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Objective. Heart rate (HR), an essential vital sign that reflects hemodynamic stability, is influenced by myocardial oxygen demand, coronary blood flow, and myocardial performance. HR at the time of the return of spontaneous circulation (ROSC) could be influenced by the β1-adrenergic effect of the epinephrine administered during cardiopulmonary resuscitation (CPR), and its effect could be decreased in patients who have the failing heart. We aimed to investigate the association between HR at the time of ROSC and the outcomes of adult out-of-hospital cardiac arrest (OHCA) patients. Methods. This study was a secondary analysis of a cardiac arrest registry from a single institution from January 2008 to July 2014. The OHCA patients who achieved ROSC at the emergency department (ED) were included, and HR was retrieved from an electrocardiogram or vital sign at the time of ROSC. The patients were categorized into four groups according to the HR (bradycardia (HR Results. A total of 330 patients were included. In the univariate logistic regression model, the rate of sustained ROSC increased by 17% as HR increased by every 10 beats per minute (bpm) (odds ratio (OR), 1.171; 95% confidence interval (CI), 1.077–1.274, p<0.001). In the multivariate logistic regression model, extreme tachycardia was independently associated with a high probability of sustained ROSC compared to normal heart rate (OR, 15.96; 95% CI, 2.04–124.93, p=0.008). Conclusion. Extreme tachycardia (HR ≥ 150) at the time of ROSC is independently associated with a high probability of sustained ROSC in nontraumatic adult OHCA patients.

BackgroundIschaemic tissue injury caused by tissue hypoperfusion is one of the major consequences of sepsis. Phosphate concentrations are elevated in ischaemic tissue injury. This study was performed to investigate the association of phosphate concentrations with mortality in patients with sepsis.MethodsThis was a retrospective cohort study of patients with sepsis conducted at an urban, tertiary care emergency department (ED) in Korea. Patients with sepsis arriving between March 2010 and April 2017 were stratified into four groups according to the initial phosphate concentration at presentation to the ED: group I (hypophosphataemia, phosphate ResultsOf the 3034 participants in the study, the overall mortality rate was 21.9%. The 28-day mortality rates were group I (hypophosphataemia) 14.6%, group II 17.4% (normophosphataemia), group III (mild hyperphosphataemia) 29.2% and group IV (moderate to severe hyperphosphataemia) 51.4%, respectively (pConclusionsModerate to severe hyperphosphataemia was associated with 28-day mortality in patients with sepsis. Phosphate level could be used as a prognostic indicator in sepsis.

Background We hypothesized utilizing machine learning (ML) algorithms for screening septic shock in ED would provide better accuracy than qSOFA or MEWS. Methods The study population was adult (≥20 years) patients visiting ED for suspected infection. Target event was septic shock within 24 h after arrival. Demographics, vital signs, level of consciousness, chief complaints (CC) and initial blood test results were used as predictors. CC were embedded into 16-dimensional vector space using singular value decomposition. Six base learners including support vector machine, gradient-boosting machine, random forest, multivariate adaptive regression splines and least absolute shrinkage and selection operator and ridge regression and their ensembles were tested. We also trained and tested MLP networks with various setting. Results A total of 49,560 patients were included and 4817 (9.7%) had septic shock within 24 h. All ML classifiers significantly outperformed qSOFA score, MEWS and their age-sex adjusted versions with their AUROC ranging from 0.883 to 0.929. The ensembles of the base classifiers showed the best performance and addition of CC embedding was associated with statistically significant increases in performance. Conclusions ML classifiers significantly outperforms clinical scores in screening septic shock at ED triage.

It is not easy to ensure optimal prevention of hospital‐acquired pressure ulcer (HAPU) in crowded emergency departments (EDs). We hypothesised that a prolonged ED length of stay (LOS) is associated with an increased risk of HAPU. This is a single‐centre observational study. Prospectively collected HAPU surveillance data were analysed. Adult (aged ≥20 years) patients admitted through the ED from April 1, 2013 to December 31, 2016 were included. The primary outcome was the development of HAPU within a month. Covariates included demographics, comorbidities, conditions at triage, initial laboratory results, primary ED diagnosis, critical ED interventions, and ED dispositions. The association between ED LOS and HAPU was modelled using logistic and extended Cox regression. A total of 48 641 admissions were analysed. The crude odds ratio (OR) and hazard ratio (HR) for HAPU were increased to 1.44 (95% CI, 1.20‐1.72) and 1.21 (95% CI, 1.02‐1.45), respectively, in ED LOS ≥24 hours relative to ED LOS

Background: Although chest radiographs have not been utilised well for classifying stroke subtypes, they could provide a plethora of information on cardioembolic stroke. This study aimed to develop a deep convolutional neural network that could diagnose cardioembolic stroke based on chest radiographs. Methods: Overall, 4,064 chest radiographs of consecutive patients with acute ischaemic stroke were collected from a prospectively maintained stroke registry. Chest radiographs were randomly partitioned into training/validation (n = 3,255) and internal test (n = 809) datasets in an 8:2 ratio. A densely connected convolutional network (ASTRO-X) was trained to diagnose cardioembolic stroke based on chest radiographs. The performance of ASTRO-X was evaluated using the area under the receiver operating characteristic curve. Gradient-weighted class activation mapping was used to evaluate the region of focus of ASTRO-X. External testing was performed with 750 chest radiographs of patients with acute ischaemic stroke from 7 hospitals. Findings: The areas under the receiver operating characteristic curve of ASTRO-X were 0.86 (95% confidence interval [CI], 0.83–0.89) and 0.82 (95% CI, 0.79–0.85) during the internal and multicentre external testing, respectively. The gradient-weighted class activation map demonstrated that ASTRO-X was focused on the area where the left atrium was located. Compared with cases predicted as non-cardioembolism by ASTRO-X, cases predicted as cardioembolism by ASTRO-X had higher left atrial volume index and lower left ventricular ejection fraction in echocardiography. Interpretation: ASTRO-X, a deep neural network developed to diagnose cardioembolic stroke based on chest radiographs, demonstrated good classification performance and biological plausibility. Funding Grant No. 14–2020–046 and 08–2016–051 from the Seoul National University Bundang Research Fund and NRF-2020M3E5D9079768 from the National Research Foundation of Korea.

PURPOSE Epinephrine is a key drug for treating anaphylaxis; however, its underuse is still a significant issue worldwide. The objective of this study was to compare epinephrine use between pediatric and adult patients who were treated with anaphylaxis in the emergency department (ED). METHODS The data were retrieved from the National Sample Cohort of South Korea, which contains claim data from the National Health Insurance Service. We included patients who visited the ED with a discharge code of anaphylaxis between 2004 and 2013. We assessed prescription information of epinephrine, antihistamine and systemic steroid, previous medical history and discharge disposition from the ED. The study population was categorized based on age at the visit. RESULTS A total of 175 pediatric and 1,605 adult patients with anaphylaxis were identified. Only 42 (24%) of the pediatric patients were treated with epinephrine, while 592 (36.9%) of the adult patients were treated with epinephrine (P = 0.001). Furthermore, the pediatric patients were less likely to be treated with systemic steroid than the adult patients (6.9% vs. 12.3%, P = 0.047). The odds ratios for the administration of epinephrine relative to the baseline in the 19-65 age group were 0.34 (95% confidence interval [CI], 0.15-0.67), 0.56 (95% CI, 0.28-1.03) and 0.79 (95% CI, 0.45-1.33) in the < 7, 7-12 and 13-18 age groups, respectively. CONCLUSIONS The pediatric patients with anaphylaxis experienced a lower rate of epinephrine injection use than the adult patients and the injection use decreased as age decreased.

Objective To investigate the epidemiology of sepsis in Korea and identify risk factors for death in sepsis. Methods We conducted a longitudinal, population-based epidemiological study of sepsis in Korea from 2005 to 2012 using the National Health Insurance Service-National Sample Cohort, a population-based cohort representing 2.2% of the Korean population. The primary objective was to assess the incidence, mortality and cost of sepsis. The secondary objective was to identify the risk factors for death in sepsis. Claim records of admitted adult patients (aged ≥15 years) were analyzed. Sepsis was defined as 1) bacterial or fungal infection or the conditions they often complicate, 2) prescription of intravenous antibiotics, and 3) presence of any organ dysfunction. Comorbidities were defined using the Charlson/Deyo method. Risk factors for 6-month mortality were assessed using multivariable logistic regression. Results A total of 22,882 cases were identified. Both incidence and 6-month mortality increased from 265.7 (95% confidence interval [CI], 254.7 to 277.1) to 453.1 (95% CI, 439.0 to 467.5) per 100,000 person-years (P-trend

Background Recently, innovative attempts have been made to identify moyamoya disease (MMD) by focusing on the morphological differences in the head of MMD patients. Following the recent revolution in the development of deep learning (DL) algorithms, we designed this study to determine whether DL can distinguish MMD in plain skull radiograph images. Methods Three hundred forty-five skull images were collected as an MMD-labeled dataset from patients aged 18 to 50 years with definite MMD. As a control-labeled data set, 408 skull images of trauma patients were selected by age and sex matching. Skull images were partitioned into training and test datasets at a 7:3 ratio using permutation. A total of six convolution layers were designed and trained. The accuracy and area under the receiver operating characteristic (AUROC) curve were evaluated as classifier performance. To identify areas of attention, gradient-weighted class activation mapping was applied. External validation was performed with a new dataset from another hospital. Findings For the institutional test set, the classifier predicted the true label with 84·1% accuracy. Sensitivity and specificity were both 0·84. AUROC was 0·91. MMD was predicted by attention to the lower face in most cases. Overall accuracy for external validation data set was 75·9%. Interpretation DL can distinguish MMD cases within specific ages from controls in plain skull radiograph images with considerable accuracy and AUROC. The viscerocranium may play a role in MMD-related skull features. Fund This work was supported by grant no. 18-2018-029 from the Seoul National University Bundang Hospital Research Fund.

We performed a large, population-based study to analyze the risk factors of the febrile seizures and the subsequent afebrile epileptic seizures.Relevant data from children born between 2002-2007 were retrieved from the Korean National Health Insurance Service-National Sample Cohort 2002-2013. Children who did not survive the first five years were excluded from the analysis. The risk factors for febrile seizures were assessed separately in per-person and per-febrile case analyses, and factors contributing to an increased risk of subsequent afebrile epileptic seizures were identified.A total of 54,233 children were included and the five-year prevalence rate of febrile seizure was 11.19%. In the per-person analysis, male sex, preterm birth and brain injury at birth increased the risk of febrile seizure with odds ratios of 1.17, 1.40 and 1.97 (all p 0.001), respectively. A high household income level was associated with reduced odds of febrile seizure. In the per-febrile illness analysis, male sex, brain injury at birth, presumed bacterial infection, gastrointestinal or genitourinary infection and unspecified sepsis were independent risk factors of a febrile seizure during febrile illness. The cumulative number of febrile seizure episodes, especially more than the third episodes, was associated with a new diagnosis of an afebrile epileptic seizure within one year.Sex, preterm birth, brain injury at birth, presumed bacterial infection, genitourinary and gastrointestinal infections and unspecified sepsis were identified as likely risk factors for febrile seizures. A greater number of febrile seizure episodes was associated with a higher probability of subsequent afebrile epileptic seizures.

Background We performed this study to establish a prediction model for 1-year neurological outcomes in out-of-hospital cardiac arrest (OHCA) patients who achieved return of spontaneous circulation (ROSC) immediately after ROSC using machine learning methods. Methods We performed a retrospective analysis of an OHCA survivor registry. Patients aged ≥ 18 years were included. Study participants who had registered between March 31, 2013 and December 31, 2018 were divided into a develop dataset (80% of total) and an internal validation dataset (20% of total), and those who had registered between January 1, 2019 and December 31, 2019 were assigned to an external validation dataset. Four machine learning methods, including random forest, support vector machine, ElasticNet and extreme gradient boost, were implemented to establish prediction models with the develop dataset, and the ensemble technique was used to build the final prediction model. The prediction performance of the model in the internal validation and the external validation dataset was described with accuracy, area under the receiver-operating characteristic curve, area under the precision-recall curve, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Futhermore, we established multivariable logistic regression models with the develop set and compared prediction performance with the ensemble models. The primary outcome was an unfavorable 1-year neurological outcome. Results A total of 1,207 patients were included in the study. Among them, 631, 139, and 153 were assigned to the develop, the internal validation and the external validation datasets, respectively. Prediction performance metrics for the ensemble prediction model in the internal validation dataset were as follows: accuracy, 0.9620 (95% confidence interval [CI], 0.9352–0.9889); area under receiver-operator characteristics curve, 0.9800 (95% CI, 0.9612–0.9988); area under precision-recall curve, 0.9950 (95% CI, 0.9860–1.0000); sensitivity, 0.9594 (95% CI, 0.9245–0.9943); specificity, 0.9714 (95% CI, 0.9162–1.0000); PPV, 0.9916 (95% CI, 0.9752–1.0000); NPV, 0.8718 (95% CI, 0.7669–0.9767). Prediction performance metrics for the model in the external validation dataset were as follows: accuracy, 0.8509 (95% CI, 0.7825–0.9192); area under receiver-operator characteristics curve, 0.9301 (95% CI, 0.8845–0.9756); area under precision-recall curve, 0.9476 (95% CI, 0.9087–0.9867); sensitivity, 0.9595 (95% CI, 0.9145–1.0000); specificity, 0.6500 (95% CI, 0.5022–0.7978); PPV, 0.8353 (95% CI, 0.7564–0.9142); NPV, 0.8966 (95% CI, 0.7857–1.0000). All the prediction metrics were higher in the ensemble models, except NPVs in both the internal and the external validation datasets. Conclusion We established an ensemble prediction model for prediction of unfavorable 1-year neurological outcomes in OHCA survivors using four machine learning methods. The prediction performance of the ensemble model was higher than the multivariable logistic regression model, while its performance was slightly decreased in the external validation dataset., Graphical Abstract

An index combining respiratory rate and oxygenation (ROX) has been introduced, and the ROX index is defined as the ratio of oxygen saturation by pulse oximetry/fraction of inspired oxygen to respiratory rate. In sepsis, hypoxemia and tachypnea are commonly observed. We performed this study to investigate the association between the ROX index and 28-day mortality in patients with sepsis or septic shock.This retrospective study included 2862 patients. The patients were divided into three groups according to the ROX index: Group I (ROX index20), Group II (ROX index10 and ≤ 20), and Group III (ROX index ≤10).The median ROX index was significantly lower in the nonsurvivors than in the survivors (12.8 and 18.2, respectively) (p 0.001). The 28-day mortality rates in Groups I, II and III were 14.5%, 21.3% and 34.4%, respectively (p 0.001). In the multivariable Cox regression analysis, Group III had an approximately 40% higher risk of death than Group I during the 28-day period (hazard ratio = 1.41, 95% confidence interval 1.13-1.76). The area under the curve of the ROX index was significantly higher than that of the quick Sequential Organ Failure Assessment score (p 0.001).The ROX index was lower in nonsurvivors than in survivors, and a ROX index less than or equal to 10 was an independent prognostic factor for 28-day mortality in patients with sepsis or septic shock. Therefore, the ROX index could be used as a prognostic marker in sepsis.

BackgroundAn artificial intelligence (AI) system capable of predicting patient needs in the prehospital phase would be instrumental. We sought to develop a neural network (NN) model capable of predicting various care needs at initial contact by emergency medical service (EMS) using multimodal input data.MethodsWe used EMS records of a single emergency department (ED). We implemented two attention-based NN model (I and P) differing only by how they use contextual information. The models predict multiple events, including hospital admission, endotracheal intubation, mechanical ventilation, vasopressor infusion, cardiac catheterization, surgery, intensive care unit (ICU) admission, and cardiac arrest. The input features include both unstructured data (chief complaints, injury summary, past medical history, history of present illness) and structured data (age, sex, pupil status and initial vital signs, level of consciousness, and O2 saturation on pulse oximetry). We applied multi-task learning for training. We evaluated the relative performance of the models compared with a human expert, an emergency physician with 10-year experience as an EMS medical director.ResultsThe study population included 42,073 cases. The receiver operating characteristics (ROC) area under the curve (AUC) values of the models I and P ranged from 0.793 to 0.929 and 0.812 to 0.934, respectively. The precision-recall (PR) AUC values ranged from 0.149 to 0.673 and 0.156 to 0.683, respectively. With decision thresholds set to achieve equivalent recall levels, our AI models achieved precision levels not significantly different from those of a human expert except in prediction of mechanical ventilation and ICU admission, where the models achieved superior performance (p=0.030 [model I] and p=0.015 [model P], respectively).ConclusionsAI models using multimodal input data can predict medical resource requirements at initial contact by EMS with high accuracies.

Background. The benefit of prehospital epinephrine in out-of-hospital cardiac arrest (OHCA) was shown in a recent large placebo-controlled trial. However, placebo-controlled studies cannot identify the nonpharmacologic influences on concurrent or downstream events that might modify the main effect positively or negatively. We sought to identify the real-world effect of epinephrine from a clinical registry using Bayesian network with time-sequence constraints. Methods. We analyzed a prospective regional registry of OHCA where a prehospital advanced life support (ALS) protocol named “Smart ALS (SALS)” was gradually implemented from July 2015 to December 2016. Using Bayesian network, a causal structure was estimated. The effect of epinephrine and SALS program was modelled based on the structure using extended Cox-regression and logistic regression, respectively. Results. Among 4324 patients, SALS was applied to 2351 (54.4%) and epinephrine was administered in 1644 (38.0%). Epinephrine was associated with faster ROSC rate in nonshockable rhythm (HR: 2.02, 6.94, and 7.43; 95% CI: 1.08–3.78, 4.15–11.61, and 2.92–18.91, respectively, for 1–10, 11–20, and >20 minutes) while it was associated with slower rate up to 20 minutes in shockable rhythm (HR: 0.40, 0.50, and 2.20; 95% CI: 0.21–0.76, 0.32–0.77, and 0.76–6.33). SALS was associated with increased prehospital ROSC and neurologic recovery in noncardiac etiology (HR: 5.36 and 2.05; 95% CI: 3.48–8.24 and 1.40–3.01, respectively, for nonshockable and shockable rhythm). Conclusions. Epinephrine was associated with faster ROSC rate in nonshockable rhythm but slower rate in shockable rhythm up to 20 minutes. SALS was associated with improved prehospital ROSC and neurologic recovery in noncardiac etiology.

Introduction. Refractory shockable rhythm has a high mortality rate and poor neurological outcome. Treatments for refractory shockable rhythm presenting after defibrillation and medical treatment are not definite. We conducted research on the application of double simultaneous defibrillation (DSiD) for refractory shockable rhythms. Methods. This is a retrospective pilot study performed using medical records from 1 January 2016 to 31 December 2017. The prephase was from January to December 2016. The post-phase was from January to December 2017. During the prephase, we conducted conventional defibrillation with one defibrillator, and during the post-phase, we conducted DSiD using two defibrillators. Primary outcome was survival to hospital discharge. Secondary outcomes included survival to hospital admission and good neurological outcome at 12 months. Statistical analysis was conducted using Fisher’s exact test. Data were regarded statistically significant when p<0.05. Result. A total of 38 patients were included. Twenty-one patients underwent conventional defibrillation, and 17 underwent DSiD. The DSiD group had a higher survival to admission rate (14/17 (82.4%) vs. 6/21 (28.6%), p=0.001) and showed a trend for higher survival to discharge (7/17 (41.2%) vs. 3/21 (14.3%), p=0.078). Good neurological outcome at 12 months of the DSiD group was higher than that of the conventional defibrillation group, but the difference was not statistically significant (5/17 (29.4%) vs 2/21 (9.5%), p=0.207). Conclusion. In patients with refractory shockable rhythms, DSiD has increased survival to hospital admission and a trend of increased survival to hospital discharge. However, DSiD did not improve neurological outcome at 12 months.

Objective The Korean Triage and Acuity Scale (KTAS) was implemented in our emergency department (ED) in May 2016 and is fully integrated into the electronic medical record (EMR) system. Our objective was to determine whether the KTAS is associated with changes in admissions to the hospital, admission disposition, inpatient mortality and length of stay (LOS). Design Quasi-experimental, uncontrolled before-and-after study. Setting The urban tertiary teaching hospital with 1100 beds and receives approximately annual 90 000 ED visits. Participants 122 370 patients who visited the ED during the before-and-the after period. Interventions ED staff were educated on the KTAS for 1 month, after which the KTAS evaluation period began. Admission, disposition, mortality and LOS were compared between the ‘before’ period (1 June 2015 to 30 April 2016) and the ‘after’ period (1 June 2016 to 30 April 2017). Main outcome measures Admissions to the hospital, admission disposition, inpatient mortality and LOS. Results A total of 59 220 and 63 150 patients were included in the before-and-after periods of KTAS implementation, respectively. The pattern of admission and disposition changed significantly after implementation of the KTAS. The mean LOS was 343 min (standard deviation [SD] = 432 min) during the before period, which significantly decreased to 289 min (SD = 333 min) after implementation (P < 0.001). The total mortality rate was significantly reduced after implementation of the KTAS (213 (0.36%) vs. 179 (0.28%), P = 0.020). Conclusion Implementation of the KTAS changed admission and disposition patterns and reduced the LOS and mortality in the ED.

Objective: We developed a novel compression assist device (palm presser) to perform chest compressions using a palm in infant cardiopulmonary resuscitation (CPR). We hypothesized that the p...

Objective Chest pain is one of the most common complaints in the emergency department (ED). Cardiac computed tomography angiography (CCTA) is a frequently used tool for the early triage of patients with low- to intermediate-risk acute chest pain. We present a study protocol for a multicenter prospective randomized controlled clinical trial testing the hypothesis that a low-dose CCTA protocol using prospective electrocardiogram (ECG)-triggering and limited-scan range can provide sufficient diagnostic safety for early triage of patients with acute chest pain. Methods The trial will include 681 younger adult (aged 20 to 55) patients visiting EDs of three academic hospitals for acute chest pain or equivalent symptoms who require further evaluation to rule out acute coronary syndrome. Participants will be randomly allocated to either low-dose or conventional CCTA protocol at a 2:1 ratio. The low-dose group will undergo CCTA with prospective ECG-triggering and restricted scan range from sub-carina to heart base. The conventional protocol group will undergo CCTA with retrospective ECG-gating covering the entire chest. Patient disposition is determined based on computed tomography findings and clinical progression and all patients are followed for a month. The primary objective is to prove that the chance of experiencing any hard event within 30 days after a negative low-dose CCTA is less than 1%. The secondary objectives are comparisons of the amount of radiation exposure, ED length of stay and overall cost. Results and conclusion Our low-dose protocol is readily applicable to current multi-detector computed tomography devices. If this study proves its safety and efficacy, dose-reduction without purchasing of expensive newer devices would be possible.

Background When an out-of-hospital cardiac arrest (OHCA) patient receives cardiopulmonary resuscitation (CPR) in the emergency department (ED), blood laboratory test results can be obtained by using point-of-care testing during CPR. In the present study, the relationship between blood laboratory test results during CPR and outcomes of OHCA patients was investigated. Methods This study was a multicenter retrospective analysis of prospective registered data that included 2716 OHCA patients. Data from the EDs of three university hospitals in different areas were collected from January 2009 to December 2014. Univariate and multivariable analyses were conducted to elucidate the factors associated with survival to discharge and neurological outcomes. A final analysis was conducted by including patients who had no prehospital return of spontaneous circulation and those who underwent rapid blood laboratory examination during CPR. Results Overall, 2229 OHCA patients were included in the final analysis. Among them, the rate of survival to discharge and a good Cerebral Performance Categories Scale score were 14% and 4.4%, respectively. The pH level was independently related to survival to hospital discharge (adjusted OR 6.287, 95% CI 2.601–15.197; p 8.5 mEq/L) during CPR. Conclusions Among the blood laboratory test results during CPR of OHCA patients, pH and potassium levels were observed as independent factors associated with survival to hospital discharge, and pH level was considered as an independent factor related to neurological recovery.

BACKGROUND AND PURPOSE: DWI of the head and neck can reveal valuable information, but the effects of fat suppression and multishot acquisition on image quality have not been thoroughly investigated. We aimed to comprehensively compare the quality of head and neck DWI at 3T using 2 fat-suppression techniques, STIR, and spectral presaturation with inversion recovery, which were used with both single- and multishot EPI. MATERIALS AND METHODS: Sixty-five study participants underwent 3 DWI sequences of single-shot EPI–STIR, single-shot EPI–spectral presaturation with inversion recovery, and multishot EPI–spectral presaturation with inversion recovery of the head and neck. In multiple anatomic regions, 2 independent readers assessed 5-point visual scores for fat-suppression uniformity and image distortion, and 1 reader measured the contrast-to-noise ratio and ADC. RESULTS: The mean visual score for fat-suppression uniformity was higher in single-shot EPI–STIR than in other sequences (all regions except for the orbital region, P < .05). The mean visual score for image distortion was higher in multishot EPI–spectral presaturation with inversion recovery than in single-shot EPI sequences (all regions, P < .001). Contrast-to-noise ratio was mostly lower in single-shot EPI–STIR than in other sequences (P < .001), and ADC was significantly higher in multishot EPI–spectral presaturation with inversion recovery than in single-shot EPI sequences (P ≤ .001). CONCLUSIONS: Overall, multishot EPI–spectral presaturation with inversion recovery provided the best image quality, with relatively homogeneous fat suppression, less image distortion than single-shot EPI sequences, and higher contrast-to-noise ratio than single-shot EPI–STIR. The measured ADC values can be higher in multishot EPI–spectral presaturation with inversion recovery, which necessitates cautious application of the previously reported ADC values to clinical settings.

Summary Background CT radiation is arguably carcinogenic. Results from single-centre studies, mostly retrospective, have advocated lowering the CT radiation dose for the diagnosis of appendicitis. However, adoption of low-dose CT has been slow. We aimed to assess the effectiveness of low-dose CT compared with standard-dose CT in the diagnosis of appendicitis in adolescents and young adults. Methods We did this pragmatic, multicentre, randomi s ed controlled non-inferiority trial at 20 South Korean teaching hospitals with little experience with low-dose CT. Patients aged 15–44 years with suspected appendicitis were randomly assigned (1:1), via computer-generated random assignments (permuted block sizes of two, four, six, and eight) concealed in sequentially numbered envelopes, to receive low-dose CT (2 mSv) or standard-dose CT (≤8 mSv). Randomisation was stratified by site. Group allocation was concealed from patients, outcome assessors, and adverse event adjudicators; care providers, site pathologists, and data collectors were aware of allocation. The primary endpoint was the negative (unnecessary) appendectomy rate among all appendectomies, with a non-interiority margin of 4·5% for low-dose versus standard-dose CT. Primary analy s is was by modified intention to treat, which included all patients who received an appendectomy in the group to which they were assigned. This trial is registered with ClinicalTrials.gov, number NCT01925014. Findings Between Dec 4, 2013, and Aug 18, 2016, we assigned 1535 patients to the low-dose CT group and 1539 patients to the standard-dose CT group. 22 (3·9%) of 559 patients had a negative appendectomy in the low-dose group versus 16 (2·7%) of 601 patients in the standard-dose group (difference 1·3%, 95% CI −0·8 to 3·3; p=0·0022 for the non-inferiority test). We recorded 43 adverse events in 43 (2·8%) of 1535 patients in the low-dose group and 41 adverse events in 40 (2·6%) of 1539 patients in the standard-dose group. One life-threatening adverse event of anaphylaxis caused by an iodinated contrast material occurred in the low-dose group. Interpretation Radiation dose of appendiceal CT for adolescents and young adults can be reduced to 2 mSv without impairing clinical outcomes. In view of the vast number of appendiceal CT examinations done worldwide, use of low-dose CT could prevent a sizeable number of radiation-associated cancers in the future. Funding Korea Health Industry Development Institute, Seoul National University Bundang Hospital, Dasol Life Science, and Bracco Imaging Korea.

Study objective Endotracheal intubation is frequently performed in emergency departments (EDs). First-pass success is important because repeated attempts are associated with poor outcomes. We sought to identify factors associated with first-pass success in emergency endotracheal intubation. Methods We analyzed emergency orotracheal intubations on adult patients in an ED located in South Korea from Jan. 2013 to Dec. 2016. Various operator-, procedure- and patient-related factors were screened with univariable logistic regression. Using variables with P-values less than 0.2, a multiple logistic regression model was constructed to identify independent predictors. Results There were 1154 eligible cases. First-pass success was achieved in 974 (84.4%) cases. Among operator-related factors, clinical experience (OR: 2.93, 5.26, 3.80 and 5.71; 95% CI: 1.62–5.26, 2.80–9.84, 1.81–8.13 and 2.07–18.67 for PGY 3, 4 and 5 residents and EM specialists, respectively, relative to PGY 2 residents) and physician based outside the ED (OR: 0.10; 95% CI: 0.04–0.25) were independently associated with first-pass success. There was no statistically or clinically significant difference for first-pass success rate as determined by operator's gender (83.6% for female vs. 84.8% for male; 95% CI for difference: −3.1% to 5.8%). Among patient-related factors, restricted mouth opening (OR: 0.47; 95% CI: 0.31–0.72), restricted neck extension (OR: 0.57; 95% CI: 0.39–0.85) and swollen tongue (OR: 0.46; 95% CI: 0.28–0.77) were independent predictors of first-pass success. Conclusions Operator characteristics, including clinical experience and working department, and patient characteristics, including restricted mouth opening, restricted neck extension and swollen tongue, were independent predictors of first-pass success in emergency endotracheal intubation.

BackgroundCURB65 and CRB65 score are simple and popular methods to estimate the mortality in patients with community-acquired pneumonia (CAP). Although there has been a global increase in life expectancy and population ageing, we are still using the same age threshold derived from patients in late 1990s to calculate the scores. We sought to assess the implication of using higher age threshold using Korean population data and a single center hospital records.MethodsUsing Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC), we analyzed annual age distribution of CAP patients in Korea from 2005 to 2013 and report how patients aged >65 years increased over time. We also assessed annual change in test characteristics of various age threshold in Korean CAP population. Using a single center hospital registry of CAP patients (2008-2017), we analyzed test characteristics of CURB65 and CRB65 scores with various age thresholds.Results116,481 CAP cases were identified from NHIS-NSC dataset. The proportion of patients aged >65 increased by 1.01% (95% CI, 0.70%-1.33%, PConclusionThere was a significant age shift in CAP population in Korea. Increasing the current age threshold of CURB65 (or CRB65) could be a viable option to reduce ever-increasing hospital referrals and admissions of CAP patients.

Summary Background & aims Although initial fluid resuscitation in sepsis is critical for the treatment of tissue hypoperfusion, little evidence supports the distribution of infused fluid in patients with sepsis. This study was designed to assess the body water distribution in patients with sepsis using bioelectrical impedance analysis and correlate the trend in body water distribution during fluid treatment with the prognosis of patients with sepsis. Methods A prospective study in a single emergency department was performed, and adult patients suspected of having sepsis were enrolled. Multi-frequency direct segmental bioelectrical impedance analysis (InBody S10, InBody) measuring total body water (TBW), intracellular water (ICW), and extracellular water (ECW) was applied to patients with sepsis at three periods: before, immediately after, and 1 hour after the fluid treatment. Survival data at 28 days after the fluid treatment were obtained. Results Forty-two patients were enrolled in this study. Overall, the ratios of TBW, ICW, and ECW to body weight increased throughout the fluid treatment except the ratio of ICW to body weight at 1 hour in non-survivors. While the ratio of ECW to TBW (ECW/TBW) and the ratio of ICW to TBW (ICW/TBW) in survivors remained stable over the period, the trend of ECW/TBW increased with corresponding decline of ICW/TBW in non-survivors (p = 0.0085 and p = 0.0034 between times and groups, respectively) such that ECW/TBW and ICW/TBW were significantly different at 1 hour after the fluid loading period (p = 0.0120 and p = 0.0085, respectively). This contrast pattern was equivalent with the trend of ECW/TBW in trunk but not that of the other extremities. Conclusions During fluid resuscitation, the trend in ECW/TBW significantly increased with corresponding decrease of ICW/TBW in non-survivors compared with that in survivors, which suggests fluid resuscitation results intracellular dehydration and extracellular edema in non-survivors of patients with sepsis.

OBJECTIVE Peripheral vertigo is one of the most common causes of the emergency department (ED) visits. It can impair balance and might predispose patients to injuries after discharge. The purpose of this study was to determine whether peripheral vertigo is associated with an increased risk of trauma. METHODS This matched-cohort study used the nationally representative dataset of de-identified claim information of 1 million randomly sampled individuals from a real Korean population, from 2002 to 2013. The exposure cohort included patients who visited EDs for new-onset peripheral vertigo without prior or concurrent injury. Each patient was randomly matched to five unexposed individuals (also without previous injury) by incidence density sampling. The primary outcome was a new injury within 1 year. The secondary outcomes were various injury subtypes. The time-dependent effect of the exposure was modeled using the extended Cox model. Age, sex, comorbidities, and household income level were included as covariates. RESULTS A total of 776 and 3,880 individuals were included as the exposure and comparison cohorts, respectively. The risks of trunk injury and upper extremity injury were significantly higher in the exposure cohort. Extended Cox models with multivariable adjustment showed significantly increased risk for up to 1 year, with the first 1-month; 1 month to 3 months; and 3 months to 1 year hazard ratios of 5.23 (95% confidence interval [CI], 2.83-9.64); 1.50 (95% CI, 1.02-2.20); and 1.37 (95% CI, 1.11-1.68), respectively. CONCLUSION Patients visiting EDs for acute peripheral vertigo are at a higher risk of a new injury for up to a year.

Background Automated surveillance for cardiac arrests would be useful in overcrowded emergency departments. The purpose of this study is to develop and test artificial neural network (ANN) classifiers for early detection of patients at risk of cardiac arrest in emergency departments. Methods This is a single-center electronic health record (EHR)-based study. The primary outcome was the development of cardiac arrest within 24 h after prediction. Three ANN models were trained: multilayer perceptron (MLP), long-short-term memory (LSTM), and hybrid. These were compared to other classifiers including the modified early warning score (MEWS), logistic regression, and random forest. We used AUROC, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the comparison. Results During the study period, there were a total of 374,605 ED visits and 2,910,321 patient status updates. The ANN models (MLP, LSTM, and hybrid) achieved higher AUROC (AUROC: 0.929, 0.933, and 0.936; 95% confidential interval: 0.926–0.932, 0.930–0.936, and 0.933–0.939, respectively) compared to the non-ANN models, and the hybrid model exhibited the best performance. The ANN classifiers displayed higher performance in most of the test characteristics when the threshold levels of the classifiers were fixed to display the same positive result as those at the three MEWS thresholds (score ≥ 3, ≥4, and ≥5), and when compared with each other. Conclusions The ANN improves upon MEWS and conventional machine learning algorithms for the prediction of cardiac arrests in emergency departments. The hybrid ANN model utilizing both baseline and sequence information achieved the best performance.

Objective Red cell distribution width (RDW) is associated with mortality in patients with community-acquired pneumonia (CAP). However, little is known about the effect of changes in RDW during treatment on mortality. Thus, the objective of this study was to evaluate the association between RDW changes and mortality in hospitalized patients with CAP. Methods Retrospective analyses were performed using medical records of patients hospitalized for CAP from April 2008 to February 2014. The abstracted laboratory values included RDW (from days one to four), clinical variables, and pneumonia severity index (PSI) scores. The ΔRDWn-1 was defined as the change in RDW calculated as: (RDWday1-RDWday-n)/RDWday1×100 (%), where ‘day n’ refers to hospital day. Results During the study period, a total of 1,069 patients were hospitalized for CAP. The 30-day mortality was 100/1,069 (9.4%). The median RDW at baseline was 14.1% (range, 11.1 to 30.2) and differed significantly between survivors and non-survivors (P

Objective The STONE score is a clinical prediction rule for the presence of uncomplicated ureter stones with a low probability of acutely important alternative findings. This study performed an external validation of the STONE score, focusing on the Korean population, and a derivation of the modified STONE score for better specificity and sensitivity. Methods We retrospectively reviewed medical records of patients complaining of flank pain at a single emergency department from January 2013 to December 2014. Patients were categorized into 3 groups according to their STONE score. The prevalence of ureter stones and other alternative findings were calculated in each group. We derived a modified STONE score based on a multivariable analysis and performed an interval validation. Results From the 700 patients included in the analysis, 555 patients (79%) had a ureter stone. The area under the receiver operating characteristic curve of the STONE score was 0.92. The sensitivity of the high stone score was 0.56. In the modified STONE score, nausea, vomiting, and racial predictors were substituted by C-reactive protein and previous stone history. The area under the receiver operating characteristic curve and sensitivity of the modified STONE score in the internal validation group significantly increased to 0.94 and 0.80, respectively. Conclusion The STONE score can be used to predict a ureter stone with a low probability of other alternative findings. The modified STONE score might increase the diagnostic performance in suspicious urinary stone cases. Key points We performed external validation of the STONE score and derivation of the modified STONE score. This scoring system could help the clinicians with radiation reducing decision making.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) was developed for controlling intra-abdominal arterial bleeding before definitive bleeding control, and is commonly used in patients with ruptured abdominal aortic aneurysms. Although there is limited evidence for other uses of REBOA, we used REBOA in a patient with massive gastrointestinal bleeding. A 53-year-old man with hematochezia was admitted to our emergency department with an initial systolic blood pressure (SBP) of 83 mmHg. His SBP decreased to 40 mmHg in 10 minutes despite rapid fluid infusion. We decided to resuscitate the patient with REBOA in the emergency department and then move him to an intervention room after stabilization. After aortic occlusion, SBP abruptly increased from 57 to 108 mmHg, and the patient could be transferred to an intervention room. The patient was admitted to intensive care, but died of massive rebleeding 24 hours after admission to the emergency department.

Introduction We developed a new neuroprognostication method for cardiac arrest (CA) using the relative volume of the most dominant cluster of low apparent diffusion coefficient (ADC) voxels and tested its performance in a multicenter setting. Methods Adult (>15 years) out-of-hospital CA patients from three different facilities who underwent an MRI 12h after resuscitation were retrospectively analyzed. Patients with unknown long-term prognosis or poor baseline neurologic function were excluded. Average ADCs (mean and median), LADCV (relative volume of low-ADC voxels) and DC-LADCV (relative volume of most dominant cluster of low-ADC voxels) were extracted using different thresholds between 400 and 800×10 −6 mm 2 s −1 at 10×10 −6 mm 2 s −1 intervals. Area under the receiver operating characteristic curve (AUROC) and sensitivity for poor outcome (6-month cerebral performance category score >2) while maintaining 100% specificity were measured. Results 110 patients were analyzed. Average ADCs showed fair performance with an AUROC of 0.822 (95% confidence interval [CI], 0.744–0.900) for the mean and 0.799 (95% CI, 0.716–0.882) for the median. LADCV showed better performance with a higher AUROC (maximum, 0.925) in an ADC threshold range of 400 to 690×10 −6 mm 2 s −1 . DC-LADCV showed the best performance with a higher AUROC (maximum, 0.955) compared with LADCV in an ADC threshold range of 600 to 680×10 −6 mm 2 s −1 . DC-LADCV had a high sensitivity for poor outcomes (>80%) in a wide threshold range from 400 to 580×10 −6 mm 2 s −1 with a maximum of 89.2%. Conclusions Quantitative analysis using DC-LADCV showed impressive performance in determining the prognosis of out-of-hospital CA patients in a multicenter setting.

Objective Head injury in children is a common problem presenting to emergency departments, and cranial computed tomography scanning is the diagnostic standard for these patients. Several decision rules are used to determine whether computed tomography scans should be used; however, the use of computed tomography scans is often influenced by guardians’ preference toward the scans. The objective of this study was to identify changes in guardian preference for minor head injuries after receiving an explanation based on the institutional clinical practice guideline. Methods A survey was conducted between July 2010 and June 2012. Patients younger than 16 years with a Glasgow Coma Scale score of 15 after a head injury and their guardians were included. Pre- and post-explanation questionnaires were given to guardians to assess their preference for computed tomography scans and factors related to the degree of preference. Treating physicians explained the risks and benefits of cranial computed tomography scanning using the institutional clinical practice guideline. Guardian preference for a computed tomography scan was examined using a 100-mm visual analog scale. Results In total, 208 patients and their guardians were included in this survey. Guardian preference for computed tomography scans was significantly reduced after explanation (46.7 vs. 17.4, P

This study was performed to evaluate the association of monocyte counts with mortality, the rate of bacteremia, and organ dysfunction and to evaluate whether the change in monocyte counts from the premorbid state to sepsis would differ between survivors and non-survivors in patients with severe sepsis including septic shock. A retrospective analysis of patients with severe sepsis including septic shock was performed. Monocyte counts were categorized into 250, 250-500, 500-750, and ≥750 cells/μL; in addition, 28-day mortality, the rate of bacteremia, and organ dysfunction were compared between the groups. Multivariate logistic regression analyses were performed to evaluate the independent association of initial blood cell counts with 28-day mortality. Subgroup analyses of patients who had premorbid data of blood cell counts were performed to evaluate the difference in the change in monocyte counts between survivors and non-survivors. During the study period, 2,012 patients were included. Neutrophil and monocyte counts were significantly different between survivors and non-survivors. However, only monocyte counts were independently associated with mortality in the multivariate logistic regression analyses. Patients with initial monocyte counts250 cells/μL showed the highest mortality, rate of bacteremia, and organ dysfunction. In patients who had premorbid blood cell counts, the monocyte counts increased in survivors but decreased in non-survivors from the premorbid to sepsis. In conclusion, monocyte counts were associated with mortality, the rate of bacteremia, and organ dysfunction in patients with sepsis, possibly due to the relative lack of monocytopoiesis related to septic insults in non-survivors.

Intussusception is one of the most common causes of intestinal obstruction in young children. We report a retrospective, observational study of the epidemiology of intussusception in South Korea using the National Health Insurance Service-National Sample Cohort (NHIS-NSC). A cohort of newborns born between 2002 and 2008 was selected. The primary objective was to assess the incidence of intussusception in the pediatric population of Korea. The secondary objectives were to describe the basic epidemiological characteristics of intussusception and to identify risk factors. A total of 362 children were identified. The highest incidence of intussusception (2.6 per 1,000) was observed in children aged 1-2 years. A total of 58.8% of the children were male, and there was no significant difference in incidence according to the birth year (P = 0.804). Most of the children diagnosed with intussusception underwent air reduction, while only 0.6% had surgery. In all, 82.3% of the children were admitted to the hospital, 0.8% of them had to be admitted to the ICU, and the 6-month mortality was only 0.3%. In this retrospective, observational study, the incidence of intussusception was highest among children between 1 and 2 years of age. Most of the children underwent air reduction.

Aim Although various quantitative methods have been developed for predicting neurological prognosis in patients with out-of-hospital cardiac arrest (OHCA), they are too complex for use in clinical practice. We aimed to develop a simple decision rule for predicting neurological outcomes following the return of spontaneous circulation (ROSC) in patients with OHCA using fast-and-frugal tree (FFT) analysis. Methods We performed a retrospective analysis of prospectively collected data archived in a multi-centre registry. Good neurological outcomes were defined as cerebral performance category (CPC) values of 1 or 2 at 28-day. Variables used for FFT analysis included age, sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation, initial shockable rhythm, prehospital defibrillation, prehospital ROSC, no flow time, low flow time, cause of arrest (cardiac or non-cardiac), pupillary light reflex, and Glasgow Coma Scale score after ROSC. Results Among the 456 patients enrolled, 86 (18.9%) experienced good neurological outcomes. Prehospital ROSC (true = good), prompt or sluggish light reflex response after ROSC (true = good), and presumed cardiac cause (true = good, false = poor) were selected as nodes for the decision tree. Sensitivity, specificity, positive predictive value, and negative predictive value of the decision tree for predicting good neurological outcomes were 100% (42/42), 64.0% (119/186), 38.5% (42/109), and 100% (119/119) in the training set and 95.5% (42/44), 57.6% (106/184), 35.0% (42/120), and 98.1% (106/108) in the test set, respectively. Conclusion A simple decision rule developed via FFT analysis can aid clinicians in predicting neurological outcomes following ROSC in patients with OHCA.

Background Hypertension-related visits to the emergency department (ED) are increasing every year. Thus, ED could play a significant role in detecting hypertension and providing necessary interventions. However, it is not known whether a hypertensive event observed in the ED is an independent risk factor for future major adverse cardiovascular events (MACE). Methods A population-based observational study was conducted using a nationally representative cohort that contained the claim data of 1 million individuals from 2002 to 2013. We included non-critical ED visits without any history of MACE, and compared the new occurrences of MACE according to the presence of hypertensive events using extended Cox regression model. The disease-modifying effect of a follow-up visit was assessed by analyzing the interaction between hypertensive event and follow-up visit. Results Among 262,927 first non-critical ED visits during the study period (from 2004 to 2013), 6,243 (2.4%) visits were accompanied by a hypertensive event. The hypertensive event group had a higher risk of having a first MACE at 3 pre-specified intervals: 0–3 years (HR, 4.25; 95% CI, 3.83–4.71; P

Background The pneumococcal urinary antigen test (UAT) has been known to improve sensitivity and specificity for the diagnosis of pneumococcal pneumonia. Associations of UAT results with prognosis in community acquired pneumonia (CAP) are not known. We hypothesized that positive UAT is associated with a good prognosis, and incorporation of UAT into CRB65 would improve its prognostic performance. Methods In this registry-based retrospective study, we analyzed CAP patients over a 10-year period beginning in April 2008. Patients who had UAT results were included in multivariable extended Cox-regression analyses to determine the association between UAT positivity and 30-day mortality. UAT results were incorporated for patients with a CRB65 score of 1 by subtracting 1 from the scoring system if the test was positive. The performance of the modified scoring systems was assessed with area under the receiver operating characteristic (AUROC) curves. Results Among 5145 CAP patients, total 2280 patients had UAT results and were included in analyses. A positive UAT result was associated with a good prognosis after a week of hospitalization (aHR, 0.14; p = 0.007). After modification of CRB65 using UAT results, positive and negative predictive values for 30-day mortality were increased from 7.7 to 8.3 (p

A 32-year-old man came to the emergency department (ED) for multiple trauma. He was found in a parking lot and was suspected to be fallen down from a nearby building. He was transferred to the ED by an emergency medical system with a cervical collar in place and strapped to a backboard. He was confused and anxious, and could not remember the situation at the time of injury, but he was able to follow commands at the ED arrival. His initial vital signs were 55/45 mmHg–124 bpm–22 cpm–32.6 °C with SpO2 at 96%. He was anxious and confused. His right limbs and pelvis had open wounds and deformities. He was suspicious for multiple facial bone fractures, including mandible fracture with oral bleeding and dislodged teeth.

Study design Retrospective large population-based study. Objective The aim of this study is to elucidate the association between vertebral compression fractures (VCFs) and pneumonia. Summary of background data VCF is known to be associated with impaired pulmonary function. However, the risk of developing pneumonia after new-onset VCF has not been evaluated. Methods The data source was the National Health Screening Program Cohort, a population-based sample cohort of national health screening enrolees. Elderly women with low bone density identified during the life transition period health check-up were target population. Patients with newly diagnosed isolated VCF after the health check-up except those with cervical VCF were included as exposure group. Matched individuals still free of any type of VCF from the same population were included as control group with case/control ratio 3:1. The time to first occurrence of pneumonia were analyzed with Cox-regression analysis. Results From the target population (N = 24,773), we matched 867 patients exposed to new-onset isolated VCFs with 2601 controls. In a multivariable Cox-regression analysis, isolated VCF was identified as an independent risk factor for development of a pneumonia (adjusted hazard ratio, 1.48; 95% confidence interval 1.14-1.91). Among the subtypes of VCF, thoracic/thoracolumbar VCF was independently associated with increased risk of pneumonia (adjusted hazard ratio, 2.13; 95% confidence interval 1.47-3.08). Conclusion Isolated VCF, especially those involving thoracic region, was associated with increased risk of pneumonia. Level of evidence 4.

Background Studies have shown that long‐term exposure to air pollution such as fine particulate matter (≤2.5 μm in aerodynamic diameter [ PM 2.5 ]) increases the risk of all‐cause and cardiovascular mortality. To date, however, there are limited data on the impact of air pollution on specific cardiovascular diseases. This study aimed to evaluate cardiovascular effects of long‐term exposure to air pollution among residents of Seoul, Korea. Methods and Results Healthy participants with no previous history of cardiovascular disease were evaluated between 2007 and 2013. Exposure to air pollutants was estimated by linking the location of outdoor monitors to the ZIP code of each participant's residence. Crude and adjusted analyses were performed using Cox regression models to evaluate the risk for composite cardiovascular events including cardiovascular mortality, acute myocardial infarction, congestive heart failure, and stroke. A total of 136 094 participants were followed for a median of 7.0 years (900 845 person‐years). The risk of major cardiovascular events increased with higher mean concentrations of PM 2.5 in a linear relationship, with a hazard ratio of 1.36 (95% confidence interval, 1.29–1.43) per 1 μg/m 3 PM 2.5 . Other pollutants including PM 2.5–10 of CO , SO 2 , and NO 2 , but not O 3 , were significantly associated with increased risk of cardiovascular events. The burden from air pollution was comparable to that from hypertension and diabetes mellitus. Conclusions This large‐scale population‐based study demonstrated that long‐term exposure to air pollution including PM 2.5 increases the risk of major cardiovascular disease and mortality. Air pollution should be considered an important modifiable environmental cardiovascular risk factor.

Objective The objective of the present study is to develop new multifaceted interventions to reduce return visits (RVs) based on identified risk factors related to RVs in the ED and to compare the RV rate before and after the implementation of the intervention. Methods The present study was a controlled before and after study that was conducted in the ED of a 900-bed tertiary hospital in an urban area. The primary outcome was the rate of unplanned RVs to the ED and hospital admission after RV. The risk and predictive factors of RVs were identified by a retrospective study of all unscheduled RVs to the ED within 72 h in 2011. We developed five new multifaceted interventions based on the results: (i) daily RV feedback; (ii) prescription set of drugs; (iii) creation of a discharge instruction sheet; (iv) early follow-up appointments of outpatient department (OPD); and (v) enhancement of referral system. A prospective interventional study in which the interventions were implemented was then conducted over 10 months, from 1 June 2012 to 31 March 2013. Results The five new multifaceted interventions significantly reduced the mean early RV rate and RV admission rate after ED discharge by an average of approximately 25%, with a maximum of approximately 55% and 47%, respectively, compared with the pre-intervention period (RV rate: P < 0.001, RV admission rate: P < 0.001). Conclusions Multifaceted interventions based on identified risk factors for early RV after ED discharge had a positive effect on reducing RVs and the admission rate after RVs for adult patients within 72 h of non-traumatic ED visits.

Objective Out-of-hospital cardiac arrest (OHCA) patients unresponsive to basic life support are frequently transferred to emergency departments (EDs) for further resuscitation. Although some survive with good neurologic outcomes, additional resuscitation in EDs is often futile. Without a dedicated termination of resuscitation (TOR) rule for ED resuscitation, the decision when to stop the resuscitation is up to emergency physicians. In this study, we assessed the association between patient characteristics and duration of resuscitation in EDs to understand how emergency physicians decide when to terminate cardiopulmonary resuscitation. Methods A retrospective analysis of the OHCA registry of a single ED was conducted. Adult (18 years or older) patients without any return of spontaneous circulation (ROSC) after unsuccessful ED advanced cardiac life support were included. The primary endpoint was duration of resuscitation attempts. Prehospital and demographic factors were assessed as independent variables. The relationship between these factors and duration of resuscitative attempts was analyzed with multivariable quantile regression. Results From January 2008 to August 2012, ED resuscitation was terminated without ROSC in 266 patients (53.5%). The duration of resuscitative attempts was significantly shorter if any of the currently recognized poor prognostic factors was present. Interestingly, controversial factors such as female sex and older age were significantly associated with shorter resuscitation duration, while factors definitively indicating poor prognosis, such as severe trauma and poor baseline neurological status, showed no significant association. Conclusion The results of this study suggest that physicians adjust the resuscitation duration according to their subjective prediction of futility despite the absence of evidence-based TOR guidelines.

Objective In cases of community acquired pneumonia (CAP), it has been known that blood cultures have low yields and rarely affect clinical outcomes. Despite many studies predicting the likelihood of bacteremia in CAP patients, those results have been rarely implemented in clinical practice, and use of blood culture in CAP is still increasing. This study evaluated impact of implementing a previously derived and validated bacteremia prediction rule. Methods In this registry-based before and after study, we used piecewise regression analysis to compare the blood culture rate before and after implementation of the prediction rule. We also compared 30-day mortality, emergency department (ED) length of stay, time-interval to initial antibiotics after ED arrival, and any changes to the antibiotics regimen as results of the blood cultures. In subgroup analysis, we compared two groups (with or without the use of the prediction rule) after implementation period, using propensity score matching. Results Following the implementation, the blood culture rate declined from 85.5% to 78.1% ( P = 0.003) without significant changes in 30-day mortality and antibiotics regimen. The interval to initial antibiotics (231 min vs. 221 min, P = 0.362) and length of stay (1019 min vs. 954 min, P = 0.354) were not significantly changed. In subgroup analysis, the group that use the prediction rule showed 25 min faster antibiotics initiation ( P = 0.002) and 48 min shorter length of stay ( P = 0.007) than the group that did not use the rule. Conclusion Implementation of the bacteremia prediction rule in CAP patients reduced the blood culture rate without affecting the 30-day mortality and antibiotics regimen.

Introduction We performed this study to investigate the association of pre-hospital supraglottic airway (SGA) on neurological outcome in cardiac arrest victims with adjustment of post-resuscitation variables as well as pre-hospital and resuscitation variables. Methods This study was a retrospective study based on a multicenter prospective cohort registry from December 2013 to April 2016. According to the 28-day cerebral performance categories (CPC) scale, patients were divided into good outcome group (CPC 1–2) and poor outcome group (CPC 3–5). We compared the two groups with respect to demographic variables, pre-hospital and in-hospital resuscitation variables, and post-resuscitation variables. Results 869 cardiac arrest victims who received in-progress cardiopulmonary resuscitation (CPR) were delivered to the emergency department of three hospitals, and 310 patients were admitted to the intensive care unit. The use of a pre-hospital SGA was independently associated with 28-day good neurological outcome [odds ratio (OR), 7.880; 95% confidence interval (CI), 1.334-46.534; p = 0.023] when post-resuscitation variables were adjusted, although there were no significant association with the acquisition of sustained return of spontaneous circulation (ROSC) [OR, 0.992; 95% CI, 0.591-1.666; p = 0.976]. Furthermore, a pre-hospital SGA was significantly associated with good neurological outcome, especially in patients who received prolonged CPR (low flow time >15 minutes) [OR, 3.411; 95% CI, 1.232-9.449; p = 0.018] rather than in patients with non-prolonged CPR [OR, 4.500; 95% CI, 0.746-27.132; P = 0.101]. Conclusions When post-resuscitation variables were adjusted, the pre-hospital SGA was independently associated with 28-day good neurological outcome in cardiac arrest victims. This article is protected by copyright. All rights reserved.

Objectives This study was performed to identify the risk factors for delayed intracranial hemorrhage and develop a risk stratification system for disposition of head trauma patients with negative initial brain imaging. Methods The data source was National Health Insurance Service-National Sample Cohort of Korea. We analyzed adult patients presenting to the ER from January 2004 to September 2012, who underwent brain imaging and discharged with or without short-term observation no longer than two days. The primary outcome was defined as any intracranial bleeding within a month defined by a new appearance of any of the diagnostic codes for intracranial hemorrhage accompanied by a new claim for brain imaging(s) within a month of the index visit. We performed a multivariable logistic regression analysis and built a parsimonious model for variable selection to develop a simple scoring system for risk stratification. Results During the study period, a total of 19,723 head injury cases were identified from the cohort and a total of 149 cases were identified as having delayed intracranial hemorrhage within 30 days. In multivariable logistic regression model, old age, craniofacial fracture, neck injury, diabetes mellitus and hypertension were independent risk factors for delayed intracranial hemorrhage. We constructed the parsimonious model included age, craniofacial fracture and diabetes mellitus. The score showed area under the curve of 0.704 and positive predictive value of the score system was 0.014 when the score ≥ 2. Conclusions We found old age, associated craniofacial fracture, any neck injury, diabetes mellitus and hypertension are the independent risk factors of delayed intracranial hemorrhage.

Background Heart failure has been associated with an increased risk for ischemic stroke. This study estimated the risk of stroke and thromboembolism for patients with congestive heart failure (CHF) in the context of the general population, especially compared to those with atrial fibrillation (AF). Methods Data of patients discharged alive from 2003 to 2012 were extracted from the National Health Insurance Corporation sample cohort. Subjects were classified into control ( n =90,277), CHF ( n =4533), AF ( n =1187), and CHF plus AF ( n =1213) groups. Results CHF was associated with an increased risk for ischemic stroke, which was significant after various adjustment models. Annualized stroke risk was 0.54 (0.52–0.57) per 100 person-years for the control group, 2.00 (1.79–2.21) for the CHF group, 2.27 (1.84–2.69) for the AF group, and 2.87 (2.38–3.36) for the CHF plus AF group. The CHA 2 DS 2 -VASc scoring schema had a moderate discriminatory value for stroke risk in patients with CHF as well as in AF. The risk of stroke for the CHF group was comparable to that of the AF group when stratified according to the CHA 2 DS 2 -VASc scores. Those with CHA 2 DS 2 -VASc score of 0 or 1 were at low risk for stroke for both CHF and AF. Conclusion Patients with CHF are at increased risk for ischemic stroke and thromboembolism. This study showed that the CHA 2 DS 2 -VASc schema can help stratify stroke risk for individual CHF patients. Stroke is a frequent complication among patients with CHF; therefore, safe and effective strategies to prevent stroke are needed.