 2018 and 34.0% in 2019 to 38.4% in 2020. Evaluating the hospitalized poisoned patients revealed that the EDLOS increased from 3.8 hours in 2018 and 3.7 hours in 2019 to 4.2 hours in 2020. ICU admissions were also markedly increased (2018, 48.2%; 2019, 51.8%; 2020, 53.2%) among hospitalized patients. Conclusion The COVID-19 pandemic has changed the epidemiology, clinical characteristics, and prognosis of acute poisoning patients visiting nationwide emergency departments in Korea. The proportion of young adults, women, and intentional poisoning patients has increased after the COVID-19 pandemic. Prolonged length of stay at the emergency department and an increased rate of intensive care unit admissions were determined in hospitalized acute poisoning patients.

Objective: The length of stay in the emergency department (ED) is a major contributor to ED overcrowding, which in turn negatively affects the quality of emergency care. Several efforts have been made to reduce the ED length of stay (ED-LOS), including a mandatory target to limit ED-LOS within certain parameters. However, the association between ED-LOS and treatment results is yet to be clarified. The authors investigated the influence of ED-LOS on patient survival by comparing severity-adjusted survival. Methods: This study was a retrospective analysis of data registered in 2018 in the National Emergency Department Information System (NEDIS). Cases registered by the regional and local emergency centers were included for analysis. The standardized W scores (Ws) based on the Emergency Department Initial Evaluation Score were used to assess treatment outcomes represented by severity-standardized survival, and the correlation between the Ws and the ED-LOS was analyzed. Results: A total of 2,281,526 cases were included for analysis. The overall mortality comprised 52,284 cases (2.3%) and the median ED-LOS was 165 minutes (interquartile range, 96-301). Although a longer ED-LOS was associated with poorer outcomes overall, the association was not apparent when an analysis of cases eligible for ED-LOS evaluation in the national evaluation program was carried out. Moreover, in the analysis of severe cases with a predicted survival probability of less than 0.9, an ED-LOS shorter than 6 hours was associated with significantly poorer severity-adjusted survival. Conclusion The study revealed that the current ED-LOS criteria used in the national evaluation program were not associated with better survival.

Objective: With trends in population aging an increasing number of older patients are visiting the emergency department (ED). This study aimed to identify the characteristics of ED utilization and risk factors for in-hospital mortality in older patients who visited EDs. Methods: This nationwide observational study used National Emergency Department Information System data collected during a 2-year period from January 2016 to December 2017. The characteristics of older patients aged 70 years or older were compared with those of younger patients aged 20 to 69 years. Risk factors associated with in-hospital mortality were analyzed by multivariable logistic regression. Results: A total of 6,596,423 younger patients and 1,737,799 older patients were included. In the medical and nonmedical older patient groups, significantly higher proportions of patients were transferred from another hospital, utilized emergency medical services, had Korean Triage and Acuity Scale scores of 1 and 2, required hospitalization, and required intensive care unit admission in the older patient group than in the younger patient group. ED and post-hospitalization mortality rates increased with age; in particular, older medical patients aged 90 or older had an in-hospital mortality rate of 9%. Older age, male sex, transfer from another hospital, emergency medical service utilization, a high Korean Triage and Acuity Scale score, systolic blood pressure <100 mmHg, respiratory rate >20/min, heart rate >100/min, body temperature <36°C, and altered mental status were associated with in-hospital mortality. Conclusion Development of appropriate decision-making algorithms and treatment protocols for high risk older patients visiting the ED might facilitate appropriate allocation of medical resources to optimize outcomes.

Objective: This study investigates the characteristics of patients who were re-transferred from other hospitals to regional or local emergency medical centers. Methods: Data from 2016 to 2017 was obtained from the National Emergency Department Information System (NEDIS). The study population was classified as ‘transferred group’ and ‘direct visit group.’ The transferred group was further subdivided into the ‘re-transfer group’ (patients transferred out to another hospital) and ‘single transfer group’ (patients not transferred out). Multiple logistic regression analysis was performed to identify factors associated with re-transfer. Results: The re-transfer rate (3.7%) of the ‘transferred group’ was higher than the transfer rate (1.3%) of the ‘direct visit group’. Multiple regression analysis revealed that older age, male (adjusted odds ratio [aOR], 1.082; 95% confidence interval [CI], 1.606-1.105), medical aid (aOR, 1.231; 95% CI, 1.191-1.105), injury origin (aOR, 1.063; 95% CI, 1.006-1.122), and Korean Triage and Acuity Scale level 1 or 2 (aOR, 1.214; 95% CI, 1.182-1.247), are associated with re-transfer. The Korean Standard Classification of Diseases group having the highest re-transfer rate was determined to be the neoplasm disease group. Conclusion Data from the current study reveals that factors associated with an increased likelihood of re-transfer were high severity, old age, medical aid, and neoplasm diagnosis. Considering these characteristics of re-transferred patients, it is necessary to improve the transfer system to reduce re-transfers. However, further research is required, including the reasons for the transfer.

Objective: The purpose of this study was to analyze the effects of emergency department length of stay (ED LOS) on the prognosis of patients classified in 28 severe illness diagnosis code groups. Methods: We used data from the National Emergency Department Information System (NEDIS) from 2016 to 2017. Patients with severe illness diagnosis codes as per the discharge diagnosis reports of the emergency department were included and classified into 28 diagnosis code groups. We used multiple logistic regression analysis on the various diagnosis groups to determine whether 6 hours of ED LOS was a factor influencing mortality. Results: Of the 18,217,034 patients in the NEDIS data, 553,918 patients were hospitalized with a severe illness code at regional or local emergency medical centers. The average ED LOS was 389 minutes in the non-survivor group and 420 minutes in the survivor group. After adjusting for confounders, ED LOS >6 hours was associated with lower mortality (odds ratio, 0.737; 95% confidence interval, 0.715-0.759). The association of ED LOS >6 hours with lower mortality was found in the diagnosis groups for acute myocardial infarction, intracranial hemorrhage, major trauma, aortic dissection, gastrointestinal bleeding/foreign bodies, intoxication, acute kidney injury, and post-resuscitation status. Conclusion In the analysis for the 28 severe disease illness code groups, ED LOS of more than 6 hours was not a factor that adversely affects the in-hospital mortality.

Purpose: It is known that the most common cause of gas poisoning in Korea is suicide attempts by burning ignition coals. Ignition coals are made from waste wood, and studies have been reported that heavy metals are emitted when this coal is burned. However, there was no study on how much heavy metal poisoning occurs in the human body through this, so this study was planned to find out whether the concentration of heavy metals in the blood increased in patients exposed to ignition coal combustion. Methods: From April 2020 to April 2021, blood lead, mercury, and cadmium concentrations were investigated in carbon monoxide poisoning patients who visited one regional emergency medical center in Seoul, and their association with exposure time, source of poisoning, and rhabdomyolysis were investigated. Results: During the study period, a total of 136 carbon monoxide poisoning patients were tested for heavy metals, and 81 cases of poisoning by ignition coal were reported. When comparing poisoning caused by combustion of ignition coal and other substances, there was no difference in the concentrations of lead, mercury, and cadmium in the blood, and there was no difference in the number of patients above the reference range. However, the patients exposed to more than 5 hours of ignition coal gas exposure are more frequent than those in the group less than 5 hours in lead (51.4% vs. 23.9%, p=0.012). Conclusion Compared to poisoning with other combustible substances, the blood concentration of lead, mercury, and cadmium does not increase further in patients with gas poisoning by ignition coal. However, prolonged exposure may result in elevated levels of lead.

Objective: With trends in population aging an increasing number of older patients are visiting the emergency department (ED). This study aimed to identify the characteristics of ED utilization and risk factors for in-hospital mortality in older patients who visited EDs. Methods: This nationwide observational study used National Emergency Department Information System data collected during a 2-year period from January 2016 to December 2017. The characteristics of older patients aged 70 years or older were compared with those of younger patients aged 20 to 69 years. Risk factors associated with in-hospital mortality were analyzed by multivariable logistic regression. Results: A total of 6,596,423 younger patients and 1,737,799 older patients were included. In the medical and nonmedical older patient groups, significantly higher proportions of patients were transferred from another hospital, utilized emergency medical services, had Korean Triage and Acuity Scale scores of 1 and 2, required hospitalization, and required intensive care unit admission in the older patient group than in the younger patient group. ED and post-hospitalization mortality rates increased with age; in particular, older medical patients aged 90 or older had an in-hospital mortality rate of 9%. Older age, male sex, transfer from another hospital, emergency medical service utilization, a high Korean Triage and Acuity Scale score, systolic blood pressure <100 mmHg, respiratory rate >20/min, heart rate >100/min, body temperature <36°C, and altered mental status were associated with in-hospital mortality. Conclusion Development of appropriate decision-making algorithms and treatment protocols for high risk older patients visiting the ED might facilitate appropriate allocation of medical resources to optimize outcomes.

In Korea, the national evaluation program for emergency medical centers (EMCs) was introduced in 2003. EMCs in Korea have three levels of emergency centers including regional emergency centers, local emergency centers, and local emergency rooms. The evaluation system assesses the performance of EMCs at all three levels. The role of both regional emergency centers and local emergency centers administer the final treatment for severe emergency patients, although the definition of severe emergency patients is unclear. These factors may aggravate crowding at the emergency department. The national evaluation system aims to reduce the length of stay in the emergency department. However, reduction of the length of stay at emergency department may cause a conflict with the administration of final treatment for critically ill emergency patients owing to a lack of in-hospital beds. Crowding of the emergency department is not a problem of EMCs but that of the health system. In 2019, the Korean Society of Emergency Medicine performed a study to improve the national evaluation program for EMC and the performance of EMC. Here, we have summarized the results.