1.Can Anodal Transcranial Direct Current Stimulation Increase Steady-State Visual Evoked Potential Responses?
Do Won KIM ; Euijin KIM ; Chany LEE ; Chang Hwan IM
Journal of Korean Medical Science 2019;34(43):e285-
BACKGROUND: It has been frequently reported that non-negligible numbers of individuals have steady-state visual evoked potential (SSVEP) responses of low signal-to-noise-ratio (SNR) to specific stimulation frequencies, which makes detection of the SSVEP difficult especially in brain–computer interface applications. We investigated whether SSVEP can be modulated by anodal transcranial direct-current stimulation (tDCS) of the visual cortex. METHODS: Each participant participated in two 20-min experiments—an actual tDCS experiment and a sham tDCS experiment—that were conducted on different days. Two representative electroencephalogram (EEG) features used for the SSVEP detection, SNR and amplitude, were tested for pre- and post-tDCS conditions to observe the effect of the anodal tDCS. RESULTS: The EEG features were significantly enhanced by the anodal tDCS for the electrodes with low pre-tDCS SNR values, whereas the effect was not significant for electrodes with relatively higher SNR values. CONCLUSION: Anodal tDCS of the visual cortex may be effective in enhancing the SNR and amplitude of the SSVEP response especially for individuals with low-SNR SSVEP.
Electrodes
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Electroencephalography
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Evoked Potentials, Visual
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Transcranial Direct Current Stimulation
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Visual Cortex
2.Kinetics of Neutralizing Antibody Responses Against SARS-CoV-2 Delta Variant in Patients Infected at the Beginning of the Pandemic
Pyoeng Gyun CHOE ; Yuri KIM ; Euijin CHANG ; Chang Kyung KANG ; Nam Joong KIM ; Nam-Hyuk CHO ; Wan Beom PARK ; Myoung-don OH
Journal of Korean Medical Science 2022;37(8):e67-
We investigated the kinetics of the neutralizing antibody responses to the severe acute respiratory syndrome-coronavirus-2 delta variant over the course of 1 year in 16 patients infected at the beginning of the pandemic. In patients with severe disease, neutralizing responses to the delta variant were detectable, albeit at lower levels than responses to the wild type. Neutralizing responses to the delta variant were undetectable, however, in asymptomatic persons. This finding implies that the vaccination strategy for persons with past natural infection should depend on the severity of the previous infection.
3.Clinical Application of the Standard Q COVID-19 Ag Test for the Detection of SARS-CoV-2 Infection
Sang-Min OH ; Hyeonju JEONG ; Euijin CHANG ; Pyoeng Gyun CHOE ; Chang Kyung KANG ; Wan Beom PARK ; Taek Soo KIM ; Woon Yong KWON ; Myoung-Don OH ; Nam Joong KIM
Journal of Korean Medical Science 2021;36(14):e101-
We evaluated the Standard Q COVID-19 Ag test for the diagnosis of coronavirus disease 2019 (COVID-19) compared to the reverse transcription-polymerase chain reaction (RT-PCR) test.We applied both tests to patients who were about to be hospitalized, had visited an emergency room, or had been admitted due to COVID-19 confirmed by RT-PCR. Two nasopharyngeal swabs were obtained; one was tested by RT-PCR and the other by the Standard Q COVID-19 Ag test. A total of 118 pairs of tests from 98 patients were performed between January 5 and 11, 2021. The overall sensitivity and specificity for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for the Standard Q COVID-19 Ag test compared to RT-PCR were 17.5% (95% confidence interval [CI], 8.8–32.0%) and 100% (95% CI, 95.3–100.0%). Analysis of the results using RT-PCR cycle thresholds of ≤ 30 or ≤ 25 increased the sensitivity to 26.9% (95% CI, 13.7–46.1%), and 41.1% (95% CI, 21.6–64.0%), respectively.
4.Work Restrictions for Healthcare Personnel with Potential In-hospital Exposure to SARS-CoV-2: Experience at a Tertiary Hospital
Hyeon Jae JO ; Ji Seon KIM ; Pyoeng Gyun CHOE ; Hyo Yeon LEE ; Euijin CHANG ; Hyemin JUNG ; Chang Kyung KANG ; Wan Beom PARK ; Nam Joong KIM ; Myoung-don OH
Journal of Korean Medical Science 2021;36(38):e274-
Applying work restrictions for asymptomatic healthcare personnel (HCP) with potential exposure to coronavirus disease 2019 (COVID-19) is recommended to prevent transmission from potentially contagious HCP to patients and other HCP. However, it can lead to understaffing, which threatens the safety of both patients and HCP. We evaluated 203 COVID-19 exposure events at a single tertiary hospital from January 2020 to June 2021. A total of 2,365 HCP were potentially exposed, and work restrictions were imposed on 320 HCP, leading to the loss of 3,311 working days. However, only one of the work-restricted HCP was confirmed with COVID-19. During the study period, the work restriction measures might be taken excessively compared to their benefit, so establishing more effective standards for work restriction is required.
5.A Direct Rapid Phenotypic Antimicrobial Susceptibility Test Enables Early Selection of Optimal Antibiotics to Treat Bacteremia in COVID-19 Patients
Do Hyeon PARK ; Euijin CHANG ; Chang Kyung KANG ; Pyoeng Gyun CHOE ; Nam Joong KIM ; Taek Soo KIM ; Wan Beom PARK ; Myoung-don OH
Infection and Chemotherapy 2021;53(4):776-785
Background:
Co-infection with bacteria and severe acute respiratory syndrome coronavirus 2 may result in greater use of healthcare resources and a poor prognosis. Therefore, early selection and use of optimal antibiotics are essential. The direct rapid antibiotic susceptibility test (dRAST) can detect antibiotic resistance within 6 h of a Gram smear result. This study aimed to assess the effectiveness of dRAST for improving early selection of appropriate antibiotics for coronavirus disease 2019 (COVID-19) patients with bacteremia.
Materials and Methods:
This retrospective study included 96 blood culture-positive COVID-19 patients. Bacterial isolates and antimicrobial resistance profiles of each case were evaluated. Cases were divided into two groups based on whether they underwent conventional antibiotic susceptibility test (AST) or dRAST. The time to optimal targeted treatment for the two groups was investigated and compared. In addition, we examined the proportion of cases for which appropriate antibiotics were selected and broad spectrum antibiotics were administered at 72 h from blood sample collection.
Results:
The mean time to optimal targeted antibiotic treatment was shorter for the dRAST group [55.7; standard deviation (SD), 28.7 vs. 92.3; SD, 51.1 h; P = 0.041]. The proportion of cases receiving optimal targeted antibiotics 72 h after blood collection for culture was higher [6/10 (60.0%) vs. 10/25 (40.0%)] and the percentage receiving broad spectrum antibiotics at 72 h was lower [6/10 (60.0%) vs. 19/25 (76.0%)] in the dRAST group than in the conventional AST group. In terms of microbiology profile, the contamination rate was high (35.5%) and multidrug-resistant strains were common (63.2%) in COVID-19 patients with bacteremia.
Conclusion
Application of dRAST for selection of antibiotics to treat bacteremia in COVID-19 patients may enable earlier and optimal treatment. The high incidence of contamination and resistant organisms in blood cultures from COVID-19 patients suggest that dRAST may speed up appropriate targeted treatment.
6.Clinical Impact of Empirical Antibiotic Therapy in Patients With Coronavirus Disease 2019 Requiring Oxygen Therapy
Do Hyeon PARK ; Chan Mi LEE ; Euijin CHANG ; Chang Kyung KANG ; Wan Beom PARK ; Nam Joong KIM ; Pyoeng Gyun CHOE ; Myoung-don OH
Journal of Korean Medical Science 2022;37(29):e238-
Despite the low prevalence of secondary bacterial infection in coronavirus disease 2019 (COVID-19) patients, most of them were administered antibiotic therapy empirically.However, the prognostic impact of empirical antibiotic therapy has not been evaluated.We conducted retrospective propensity score-matched case-control study of 233 COVID-19 patients with moderate to severe illnesses who required oxygen therapy and evaluated whether empirical antibiotic therapy could improve clinical outcomes. Empirical antibiotic therapy did not improve clinical outcomes including length of stay, days with oxygen requirement, the proportion of patients with increased oxygen demand, the proportion of patients who required mechanical ventilation, and overall mortality. This finding implies that routine administration of antibiotics for the treatment of COVID-19 is not essential and should be restricted.
7.Clinical Application of the Standard Q COVID-19 Ag Test for the Detection of SARS-CoV-2 Infection
Sang-Min OH ; Hyeonju JEONG ; Euijin CHANG ; Pyoeng Gyun CHOE ; Chang Kyung KANG ; Wan Beom PARK ; Taek Soo KIM ; Woon Yong KWON ; Myoung-Don OH ; Nam Joong KIM
Journal of Korean Medical Science 2021;36(14):e101-
We evaluated the Standard Q COVID-19 Ag test for the diagnosis of coronavirus disease 2019 (COVID-19) compared to the reverse transcription-polymerase chain reaction (RT-PCR) test.We applied both tests to patients who were about to be hospitalized, had visited an emergency room, or had been admitted due to COVID-19 confirmed by RT-PCR. Two nasopharyngeal swabs were obtained; one was tested by RT-PCR and the other by the Standard Q COVID-19 Ag test. A total of 118 pairs of tests from 98 patients were performed between January 5 and 11, 2021. The overall sensitivity and specificity for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for the Standard Q COVID-19 Ag test compared to RT-PCR were 17.5% (95% confidence interval [CI], 8.8–32.0%) and 100% (95% CI, 95.3–100.0%). Analysis of the results using RT-PCR cycle thresholds of ≤ 30 or ≤ 25 increased the sensitivity to 26.9% (95% CI, 13.7–46.1%), and 41.1% (95% CI, 21.6–64.0%), respectively.
8.Work Restrictions for Healthcare Personnel with Potential In-hospital Exposure to SARS-CoV-2: Experience at a Tertiary Hospital
Hyeon Jae JO ; Ji Seon KIM ; Pyoeng Gyun CHOE ; Hyo Yeon LEE ; Euijin CHANG ; Hyemin JUNG ; Chang Kyung KANG ; Wan Beom PARK ; Nam Joong KIM ; Myoung-don OH
Journal of Korean Medical Science 2021;36(38):e274-
Applying work restrictions for asymptomatic healthcare personnel (HCP) with potential exposure to coronavirus disease 2019 (COVID-19) is recommended to prevent transmission from potentially contagious HCP to patients and other HCP. However, it can lead to understaffing, which threatens the safety of both patients and HCP. We evaluated 203 COVID-19 exposure events at a single tertiary hospital from January 2020 to June 2021. A total of 2,365 HCP were potentially exposed, and work restrictions were imposed on 320 HCP, leading to the loss of 3,311 working days. However, only one of the work-restricted HCP was confirmed with COVID-19. During the study period, the work restriction measures might be taken excessively compared to their benefit, so establishing more effective standards for work restriction is required.
9.Bacterial Co-Infection and Empirical Antibacterial Therapy in Patients With COVID-19
Jiyoung LEE ; Euijin CHANG ; Jiwon JUNG ; Min Jae KIM ; Yong Pil CHONG ; Sung-Han KIM ; Sang-Oh LEE ; Sang-Ho CHOI ; Yang Soo KIM ; Seongman BAE
Journal of Korean Medical Science 2023;38(4):e37-
Background:
The rate and composition of bacterial co-infection in patients with coronavirus disease 2019 (COVID-19) were evaluated when microbiological testing was conducted on the majority of patients. We also evaluated whether the use of empirical antibacterials was associated with mortality.
Methods:
In this retrospective study, all of the adult patients with COVID-19 hospitalized in a single tertiary hospital in South Korea between February 2020 and December 2021 were included. Bacterial co-infection was assessed by sputum cultures, blood cultures, and molecular testing, including polymerase chain reaction sputum testing and urinary antigen tests. Mortality was compared between patients who received empirical antibacterials and those who did not.
Results:
Of the 367 adult patients admitted during the study period, 300 (81.7%) had sputum culture results and were included in the analysis. Of these 300 patients, 127 (42.3%) had a history of antibiotic exposure. The co-infection rate within 48 hours was 8.3% (25/300):6.4% (11/173) of patients without prior antibiotic exposure and 11% (14/127) of patients with prior antibacterial exposure. The co-infected bacteria were different according to antibacterial exposure before admission, and multi-drug resistant pathogens were detected exclusively in the antibacterial exposed group. Among the patients without positive results for the microbiological tests, empirical antibacterials were used in 33.3% of cases (100/300). Empirical antibacterial therapy was not significantly related to the 30-day mortality or inhospital mortality rates in the study cohort before or after the propensity score-matching.
Conclusion
In this study including only patients underwent microbiological testing, bacterial co-infection was not frequent, and the co-infected organisms varied depending on previous antibacterial exposures. Given the rarity of co-infection and the lack of potential benefits, empiric antibacterial use in COVID-19 should be an important target of antibiotic stewardship.
10.A Universal Screening Strategy for SARS-CoV-2 Infection in Intensive Care Units: Korean Experience in a Single Hospital
Euijin CHANG ; Jae-Sung CHOI ; Tae Yun PARK ; Seung Bin K KIM ; Suhui KO ; Yang Sun KWON ; Eun Jin KIM ; Hyunju SONG ; Hwa Kyung NOH ; Sang-Won PARK
Infection and Chemotherapy 2020;52(3):352-359
Background:
Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection is not differentiated clinically from other respiratory infections, and intensive care units (ICUs) are vulnerable to in-hospital transmission due to interventions inducing respiratory aerosols.This study evaluated the effectiveness of universal SARS-CoV-2 screening in ICUs in terms of screened-out cases and reduction in anxiety of healthcare personnel (HCP).Materials and
Methods:
This prospective single-armed observational study was conducted in 2 ICUs of a single hospital. The number of patients diagnosed with SARS-CoV-2 infection by the screening program and healthcare workers in ICUs that visited the SARS-CoV-2 screening clinic or infection clinic were investigated.
Results:
During the 7-week study period, no positive screening case was reported among a total of 142 patients. Among 86 HCP in the ICUs, only 2 HCP sought medical consultation for SARS-CoV-2 infection during the initial 2 weeks.
Conclusion
A universal screening program for SARS-CoV-2 infection in ICUs with the coordination of other countermeasures in the hospital was reasonably effective in preventing in-hospital transmission in a pandemic situation and making clinical practices and HCP stable.