Yu Jin Lee

Effect of Dispatcher-Assisted Cardiopulmonary Resuscitation Program and Location of Out-of-Hospital Cardiac Arrest on Survival and Neurologic Outcome

Study objective: We study the effect of a nationwide dispatcher‐assisted cardiopulmonary resuscitation (CPR) program on out‐of‐hospital cardiac arrest outcomes by arrest location (public and private settings). Methods: All emergency medical services (EMS)–treated adults in Korea with out‐of‐hospital cardiac arrests of cardiac cause were enrolled between 2012 and 2013, excluding cases witnessed by EMS providers and those with unknown outcomes. Exposure was bystander CPR categorized into 3 groups: bystander CPR with dispatcher assistance, bystander CPR without dispatcher assistance, and no bystander CPR. The endpoint was good neurologic recovery at discharge. Multivariable logistic regression analysis was performed. The final model with an interaction term was evaluated to compare the effects across settings. Results: A total of 37,924 patients (31.1% bystander CPR with dispatcher assistance, 14.3% bystander CPR without dispatcher assistance, and 54.6% no bystander CPR) were included in the final analysis. The total bystander CPR rate increased from 30.9% in quarter 1 (2012) to 55.7% in quarter 4 (2014). Bystander CPR with and without dispatcher assistance was more likely to result in higher survival with good neurologic recovery (4.8% and 5.2%, respectively) compared with no bystander CPR (2.1%). The adjusted odds ratios for good neurologic recovery were 1.50 (95% confidence interval [CI] 1.30 to 1.74) in bystander CPR with dispatcher assistance and 1.34 (95% CI 1.12 to 1.60) in bystander CPR without it compared with no bystander CPR. For arrests in private settings, the adjusted odds ratios were 1.58 (95% CI 1.30 to 1.92) in bystander CPR with dispatcher assistance and 1.28 (95% CI 0.98 to 1.67) in bystander CPR without it; in public settings, the adjusted odds ratios were 1.41 (95% CI 1.14 to 1.75) and 1.37 (95% CI 1.08 to 1.72), respectively. Conclusion: Bystander CPR regardless of dispatcher assistance was associated with improved neurologic recovery after out‐of‐hospital cardiac arrest. However, for out‐of‐hospital cardiac arrest cases in private settings, bystander CPR was associated with improved neurologic recovery only when dispatcher assistance was provided.

Interaction effects between hypothermia and diabetes mellitus on survival outcomes after out-of-hospital cardiac arrest

OBJECTIVES Mild therapeutic hypothermia (MTH) is the core hospital intervention to enhance neurological outcome after out-of-hospital cardiac arrest (OHCA). Diabetes mellitus (DM) has been known to be a harmful risk factor on survival after OHCA. This study aimed to investigate whether the effect of MTH on brain recovery after OHCA differed between patients with or without DM. METHODS We used a Korean national OHCA database composed of hospital and ambulance data. We included adult OHCA patients who survived to admission with presumed cardiac etiology during the study period from 2009 to 2013. We excluded cases without hospital outcome data. The primary exposure was MTH, which included all kinds of cooling methods that had been initiated within 6h after return of spontaneous circulation. DM was coded positive when the patient had a clinical history diagnosed by a physician before an OHCA event. The endpoints were discharge with good neurological recovery (cerebral performance category 1 or 2) and survival to discharge. We compared outcomes between MTH vs. non-MTH groups using multivariable logistic regression with an interaction term between MTH and DM for calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs) after adjusting for potential confounders. RESULTS Among 9735 patients following OHCA survived to hospital admission with cardiac etiology, MTH was performed in 16.5%. History of DM was observed in 25.4% among MTH group and 27.4% in non-MTH group (p=0.09). MTH group showed better outcomes than non-MTH group; 23.6% vs. 15.7% for good neurological recovery (p<0.01). AOR (95% CI) of MTH for good neurological recovery for all study groups was 1.23 (1.03-1.47). In the interaction model, AOR (95% CI) of MTH for good neurological recovery was 1.40 (1.16-1.70) in patients without DM vs. 0.69 (0.46-1.04) in patients with DM. For survival to discharge, the effects of MTH were different in patients without DM (1.97 (1.70-2.29)) and patients with DM (1.23 (0.96-1.57)). CONCLUSION DM modified the effect of MTH on survival and neurological outcomes for OHCA survivors. MTH is significantly associated with good neurological recovery in patients without DM, but not in patients with DM.

Analysis of the appropriate age and weight for pediatric patient sedation for magnetic resonance imaging.

Sedatives with a long duration are required for pediatric magnetic resonance imaging (MRI) in the emergency department. The success rate of chloral hydrate for pediatric sedation is 80% to 100% according to some studies. However, the success rate varies by age, weight, and underlying disease. To identify factors affecting the success rate, we compared the chloral hydrate sedation success rate and adverse event rate by age, weight, and underlying disease. Compared with patients in the failure group, patients in the successful group were younger (23.8 vs 36.9 months, P < .01) and weighed less (11.4 vs 14.4 kg, P < .01). No differences in neurological problems, reasons for MRI, or adverse events were observed between the 2 groups. Patients 18 months old had a success rate greater than 95%, but the success rate decreased in children older than 18 months. The adverse event rate was about 10% in patients 18 months old and increased to 20% in patients older than 36 months. Patients 24 months of age who had a neurological problem (seizure disorder or developmental delay) had a success rate greater than 95%, but the adverse event rate increased after 24 months of age. Chloral hydrate sedation was appropriate for pediatric MRI in patients younger than 18 months. Although we observed no fatal adverse events, it is necessary to monitor patients until full recovery from sedation.

The effect of mild therapeutic hypothermia on good neurological recovery after out-of-hospital cardiac arrest according to location of return of spontaneous circulation: A nationwide observational study

BACKGROUND Mild therapeutic hypothermia (MTH) has been known to be associated with good neurological recovery after out-of-hospital cardiac arrest (OHCA). Prehospital return of spontaneous circulation (P-ROSC) is associated with better hospital outcomes than ROSC at emergency department (ED-ROSC). The study aims to examine the association between MTH by location of ROSC and good neurological recovery after OHCA. METHODS Adult OHCA cases with presumed cardiac etiology who survived to hospital admission were collected from a nationwide cardiac registry between 2008 and 2013. MTH was defined as a case receiving hypothermia procedure regardless of procedure method. Primary outcome was good neurological recovery with cerebral performance category score of 1 and 2. Multivariable logistic regression analysis was performed adjusting for potential confounders with an interaction term between MTH and location of ROSC to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs). RESULTS Among 11,158 patients survived to admission, good neurological recovery was 23.6% (399/1691) in MTH vs. 15.0% (1400/9316) in non-MTH (p<0.001), and 58.2% (1074/1864) in P-ROSC vs. 7.9% (725/9161) in ED-ROSC (p<0.001). There was a significant association between MTH and good neurological recovery (AOR=1.32, 95% CI=1.11-1.57). In the interaction model, AOR of MTH and interaction effect with P-ROSC and ED-ROSC was 0.78 (0.58-2.70) and 1.68 (1.34-1.98), respectively. CONCLUSION MTH was significantly associated with good neurological recovery among OHCA survivors. In the interaction model, MTH showed significant benefits in patient group with ROSC at ED, not in P-ROSC group.

Effect of Emergency Medical Service Use and Inter-hospital Transfer on Time to Percutaneous Coronary Intervention in Patients with ST Elevation Myocardial Infarction: A Multicenter Observational Study

Abstract Background: The 2013 ACCF/AHA guideline for the management of ST elevation myocardial infarction (STEMI) recommends that patients be transported by emergency medical services (EMS) directly to a percutaneous coronary intervention (PCI)-capable hospital. We examined the effects of EMS use according to inter-hospital transfer on time to PCI in STEMI patients. Methods: Adult patients diagnosed with STEMI from November 2007 to December 2012 with symptom onset less than 24 hours treated with primary PCI at 29 emergency departments (ED) were included. Patients with unknown information about important time variables, inter-hospital transfer and EMS use, and patients who already received PCI at another hospital were excluded. Patients were divided into groups according to EMS use and inter-hospital transfer: Group A (direct to final ED by EMS), Group B (transferred to final ED after EMS transport), Group C (direct to final ED not by EMS), and Group D (transferred to final ED after non-EMS transport). Symptom to balloon time less than 120 minutes was considered timely PCI. Multivariable logistic regression model adjusting for potential risk factors examined the relationship between the groups and timely PCI. Interactions between EMS use and inter-hospital transfer were also tested for the outcome. Results: A total of 5826 patients were analyzed in this study, of which 28.3% called for EMS and 50% were transferred to another hospital for PCI. Median symptom to balloon time was 216 minutes. Timely PCI was achieved in 20.3% of the patients. With the Group D as the reference, the adjusted odds ratio (AOR) with 95% confidence intervals (95% CI) for timely PCI was 5.78 (4.81–6.95) for Group A, 0.80 (0.53–1.20) for Group B, and 2.87 (2.39–3.44) for Group C. In the interaction model, the AOR (95% CI) of EMS use in nontransferred groups and transferred groups was 2.01(1.71–2.38) and 0.80(0.53–1.20). Conclusions: EMS use significantly increased the odds of timely primary PCI to patients directly transported to a primary PCI center, but not in patients transferred from another hospital. EMS systems that identify STEMI patients and transport them to PCI capable hospitals, and processes to expedite the transfer of patients between non-PCI and PCI hospitals need to be developed further.

Emergency Department Overcrowding and Ambulance Turnaround Time

Objective The aims of this study were to describe overcrowding in regional emergency departments in Seoul, Korea and evaluate the effect of crowdedness on ambulance turnaround time. Methods This study was conducted between January 2010 and December 2010. Patients who were transported by 119-responding ambulances to 28 emergency centers within Seoul were eligible for enrollment. Overcrowding was defined as the average occupancy rate, which was equal to the average number of patients staying in an emergency department (ED) for 4 hours divided by the number of beds in the ED. After selecting groups for final analysis, multi-level regression modeling (MLM) was performed with random-effects for EDs, to evaluate associations between occupancy rate and turnaround time. Results Between January 2010 and December 2010, 163,659 patients transported to 28 EDs were enrolled. The median occupancy rate was 0.42 (range: 0.10-1.94; interquartile range (IQR): 0.20-0.76). Overcrowded EDs were more likely to have older patients, those with normal mentality, and non-trauma patients. Overcrowded EDs were more likely to have longer turnaround intervals and traveling distances. The MLM analysis showed that an increase of 1% in occupancy rate was associated with 0.02-minute decrease in turnaround interval (95% CI: 0.01 to 0.03). In subgroup analyses limited to EDs with occupancy rates over 100%, we also observed a 0.03 minute decrease in turnaround interval per 1% increase in occupancy rate (95% CI: 0.01 to 0.05). Conclusions In this study, we found wide variation in emergency department crowding in a metropolitan Korean city. Our data indicate that ED overcrowding is negatively associated with turnaround interval with very small practical significance.

Risk of Diabetes Mellitus on Incidence of Out-of-Hospital Cardiac Arrests: A Case-Control Study

Background This study aimed to determine the risk of diabetes mellitus (DM) on incidence of out-of-hospital cardiac arrest (OHCA) and to investigate whether difference in effects of DM between therapeutic methods was observed. Methods This study was a case-control study using the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES) project database and 2013 Korean Community Health Survey (CHS). Cases were defined as EMS-treated adult (18 year old and older) OHCA patients with presumed cardiac etiology collected at 27 emergency departments from January to December 2014. OHCA patients whose arrest occurred at nursing homes or clinics and cases with unknown information on DM were excluded. Four controls were matched to one case with strata including age, gender, and county from the Korean CHS database. Multivariable conditional logistic regression analysis was conducted to estimate the risk of DM and treatment modality on incidence of OHCA. Results Total 1,386 OHCA patients and 5,544 community-based controls were analyzed. A total of 370 (26.7%) among cases and 860 (15.5%) among controls were diagnosed with DM. DM was associated with increasing risk of OHCA (AOR: 1.92 (1.65–2.24)). By DM treatment modality comparing with non-DM group, AOR (95% CI) was the highest in non-pharmacotherapy only group (4.65 (2.00–10.84)), followed by no treatment group (4.17 (2.91–5.96)), insulin group (2.69 (1.82–3.96)), and oral hypoglycemic agent group (1.55 (1.31–1.85)). Conclusion DM increased the risk of OHCA, which was the highest in the non-pharmacotherapy group and decreased in magnitude with pharmacotherapy.

Neurological prognostication by gender in out-of-hospital cardiac arrest patients receiving hypothermia treatment

OBJECTIVES This study examined whether the extent to which out-of-hospital cardiac arrest (OHCA) patients recover neurological function after therapeutic hypothermia (TH) is augmented in specific gender, age, and primary ECG group. METHODS A cross-sectional analysis was conducted using a nationwide database of OHCAs in Korea which was constructed from emergency medical services (EMS) run sheet and hospital medical record review between 2008 and 2012. Patients survived to admission were enrolled. Study endpoint was survival with neurological recovery (cerebral performance category 1 and 2). Main exposure was hypothermia. Gender, age group (<45, 45-65, and >65 years old) and primary ECG rhythm were considered as potential effect modifiers. Potential factors were accounted for adjustment using multivariable logistic regression. RESULTS Survival with good neurological recovery was 14.6% (9.3% in men and 17.2% in women). TH was performed in 15.5% (n=1140). Strata-specific crude analysis showed enhanced neurological recovery for women of childbearing ages compared to men counterparts (OR=4.38 (1.39, 13.74) vs. OR=1.73 (0.97, 3.10)). After adjusted for effect modifiers and covariates, the strongest effect of TH on neurological recovery was observed in men younger than 45 years of age with shockable rhythm (OR=2.00 (1.26, 3.19)), whereby no statistically significant associations were found in all women. In both genders, the magnitude of association decreased with age and having non-shockable cardiac rhythm. CONCLUSION TH was the strongest indicator for good neurological recovery in <45-year old men with shockable cardiac rhythm. Across all age groups, women were less likely to benefit from TH than men.

Effect of Emergency Medical Services Use on Hospital Outcomes of Acute Hemorrhagic Stroke

Abstract Background: It is unclear whether the use of emergency medical services (EMS) is associated with enhanced survival and decreased disability after hemorrhagic stroke and whether the effect size of EMS use differs according to the length of stay (LOS) in emergency department (ED). Methods: Adult patients (19 years and older) with acute hemorrhagic stroke who survived to admission at 29 hospitals between 2008 and 2011 were analyzed, excluding those who had symptom-to-ED arrival time of 3 h or greater, received thrombolysis or craniotomy before inter-hospital transfer, or had experienced cardiac arrest, had unknown information about ambulance use and outcomes. Exposure variable was EMS use. Endpoints were survival at discharge and worsened modified Rankin Scale (W-MRS) defined as 3 or greater points difference between pre- and post-event MRS. Adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs) for the outcomes were calculated, including potential confounders (demographic, socioeconomic status, clinical parameter, comorbidity, behavior, and time of event) in the final model and stratifying patients by inter-hospital transfer and by time interval from symptom to ED arrival (S2D). ED LOS, classified into short (<120 min) and long (≥120 min), was added to the final model for testing of the interaction model. Results: A total of 2,095 hemorrhagic strokes were analyzed in which 75.6% were transported by EMS. For outcome measures, 17.4% and 41.4% were dead and had worsened MRS, respectively. AORs (95% CIs) of EMS were 0.67 (0.51–0.89) for death and 0.74 (0.59–0.92) for W-MRS in all patients. The effect size of EMS, however, was different according to LOS in ED. AORs (95% CIs) for death were 0.74 (0.54–1.01) in short LOS and 0.60 (0.44–0.83) in long LOS group. AORs (95% CIs) for W-MRS were 0.76 (0.60–0.97) in short LOS and 0.68 (0.52–0.88) in long LOS group. Conclusions: EMS transport was associated with lower hospital mortality and disability after acute hemorrhagic stroke. Effect size of EMS use for mortality was significant in patients with long ED LOS. Key  words: emergency medical service; hemorrhagic stroke; mortality; disability

The impact of recommended percutaneous coronary intervention care on hospital outcomes for interhospital-transferred STEMI patients

Background: Timely transfer and percutaneous coronary intervention (PCI) with or without thrombolysis are recommended by the American Heart Association (AHA) to care for ST‐segment elevation myocardial infarction (STEMI) patients who present first to a non–PCI‐capable hospital. This study was to evaluate the impact on in‐hospital mortality of the compliance with guidelines regarding to the time of PCI for patients with STEMI who were transferred to a capable PCI hospital. Methods: We used the CArdioVAscular disease Surveillance data from November 2007 to December 2012 for this study. Adult patients who were diagnosed with STEMI and transferred from a primary hospital for PCI were included. Patients who underwent PCI or coronary artery bypass graft surgery in the primary hospital and patients with an unknown emergency department disposition were excluded. The main exposure was the AHA recommendation for reperfusion therapy. We tested the association between compliance with AHA and hospital mortality. Results: A total of 2078 patients were analyzed, 30.0% of whom were treated in compliance with the guidelines, whereas the remaining 70.0% were not. Thrombolysis was performed in 7.9% and 0.8% (P value < .01) and hospital mortality was 5.0% and 6.8% (P value = .11) in the compliant and violence groups, respectively. The adjusted odds ratios (95% confidence intervals) of the compliant group for hospital mortality were 0.75 (0.46‐1.21), respectively. A sensitivity analysis of symptom onset to arrival time was a trend for a beneficial effect in the compliant group. Conclusions: Among the patients who were transferred for STEMI care, undergoing PCI as recommended by the AHA was not associated with a mortality benefit, but the patients whose symptom onset to hospital arrival time was within 30 minutes showed an association between compliance and lower mortality.