Characteristics of pediatric emergency department visits before and during the COVID-19 pandemic: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018-2022.

OBJECTIVE: : As of 2018, approximately 1.2 million pediatric patients visited emergency departments (EDs) in Korea, showing a steady increase. Given the distinct differences between children and adults, it is vital to examine the epidemiological characteristics of pediatric patients visiting the ED. METHODS: : This study retrospectively analyzed the ED use patterns of pediatric patients <18 years old in Korea from January 1, 2018, to December 31, 2022, using data from the National Emergency Department Information System (NEDIS). RESULTS: : Most pediatric ED patients were boys, with an average age of 6.6±5.3 years. Patients younger than 1 year and those in critical condition had longer ED stays and more frequently required hospital admission and used the 119-ambulance service. The primary symptom was fever, and the most common discharge diagnosis was gastroenteritis. Following the declaration of the COVID-19 pandemic in 2020, ED visits decreased by 49%. Meanwhile, there was an increase in in-hospital mortality rate/age- and sex-standardized mortality rate per 100,000 ED visits, Admission and transfer rates remained similar between before and after the start of the pandemic. CONCLUSION: : Through this analysis, we identified the characteristics of pediatric patients visiting EDs in Korea. We observed a sharp decline in ED visits after the start of the COVID-19 pandemic. From there, ED visits slowly increased but remained below prepandemic levels for 3 years. This research will serve as a foundational resource for appropriately allocating and preparing pediatric ED resources.

A mutation in keratin 18 that causes caspase-digestion resistance protects homozygous transgenic mice from hepatic apoptosis and injury.

Cytoskeletal keratin 18 (K18) undergoes caspase-mediated digestion during apoptosis, which leads to dramatic disassembly of keratin filaments. We studied the significance of K18 caspase digestion in a mouse model and generated transgenic mice expressing the human K18 caspase digestion-resistant double-mutant K18-D238/397E in a mouse (m) K18-null background, and compared their response to injury mediated by administration of antibody against tumor necrosis factor receptor superfamily member 6 (Fas), anti-FasAb. Notably, K18-D238/397E;mK18-null mice were significantly more resistant to anti-FasAb-induced injury as compared with K18-WT;mK18-null mice (23% vs 57% lethality, respectively; P<0.001). The same applied when the toxin microcystin-LR (MLR) was used to induce liver injury, i.e. lethality of K18-D238/397E;mK18-null mice in response to MLR treatment was reduced compared with the control mouse strain. The lesser rate of apoptosis in K18-D238/397E;mK18-null livers is associated with delayed degradation and, thus, sustained activation of cell-survival-related protein kinases, including stress-activated protein kinases and the NF-κB transcription factor, up to 6-8 h after administration of anti-FasAb. However, activation of the kinases and NF-κB in K18-WT-reconstituted livers decreases dramatically 8 h after anti-FasAb administration. In addition, the D238/397E double-mutation results in prolonged stability of K18 protein in transfected cells and transgenic livers. Therefore, our results show that the caspase digestion-resistant K18 helps to maintain keratin filament organization and delays apoptosis, thereby resulting in protection from liver injury.