Background/Aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested.This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy. Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy.

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: This study reports trends in pediatric out-of-hospital cardiac arrest (OHCA) and factors affecting clinical outcomes by age group. Methods: We identified 4,561 OHCA patients younger than 18 years between January 2009 and December 2018 in the Korean OHCA Registry. The patients were divided into four groups: group 1 (1 year or younger), group 2 (1 to 5 years), group 3 (6 to 12 years), and group 4 (13 to 17 years). The primary outcome was survival to hospital discharge, and the secondary outcomes were return of spontaneous circulation (ROSC) at the emergency department (ED) and good neurological status at discharge. Multivariate logistic analyses were performed. Results: The incidence rate of pediatric OHCA in group 1 increased from 45.57 to 60.89 per 100,000 person-years, while that of the overall population decreased over the 10 years. The rates of ROSC at the ED, survival to hospital discharge, and good neurologic outcome were highest in group 4 (37.9%, 9.7%, 4.9%, respectively) and lowest in group 1 (28.3%, 7.1%, 3.2%). The positive factors for survival to discharge were event location of a public/commercial building or place of recreation, type of first responder, prehospital delivery of automated external defibrillator shock, initial shockable rhythm at the ED. The factors affecting survival outcomes differed by age group. Conclusion This study reports comprehensive trends in pediatric OHCA in the Republic of Korea. Our findings imply that preventive methods for the targeted population should be customized by age group.

Background: Ear-loop-type Korean Filter 94 masks (KF94 masks, equivalent to the N95 and FFP2) are broadly used in health care settings in Korea for the coronavirus disease 2019 pandemic. Methods: A prospective randomized open-label study was designed to identify differences in the fitting performance between mask wearing methods in three different types of KF94 mask with ear loops between January to March 2021. General-fitting involved wearing an earloop-type KF94 mask, and tight-fitting involved wearing a mask aided by a clip connecting the ear loops. Each of the 30 participants wore three types of masks according to a randomly assigned order in both methods and performed a total of six quantitative fit tests (QNFTs) according to the occupational safety and health administration protocol. Results: All fit factors (FFs) measured by the QNFT were significantly higher for tight-fitting method with the clip in all KF94 masks (P < 0.001). However, the total FFs were very low, with a median (interquartile range) of 6 (3–23) and 29 (9–116) for general-fitting and tight-fitting, respectively. When wearing tightly, the horizontal 3-fold type mask with adjustable ear-loop length had the highest FF, with a median of 125, and the QNFT pass rate (FF ≥ 100) increased significantly from 4 (13%) to 18 (60%). Conclusion Even with sufficient filter efficiency, ear-loop-type-KF94 masks do not provide adequate protection. However, in relatively low-risk environments, wearing a face-seal adjustable KF94 mask and tight wearing with a clip can improve respiratory protection for healthcare workers.

Background: Point-of-care ultrasound (POCUS) is an essential tool in emergency medicine (EM). We aimed to investigate the current status and perception of POCUS use in emergency medical centers in Korea. Methods: A cross-sectional, nationwide survey was conducted using a mobile survey of physicians at emergency medical centers in Korea. The first message was sent on November 27, 2020, and the second message was sent on December 3, 2020 to the non-responders.The questionnaire comprised 6 categories and 24 questionnaires on demographics, current practice, education, perception, and barriers to the use of POCUS. Results: A total of 467 physicians participated in the survey (a response rate of 32% among 1,458 target physicians), of which 43% were residents and 57% were EM specialists. Most of the respondents (96%) answered that they use POCUS, of which 89% reported using it at least once a week. The most frequently used types of POCUS were focused assessment with sonography for trauma (68%) and echocardiography (66%). Musculoskeletal, male genital, and pediatric scans were rarely performed tests but ranked as of the scans physicians most wanted to learn. About 73% of the respondents received ultrasound education, and 41% received ultrasound education at their own institutions. Nevertheless, educationrelated barriers are still the biggest deterrent to POCUS use (60%). In addition, multivariate multinomial logistic regression analysis revealed that the greater the number of ultrasound devices and the total number of physicians in the emergency center, the more likely they were to use POCUS every day. Conclusion This study found that most physicians currently working in emergency medical centers in Korea more frequently perform various types of ultrasound scans compared to those 10 years prior. To further promote the use of POCUS, it is important to have an appropriate number of ultrasound devices and physicians in the emergency center along with systematic POCUS education.

Background/Aims: Belching disorder (BD) is clinically distinct from gastroesophageal reflux disease (GERD) with belching. Supragastric belching (SGB) is closely associated with reflux episodes. This study investigates belch characteristics in association with reflux, compared between patients with BD and those who had GERD with belching. Methods: Impedance pH monitoring data from 10 patients with BD and 10 patients with GERD who exhibited belching were retrospectively analyzed. Belches were considered “isolated“ or “reflux-related” and acidicon-acidic. Belch characteristics were compared between patients with BD and those with GERD. Results: Symptomatic belches were more frequent in patients with BD than in patients with GERD (median, 160.5 vs 56.0, P < 0.05). SGB was the most common type in both groups; common subtypes comprised “isolated“ in patients with BD and “isolated during the reflux period” in patients with GERD. Reflux-related SGB was more common in patients with GERD than in BD (78.3% vs 45.2%, P < 0.005).Both “preceding belching” including the reflux period and acidic SGB were more common in patients with GERD than in BD (31.8% vs 8.6% and 38.1% vs 8.9%, both P < 0.05). Supragastric belch number positively correlated with all reflux episodes in patients with GERD (adjusted R2 = 0.572, P = 0.007). Conclusions BD is characterized by more belching, compared to GERD. SGB is more frequently associated with reflux in GERD than in BD; acidity may be related to GERD. In BD, SGB is typically non-acidic and unrelated to reflux. Distinct SGB characteristics may reflect different pathogenic mechanisms of reflux and associated symptoms.

Objective: As the cycling population grows, the lack of public awareness about the dangers of cycling while under the influence of alcohol is a signifant problem. The purpose of this study was to investigate the association between alcohol consumption and bicycle-related injuries such as traumatic brain injuries (TBI) and excess mortality ratio-adjusted injury severity score (EMR-ISS). Methods: We conducted a retrospective analysis using data collected from the Korean Emergency Department-based Injury In-depth Surveillance (EDIIS) database from 20 emergency departments during the period 2011-2016. The study subjects who had sustained bicycle-related injuries were over 18 years of age. The covariates included the mechanism, place, and time of injury. The outcomes were TBI incidence and severe and critical injury of EMR-ISS≥25. The effects of alcohol consumption on these outcomes were analyzed, and the variations in effects were determined using logistic regression. Results: Of the 24,297 individuals studied, 1,912 had alcohol-related bicycle injuries, which led to a higher proportion of single-vehicle injury incidents (alcohol 63.7% vs. non-alcohol 46.4%, P<0.001). The alcohol group had a higher rate of TBI (alcohol 11.5% vs. non-alcohol 4.6%, P<0.001) and severe and critical injury of EMR-ISS (alcohol 23.1% vs. nonalcohol 11.7%, P<0.001). TBI (odds ratio [OR], 2.72; 95% confidence interval [CI], 2.33-3.16) and severe and critical injury of EMR-ISS (OR, 2.26; 95% CI, 2.01-2.53) showed a significant association with alcohol. Conclusion Our study showed an association of alcohol consumption with a higher incidence of TBI and severe and critical EMR-ISS. Education should focus more on the association between cycling under alcohol influence and injury severity.