Kyoung Jun Song

A trend in epidemiology and outcomes of out-of-hospital cardiac arrest by urbanization level: a nationwide observational study from 2006 to 2010 in South Korea.

BACKGROUND The goal of this study is to better understand the trend in epidemiological features and the outcomes of emergency medical service (EMS)-assessed out-of-hospital cardiac arrest (OHCA) according to the community urbanization level: metropolitan, urban, and rural. METHODS This study was performed within a nationwide EMS system with a single-tiered basic-to-intermediate service level and approximately 900 destination hospitals for eligible OHCA cases in South Korea (with 48 million people). A nationwide OHCA database, which included information regarding demographics, Utstein criteria, EMS, and hospital factors and outcomes, was constructed using the EMS run sheets of eligible cases who were transported by 119 EMS ambulances and followed by a medical record review from 2006 to 2010. Cases with an unknown outcome were excluded. The community urbanization level was categorized according to population size, with metropolitan areas (more than 500,000 residents), urban areas (100,000-500,000 residents), and rural areas (<100,000 residents). The primary end point was the survival to discharge rate. Age- and sex-adjusted survival rates (ASRs) and standardized survival ratios (SSRs) with 95% confidence intervals (CIs) were calculated compared to a standard population. The adjusted odds ratios (AORs) and 95% CIs for survival were calculated and adjusted for potential risk factors using stratified multivariable logistic regression analysis. RESULTS There were 97,291 EMS-assessed OHCAs with 73,826 (75.9%) EMS-treated cases analyzed, after excluding the patients with unknown outcome (N=4172). The standardized incidence rate increased from 37.5 in 2006 to 46.8 in 2010 per 100,000 person-years for EMS-assessed OHCAs, and the survival rate was 3.0% for EMS-assessed OHCAs (3.3% for cardiac etiology and 2.3% for non-cardiac etiology) and 3.6% for EMS-treated OHCAs. Significantly different trends were found by urbanization level for bystander CPR, EMS performance, and the level of the destination hospital. The ASRs for survival were significantly improved by year in the metropolitan areas (3.6% in 2006 to 5.3% in 2010) but remained low in the urban areas (1.4% in 2006 to 2.3% in 2010) and very low in the rural areas (0.5 in 2006 and 0.8 in 2010). The SSRs (95% CIs) in the metropolitan areas were 1.19 (1.06-1.34) in 2006 and 1.77 (1.64-1.92) in 2010, whereas the SSRs were observed to be less than 1.00 during the five-year period in both urban and rural areas. The AORs (95% CIs) for survival significantly increased to 1.42 (1.22-1.66) in the metropolitan areas and to 1.58 (1.18-2.11) in the urban areas while not increasing in the rural areas, compared to the level of each group of areas in 2006. CONCLUSIONS In this nationwide cohort study from 2006 to 2010, the standardized incidence rate and survival to discharge rate of EMS-assessed OHCAs increased annually in metropolitan and urban communities but did not increase in rural communities. Further investigations should be undertaken to improve the performance and outcomes in rural communities.

Out-of-hospital airway management and cardiac arrest outcomes: A propensity score matched analysis

OBJECTIVE It is unclear whether advanced airway management during ambulance transport is associated with improved out-of-hospital cardiac arrest (OHCA) outcomes compared with bag-valve mask ventilation (BVM). This study aimed to determine whether EMT-intermediate ETI or LMA is associated with improved OHCA outcomes in Korea. METHODS We used a Korean national OHCA cohort database composed of hospital and ambulance data. We included all EMS-treated by level 1 EMTs (EMT-intermediate level) and OHCA with presumed cardiac etiology for the period January 2006-December 2008. We excluded cases not receiving continued resuscitation in the emergency department (ED), treated by level 2 EMT, as well as those without available hospital outcome data. The primary exposure was airway management technique during ambulance transport (endotracheal tube (ETI), laryngeal mask airway (LMA) or bag-valve-mask ventilation with an oropharyngeal airway). The primary outcomes were survival to admission and survival to hospital discharge. We compared outcomes between each airway management group using multivariable logistic regression, adjusting for sex, age, witnessed, prehospital defibrillation, bystander cardiopulmonary resuscitation (CPR), call to ambulance arrival time to the scene, call to ambulance arrival time to ED, initial ECG, metropolitan (defined as population>1 million), and level of ED (higher versus lower level). We repeated the analysis using propensity-score matched subsets. RESULTS Of 54,496 patients with OHCA, we included 5278 (9.7%). Overall survival to admission and to discharge was 20.2% and 6.9%, respectively. ETI and LMA were performed in 250 (4.7%) and 391 (7.4%), respectively. In the full multivariable models using total patients, adjusted survival to admission and discharge were similar for ETI and BVM: OR 0.91 (0.66-1.27) and 1.00 (0.60-1.66), respectively. Adjusted survival to admission and discharge were significantly lower in LMA than BVM: OR 0.72 (0.54-0.95) and 0.52 (0.32-0.85), respectively. In the full multivariable models using propensity matched samples, adjusted survival to admission and discharge were similar for ETI and BVM; OR 1.32 (0.81-2.16) and 1.44 (0.66-3.15), respectively. Adjusted survival to admission was similar for LMA and BVM: OR 0.72 (0.50-1.02). However, survival to discharge was significantly lower for LMA than BVM: OR 0.45 (0.25-0.82). CONCLUSIONS In Korea, EMT-I placed LMA during ambulance transport was associated with worsened OHCA survival to discharge than BVM. Outcomes were similar between EMT-I endotracheal intubation and bag-valve-mask ventilation.

Epidemiology and outcomes from non-traumatic out-of-hospital cardiac arrest in Korea: A nationwide observational study ☆

OBJECTIVES We aimed to describe the epidemiological features and to determine the predictors for survival to discharge of non-traumatic out-of-hospital cardiac arrest (OHCA) in Korea. SUBJECTS AND METHODS A nationwide Utstein style OHCA database (2006-2007) was constructed from ambulance records and hospital medical record review. Cases were enrolled when they were non-traumatic OHCA with presumed cardiac aetiology. Using the population census (2005), we calculated age-gender standardized incidence rates (SIR) and mortality (SMR). We modelled a multivariate logistic regression analysis to determine the effect of risk factors on hospital outcomes. RESULTS The total number of EMS-assessed non-traumatic OHCA patients was 19045. The SIR was 20.9 (2006) and 22.2 (2007) per 100000 and survival-to-discharge rate was 2.3% for EMS-assessed non-traumatic OHCA, and was 3.5% for the resuscitation-attempted group. From a multivariate logistic regression analysis, witnessed arrest, and shorter basic life support (BLS) and EMS intervals turned out to be significant predictors of good outcome in the resuscitation-attempted group. CONCLUSION From a nationwide OHCA cohort, the incidence of EMS-assessed non-traumatic OHCA was found to be low. Survival-to-discharge rate in the resuscitation-attempted group was 3.5%, which was significantly associated with witnessed arrest, and shorter BLS and EMS intervals.

Dispatcher-assisted bystander cardiopulmonary resuscitation in a metropolitan city: A before–after population-based study

BACKGROUND The goal of this study was to determine the effects of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-CPR) on outcomes of out-of-hospital cardiac arrest (OHCA). METHODS All EMS in a metropolitan city with a population of 10 million are dispatched by a single, centralized, and physician-supervised center. Data on patients with adult OHCA with cardiac etiology were collected from the dispatch center registry and from EMS run sheets and hospital medical record review from 2009 to 2011. A standardized DA-CPR protocol (aligned with the 2010 AHA guidelines) we implemented as an intervention in January 2011. The end points were survival to discharge, good neurological outcome, and bystander CPR rate. Multivariate logistic analysis was used to compare between intervention group (2011) and historical control group (2009-2010). RESULTS Of 8.144 eligible patients, bystander CPR was performed for the patients in 5.7% (148/2600) of cases in 2009, 6.7% (190/2857) in 2010, and 12.4% (334/2686) in 2011 (p<0.001). The survival to discharge rates was 7.1% (2009), 7.1% (2010), and 9.4% (2011) (p=0.001). Good neurological outcomes occurred in 2.1% (2009), 2.0% (2010), and 3.6% (2011) of cases (p<0.001). The adjusted ORs (95% CIs) for survival to discharge compared with 2009 were 1.33 (1.07-1.66) in 2011 and 1.12 (0.89-1.41) in 2010. The adjusted ORs (95% CIs) for good neurological outcomes were 1.67 (1.13-2.45) in 2011 and 1.13 (0.74-1.72) in 2010. CONCLUSIONS An EMS intervention using the DA-CPR protocol was associated with a significant increase in bystander CPR and an improved survival and neurologic outcome after OHCA.

Pediatric out-of-hospital cardiac arrest in Korea: A nationwide population-based study☆☆☆

STUDY OBJECTIVES Our objective was to describe the incidence and demographics of pediatric out-of-hospital cardiac arrest (OHCA) in Korea. METHODS We identified non-traumatic OHCA patients aged less than 20 years from a Korean nationwide OHCA registry (2006-2007). Data from emergency medical service (EMS) run-sheets and hospital records were reviewed. We excluded cases with unknown hospital outcomes. Patient characteristics, treatment by EMS, and outcomes were compared by age groups: infant (<1 year), children (1-11 years), and adolescents (12-19 years). RESULTS A total of 971 patients including infants (n=299, 30.8%), children (n=305, 31.4%), and adolescents (n=367, 37.8%) met inclusion criteria. The incidence of pediatric OHCA was 4.2 per 100,000 person-years (67.1 in infants, 2.5 in children, and 3.5 in adolescents). The rate of cardiopulmonary resuscitation administered was 82.1% (infants 80.6%, children 82.0%, and adolescent 83.4%). The rate of applying automated external defibrillators and advanced airway management (endotracheal intubation or laryngeal mask airway), was only 4.1% and 2.5%, respectively. 7.4% showed ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in the initial ECG. Survival to hospital discharge for all pediatric OHCA was 4.9% (2.9% for infants, 4.7% for children, and 7.2% of adolescents). For EMS-treated pediatric OHCA or patients with VF or pulseless VT, the rate was 5.0% and 31.6%, respectively. CONCLUSION Incidence and hospital outcomes in pediatric OHCA in Korea were comparable to other population-based nationwide reports.

Outcomes for out-of-hospital cardiac arrests across 7 countries in Asia: The Pan Asian Resuscitation Outcomes Study (PAROS)

BACKGROUND The Pan Asian Resuscitation Outcomes Study (PAROS) Clinical Research Network (CRN) was established in collaboration with emergency medical services (EMS) agencies and academic centers in Japan, Singapore, South Korea, Malaysia, Taiwan, Thailand, and UAE-Dubai and aims to report out-of-hospital cardiac arrests (OHCA) and provide a better understanding of OHCA trends in Asia. METHODS AND RESULTS This is a prospective, international, multi-center cohort study of OHCA across the Asia-Pacific. Each participating country provided between 1.5 and 2.5 years of data from January 2009 to December 2012. All OHCA cases conveyed by EMS or presenting at emergency departments were captured. 66,780 OHCA cases were submitted to the PAROS CRN; 41,004 cases were presumed cardiac etiology. The mean age OHCA occurred varied from 49.7 to 71.7 years. The proportion of males ranged from 57.9% to 82.7%. Proportion of unwitnessed arrests ranged from 26.4% to 67.9%. Presenting shockable rhythm rates ranged from 4.1% to 19.8%. Bystander cardiopulmonary resuscitation (CPR) rates varied from 10.5% to 40.9%, however <1.0% of these arrests received bystander defibrillation. For arrests that were with cardiac etiology, witnessed arrest and VF, the survival rate to hospital discharge varied from no reported survivors to 31.2%. Overall survival to hospital discharge varied from 0.5% to 8.5%. Survival with good neurological function ranged from 1.6% to 3%. CONCLUSIONS Survival to hospital discharge for Asia varies widely and this may be related to patient and system differences. This implies that survival may be improved with interventions such as increasing bystander CPR, public access defibrillation and improving EMS.

Comparison of Emergency Medical Services Systems Across Pan-Asian Countries: A Web-based Survey

Abstract Background. There are great variations in out-of-hospital cardiac arrest (OHCA) survival outcomes among different countries and different emergency medical services (EMS) systems. The impact of different systems and their contribution to enhanced survival are poorly understood. This paper compares the EMS systems of several Asian sites making up the Pan-Asian Resuscitation Outcomes Study (PAROS) network. Some preliminary cardiac arrest outcomes are also reported. Methods. This is a cross-sectional descriptive survey study addressing population demographics, service levels, provider characteristics, system operations, budget and finance, medical direction (leadership), and oversight. Results. Most of the systems are single-tiered. Fire-based EMS systems are predominant. Bangkok and Kuala Lumpur have hospital-based systems. Service level is relatively low, from basic to intermediate in most of the communities. Korea, Japan, Singapore, and Bangkok have intermediate emergency medical technician (EMT) service levels, while Taiwan and Dubai have paramedic service levels. Medical direction and oversight have not been systemically established, except in some communities. Systems are mostly dependent on public funding. We found variations in available resources in terms of ambulances and providers. The number of ambulances is 0.3 to 3.2 per 100,000 population, and most ambulances are basic life support (BLS) vehicles. The number of human resources ranges from 4.0 per 100,000 population in Singapore to 55.7 per 100,000 population in Taipei. Average response times vary between 5.1 minutes (Tainan) and 22.5 minutes (Kuala Lumpur). Conclusion. We found substantial variation in 11 communities across the PAROS EMS systems. This study will provide the foundation for understanding subsequent studies arising from the PAROS effort.

Cardiopulmonary resuscitation outcome of out-of-hospital cardiac arrest in low-volume versus high-volume emergency departments: An observational study and propensity score matching analysis

OBJECTIVE This study aimed to determine whether cardiopulmonary resuscitation (CPR) volume is associated with survival to discharge rate for out-of hospital cardiac arrest (OHCA) victims. METHODS This study was performed in an emergency medical service (EMS) system with single-tiered basic to intermediate service level. A nationwide OHCA cohort database from January 2006 to December 2007 was used and composed of hospital chart review and ambulance run sheet data. We enrolled data from the 410 emergency departments and excluded cases without available hospital outcome data. From sensitivity analysis, we decided cut-off value for the high volume (HV) versus low volume (LV) EDs. A matching process based on propensity score was used to equalize potential prognostic factors in both groups. The adjusted odds ratio (OR) and its 95% confidence interval (95% CI) for survival to admission and to discharge were calculated. RESULTS Of the 34,408 patients with OHCA, 20,457 (59.5%) were included except cases with unknown outcome (n=1284), traumatic cause (n=4894), no CPR attempt by EMS (n=7779), and cases transferred to non-ED facilities (n=3885). Overall survival to admission and to discharge was 10.9% and 3.4%, respectively. When we performed the sensitivity analysis for deciding the cut-off value for HV versus LV, the number was 68 per two years (sensitivity 67.0%, specificity 67.0%). Using propensity score matching, 3533 cases were randomly assigned to HV and LV group, respectively. The unadjusted and adjusted OR for survival to admission in HV was 1.35 (95% CI 1.19-1.54) and 1.44 (95% CI 1.24-1.66), respectively. The unadjusted and adjusted OR for survival to discharge was 1.71 (95% CI 1.36-2.14) and 1.81 (95% 1.43-2.30), respectively. CONCLUSIONS Emergency departments with high volumes of CPR cases showed significantly better outcomes for OHCA patients than those with low volumes in an EMS system with single-tiered basic to intermediate service level.

Triple-negative, basal-like, and quintuple-negative breast cancers: better prediction model for survival

BackgroundTriple-negative breast cancers (TNBCs) and basal-like breast cancers (BLBCs) are known as poor outcome subtypes with a lack of targeted therapy. Previous studies have shown conflicting results regarding the difference of prognostic significance between TNBCs and BLBCs. In this study, we aimed to characterize the prognostic features of TNBCs, in view of BLBCs and quintuple-negative breast cancers (QNBC/5NPs).MethodsUsing tissue microarray-based immunohistochemical analysis, we categorized 951 primary breast cancers into four or five subtypes according to the expression of ER, PR, HER2, and basal markers (CK5/6, EGFR).ResultsThe results of this study showed that both TNBCs and BLBCs were associated with high histological and/or nuclear grades. When the TNBCs are divided into two subtypes by the presence of basal markers, the clinicopathologic characteristics of TNBCs were mainly maintained in the BLBCs. The 5-subgrouping was the better prediction model for both disease free and overall survival in breast cancers than the 4-subgrouping. After multivariate analysis of TNBCs, the BLBCs did not have a worse prognosis than the QNBC/5NPs. Interestingly, the patients with BLBCs showed significant adjuvant chemotherapy benefit. In addition, QNBC/5NPs comprised about 6~8% of breast cancers in publicly available breast cancer datasetsConclusionThe QNBC/5NP subtype is a worse prognostic subgroup of TNBCs, especially in higher stage and this result may be related to adjuvant chemotherapy benefit of BLBCs, calling for caution in the identification of subgroups of patients for therapeutic classification.

Comparison of clinical performance of cranial computed tomography rules in patients with minor head injury: a multicenter prospective study.

OBJECTIVES The objective was to compare the predictive performance of three previously derived cranial computed tomography (CT) rules, the Canadian CT Head Rule (CCHR), the New Orleans Criteria (NOC), and National Emergency X-Ray Utilization Study (NEXUS)-II, for detecting clinically important traumatic brain injury (TBI) and the need for neurosurgical intervention in patients with blunt head trauma. METHODS This was a prospective, multicenter, observational cohort study of patients with blunt head trauma from June 2008 to May 2009. The historical and physical examination components of the CCHR, NOC, and NEXUS-II were documented on a data collection form and the performance of each of the three rules was compared. Patient eligibility for each specific rule was defined exactly as previously described for each specific rule. To compare the three decision rules in terms of sensitivity and specificity, an intersection cohort satisfying inclusion criteria of all three decision rules was derived. The primary outcome was clinically important TBI, and the secondary outcome was neurosurgical intervention. The sensitivity and specificity of each rule were calculated with 95% confidence intervals (95% CIs). We also calculated the potential reduction rate in cranial CT scan utilization realized by theoretical implementation of these rules. RESULTS A total of 7,131 patients were prospectively enrolled, including 692 (9.7%) with clinical TBI. Among the enrolled population, patients eligible for CCHR, NOC, and NEXUS-II totaled 696, 677, and 2,951, respectively. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 112 of 144 (79.2%, 95% CI = 70.8% to 86.0%) and 228 of 552 (41.3%, 95% CI = 37.3% to 45.5%); NOC, 91 of 99 (91.9%, 95% CI = 84.7% to 96.5%) and 125 of 558 (22.4%, 95% CI = 19.0% to 26.1%); and NEXUS-II, 511 of 576 (88.7%, 95% CI = 85.8% to 91.2%) and 1,104 of 2,375 (46.5%, 95% CI = 44.5% to 48.5%). The sensitivity and specificity for neurosurgical intervention were as follows: CCHR, 100% (95% CI = 59.0% to 100.0%) and 38.3% (95% CI = 34.5% to 41.9%); NOC, 100% (95% CI = 54.1% to 100.0%) and 20.4% (95% CI = 17.4% to 23.7%); and NEXUS-II, 95.1% (95% CI = 90.1% to 98.0%) and 41.4% (95% CI = 39.5% to 43.2%). Among the enrolled population, intersection patients of CCHR, NOC, and NEXUS-II totaled 588. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 73 of 98 (74.5%, 95% CI = 64.7% to 82.8%) and 201 of 490 (41.0%, 95% CI = 36.6% to 45.5%); NOC, 89 of 98 (90.8%, 95% CI = 83.3% to 95.7%) and 112 of 490 (22.9%, 95% CI = 19.2% to 26.8%); and NEXUS-II, 82 of 98 (83.7%, 95% CI = 74.8% to 90.4%) and 172 of 490 (35.1%, 95% CI = 30.9% to 39.5%). The potential reduction in emergency CT scans by using these decision rules would have been higher with the NEXUS-II rule (39.6%, 95% CI = 37.8% to 41.4%) than with the CCHR rule (27.0%, 95% CI = 23.7% to 30.3%) or NOC rule (20.2%, 95% CI = 17.2% to 23.3%). CONCLUSIONS For clinically important TBI, the three cranial CT decision rules had much lower sensitivities in this population than the original published studies, while the specificities were comparable to those studies. The sensitivities for neurosurgical intervention, however, were comparable to the original studies. The NEXUS-II rule showed the highest reduction rate for CT scans compared to other rules, but failed to identify all undergoing neurosurgical intervention for their original inclusion cohort.