Arterial pH reflects both metabolic and respiratory distress in cardiac arrest and has prognostic implications. However, it was excluded from the 2024 update of the Utstein out-of-hospital cardiac arrest (OHCA) registry template. We investigated the rationale for including arterial pH into models predicting clinical outcomes. Methods: Data were sourced from the Korean Cardiac Arrest Research Consortium, a nationwide OHCA registry (NCT03222999). Prediction models were constructed using logistic regression, random forest, and eXtreme Gradient Boosting frameworks. Each framework included three model types: pH, low-flow time, and combined models. Then the area under the receiver operating characteristic curve (AUROC) of each predicting model was compared. The primary outcome was 30- day death or neurologically unfavorable status (cerebral performance category ≥3). Results: Among the 15,765 patients analyzed, 92.2% experienced death or unfavorable neurological outcomes. The predicting performance of the models including pH (AUROC, 0.92–0.94) were comparable to the models including low-flow time in all frameworks (0.93–0.94) (all P>0.05). Inclusion of pH into low-flow time models consistently showed higher AUROCs than individual models in all frameworks (AUROC, 0.93–0.95; all P<0.05). Conclusions: The predicting performance of models including arterial pH was comparable to models including low-flow time, and addition of arterial pH into low-flow time models could increase the performance of the models. Key Words: blood pH; hydrogen-ion con

Background: The effects of sugammadex, which reverses neuromuscular blockade, on emergence-related respiratory events in children remains unclear. This study compared the respiratory outcomes of sugammadex and neostigmine in pediatric tonsillectomy. Methods: Children aged 2 years to 6 years old undergoing tonsillectomy were randomly assigned to sugammadex or neostigmine groups. The primary outcome was the occurrence of respiratory adverse events, including oxygen desaturation < 95%, airway obstruction, laryngospasm, bronchospasm, severe coughing, or postoperative stridor. Secondary outcomes included bradycardia, allergic reactions, and emergence delirium. Results: The study included 172 pediatric patients (n = 86 per group). Neuromuscular blockade reversal was faster in the sugammadex group than in the neostigmine group, achieving a train-of-four ratio of 90% in a median of 1 min vs. 4 min in the neostigmine group (P < 0.001). The time to extubation was comparable between the two groups (median, 8 min; P = 0.679), as was the overall incidence of respiratory adverse events (29.0% vs. 30.2%; relative risk, 0.962; 95% confidence interval [CI], 0.607–1.524; P = 0.858). Emergence delirium occurred in 27.9% of patients overall, but the incidence was higher in the sugammadex group than in the neostigmine group (34.9% vs. 20.9%; relative risk, 1.214; 95% CI, 1.005–1.467; P = 0.044). Conclusions Sugammadex provides significantly faster neuromuscular blockade reversal compared to neostigmine but does not shorten the time to extubation or reduce the incidence of emergence-related respiratory adverse events in children undergoing tonsillectomy. Moreover, its use may be associated with an increased risk of emergence delirium.

We explored the utility of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) sequencing as a noninvasive diagnostic tool for detecting central nervous system (CNS) involvement in patients with diffuse large B-cell lymphoma (DLBCL). Secondary CNS involvement in DLBCL, although rare (~5% of cases), presents diagnostic and prognostic challenges during systemic disease progression or relapse. Effective treatment is impeded by the blood–brain barrier. This was a prospective cohort study (Samsung Lymphoma Cohort Study III) involving 17 patients with confirmed CNS involvement. High-throughput sequencing was conducted using targeted gene panels designed to detect low-frequency variants and copy number alterations pertinent to lymphomas in ctDNA extracted from archived CSF samples. Despite challenges such as low DNA concentrations affecting library construction, the overall variant detection rate was 76%. Detected variants included those in genes commonly implicated in CNS lymphoma, such as MYD88. The study highlights the potential of CSF ctDNA sequencing to identify CNS involvement in DLBCL, providing a promising alternative to more invasive diagnostic methods such as brain biopsy, which are not always feasible. Further validation is necessary to establish the clinical utility of this method, which could significantly enhance the management and outcomes of DLBCL patients with suspected CNS involvement.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Background: Because of the low prevalence of inherited retinal diseases, reports on the distribution of retinitis pigmentosa (RP)-related genes in Korean patients are scarce. The aim of this study was to determine the mutation spectrum and allele frequency and observe the final diagnoses in a Korean cohort clinically diagnosed with RP. Methods: We used whole-exome sequencing (WES) to analyze a Korean cohort of 100 unrelated patients clinically diagnosed with RP. The possible pathogenicity of each variant was assessed based on the guidelines of the American College of Medical Genetics and Genomics and Association for Molecular Pathology, in-silico prediction tools, known clinical phenotypes, and inheritance patterns. Results: Definite causative genes were detected in 60/100 patients (60.0%). Of these 60 cases, USH2A was the most common causative gene (14/60, 23.3%), followed by EYS (13/60, 21.7%) and RP1 (6/60, 10.0%). The clinical diagnosis was redefined in 9 of the 60 probands (15.0%) with causative genes after WES. Five of the 60 patients (8.3%) carried a causative variant in CHM, and the clinical diagnosis was redefined as choroideremia. Leber congenital amaurosis was diagnosed in 2/60 probands (3.3%), and RDH12 and RPGRIP1 were the causative genes in each patient. One patient (1/60, 1.7%) was diagnosed with Bietti’s crystalline dystrophy, with CYP4V2 identified as the causative gene. In another patient (1/60, 1.7%), ABCA4 variants were detected with clinical findings suggestive of cone-rod dystrophy. Conclusion This study reports the mutational spectrum of a cohort of Korean patients with a clinical diagnosis of RP who were referred for genetic testing. This study adds valuable data regarding the frequency of genes as well as their relation to the age of symptom onset and relation to other inherited retinal degenerations.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Objective: We aimed to investigate the associations of the triglyceride-glucose index, which measures insulin resistance, and the incidence of Parkinson’s disease. Methods: Our study used the Health Screening Cohort database of the National Health Insurance Service of South Korea (2002–2019). We included 310,021 participants who had no previous history of Parkinson’s disease and for whom more than 3 triglyceride-glucose index measurements were available. A diagnosis of Parkinson’s disease was determined via the International Classification of Diseases Tenth edition (G20) with a specific reimbursement code for rare intractable diseases and a history of prescriptions for anti-Parkinsonism drugs. Results: During a median of 9.64 years (interquartile range 8.72–10.53), 4,587 individuals (1.5%) had Parkinson’s disease. Based on a multivariable time-dependent Cox proportional hazards model, a per-unit increase in triglyceride-glucose index score was associated with a significantly increased risk of Parkinson’s disease (hazard ratio [HR]: 1.062; 95% confidence interval [CI] 1.007–1.119). In a sensitivity analysis, the triglyceride-glucose index was associated with the incidence of Parkinson’s disease in a non–diabetes mellitus cohort (HR: 1.093; 95% CI 1.025–1.165), but not in the diabetes mellitus cohort (HR: 0.990; 95% CI 0.902–1.087). In a restricted cubic spline analysis, the association between the triglyceride-glucose index and the incidence risk of Parkinson’s disease showed a nonlinear increasing (J-shaped) trend. Conclusion Our study demonstrated that higher triglyceride-glucose index scores were associated with the incidence of Parkinson’s disease in the general population, particularly in a nondiabetic mellitus cohort.

Background: and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes. Methods: We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data. Results: Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4. Conclusion Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.