1.A Novel Approach to Total Ankle Arthroplasty with Simultaneous Structural Tibial Cut Autograft for Anterior Tibial Bone Defects
Yeo Kwon YOON ; Kwang Hwan PARK ; Dong Woo SHIM ; Wonwoo LEE ; Seung Hwan HAN ; Jin Woo LEE
Clinics in Orthopedic Surgery 2024;16(4):674-678
Severe bone defects pose a clinical challenge in total ankle arthroplasty (TAA) and are frequently considered contraindicated. We introduce an innovative approach that utilizes a structural tibial cut autograft to address anterior distal tibia bone defects during TAA. This technique is a viable alternative to employing revision TAA systems or resorting to excessively high tibial cuts. Furthermore, it facilitates achieving favorable sagittal alignment and ensures adequate fixation strength of the tibial component.
3.Early Prediction of Mortality for Septic Patients Visiting Emergency Room Based on Explainable Machine Learning: A Real-World Multicenter Study
Sang Won PARK ; Na Young YEO ; Seonguk KANG ; Taejun HA ; Tae-Hoon KIM ; DooHee LEE ; Dowon KIM ; Seheon CHOI ; Minkyu KIM ; DongHoon LEE ; DoHyeon KIM ; Woo Jin KIM ; Seung-Joon LEE ; Yeon-Jeong HEO ; Da Hye MOON ; Seon-Sook HAN ; Yoon KIM ; Hyun-Soo CHOI ; Dong Kyu OH ; Su Yeon LEE ; MiHyeon PARK ; Chae-Man LIM ; Jeongwon HEO ; On behalf of the Korean Sepsis Alliance (KSA) Investigators
Journal of Korean Medical Science 2024;39(5):e53-
Background:
Worldwide, sepsis is the leading cause of death in hospitals. If mortality rates in patients with sepsis can be predicted early, medical resources can be allocated efficiently. We constructed machine learning (ML) models to predict the mortality of patients with sepsis in a hospital emergency department.
Methods:
This study prospectively collected nationwide data from an ongoing multicenter cohort of patients with sepsis identified in the emergency department. Patients were enrolled from 19 hospitals between September 2019 and December 2020. For acquired data from 3,657 survivors and 1,455 deaths, six ML models (logistic regression, support vector machine, random forest, extreme gradient boosting [XGBoost], light gradient boosting machine, and categorical boosting [CatBoost]) were constructed using fivefold cross-validation to predict mortality. Through these models, 44 clinical variables measured on the day of admission were compared with six sequential organ failure assessment (SOFA) components (PaO 2 /FIO 2 [PF], platelets (PLT), bilirubin, cardiovascular, Glasgow Coma Scale score, and creatinine).The confidence interval (CI) was obtained by performing 10,000 repeated measurements via random sampling of the test dataset. All results were explained and interpreted using Shapley’s additive explanations (SHAP).
Results:
Of the 5,112 participants, CatBoost exhibited the highest area under the curve (AUC) of 0.800 (95% CI, 0.756–0.840) using clinical variables. Using the SOFA components for the same patient, XGBoost exhibited the highest AUC of 0.678 (95% CI, 0.626–0.730). As interpreted by SHAP, albumin, lactate, blood urea nitrogen, and international normalization ratio were determined to significantly affect the results. Additionally, PF and PLTs in the SOFA component significantly influenced the prediction results.
Conclusion
Newly established ML-based models achieved good prediction of mortality in patients with sepsis. Using several clinical variables acquired at the baseline can provide more accurate results for early predictions than using SOFA components. Additionally, the impact of each variable was identified.
4.Evaluation of the Current Urgency-Based Lung Allocation System in Korea with Simulation of the Eurotransplant Lung Allocation Score
Woo Sik YU ; Sun Mi CHOI ; Hye Ju YEO ; Dong Kyu OH ; Sung Yoon LIM ; Young Tae KIM ; Kyeongman JEON ; Jin Gu LEE
Yonsei Medical Journal 2024;65(8):463-471
Purpose:
Due to the shortage of lung donors relative to the number of patients waiting for lung transplantation (LTx), more than one-third of patients on the waitlist have died without receiving LTx in Korea. Therefore, the importance of fair and effective allocation policies has been emphasized. This study investigated the characteristics of the current urgency-based allocation system in Korea by simulating the Eurotransplant lung allocation score (ET-LAS) using a nationwide multi-institutional registry for LTx in Korea.
Materials and Methods:
This study used data from the Korean Organ Transplantation Registry (KOTRY), along with additional retrospective data for ET-LAS calculation. A total of 194 patients were included in this study between January 2015 and December 2019. The Korean urgency definition classifies an LTx candidate as having statuses 0–3 according to urgency. The ET-LAS was analyzed according to the Korean urgency status.
Results:
In total, 92 patients received lung transplants at status 0, 85 at status 1, and 17 at status 2/3. The ET-LAS showed a bimodal distribution with distinct peaks corresponding to status 0 and non-status 0. There was no significant difference in the ET-LAS among non-status 0 patients. In logistic and decision tree analyses, oxygen supplementation methods, particularly oxygen masks and high-flow nasal cannulas, were significantly associated with a high ET-LAS (≥50) among non-status 0 patients.
Conclusion
Simulation of the ET-LAS with KOTRY data showed that the Korean urgency definition may not allocate lungs by urgency, especially for patients in non-status 0; therefore, it needs to be revised.
5.Anaplastic Large Cell Lymphoma Mimicking a Muscle Abscess:A Case Report
Jaehyeok BAEK ; Younghyun KIM ; Wonwoo LEE ; Yeo Kwon YOON ; Jin Woo LEE ; Dong Woo SHIM
Journal of Korean Foot and Ankle Society 2023;27(3):108-111
Anaplastic large cell lymphoma (ALCLs) are a group CD30-positive mature T-cell lymphomas, an uncommon subtype of non-Hodgkin lymphomas, characterized by diverse clinical and genetic features. Among the types of ALCL, anaplastic lymphoma kinase (ALK)-negative ALCL, though typically involves the lymph nodes, can infrequently invade other tissues. When soft tissue involvement occurs, it may mimic the clinical presentation of infectious diseases, leading to potential misdiagnosis. Therefore, a histological examination is necessary to differentiate between ALK-negative ALCL and similar phenotypes associated with infectious conditions. This paper reports a case of ALCL, initially misdiagnosed as an infection.
6.Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation–Positive Non–Small Cell Lung Cancer
Jang Ho LEE ; Eun Young KIM ; Cheol-Kyu PARK ; Shin Yup LEE ; Min ki LEE ; Seong-Hoon YOON ; Jeong Eun LEE ; Sang Hoon LEE ; Seung Joon KIM ; Sung Yong LEE ; Jun Hyeok LIM ; Tae-Won JANG ; Seung Hun JANG ; Kye Young LEE ; Seung Hyeun LEE ; Sei Hoon YANG ; Dong Won PARK ; Chan Kwon PARK ; Hye Seon KANG ; Chang Dong YEO ; Chang-Min CHOI ; Jae Cheol LEE
Cancer Research and Treatment 2023;55(1):112-122
Purpose:
Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation–positive non–small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation–positive non–small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea.
Materials and Methods:
Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints.
Results:
A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects.
Conclusion
Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation–positive in Korean patients with no new safety signals.
7.A Case of Transverse Myelitis Following Treatment with Atezolizumab for Advanced Hepatocellular Carcinoma
Kyung Han KIM ; Yang-Hyun BAEK ; Yeo Wool KANG ; Byeol-A YOON ; Sang Yi MOON
The Korean Journal of Gastroenterology 2023;82(1):35-39
The results of the IMbrave150 study have led to widespread use of the combination therapy of atezolizumab and bevacizumab as a first-line treatment for unresectable or metastatic hepatocellular carcinoma (HCC). Compared to traditional cytotoxic chemotherapy agents, immune checkpoint inhibitors show a spectrum of side effects ranging from mild side effects such as skin rash to potentially severe systemic effects such as myocarditis. We present a case of transverse myelitis diagnosed during the treatment of HCC with atezolizumab and bevacizumab combination therapy.
8.The work and socioeconomic burden of emergency physicians in the COVID-19 pandemic: 2020 Korean Emergency Physician Survey
In Hwan YEO ; Mi Jin LEE ; Tae Jin SIM ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):67-75
Objective:
This study evaluated the anxiety, work, and socioeconomic burden of emergency physicians (EP) during the coronavirus disease 2019 (COVID-19) pandemic in South Korea.
Methods:
A cross-sectional observational study was conducted using data from the 2020 Korean Emergency Physician Survey that included the following domains: hospital resources of suspected COVID-19 patients, availability of personal protective equipment, levels of home and workplace anxiety, the severity of work burnout, identification of stressors, changes in personal environments, and measures to decrease stress/anxiety.
Results:
Totally, 855 eligible participants were enrolled in the study. A statistically significant deterioration was observed in response to decreased working income or an unstable employment situation (0.46±0.88 points). The median number of patients with confirmed COVID-19 was 2.72. The risk of infection during emergency department (ED) work was found to be significantly increased (P<0.01). Of the 751 respondents (91.4%) who reported patient contact during their survey phase, 516 (62.8%) reported having taken the COVID-19 reverse transcription polymerase chain reaction test. The major factors that affected worsening of the work burden were determined to be unsuitable inter-hospital transfer arrangements for febrile patients (3.46±1.06 before vs. 1.99±1.16 after the pandemic, P<0.01) and delayed consultation for patients with fever or respiratory symptoms in the ED (3.20±1.06 before vs. 2.66±1.10 after the pandemic, P<0.01).
Conclusion
During the peak phase, the COVID-19 pandemic induced substantial workplace and socioeconomic burdens for Korean EPs. The sustained impact of the pandemic on the wellness of EPs deserves further investigation to guide targeted interventions.
9.Analysis of factors influencing emergency physician’s choice of specialty again using machine learning method
Jee Young PARK ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):57-66
Objective:
Machine learning is emerging as a new alternative in various scientific fields and is potentially a new method of interpretation. Using the Light Gradient Boosting Machine (LightGBM), we analyzed the factors that influence the rechoice of emergency medicine responders. The survey is a cross-sectional study which provides an accurate understanding of a responder's current status. However, the results may vary depending on the composition, format, and question, and the relationship between the answers may be unclear.
Methods:
This study evaluated the modified 2020 Korean Emergency Physician Survey raw data. We applied the preferred model for random relationship check, random forest, support vector machine, and LightGBM models. The stacking ensemble model was used for the final decision process.
Results:
‘It is fun working in an emergency room’was the most selected response factor for re-choice, followed by ‘interesting major’. The physical burden of age and lack of identity had a negative impact, whereas burnout and emotional stress factors had a lesser effect. Anxiety caused by the coronavirus disease 2019 (COVID-19) is thought to have a significant impact on this decision making.
Conclusion
Establishing the identity of emergency medicine and being faithful to its fundamental mission is a way to increase the rate of re-choice. Decreasing the burden of workload modified according to age is recommended to establish career longevity. The method of machine learning presents us with a new possibility of checking the relevance of survey results quickly and easily.
10.The workload of emergency physician using Korean Emergency Physician Survey
Yoo Sang YOON ; DongWoo SON ; Ji Hun KANG ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Hyung Min LEE ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):49-56
Objective:
It has been reported that emergency physicians experience high levels of depression and psychological burnout due to night shifts and tend to consider early retirement. This study intended to check working hours and intensity, individual health, satisfaction, and overall welfare, given the increase in the numbers of emergency physicians.
Methods:
The study used the results of the ‘2020 Korean Emergency Physician Survey (KEPS)’ conducted from January 15 to February 26, 2021, which targeted 2,138 emergency physicians registered with the Korean Society of Emergency Medicine. The survey was conducted online through the web and mobile application.
Results:
One thousand three hundred seven out of the 2,167 emergency physicians (60.3%) registered at the society responded. The average age of the respondents was 42.6 years, and there were 1,148 male emergency physicians and 158 female emergency physicians. The average professional experience was 8.2 years, with 325 professors, 122 commissioned doctors, 648 public servants of which 90 had military service, and 45 medical practitioners.
Conclusion
In conclusion, the number of working hours of emergency physicians showed a decreasing trend compared to 2010 and 2015. However, emergency physicians often expected early retirement. This suggests that, while the absolute working hours are decreasing, the actual working intensity has not decreased. For the proper development of the emergency medical system, it is necessary to establish a stable working environment for emergency physicians. A systematic study is needed on the working hours and work intensity of emergency physicians.

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