Chun Song Youn

Catholic University of Korea, Seoul, Seoul, South Korea

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Publications (10)23.51 Total impact

  • Article: The prognostic value of continuous amplitude-integrated electroencephalogram applied immediately after return of spontaneous circulation in therapeutic hypothermia-treated cardiac arrest patients.
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    ABSTRACT: INTRODUCTION: The purpose of this study was to examine the prognostic value of continuous amplitude-integrated electroencephalogram (aEEG) applied immediately after return of spontaneous circulation (ROSC) in therapeutic hypothermia (TH)-treated cardiac arrest patients. METHODS: From September 2010 to August 2011, we prospectively studied comatose patients treated with TH after cardiac arrest who were monitored with aEEG. Monitoring at the forehead was applied as soon as possible after ROSC in the emergency department and continued until recovery of consciousness, death, or 72h after ROSC. Neurological outcome was assessed with the Cerebral Performance Category (CPC) scale at hospital discharge, and good neurological outcome was defined as a CPC score of 1 or 2. RESULTS: A total of 55 TH-treated patients were included. Monitoring started at a median of 96min after ROSC (interquartile range, 49-174). At discharge, 28 patients had a CPC of 1-2, and 27 patients had a CPC of 3-5. Seventeen patients had a continuous normal voltage (CNV) trace at the start of monitoring, and this voltage was strongly associated with a good outcome (16/17 [94.1%]; sensitivity and specificity of 57.1 and 96.3%, respectively). No development of a CNV trace within the recorded period accurately predicted a poor outcome (21/21 [100%]; sensitivity and specificity of 77.8 and 100%, respectively). CONCLUSIONS: An initial CNV trace in aEEG applied to forehead immediately after ROSC is a good early predictor of a good outcome in TH-treated cardiac arrest patients. Conversely, no development of a CNV trace within 72h is an accurate and reliable predictor of a poor outcome with a false-positive rate of 0%.
    Resuscitation 09/2012; · 3.60 Impact Factor
  • Article: Serum highly selective C-reactive protein concentration is associated with the volume of ischemic tissue in acute ischemic stroke.
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    ABSTRACT: There is growing evidence that inflammation plays an important role in atherogenesis. Previous studies have shown that the concentration of peripheral inflammatory markers, particularly C-reactive protein (CRP), strongly correlates with stroke severity and independently predicts mortality and recurrent vascular events in patients with acute ischemic stroke. The aim of this study was to clarify the relationship between inflammatory markers and stroke severity by means of volumetric measurement of infarct size. From March 1, 2008, to February 28, 2009, 96 patients who had laboratory investigations and magnetic resonance imaging scans were included retrospectively in this study. Diffusion-weighted imaging (DWI) lesions were outlined using a semiautomatic threshold technique. Diffusion-weighted imaging lesion volumes were measured with MIPAV software (Medical Image Processing, Analysis and Visualization, version 4.1.1; National Institutes of Health, Bethesda, MD). The relationship between highly selective CRP (hs-CRP) levels and DWI infarct volume quartiles was examined. The mean age of patients was 66.9 years, and 50 patients (51.2%) were male. There was a significant correlation between hs-CRP and DWI volumes (Spearman ρ = 0.239, P = .010). The median hs-CRP values for successive volumes of DWI lesion quartiles (lowest to highest quartile) were as follows: 1.17, 1.14, 1.63, and 3.76 (P = .029). Higher hs-CRP levels were associated with larger infarct volumes in patients with acute ischemic stroke. These results suggest that elevated hs-CRP levels, reflecting a large volume of infarct, may serve as a helpful serologic marker in the evaluation of severity of acute ischemic stroke.
    The American journal of emergency medicine 01/2012; 30(1):124-8. · 1.54 Impact Factor
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    Article: The validity of the Canadian Triage and Acuity Scale in predicting resource utilization and the need for immediate life-saving interventions in elderly emergency department patients.
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    ABSTRACT: We evaluated the validity of the Canadian Triage and Acuity Scale (CTAS) in elderly emergency department (ED) patients. In particular, we examined the sensitivity and specificity of the CTAS for identifying elderly patients who received an immediate life-saving intervention in the ED. We reviewed the medical records of consecutive patients who were 65 years of age or older and presented to a single academic ED within a three-month period. The CTAS triage scores were compared to actual patient course, including disposition, discharge outcome and resource utilization. We calculated the sensitivity and specificity of the CTAS triage for identifying patients who received an immediate intervention. Of the 1903 consecutive patients who were ≥ 65 years of age, 113 (5.9%) had a CTAS level of 1, 174 (9.1%) had a CTAS level of 2, 1154 (60.6%) had a CTAS level of 3, 347 (18.2%) had a CTAS level of 4, and 115 (6.0%) had a CTAS level of 5. As a patient's triage score increased, the severity (such as mortality and intensive care unit admission) and resource utilization increased significantly. Ninety-four of the patients received a life-saving intervention within an hour following their arrival to the ED. The CTAS scores for these patients were 1, 2 and 3 for 46, 46 and 2 patients, respectively. The sensitivity and specificity of a CTAS score of ≤ 2 for identifying patients for receiving an immediate intervention were 97.9% and 89.2%, respectively. The CTAS is a triage tool with high validity for elderly patients, and it is an especially useful tool for categorizing severity and for recognizing elderly patients who require immediate life-saving intervention.
    Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 11/2011; 19:68. · 1.85 Impact Factor
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    Article: Effects of a radiation dose reduction strategy for computed tomography in severely injured trauma patients in the emergency department: an observational study.
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    ABSTRACT: Severely injured trauma patients are exposed to clinically significant radiation doses from computed tomography (CT) imaging in the emergency department. Moreover, this radiation exposure is associated with an increased risk of cancer. The purpose of this study was to determine some effects of a radiation dose reduction strategy for CT in severely injured trauma patients in the emergency department. We implemented the radiation dose reduction strategy in May 2009. A prospective observational study design was used to collect data from patients who met the inclusion criteria during this one year study (intervention group) from May 2009 to April 2010. The prospective data were compared with data collected retrospectively for one year prior to the implementation of the radiation dose reduction strategy (control group). By comparison of the cumulative effective dose and the number of CT examinations in the two groups, we evaluated effects of a radiation dose reduction strategy. All the patients met the institutional adult trauma team activation criteria. The radiation doses calculated by the CT scanner were converted to effective doses by multiplication by a conversion coefficient. A total of 118 patients were included in this study. Among them, 33 were admitted before May 2009 (control group), and 85 were admitted after May 2009 (intervention group). There were no significant differences between the two groups regarding baseline characteristics, such as injury severity and mortality. Additionally, there was no difference between the two groups in the mean number of total CT examinations per patient (4.8 vs. 4.5, respectively; p = 0.227). However, the mean effective dose of the total CT examinations per patient significantly decreased from 78.71 mSv to 29.50 mSv (p < 0.001). The radiation dose reduction strategy for CT in severely injured trauma patients effectively decreased the cumulative effective dose of the total CT examinations in the emergency department. But not effectively decreased the number of CT examinations.
    Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 11/2011; 19:67. · 1.85 Impact Factor
  • Article: The associative factors of delayed-onset rhabdomyolysis in patients with doxylamine overdose.
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    ABSTRACT: The aim of this study was to investigate the associative factors of rhabdomyolysis in patients with doxylamine overdose who had normal creatine phosphokinase levels at admission. This study included 169 patients who visited the emergency department of a tertiary teaching hospital after doxylamine overdose between January 1, 1998, and March 31, 2009. Demographic information, clinical variables, and laboratory data were investigated for the associative factors of rhabdomyolysis. Thirty-five (21%) of the 169 patients developed rhabdomyolysis. Patients who developed rhabdomyolysis differed from those who did not in the amount of doxylamine ingested, sex, heart rate, initial value of serum creatinine, and alanine aminotransferase. In the multivariate regression analysis, the only reliable predictors of rhabdomyolysis were the amount of doxylamine ingested (P = .004) and heart rate (P < .001). Observation and laboratory follow-up are required for patients with large reported ingestions or tachycardia on admission, even if their creatine phosphokinase levels were normal.
    The American journal of emergency medicine 10/2011; 29(8):903-7. · 1.54 Impact Factor
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    Article: The appropriateness of single page of activation of the cardiac catheterization laboratory by emergency physician for patients with suspected ST-segment elevation myocardial infarction: a cohort study.
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    ABSTRACT: The early use of reperfusion therapy has a significant effect on the prognosis of patients with ST-segment elevation myocardial infarction (STEMI), and it is recommended that emergency department (ED) physicians activate the cardiac catheterization laboratory (CCL) as soon as possible to treat these patients. The aim of this study was to examine the appropriateness of emergency physician activation of the CCL for patients with suspected STEMI. Inappropriate activations (i.e., false positive activations) were identified according to a variety of criteria. All patients with emergency physician CCL activations between August 2009 and April 2011 were included in the study. False positive cases were defined according to ECG criteria and cardiologists' reviews of patients' initial clinical information. ED physicians used a STEMI page to activate the CCL 117 times. According to reviews by cardiologists, this activation was appropriate 89.8% of the time (in 105/117 cases). Truly unnecessary activation (i.e., cases in which STEMI was not identified by the cardiologists, no clear culprit coronary artery was present, no significant coronary artery disease and cardiac biomarkers were negative) occurred 5.1% of the time (in 6/117 cases). CCL activation was appropriate for most patients and was unnecessary in a relatively small percentage of cases. This result supports the current recommendation for CCL activation by emergency physicians. Such early activation is a key strategy in the reduction of door-to-balloon time.
    Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 09/2011; 19:50. · 1.85 Impact Factor
  • Article: Outcome analysis of cardiac arrest due to hanging injury.
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    ABSTRACT: The aim of this study was to review patient characteristics and analyze the outcomes in patients who have had cardiac arrest from hanging injuries. A retrospective review was performed that examined the victims of out-of-hospital cardiac arrest (OHCA) due to hanging who presented to a tertiary general hospital from January 2000 to December 2009. Utstein style variables were evaluated, and patient outcomes were assessed at the time of hospital discharge using the cerebral performance category (CPC) scale. Fifty-two patients with OHCA due to hanging were enrolled in this study from the aforementioned 10-year inclusion period. Resuscitation attempts were performed in 31 patients (60%), and 21 patients were pronounced dead. In all cases, the first monitored cardiac rhythms were either asystole or pulseless electrical activity (PEA) and were therefore nonshockable rhythms. Of the patients for whom resuscitation was attempted, 13 (42%) experienced a return of spontaneous circulation and 1 revealed cervical spine fracture. Of the 13 return-of-spontaneous-circulation patients, 5 survived to be discharged. The mean age of these 5 surviving patients was 36 years. All 5 patients were graded as cerebral performance category 4 at discharge. The first monitored cardiac rhythms of patients presenting with OHCA due to hanging were nonshockable rhythms wherein the survival rate of these patients was 9.6%. All of the survivors were relatively young and demonstrated poor neurologic outcomes at discharge. Physicians must consider cervical spine fracture in patients who had cardiac arrest from hanging.
    The American journal of emergency medicine 06/2011; 30(5):690-4. · 1.54 Impact Factor
  • Article: Implication of cardiac marker elevation in patients who resuscitated from out-of-hospital cardiac arrest.
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    ABSTRACT: It is often difficult to diagnose acute myocardial infarction (AMI) in patients who resuscitated after out-of-hospital cardiac arrest (OHCA) and had a delayed elevation in cardiac marker. This study explored whether elevations in cardiac marker were due to coronary artery occlusion or resulted from other causes. The study included 19 non-ST-segment elevation patients who resuscitated after OHCA and underwent delayed coronary angiography. We checked patients' serial creatine kinase-myocardial band (CK-MB) and troponin I (cTnI) levels on arrival and 6, 12, 24, 48, 72, and 96 hours postarrest. Based on the association of elevated cTnI and the results of their delayed angiographies, the patients were retrospectively divided into 2 groups: an AMI group (n=5) and a non-AMI group (n=14). We then analyzed the serial cardiac marker measurements in each group. Peak marker levels were significantly higher in the AMI group than in the non-AMI group (CK-MB, 177.0±112.7 vs 66.4±85.2 ng/mL; P=.033 and cTnI, 40.4±14.5 vs 10.6±13.5 ng/mL; P=.005). After adjusting for covariates, the peak and 6-, 12-, and 24-hour cTnI and 6-hour CK-MB were significantly different between the 2 groups (P=.005, P=.004, P=.005, P=.020, and P=.007). In the non-AMI group, 3 patients had cTnI values that were within the reference range at all of the evaluated times. Most patients had only low cTnI elevations that rapidly fell back to normal. The resuscitation of patients who experience sudden OHCA but do not have an AMI may lead to elevations of cardiac markers. However, these elevations are low and normalize early.
    The American journal of emergency medicine 02/2011; 30(3):464-71. · 1.54 Impact Factor
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    Article: Diffusion-weighted magnetic resonance imaging for predicting the clinical outcome of comatose survivors after cardiac arrest: a cohort study.
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    ABSTRACT: The aim of this study was to examine whether the patterns of diffusion-weighted imaging (DWI) abnormalities and quantitative regional apparent diffusion coefficient (ADC) values can predict the clinical outcome of comatose patients following cardiac arrest. Thirty-nine patients resuscitated from out-of-hospital cardiac arrest were prospectively investigated. Within five days of resuscitation, axial DWIs were obtained and ADC maps were generated using two 1.5-T magnetic resonance scanners. The neurological outcomes of the patients were assessed using the Glasgow Outcome Scale (GOS) score at three months after the cardiac arrest. The brain injuries were categorised into four patterns: normal, isolated cortical injury, isolated deep grey nuclei injury, and mixed injuries (cortex and deep grey nuclei). Twenty-three subjects with normal DWIs served as controls. The ADC and percent ADC values (the ADC percentage as compared to the control data from the corresponding region) were obtained in various regions of the brains. We analysed the differences between the favourable (GOS score 4 to 5) and unfavourable (GOS score 1 to 3) groups with regard to clinical data, the DWI abnormalities, and the ADC and percent ADC values. The restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups. The cortical pattern of injury was seen in one patient (3%), the deep grey nuclei pattern in three patients (8%), the cortex and deep grey nuclei pattern in 21 patients (54%), and normal DWI findings in 14 patients (36%). The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001). In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group. The optimal cutoffs for the mean ADC and the percent ADC values determined by receiver operating characteristic (ROC) curve analysis in the cortex, caudate nucleus, putamen, and thalamus predicted the unfavourable outcome with sensitivities of 67 to 93% and a specificity of 100%. The patterns of brain injury in early diffusion-weighted imaging (DWI) (less than or equal to five days after resuscitation) and the quantitative measurement of regional ADC may be useful for predicting the clinical outcome of comatose patients after cardiac arrest.
    Critical care (London, England) 02/2010; 14(1):R17. · 4.61 Impact Factor
  • Article: Out-of-hospital cardiac arrest due to drowning: An Utstein Style report of 10 years of experience from St. Mary's Hospital.
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    ABSTRACT: Drowning is a unique form of cardiac arrest and is often preventable. "Utstein Style for Drowning" was published in 2003 by the International Liaison Committee on Resuscitation (ILCOR) to improve the knowledge-base, to provide epidemiological stratification, to recommend appropriate treatments and to ultimately save lives. We report on the largest single-center study of the Utstein Style resuscitation for drowning. All patients with out-of-hospital cardiac arrest (OHCA) due to drowning admitted to St. Mary's Hospital between 1998 and 2007 were included. Utstein Style variables and other time intervals not included in the Utstein Style guidelines were evaluated for their ability to predict survival. The primary end point of this study was survival to discharge. We enrolled 131 patients with OHCA due to drowning; 21 patients (16.03%) had survival to discharge and 9 patients (6.87%) were discharged with a good neurologic outcome, i.e., cerebral performance categories (CPC) of 1 or 2. For the Utstein Style variables witnessed, the duration of submersion and the time of first emergency medical systems (EMS) resuscitation attempt influenced survival. For other time intervals, the transportation time (i.e., time interval from witnessing of the drowning to EMS arrival at the hospital, or if events were not witnessed, the time interval from calling the EMS to EMS arrival at the hospital), the duration of advanced cardiovascular life support (ACLS) and the duration of total arrest time were associated with survival. Our report is the largest single-center study of OHCA due to drowning reported according to the guidelines of the Utstein Style. Being witnessed, having a short duration of submersion, having early resuscitation by EMS, and rapid transportation are important for survival after drowning.
    Resuscitation 06/2009; 80(7):778-83. · 3.60 Impact Factor