Vitamin D deficiency as a risk factor for sudden cardiac arrest: A multicenter case-control study.

BACKGROUND AND AIMS: Vitamin D is known to influence the risk of cardiovascular disease, which is a recognized risk factor for sudden cardiac arrest (SCA). However, the relationship between vitamin D and SCA is not well understood. Therefore, this study aims to investigate the association between vitamin D and SCA in out-of-hospital cardiac arrest (OHCA) patients compared to healthy controls. METHODS AND RESULTS: Using the Phase II Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES II) registry, a 1:1 propensity score-matched case-control study was conducted between 2017 and 2020. Serum 25-hydroxyvitamin D (vitamin D) levels in patients with OHCA (454 cases) and healthy controls (454 cases) were compared after matching for age, sex, cardiovascular risk factors, and lifestyle behaviors. The mean vitamin D levels were 14.5 ± 7.6 and 21.3 ± 8.3 ng/mL among SCA cases and controls, respectively. Logistic regression analysis was used adjusting for cardiovascular risk factors, lifestyle behaviors, corrected serum calcium levels, and estimated glomerular filtration rate (eGRF). The adjusted odds ratio (aOR) for vitamin D was 0.89 (95% confidence interval [CI] 0.87-0.91). The dose-response relationship demonstrated that vitamin D deficiency was associated with SCA incidence (severe deficiency, aOR 10.87, 95% CI 4.82-24.54; moderate deficiency, aOR 2.24, 95% CI 1.20-4.20). CONCLUSION: Vitamin D deficiency was independently and strongly associated with an increased risk of SCA, irrespective of cardiovascular and lifestyle factors, corrected calcium levels, and eGFR.

Association Between Ambulance Station Case Volume and Clinical Outcomes in Moderate to Severe Trauma.

OBJECTIVES: The effect of the case volume of emergency medical services (EMS) on the clinical outcomes of trauma is uncertain. The purpose of this study was to evaluate the association between the case volume of an ambulance station and clinical outcomes in moderate to severe trauma patients. METHODS: Adult trauma patients with injury severity scores greater than 8 who were transported by the EMS between 2018 and 2019 were analyzed. The main exposure was the annual case volume of moderate to severe trauma at the ambulance station where the patient-transporting ambulance was based: low-volume (less than 60 cases), intermediate-volume (between 60 and 89 cases), and high-volume (equal or greater than 90 cases). The primary outcome was in-hospital mortality. Multilevel multivariable logistic regression analysis was conducted to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs), with the high-volume group used as the reference. RESULTS: In total, 21,498 trauma patients were analyzed. The high-volume group exhibited lower in-hospital mortality, 447 (9.0%), compared to 867 (14.1%) in the intermediate-volume group and 1,458 (14.1%) in the low-volume group. There were a significantly higher odds of in-hospital mortality: the low-volume group (AOR 95% CI: 1.20 (0.95-1.51)) and intermediate-volume group (AOR 95% CI: 1.29 (1.02-1.64)) when compared to the high-volume group. CONCLUSIONS: The case volume at an ambulance station is associated with in-hospital mortality in patients with moderate to severe trauma. These results should be considered when constructing an EMS system and education program for prehospital trauma care.

Association between Case Volumes of Extracorporeal Life Support and Clinical Outcome in Out-of-Hospital Cardiac Arrest.

AIM: Extracorporeal life support (ECLS) for out-of-hospital cardiac arrest (OHCA) is increasing. There is little evidence identifying the association between hospital ECLS case volumes and outcomes in different populations receiving ECLS or conventional cardiopulmonary resuscitation (CPR). The goal of this investigation was to identify the association between ECLS case volumes and clinical outcomes of OHCA patients. METHODS: This cross-sectional observational study used the National OHCA Registry for adult OHCA cases in Seoul, Korea between January 2015 and December 2019. If the ECLS volume during the study period was >20, the institution was defined as a high-volume ECLS center. Others were defined as low-volume ECLS centers. Outcomes were good neurologic recovery (cerebral performance category 1 or 2) and survival to discharge. We performed multivariate logistic regression and interaction analyses to assess the association between case volume and clinical outcome. RESULTS: Of the 17,248 OHCA cases, 3,731 were transported to high-volume centers. Among the patients who underwent ECLS, those at high-volume centers had a higher neurologic recovery rate than those at low-volume centers (17.0% vs. 12.0%), and the adjusted OR for good neurologic recovery was 2.22 (95% confidence interval (CI): 1.15-4.28) in high-volume centers compared to low-volume centers. For patients who received conventional CPR, high-volume centers also showed higher survival-to-discharge rates (adjusted OR of 1.16, 95%CI: 1.01-1.34). CONCLUSIONS: High-volume ECLS centers showed better neurological recovery in patients who underwent ECLS. High-volume centers also had better survival-to-discharge rates than low-volume centers for patients not receiving ECLS.

Spatiotemporal Analysis of Out-of-Hospital Cardiac Arrest Incidence and Survival Outcomes in Korea (2009-2021).

BACKGROUND: Out-of-hospital cardiac arrest is a major public health concern in Korea. Identifying spatiotemporal patterns of out-of-hospital cardiac arrest incidence and survival outcomes is crucial for effective resource allocation and targeted interventions. Thus, this study aimed to investigate the spatiotemporal epidemiology of out-of-hospital cardiac arrest in Korea, with a focus on identifying high-risk areas and populations and examining factors associated with prehospital outcomes. METHODS: We conducted this population-based observational study using data from the Korean out-of-hospital cardiac arrest registry from January 2009 to December 2021. Using a Bayesian spatiotemporal model based on the Integrated Nested Laplace Approximation, we calculated the standardized incidence ratio and assessed the relative risk to compare the spatial and temporal distributions over time. The primary outcome was out-of-hospital cardiac arrest incidence, and the secondary outcomes included prehospital return of spontaneous circulation, survival to hospital admission and discharge, and good neurological outcomes. RESULTS: Although the number of cases increased over time, the spatiotemporal analysis exhibited a discernible temporal pattern in the standardized incidence ratio of out-of-hospital cardiac arrest with a gradual decline over time (1.07; 95% credible interval [CrI], 1.04-1.09 in 2009 vs. 1.00; 95% CrI, 0.98-1.03 in 2021). The district-specific risk ratios of survival outcomes were more favorable in the metropolitan and major metropolitan areas. In particular, the neurological outcomes were significantly improved from relative risk 0.35 (0.31-0.39) in 2009 to 1.75 (1.65-1.86) in 2021. CONCLUSION: This study emphasized the significance of small-area analyses in identifying high-risk regions and populations using spatiotemporal analyses. These findings have implications for public health planning efforts to alleviate the burden of out-of-hospital cardiac arrest in Korea.

Effects of Transport to Trauma Centers on Survival Outcomes Among Severe Trauma Patients in Korea: Nationwide Age-Stratified Analysis.

BACKGROUND: Previous studies showed that the prognosis for severe trauma patients is better after transport to trauma centers compared to non-trauma centers. However, the benefit from transport to trauma centers may differ according to age group. The aim of this study was to compare the effects of transport to trauma centers on survival outcomes in different age groups among severe trauma patients in Korea. METHODS: Cross-sectional study using Korean national emergency medical service (EMS) based severe trauma registry in 2018-2019 was conducted. EMS-treated trauma patients whose injury severity score was above or equal to 16, and who were not out-of-hospital cardiac arrest or death on arrival were included. Patients were classified into 3 groups: pediatrics (age < 19), working age (age 19-65), and elderly (age > 65). The primary outcome was in-hospital mortality. Multivariable logistic regression analysis was conducted to evaluate the effect of trauma center transport on outcome after adjusting of age, sex, comorbidity, mechanism of injury, Revised Trauma Score, and Injury Severity Score. All analysis was stratified according to the age group, and subgroup analysis for traumatic brain injury was also conducted. RESULTS: Overall, total of 10,511 patients were included in the study, and the number of patients in each age group were 488 in pediatrics, 6,812 in working age, and 3,211 in elderly, respectively. The adjusted odds ratio (95% confidence interval [CI]) of trauma center transport on in-hospital mortality from were 0.76 (95% CI, 0.43-1.32) in pediatrics, 0.78 (95% CI, 0.68-0.90) in working age, 0.71(95% CI, 0.60-0.85) in elderly, respectively. In subgroup analysis of traumatic brain injury, the benefit from trauma center transport was observed only in elderly group. CONCLUSION: We found out trauma centers showed better clinical outcomes for adult and elderly groups, excluding the pediatric group than non-trauma centers. Further research is warranted to evaluate and develop the response system for pediatric severe trauma patients in Korea.

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry.

BACKGROUND: There is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis. METHODS: Using a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed. RESULTS: Among 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85-1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45 min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33-4.75] in 1-30 min, 1.81 [1.11-2.93] in 31-45 min, 1.07 (0.56-2.04) in 46-60 min, and 0.45 (0.11-1.91) in over 60 min). CONCLUSIONS: ECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted.

Effects of a Designated Ambulance Team Response on Prehospital Return of Spontaneous Circulation and Advanced Cardiac Life Support of Out-of-Hospital Cardiac Arrest: A Nationwide Natural Experimental Study.

OBJECTIVES: This study aimed to investigate the effects of adding advanced cardiac life support (ACLS) training to an existing basic life support program and the operation of a designated team response for patients with out-of-hospital cardiac arrest (OHCA) on prehospital return of spontaneous circulation (ROSC) and ACLS management. METHODS: A natural experimental study was conducted for emergency medical service (EMS)-treated adult patients with OHCA in 2020. In 2019, a quarter of the EMS clinicians were trained in a 3-day ACLS courses, and they were designated to be dispatched first in suspected OHCA. Some were dispatched only to major emergencies, such as OHCA and myocardial infarction (dedicated team), while others were dispatched to all emergencies with priority to major ones (non-dedicated team). The exposure was the ambulance response type: dedicated, non-dedicated, and basic teams (others). The primary outcome was prehospital ROSC. The secondary outcomes were prehospital ACLS (advanced airway management and intravenous access). A multivariable logistic regression analysis was conducted to investigate the effect of ambulance response type on study outcomes. RESULTS: Among 23,512 eligible patients with OHCA, 54.8% (12,874) were treated by the basic team, 36.5% (8,580) by the non-dedicated ACLS team, and 8.8% (2,058) were treated by the dedicated ACLS team. Prehospital ROSC was greater for the designated team than for the basic team (dedicated ACLS team 13.8%, non-dedicated ACLS team 11.3%, and basic team 6.7%) (p < 0.01). In the final logistic regression analysis, compared with the basic team, the designated ACLS team was associated with a higher probability of prehospital ROSC (AOR (95% CIs), 1.88 (1.68-2.09) compared to the non-dedicated ACLS team, and 2.46 (2.09-2.90) compared to the dedicated ACLS team), prehospital advanced airway management (1.72 (1.57-1.87) and 1.73 (1.48-2.03), respectively), and intravenous access (2.29 (2.16-2.43) and 2.76 (2.50-3.04), respectively). CONCLUSION: Additional ACLS training and operation of a designated OHCA team response were associated with higher rates of prehospital ROSC and prehospital ACLS provision. However, further research is needed to find the optimal operation for EMS to improve survival outcomes.

Sex Disparities in Prehospital Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest in South Korea.

OBJECTIVE: Sex disparities have been reported in the prehospital and in-hospital care among patients with out-of-hospital cardiac arrest (OHCA). The aim of this study was to investigate the association between sex and prehospital advanced cardiac life support (ACLS) interventions provided by emergency medical services (EMS). METHODS: This was a cross-sectional observational study using a nationwide OHCA registry in South Korea. The study included adult OHCAs with presumed cardiac etiology from January 2016 to December 2019. The main exposure was the sex of the victim, and the primary outcomes were prehospital ACLS interventions, including advanced airway management (AAM), intravenous access (IV), and epinephrine (EPI) administration. Multivariable logistic regression analysis accounted for age group, health insurance, comorbidities, place of arrest, urbanization level, witness status, bystander CPR and initial rhythm was performed to calculate adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs). RESULTS: Among 71,154 eligible patients, females with OHCA received less prehospital ACLS interventions than males: risk difference, (95% CIs) -2.76 (-3.41;-2.11) for AAM, -6.03 (-6.79;-5.27) for IV, and -3.81 (-4.37;-3.25) for EPI. In multivariable logistic regression analysis, female sex was significantly associated with a lower probability of prehospital ACLS provision: AOR, (95% CIs) 0.87 (0.84-0.91) for AAM, 0.85 (0.82-0.88) for IV, and 0.81 (0.77-0.84) for EPI. CONCLUSION: Compared to male patients, female patients were less likely to receive prehospital ACLS. This offers opportunities for EMS systems to reduce disparities and to improve compliance with OHCA resuscitation guidelines and outcomes through quality improvement and educational interventions.

The impact of COVID-19 pandemic on out-of-hospital cardiac arrest system-of-care: Which survival chain factor contributed the most?

OBJECTIVES: In many communities, out-of-hospital cardiac arrest (OHCA) survival outcomes decreased after the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to identify and compare the impacts of each survival chain factor on the change of survival outcomes after COVID-19. METHODS: Using a Korean out-of-hospital cardiac arrest registry, we analyzed OHCA patients whose arrest was not witnessed by emergency medical service (EMS) providers between 2017 and 2021. Because lack of hospital and survival information in 2021, the 2021 data were used only to identify the expected trend. We developed a prediction model for survival to discharge using patients from 2017 to 2019 (Pre-COVID-19 set) and validated it using patients from 2020 (post-COVID-19 set). Using Utstein elements, a stepwise logistic regression model was constructed, and discrimination and calibration were evaluated by c-statistics and scaled Brier score. Using the distribution change of predictors from one year before the pandemic (2019) to post-COVDI-19, we calculated the magnitude of survival difference according to each predictor's distribution change using the marginal standardization method. RESULTS: Among 83,273 patients (mean age 67.2 years and 64.3% males), 61,180 and 22,092 patients belonged to pre-COVOD-19 and post-COVID-19 sets. Survival to discharge was 5019 (8.2%) in pre-COVID-19 set and 1457 (6.6%) in post-COVID-19 set. The proportion of bystander cardiopulmonary resuscitation was 59.0% in the pre-COVID-19 set and 61.0% in the post-COVID-19 set. The median (interquartile range) response time was 7 (5-9) minutes in the pre-COVID-19 set and 8 (6-10) minutes in the post-COVID-19 set. The area under the receiver operating characteristic (AUROC) curve (95% confidence interval) was 0.907 (0.902-0.912) in the pre-COVID-19 set, and 0.924 (0.916-0.931) in the post-COVID-19 set, and scaled Brier score were 0.39 in pre-COVID-19 sets, and 0.40 in the post-COVID-19 set. Among various predictors, EMS factors showed the highest impact. Response time and on-scene management of EMS showed the highest impact on decreased survival. A similar trend was also expected in the 2021. CONCLUSION: The effort to create a rapid response system for OHCA patients could have priority for the recovery of survival outcomes in OHCA patients in the post-COVID-19 period. Further studies to recover survival outcomes of OHCA are warranted.

Association between prehospital airway type and oxygenation and ventilation in out-of-hospital cardiac arrest.

OBJECTIVES: This study aimed to evaluate the association between prehospital airway type and oxygenation and ventilation in out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective observational study included OHCA patients who visited the emergency departments (EDs) between October 2015 and June 2021. The study groups were categorized according to the prehospital airway type: endotracheal intubation (ETI), supraglottic airway (SGA), or bag-valve-mask ventilation (BVM). The primary outcome was good oxygenation: partial pressure of oxygen (PaO2) ≥ 60 mmHg on the first arterial blood gas (ABG) test. The secondary outcome was good ventilation: partial pressure of carbon dioxide (PaCO2) ≤ 45 mmHg. Multivariate logistic regression was conducted to calculate the adjusted odds ratio (AOR) and 95% confidence interval (CI). RESULTS: A total of 7,372 patients were enrolled during the study period: 1,819 patients treated with BVM, 706 with ETI, and 4,847 who underwent SGA. In multivariable logistic regression analysis for good oxygenation outcomes, the ETI group showed a higher AOR than the BVM group (AOR [95% CIs]: 1.30 [1.06-1.59] in ETI and 1.05 [0.93-1.20] in SGA groups). Regarding good ventilation, the ETI group showed a higher AOR, and the SGA group showed a lower AOR compared to the BVM group (AOR [95% CIs] 1.33 [1.02-1.74] in the ETI and 0.83 (0.70-0.99) in the SGA groups). There was no significant difference in survival to discharge. CONCLUSIONS: ETI was significantly associated with good oxygenation and good ventilation compared to BVM in patients with OHCA, particularly during longer transports. This should be taken into consideration when deciding the prehospital advanced airway management in patients with OHCA.

Bystander cardiopulmonary resuscitation, automated external defibrillator use, and survival after out-of-hospital cardiac arrest.

INTRODUCTION: We aimed to investigate the association between bystander cardiopulmonary resuscitation (CPR) with and without automated external defibrillator (AED) use and neurological outcomes after out-of-hospital cardiac arrest (OHCA) in Korea. METHODS: This cross-sectional study used a nationwide Korean OHCA registry between 2015 and 2019. Patients were categorised into no bystander CPR and bystander CPR with and without AED use groups. The primary outcome was good neurological recovery at discharge. We also analysed the interaction effects of place of arrest, response time, and whether the OHCA was witnessed. RESULTS: In total, 93,623 patients were included. Among them, 35,486 (37.9%) were in the no bystander CPR group, 56,187 (60.0%) were in the bystander CPR without AED use group, and 1950 (2.1%) were in the bystander CPR with AED use group. Good neurological recovery was demonstrated in 1286 (3.6%), 3877 (6.9%), and 208 (10.7%) patients in the no CPR, bystander CPR without AED use, and bystander CPR with AED use groups, respectively. Compared to the no bystander CPR group, the adjusted odds ratio (95% confidence intervals) for good neurological recovery was 1.54 (1.45-1.65) and 1.37 (1.15-1.63) in the bystander CPR without and with AED use groups, respectively. The effect of bystander CPR with AED use was more apparent in OHCAs with witnessed arrest and prolonged response time (≥8 min). CONCLUSION: Bystander CPR was associated with better neurological recovery compared to no bystander CPR; however, the benefits of AED use were not significant. Efforts to disseminate bystander AED availability and ensure proper utilisation are warranted.

A simple scoring rule to predict survival to discharge after out of hospital cardiac arrest at the time of ED arrival.

BACKGROUND: It is important to be able to predict the chance of survival to hospital discharge upon ED arrival in order to determine whether to continue or terminate resuscitation efforts after out of hospital cardiac arrest. This study was conducted to develop and validate a simple scoring rule that could predict survival to hospital discharge at the time of ED arrival. METHODS: This was a multicenter retrospective cohort study based on a nationwide registry (Korean Cardiac Arrest Research Consortium) of out of hospital cardiac arrest (OHCA). The study included adult OHCA patients older than 18 years old, who visited one of 33 tertiary hospitals in South Korea from September 1st, 2015 to June 30th, 2020. Among 12,321 screened, 5471 patients were deemed suitable for analysis after exclusion. Pre-hospital ROSC, pre-hospital witness, shockable rhythm, initial pH, and age were selected as the independent variables. The dependent variable was set to be the survival to hospital discharge. Multivariable logistic regression (LR) was performed, and the beta-coefficients were rounded to the nearest integer to formulate the scoring rule. Several machine learning algorithms including the random forest classifier (RF), support vector machine (SVM), and K-nearest neighbor classifier (K-NN) were also trained via 5-fold cross-validation over a pre-specified grid, and validated on the test data. The prediction performances and the calibration curves of each model were obtained. Pre-processing of the registry was done using R, model training & optimization using Python. RESULTS: A total of 5471 patients were included in the analysis. The AUROC of the scoring rule over the test data was 0.7620 (0.7311-0.7929). The AUROCs of the machine learning classifiers (LR, SVM, k-NN, RF) were 0.8126 (0.7748-0.8505), 0.7920 (0.7512-0.8329), 0.6783 (0.6236-0.7329), and 0.7879 (0.7465-0.8294), respectively. CONCLUSION: A simple scoring rule consisting of five, binary variables could aid in the prediction of the survival to hospital discharge at the time of ED arrival, showing comparable results to conventional machine learning classifiers.

Extracorporeal cardiopulmonary resuscitation location, coronary angiography and survival in out-of-hospital cardiac arrest.

INTRODUCTION: The best location for safe and timely implementation of extracorporeal cardiopulmonary resuscitation (ECPR) is currently uncertain. We aimed to evaluate the association between the location of ECPR and survival outcomes in out-of-hospital cardiac arrest (OHCA) patients. We also evaluated whether the effects of ECPR location on survival differed between patients who underwent coronary angiography (CAG) and those who did not. METHODS: We used data collected between 2013 and 2020 from a nationwide OHCA database. Adult OHCA patients with presumed cardiac etiology who underwent ECPR were included in the study. The primary outcome was survival to discharge. The main exposure was the ECPR location (emergency department [ED] or cardiac catheterization laboratory [Cath lab]). We compared primary outcomes of ECPR between the ED and Cath lab using multivariable logistic regression. The interaction between ECPR location and CAG was also evaluated. RESULTS: Of 564 ECPR patients, 448 (79.4%) and 116 (20.6%) underwent ECPR in the ED and Cath lab, respectively. CAG was observed in 52.5% and 72.4% of the patients in the ED and Cath lab groups, respectively. There were no significant differences in survival to discharge between the ED and Cath lab groups (14.1% vs. 12.9%, p = 0.75, adjusted odds ratio [AOR] [95% confidence interval] 1.87 [0.85-4.11]). AOR of interaction analysis (95% CI) for survival to discharge of the ED group was 2.34 (1.02-5.40) in patients with CAG and 0.28 (0.04-1.84) in patients without CAG (p for interaction was 0.04). CONCLUSION: In adult OHCA patients who underwent ECPR and CAG, ECPR in the ED shortened time to ECMO pump-on time and increased survival to discharge compared to ECPR in the Cath lab.

Efficacy of distance training program for cardiopulmonary resuscitation utilizing smartphone application and home delivery system.

AIM OF THE STUDY: Community cardiopulmonary resuscitation (CPR) education is important for laypersons. However, during the COVID-19 pandemic, with social distancing, conventional face-to-face CPR training was unavailable. We developed a distance learning CPR training course (HEROS-Remote) using a smartphone application that monitors real-time chest compression quality and a home delivery collection system for mannikins. This study aimed to evaluate the efficacy of the HEROS-Remote course by comparing chest compression quality with that of conventional CPR training. METHODS: We applied layperson CPR education with HEROS-Remote and conventional education in Seoul during the COVID-19 pandemic. Both groups underwent a 2-min post-training chest compression test, and we tested non-inferiority. Chest compression depth, rate, complete recoil, and composite chest compression score was measured. Trainees completed a satisfaction survey on CPR education and delivery. The primary outcome was the mean chest compression depth. RESULTS: A total of 180 trainees were enrolled, with 90 assigned to each training group. Chest compression depth of HEROS-Remote training showed non-inferiority to that of conventional training (67.4 vs. 67.8, p = 0.78), as well as composite chest compression score (92.7 vs. 95.5, p = 0.16). The proportions of adequate chest compression depth, chest compression rate, and chest compressions with complete chest recoil were similar in both training sessions. In the HEROS-Remote training, 90% of the trainees were satisfied with CPR training, and 96% were satisfied with the delivery and found it convenient. CONCLUSION: HEROS-Remote training was non-inferior to conventional CPR training in terms of chest compression quality. Distance learning CPR training using a smartphone application and mannikin delivery had high user satisfaction and was logistically feasible.

Prehospital National Early Warning Score as a predictor of massive transfusion in adult trauma patients.

BACKGROUND: Previous studies have shown that an elevated prehospital National Early Warning Score (preNEWS) is associated with increased levels of adverse outcomes in patients with trauma. However, whether preNEWS is a predictor of massive transfusion (MT) in patients with trauma is currently unknown. This study investigated the accuracy of preNEWS in predicting MT and hospital mortality among trauma patients. METHODS: We analyzed adult trauma patients who were treated and transported by emergency medical services (EMS) between January 2018 and December 2019. The main exposure was the preNEWS calculated for the scene. The primary outcome was the predictive ability for MT, and the secondary outcome was 24 h mortality. We compared the prognostic performance of preNEWS with the shock index, modified shock index, and reverse shock index, and reverse shock index multiplied by Glasgow Coma Scale in the prehospital setting. RESULTS: In total, 41,852 patients were included, and 1456 (3.5%) received MT. preNEWS showed the highest area under the receiver operating characteristic (AUROC) curve for predicting MT (0.8504; 95% confidence interval [CI], 0.840-0.860) and 24 h mortality (AUROC 0.873; 95% CI, 0.863-0.883). The sensitivity of preNEWS for MT was 0.755, and the specificity of preNEWS for MT was 0.793. All indicies had a high negative predictive value and low positive predictive value. CONCLUSION: preNEWS is a useful, rapid predictor for MT and 24 h mortality. Calculation of preNEWS would be helpful for making the decision at the scene such as transfer straightforward to trauma center and advanced treatment.

The Impact of the COVID-19 Outbreak on Emergency Medical Service: An Analysis of Patient Transportations and Time Intervals.

BACKGROUND: This study aimed to investigate the impact of the coronavirus disease 2019 (COVID-19) outbreak on the Emergency Medical Service (EMS) system in South Korea. The study focused on the differences in EMS time intervals following the COVID-19 outbreak, particularly for patients with fever. METHODS: A retrospective analysis of EMS patient transportation data from 2017 to 2022 was conducted using the national EMS database. RESULTS: Starting from the year 2020, coinciding with the COVID-19 outbreak, all EMS time intervals experienced an increase. For the years 2017 to 2022, the mean response time interval values were 8.6, 8.6, 8.6, 10.2, 12.8, and 11.4 minutes, and the mean scene time interval values were 7.1, 7.2, 7.4, 9.0, 9.8, and 10.9 minutes. The mean transport time interval (TTI) values were 12.1, 12.3, 12.4, 14.2, 16.9, and 16.2 minutes, and the mean turnaround time interval values were 27.6, 27.9, 28.7, 35.2, 42.0, and 43.1 minutes. Fever (≥ 37.5°C) patients experienced more pronounced prolongations in EMS time intervals compared to non-fever patients and had a higher probability of being non-transported. The mean differences in TTI between fever and non-fever patients were 0.8, 0.8, 0.8, 4.3, 4.8, and 3.2 minutes, respectively, from 2017 to 2022. Furthermore, the odds ratios for fever patients being transported to the emergency department were 2.7, 2.9, 2.8, 1.1, 0.8, and 0.7, respectively, from 2017 to 2022. CONCLUSION: The study findings highlight the significant impact of the COVID-19 outbreak on the EMS system and emphasize the importance of ongoing monitoring to evaluate the burden on the EMS system.

Developing new intermuscular coordination patterns through an electromyographic signal-guided training in the upper extremity.

BACKGROUND: Muscle synergies, computationally identified intermuscular coordination patterns, have been utilized to characterize neuromuscular control and learning in humans. However, it is unclear whether it is possible to alter the existing muscle synergies or develop new ones in an intended way through a relatively short-term motor exercise in adulthood. This study aimed to test the feasibility of expanding the repertoire of intermuscular coordination patterns through an isometric, electromyographic (EMG) signal-guided exercise in the upper extremity (UE) of neurologically intact individuals. METHODS: 10 participants were trained for six weeks to induce independent control of activating a pair of elbow flexor muscles that tended to be naturally co-activated in force generation. An untrained isometric force generation task was performed to assess the effect of the training on the intermuscular coordination of the trained UE. We applied a non-negative matrix factorization on the EMG signals recorded from 12 major UE muscles during the assessment to identify the muscle synergies. In addition, the performance of training tasks and the characteristics of individual muscles' activity in both time and frequency domains were quantified as the training outcomes. RESULTS: Typically, in two weeks of the training, participants could use newly developed muscle synergies when requested to perform new, untrained motor tasks by activating their UE muscles in the trained way. Meanwhile, their habitually expressed muscle synergies, the synergistic muscle activation groups that were used before the training, were conserved throughout the entire training period. The number of muscle synergies activated for the task performance remained the same. As the new muscle synergies were developed, the neuromotor control of the trained muscles reflected in the metrics, such as the ratio between the targeted muscles, number of matched targets, and task completion time, was improved. CONCLUSION: These findings suggest that our protocol can increase the repertoire of readily available muscle synergies and improve motor control by developing the activation of new muscle coordination patterns in healthy adults within a relatively short period. Furthermore, the study shows the potential of the isometric EMG-guided protocol as a neurorehabilitation tool for aiming motor deficits induced by abnormal intermuscular coordination after neurological disorders. TRIAL REGISTRATION: This study was registered at the Clinical Research Information Service (CRiS) of the Korea National Institute of Health (KCT0005803) on 1/22/2021.

Radotinib Decreases Prion Propagation and Prolongs Survival Times in Models of Prion Disease.

The conversion of cellular prion protein (PrPC) into pathogenic prion isoforms (PrPSc) and the mutation of PRNP are definite causes of prion diseases. Unfortunately, without exception, prion diseases are untreatable and fatal neurodegenerative disorders; therefore, one area of research focuses on identifying medicines that can delay the progression of these diseases. According to the concept of drug repositioning, we investigated the efficacy of the c-Abl tyrosine kinase inhibitor radotinib, which is a drug that is approved for the treatment of chronic myeloid leukemia, in the treatment of disease progression in prion models, including prion-infected cell models, Tga20 and hamster cerebellar slice culture models, and 263K scrapie-infected hamster models. Radotinib inhibited PrPSc deposition in neuronal ZW13-2 cells that were infected with the 22L or 139A scrapie strains and in cerebellar slice cultures that were infected with the 22L or 263K scrapie strains. Interestingly, hamsters that were intraperitoneally injected with the 263K scrapie strain and intragastrically treated with radotinib (100 mg/kg) exhibited prolonged survival times (159 ± 28.6 days) compared to nontreated hamsters (135 ± 9.9 days) as well as reduced PrPSc deposition and ameliorated pathology. However, intraperitoneal injection of radotinib exerted a smaller effect on the survival rate of the hamsters. Additionally, we found that different concentrations of radotinib (60, 100, and 200 mg/kg) had similar effects on survival time, but this effect was not observed after treatment with a low dose (30 mg/kg) of radotinib. Interestingly, when radotinib was administered 4 or 8 weeks after prion inoculation, the treated hamsters survived longer than the vehicle-treated hamsters. Additionally, a pharmacokinetic assay revealed that radotinib effectively crossed the blood-brain barrier. Based on our findings, we suggest that radotinib is a new candidate anti-prion drug that could possibly be used to treat prion diseases and promote the remission of symptoms.

Effects of anodal stimulation and motor practice on limb-kinetic apraxia in Parkinson's disease.

Limb-kinetic apraxia, the loss of the ability to make precise, independent but coordinated finger and hand movements affects quality of life in patients with Parkinson's disease. We aimed to examine the effects of anodal transcranial direct current stimulation of the left posterior parietal cortex and upper extremity motor practice on limb-kinetic apraxia in Parkinson's disease. This study was conducted in a randomized, double-blind, sham-controlled fashion. Patients confirmed to have Parkinson's disease were recruited. Twenty-eight participants completed the study and were randomized to two groups: anodal or sham stimulation. For participants assigned to active stimulation, anodal stimulation of the left posterior parietal cortex was performed using 2 mA current for 20 min. Patients received anodal or sham stimulation, followed by motor practice in both groups. The primary outcome measure was time-performing sequential buttoning and unbuttoning, and several secondary outcome measures were obtained. A statistically significant interaction between stimulation type and timepoint on time taken to perform buttoning and unbuttoning was found. Patients who received anodal stimulation were found to have a significant decrease in sequential buttoning and unbuttoning time immediately following stimulation and at 24 h in the medication-ON state, compared to the medication-OFF state (31% and 29% decrease, respectively). Anodal stimulation of the left posterior parietal cortex prior to motor practice appears to be effective for limb-kinetic apraxia in Parkinson's disease. Future long-term, multi-session studies looking at the long-term effects of anodal stimulation and motor practice on limb-kinetic apraxia in Parkinson's disease may be worthwhile.

Use of Time-to-Event Analysis to Develop On-Scene Return of Spontaneous Circulation Prediction for Out-of-Hospital Cardiac Arrest Patients.

STUDY OBJECTIVE: We aimed to train and validate the time to on-scene return of spontaneous circulation prediction models using time-to-event analysis among out-of-hospital cardiac arrest patients. METHODS: Using a Korean population-based out-of-hospital cardiac arrest registry, we selected a total of 105,215 adults with presumed cardiac etiologies between 2013 and 2018. Patients from 2013 to 2017 and from 2018 were analyzed for training and test, respectively. We developed 4 time-to-event analyzing models (Cox proportional hazard [Cox], random survival forest, extreme gradient boosting survival, and DeepHit) and 4 classification models (logistic regression, random forest, extreme gradient boosting, and feedforward neural network). Patient characteristics and Utstein elements collected at the scene were used as predictors. Discrimination and calibration were evaluated by Harrell's C-index and integrated Brier score. RESULTS: Among the 105,215 patients (mean age 70 years and 64% men), 86,314 and 18,901 patients belonged to the training and test sets, respectively. On-scene return of spontaneous circulation was achieved in 5,240 (6.1%) patients in the former set and 1,709 (9.0%) patients in the latter. The proportion of emergency medical services (EMS) management was higher and scene time interval longer in the latter. Median time from EMS scene arrival to on-scene return of spontaneous circulation was 8 minutes for both datasets. Classification models showed similar discrimination and poor calibration power compared to survival models; Cox showed high discrimination with the best calibration (C-index [95% confidence interval]: 0.873 [0.865 to 0.882]; integrated Brier score at 30 minutes: 0.060). CONCLUSION: Incorporating time-to-event analysis could lead to improved performance in prediction models and contribute to personalized field EMS resuscitation decisions.