Hyperkalemia Detection in Emergency Departments Using Initial ECGs:A Smartphone AI ECG Analyzer vs. Board-Certified Physicians

Background@#Hyperkalemia is a potentially fatal condition that mandates rapid identification in emergency departments (EDs). Although a 12-lead electrocardiogram (ECG) can indicate hyperkalemia, subtle changes in the ECG often pose detection challenges. An artificial intelligence application that accurately assesses hyperkalemia risk from ECGs could revolutionize patient screening and treatment. We aimed to evaluate the efficacy and reliability of a smartphone application, which utilizes camera-captured ECG images, in quantifying hyperkalemia risk compared to human experts. @*Methods@#We performed a retrospective analysis of ED hyperkalemic patients (serum potassium ≥ 6 mmol/L) and their age- and sex-matched non-hyperkalemic controls. The application was tested by five users and its performance was compared to five board-certified emergency physicians (EPs). @*Results@#Our study included 125 patients. The area under the curve (AUC)-receiver operating characteristic of the application’s output was nearly identical among the users, ranging from 0.898 to 0.904 (median: 0.902), indicating almost perfect interrater agreement (Fleiss’ kappa 0.948). The application demonstrated high sensitivity (0.797), specificity (0.934), negative predictive value (NPV) (0.815), and positive predictive value (PPV) (0.927). In contrast, the EPs showed moderate interrater agreement (Fleiss’ kappa 0.551), and their consensus score had a significantly lower AUC of 0.662. The physicians’ consensus demonstrated a sensitivity of 0.203, specificity of 0.934, NPV of 0.527, and PPV of 0.765. Notably, this performance difference remained significant regardless of patients’ sex and age (P < 0.001 for both). @*Conclusion@#Our findings suggest that a smartphone application can accurately and reliably quantify hyperkalemia risk using initial ECGs in the ED.

A Retrospective Clinical Evaluation of an Artificial Intelligence Screening Method for Early Detection of STEMI in the Emergency Department

Background@#Rapid revascularization is the key to better patient outcomes in ST-elevation myocardial infarction (STEMI). Direct activation of cardiac catheterization laboratory (CCL) using artificial intelligence (AI) interpretation of initial electrocardiography (ECG) might help reduce door-to-balloon (D2B) time. To prove that this approach is feasible and beneficial, we assessed the non-inferiority of such a process over conventional evaluation and estimated its clinical benefits, including a reduction in D2B time, medical cost, and 1-year mortality. @*Methods@#This is a single-center retrospective study of emergency department (ED) patients suspected of having STEMI from January 2021 to June 2021. Quantitative ECG (QCG™), a comprehensive cardiovascular evaluation system, was used for screening. The non-inferiority of the AI-driven CCL activation over joint clinical evaluation by emergency physicians and cardiologists was tested using a 5% non-inferiority margin. @*Results@#Eighty patients (STEMI, 54 patients [67.5%]) were analyzed. The area under the curve of QCG score was 0.947. Binned at 50 (binary QCG), the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 98.1% (95% confidence interval [CI], 94.6%, 100.0%), 76.9% (95% CI, 60.7%, 93.1%), 89.8% (95% CI, 82.1%, 97.5%) and 95.2% (95% CI, 86.1%, 100.0%), respectively. The difference in sensitivity and specificity between binary QCG and the joint clinical decision was 3.7% (95% CI, −3.5%, 10.9%) and 19.2% (95% CI, −4.7%, 43.1%), respectively, confirming the non-inferiority. The estimated median reduction in D2B time, evaluation cost, and the relative risk of 1-year mortality were 11.0 minutes (interquartile range [IQR], 7.3–20.0 minutes), 26,902.2 KRW (22.78 USD) per STEMI patient, and 12.39% (IQR, 7.51–22.54%), respectively. @*Conclusion@#AI-assisted CCL activation using initial ECG is feasible. If such a policy is implemented, it would be reasonable to expect some reduction in D2B time, medical cost, and 1-year mortality.

Prediction of Neurological Outcomes in Out-of-hospital Cardiac Arrest Survivors Immediately after Return of Spontaneous Circulation: Ensemble Technique with Four Machine Learning Models

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 153were 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.

Prediction of Neurological Outcomes in Out-of-hospital Cardiac Arrest Survivors Immediately after Return of Spontaneous Circulation: Ensemble Technique with Four Machine Learning Models

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 153were 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.

Risk of injury after emergency department visit for acute peripheral vertigo: a matched-cohort study

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.

Epidemiology of sepsis in Korea: a population-based study of incidence, mortality, cost and risk factors for death in sepsis

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 <0.001) and from 26.5% (95% CI, 24.4% to 28.8%) to 30.1% (95% CI, 28.4% to 31.9%), respectively. After standardization, the increasing trend of incidence was slower but still significant (P-trend <0.001), while that for mortality was not (P-trend 0.883). The average cost increased by 75.5% (P-trend <0.001). Multivariable logistic regression identified various risk factors for mortality.CONCLUSION: The burden of sepsis in Korea was high and is expected to increase considering the aging population. Proactive measures to curtail this increase should be sought and implemented.

Underuse of Epinephrine for Pediatric Anaphylaxis Victims in the Emergency Department: A Population-based Study

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.

Relationship between the time to positivity of blood culture and mortality according to the site of infection in sepsis

OBJECTIVE: The time to positivity (TTP) of blood culture reflects bacterial load and has been reported to be associated with outcome in bloodstream infections. This study was performed to evaluate the relationship between the TTP of blood culture and the mortality rates associated with sepsis and septic shock according to the site of infection. METHODS: We performed a retrospective cohort study on patients with sepsis and septic shock. The rates of blood culture positivity and mortality as well as the relationship between the TTP and 28-day mortality rate were compared among patients with different sites of infection, such as the lungs, abdomen, urogenital tract, and other sites. RESULTS: A total of 2,668 patients were included, and the overall mortality rate was 21.6%. The rates of blood culture positivity and mortality were different among the different infection sites. There was no relationship between the TTP and mortality rates of total, lung, and urogenital infections. Patients with abdominal infections showed a negative correlation between the TTP and 28-day mortality rate. In patients with abdominal infections, a TTP < 20 hours was independently associated with 28-day mortality compared with patients with negative blood culture (hazard ratio, 1.73; 95% confidence interval, 1.16–2.58). However, there was no difference in mortality rates of patients with a TTP≥20 hours and a negative blood culture. CONCLUSION: The shorter TTP in patients with abdominal infections in sepsis and septic shock was associated with a higher 28-day mortality rate.

Time Interval from Intubation to Return of Spontaneous Circulation in Out-of-hospital Cardiac Arrest Patient with Brain Hemorrhage

PURPOSE: This study was conducted to investigate the relationship of time interval from intubation to return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients according to the presence or absence of intracranial hemorrhage (ICH). METHODS: This retrospective study used data from a prospectively collected OHCA registry for patients treated from January 2008 to December 2016. Non-traumatic adult OHCA patients who underwent brain computed tomography were included, while patients who achieved a prehospital ROSC or required advanced airway management were excluded. Utstein variables, initial blood gas analysis, electrolyte levels, and the time interval from intubation to ROSC were used to compare the ICH and non-ICH groups. RESULTS: A total of 448 patients were analyzed. The ICH group was younger and had more females than the non-ICH group. The time interval from intubation to ROSC was significantly shorter in the ICH group than the non-ICH group. The median time and interquartile range were 3 (2 to 7) minutes in the ICH group and 6 (3 to 10) minutes in the non-ICH group. The patient age, gender, potassium level, and time interval from intubation to ROSC were significant variables in the multivariable analysis. In a multivariable logistic regression model that included these variables, the area under the receiver operating characteristic curve was 0.838. CONCLUSION: OHCA patients with ICH achieve ROSC after intubation in a shorter amount of time than those without ICH.

SEALONE (Safety and Efficacy of Coronary Computed Tomography Angiography with Low Dose in Patients Visiting Emergency Room) trial: study protocol for a randomized controlled trial

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.

Use of resuscitative endovascular balloon occlusion of the aorta in a patient with gastrointestinal bleeding

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.

Multiple Shock Failures during Resuscitation: Risk Factors and Prognostic Implications

PURPOSE: Electrical shock is not always followed by a perfusing rhythm, and multiple shock failure (MSF) is common during CPR. We sought to investigate its risk factors and prognostic implications. METHODS: Adult OHCA patients with emergency department (ED) ACLS attempts were identified from a tertiary hospital OHCA registry extending from 2008 to 2012. Shock failure was defined as any electrical shock attempt not followed by a pulse-generating rhythm. Patients were assigned to one of three groups based on the number of shock failures: 1) MSF: ≥3 electrical shock failures before the first ROSC or CPR termination (if there was no ROSC), 2) early shock success (ESS): pulse-generating rhythm achieved within 3 electrical shock attempts and 3) others: all remaining patients. Baseline characteristics, initial laboratory measurements, and outcomes were compared. RESULTS: A total of 590 patients were included. There was no significant difference in baseline characteristics between the MSF group (n=49) and the early shock success group (n=50) except in its higher proportion of presumed cardiac aetiology. The MSF group showed less severe metabolic acidosis and coagulopathy on ED arrival and better renal function and higher haematocrit and serum albumin levels compared with the ESS group. MSF was associated with less sustained ROSC, but was also associated with more survival discharge and better long-term neurologic outcomes after sustained ROSC. CONCLUSION: MSF may indicate heart-specific problems rather than severe metabolic derangements. Better long-term outcomes can be expected once sustained ROSC is achieved, therefore, this phenomenon warrants more focused research.

Change in Guardians' Favor in Computed Tomography after Explained by Emergency Physicians in Pediatric Head Injury

PURPOSE: Head injury in children is a common problem presenting to emergency departments, and cranial computed tomography scan 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 guardian favor toward the scans. The objective of this study was to identify changes in guardian favor for explanation of minor head injuries based on the institutional clinical practice guidelines. 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 guardians of these patients were included. Pre- and post-explanation questionnaires were administered to guardians to evaluate their favor for computed tomography scans and factors related to the degree of favor. Treating physicians explained the risks and benefits of cranial computed tomography scans using the institutional clinical practice guidelines. Guardian favor for a computed tomography (CT) scan was examined using a 100-mm visual analog scale. RESULTS: A total of 208 patients and their guardians were included in this survey. Guardian favor for computed tomography scans was significantly reduced after explanation (46.7 vs. 17.4, p<0.01). Pre-explanation favor and the degree of physician recommending computed tomography were the most important factors affecting pre- and postexplanation changes in favor. CONCLUSION: Explanation of the risks and benefits of cranial computed tomography scans using the institutional clinical practice guidelines may significantly reduce guardian favor for computed tomography scans.

The clinical significance of changes in red blood cell distribution width in patients with community-acquired pneumonia

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 ΔRDW(n-1) was defined as the change in RDW calculated as: (RDW(day1)-RDW(day-n))/RDW(day1)×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<0.05). There were 470 patients with available serial RDW data (30-day mortality 58/470 [12.3%]). Of those, age, PSI score, blood urea nitrogen level, total protein concentration, albumin level, RDW at day 1, and the ΔRDW₄₋₁ differed significantly between survivors and non-survivors. Multivariate Cox regression analysis showed that the significance of the relationship between ΔRDW₄₋₁ and 30-day mortality risk remained after adjusting for age, PSI score, RDW at day 1, total protein concentration, and initial albumin level. CONCLUSION: RDW change from day 1 to day 4 was an independent predictor of mortality in patients with CAP.

Clinical Predictors of Subarachnoid Hemorrhage in Patients with Acute Non-traumatic Headache in Emergency Department

PURPOSE: Missing subarachnoid hemorrhage (SAH) can cause catastrophic results. We aimed to find clinical factors for predicting SAH in neurologically intact patients with acute non-traumatic headache visiting the emergency department (ED). METHODS: This was a retrospective chart review study. Data were collected from September 2006 until October 2011. We included patients aged over 16 with acute non-traumatic headache who had brain imaging work up results during ED visits. Information on candidate clinical predictor variables was obtained from previous reports, and the outcome was confirmed SAH in brain imaging work up or cerebrospinal fluid study. We found the predictors for SAH through multivariable analysis with variables chosen in univariable analysis considering clinical application. Then we simulated possible SAH prediction scoring models using receiver operating characteristic (ROC) analysis and assessed model fit through the Hosmer-Lemeshow test. RESULTS: A total of 3294 patients were enrolled. Seven clinical characteristics were proven for relation of SAH; age, visiting emergency department within six hours from symptom onset time, visiting mode, vomiting, neck pain or neck stiffness, blood pressure, and respiratory rate. We constructed six available SAH prediction scoring models. The area under the ROC curves of each model ranged from 0.810 to 0.834 and all simulated models were good-fit. With these models, we can expect to reduce unnecessary computed tomography use. CONCLUSION: Seven clinical predictors could be helpful in selection of high risk patients of SAH. The proposed SAH prediction models using these characteristics will have to be tested prospectively for external validation.

Prognostic Significance of Initial Serum Albumin on Mortality in Out-of-hospital Cardiac Arrest

PURPOSE: The association of serum albumin concentration on hospital arrival with long-term mortality in survivors from out-of-hospital cardiac arrest (OHCA) was investigated. METHODS: A retrospective analysis was conducted of patients presumed to have cardiac cause of arrest and achieved sustained return of spontaneous circulation (ROSC) from prospective OHCA. The individual medical records were reviewed for data, including initial serum albumin. The primary outcome was survival at 6 months and the secondary outcome was Cerebral Performance Category (CPC) at 6 months. Differences in variables between survivors and non-survivors at 6 months after cardiac arrest were analyzed. Albumin was categorized into tertiles of 3.7 g/dL. Hazard ratios (HRs) were estimated using Cox-proportional hazard models in both univariate and multivariate analysis. All prognostic variables with p value<0.1 in univariate analysis were used in multivariate analysis for adjustment. Receiver operating curve (ROC) analysis was performed to evaluate the discriminative power of albumin. RESULTS: In a total of 547 OHCA patients, 136 patients had a presumed cardiac cause of arrest and sustained ROSC with available initial serum albumin. The survival rate at 6 months was significantly higher in patients in the higher albumin group and neurological outcomes were also more favorable in the higher albumin group (log rank test, p<0.05). In a Cox proportional hazard regression analysis, initial serum lactate and albumin levels were independently associated with 6-month mortality and albumin levels showed moderate discriminative power for 6-month mortality by ROC analysis (AUC=0.738, 95% CI: 0.652-0.825). CONCLUSION: Serum albumin is associated with long-term mortality and neurological outcome in patients with presumed cardiac cause of arrest and sustained ROSC from OHCA.

Prognostic Significance of Initial Serum Albumin on Mortality in Out-of-hospital Cardiac Arrest

PURPOSE: The association of serum albumin concentration on hospital arrival with long-term mortality in survivors from out-of-hospital cardiac arrest (OHCA) was investigated. METHODS: A retrospective analysis was conducted of patients presumed to have cardiac cause of arrest and achieved sustained return of spontaneous circulation (ROSC) from prospective OHCA. The individual medical records were reviewed for data, including initial serum albumin. The primary outcome was survival at 6 months and the secondary outcome was Cerebral Performance Category (CPC) at 6 months. Differences in variables between survivors and non-survivors at 6 months after cardiac arrest were analyzed. Albumin was categorized into tertiles of 3.7 g/dL. Hazard ratios (HRs) were estimated using Cox-proportional hazard models in both univariate and multivariate analysis. All prognostic variables with p value<0.1 in univariate analysis were used in multivariate analysis for adjustment. Receiver operating curve (ROC) analysis was performed to evaluate the discriminative power of albumin. RESULTS: In a total of 547 OHCA patients, 136 patients had a presumed cardiac cause of arrest and sustained ROSC with available initial serum albumin. The survival rate at 6 months was significantly higher in patients in the higher albumin group and neurological outcomes were also more favorable in the higher albumin group (log rank test, p<0.05). In a Cox proportional hazard regression analysis, initial serum lactate and albumin levels were independently associated with 6-month mortality and albumin levels showed moderate discriminative power for 6-month mortality by ROC analysis (AUC=0.738, 95% CI: 0.652-0.825). CONCLUSION: Serum albumin is associated with long-term mortality and neurological outcome in patients with presumed cardiac cause of arrest and sustained ROSC from OHCA.

Cardiopulmonary Resuscitation Training for a Layperson Through Conventional Instructor-led Training and a Self-learning Program Using the CPR Anytime Kit

PURPOSE: We aimed to investigate whether a trained layperson could perform high quality Cardiopulmonary Resuscitation (CPR) after conventional training and a self-learning program using the "CPR Anytime" kit. METHODS: Traditional CPR training for a lay rescuer was conducted two weeks before a CPR contest for high school students. "CPR Anytime" training kits were distributed to the students for their practical training at home or in school. The students were tested in pairs for two-person CPR with rescuer breaths and an automated external defibrillator. The quantitative and qualitative data regarding the quality of CPR, including chest compression and rescuer breaths, were collected using a standardized checklist and a skill reporter. RESULTS: A total of 161 teams with 322 students, including 116 males and 206 females, participated in the CPR contest in pairs. The mean depth and rate for the chest compression were 49.0+/-8.2 mm and 110.2+/-10.2 /min, respectively. The mean tidal volume for the rescue breaths was 604.8+/-208.7 ml. The percentage of participants satisfying the correct chest compression rate of > or =100/min and depth of > or =50 mm was 87.3% and 52.2%, respectively. Only 25.2% of the participants satisfied an optimal tidal volume (between 500 ml and 600 ml). Shallow compression (57.5%) and under-ventilation (44.4%) were the major causes of incorrect compression and ventilation, respectively. CONCLUSION: The quality of CPR with rescuer breaths in the trained lay rescuer was not adequate, especially for mouth-to-mouth rescue breathing. Therefore, the development of teaching methods to improve rescue breathing or omit mouth-to-mouth ventilation in training should be considered.

Efficacy and Safety of the Computed Tomography Coronary Angiography Based Approach for Patients with Acute Chest Pain at an Emergency Department: One Month Clinical Follow-up Study

To evaluate the safety and efficacy of the computed tomography coronary angiography (CTCA) for evaluation of acute chest pain in real world population, we prospectively enrolled 296 patients with acute chest pain at emergency department (ED) from November 2005 to February 2007. The patients were grouped based on the clinical information and CTCA result. The patients with a low risk profile and no significant coronary stenosis (>50%) in CTCA were discharged immediately (Group 1, n=103). On the other hand, the patients with an intermediate risk profile without significant stenosis were observed in ED for 24 hr (Group 2, n=104). The patients with significant stenosis underwent further coronary evaluation and management accordingly (Group 3, n=89). While no false negative case was found in Group 1, seven cases (6.73%) were found in Group 2, mostly during the observation period. In Group 3, there were 54 (60.67%) cases of acute coronary syndrome including 10 myocardial infarctions. The overall accuracy of CTCA for acute coronary syndrome was 88.5% (sensitivity), 85.1% (specificity), 60.7% (positive predictive value) and 96.6% (negative predictive value). In conclusion, clinical decision based on CTCA is safe and effective for low risk patients. Further validation is needed in patients with intermediate risk profile.