Gil Joon Suh

Seoul National University, Seoul, Seoul, South Korea

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Publications (47)111.91 Total impact

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    Jung Chan Lee, Gil Joon Suh, Hee Chan Kim
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    ABSTRACT: Extracorporeal cardiopulmonary resuscitation (ECPR) refers to the application of extracorporeal blood circulation with oxygenation as a resuscitation tool. The objective of this study is to observe the frequency component changes in the electrocardiogram (ECG) by ECPR during prolonged ventricular fibrillation (VF). Six swine were prepared as a VF model. Extracorporeal blood circulation with a pulsatile blood pump and oxygenator was set up for the model. ECG signals were measured for 13 min during VF and analyzed using frequency analysis methods. The median frequency (MF), dominant frequency (DF), and amplitude spectrum area (AMSA) were calculated from a spectrogram obtained using short-time Fourier transform (STFT). MF decreased from 11 Hz at the start to 9 Hz at 2 min after VF and then increased to 11 Hz at 4.5 min after VF. DF started at 7 Hz and increased to 11 Hz within the first min and decreased to 9 Hz at 2 min, then increased to 12 Hz at 4.5 min after VF. Both frequency components decreased gradually from 4.5 min until 10 min after VF. After the oxygenated blood perfusion was initiated, both MF and DF increased remarkably and exceeded 12 and 14 Hz, respectively. Similarly, AMSA decreased gradually for the first 10 min, but increased remarkably and varied beyond 13 mV[bullet operator]Hz after the oxygenated blood supply started. Remarkable frequency increases in ECG due to the oxygenated blood perfusion during ECPR were observed in the swine VF model. The ECG frequency analysis during ECPR can give the resuscitation provider important information about the cardiac perfusion status and the appropriateness of the ECPR setup as well as the prediction of defibrillation success.
    BioMedical Engineering OnLine 11/2013; 12(1):123. · 1.61 Impact Factor
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    ABSTRACT: To investigate whether 48 hours of therapeutic hypothermia is more effective to attenuate brain apoptosis than 24 hours and to determine whether the antiapoptotic effects of therapeutic hypothermia are associated with the suppressions of the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3 in a swine cardiac arrest model. Prospective laboratory study. University laboratory. Male domestic pigs (n = 24). After 6 minutes of no-flow time that was induced by ventricular fibrillation, cardiopulmonary resuscitation was provided, and the return of spontaneous circulation was achieved. The animals were randomly assigned to the following groups: sham, normothermia, 24 hours of therapeutic hypothermia, or 48 hours of therapeutic hypothermia. Therapeutic hypothermia (core temperature, 32-34°C) was maintained for 24 or 48 hours post return of spontaneous circulation, and the animals were rewarmed for 8 hours. At 60 hours post return of spontaneous circulation, the animals were killed, and brain tissues were harvested. We examined cellular apoptosis and neuronal damage in the brain hippocampal cornu ammonis 1 region. We also measured the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3 in the hippocampus. The 48 hours of therapeutic hypothermia attenuated cellular apoptosis and neuronal damage when compared with normothermia. There was also a decrease in the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3. However, 24 hours of therapeutic hypothermia did not significantly attenuate cellular apoptosis or neuronal damage. We found that 48 hours of therapeutic hypothermia was more effective in attenuating brain apoptosis than 24 hours of therapeutic hypothermia. We also found that the antiapoptotic effects of therapeutic hypothermia were associated with the suppressions of the cleavage of protein kinase C-δ, the cytosolic release of cytochrome c, and the cleavage of caspase 3.
    Critical care medicine 10/2013; · 6.37 Impact Factor
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    ABSTRACT: OBJECTIVES:: To determine whether niacin attenuates brain injury and improves neurological outcome after cardiac arrest in rats and if its therapeutic benefits are associated with suppression of the mitogen-activated protein kinase pathway. DESIGN:: Prospective laboratory study. SETTING:: University laboratory. SUBJECTS:: Male Sprague-Dawley rats (n = 77). INTERVENTIONS:: After 6 minutes of no flow time induced by ventricular fibrillation, cardiopulmonary resuscitation was provided and return of spontaneous circulation was achieved. Animals were then administered vehicle, single low dose (360 mg/kg; at 1 hr postreturn of spontaneous circulation), single high dose (1080 mg/kg; at 1 hr), or repeated low dose of niacin (360 mg/kg/d for 3 d; at 1, 24, and 48 hr) through an orogastric tube. MEASUREMENTS AND MAIN RESULTS:: Neurologic deficit scales were scored at 24 hours, 72 hours, and 7 days postreturn of spontaneous circulation. Single high dose of niacin improved neurologic deficit scales at 48 hours and 7 days, and repeated low dose of niacin improved neurologic deficit scales at 7 days. Then, a separate set of animals were killed at 72 hours postreturn of spontaneous circulation, and brain tissues were harvested. Single high dose and repeated low dose of niacin attenuated cellular apoptosis and neuronal damage in hippocampal cornu ammonis 1 and decreased axonal injury and microglial activation in corpus callosum. They increased nicotinamide adenine dinucleotide, reduced nicotinamide adenine dinucleotide phosphate and reduced glutathione levels, and decreased malondialdehyde level in brain tissues. Furthermore, they suppressed the phosphorylations of p38 and c-Jun N-terminal kinase/stress-activated protein kinase and the cleavage of caspase 3. However, they failed to enhance extracellular signal-regulated kinases 1/2 phosphorylation. CONCLUSIONS:: Single high dose and repeated low dose of niacin attenuated brain injury and improved neurological outcome after cardiac arrest in rats. Their therapeutic benefits were associated with suppressions of the phosphorylations of p38 and c-Jun N-terminal kinase/stress-activated protein kinase and the cleavage of caspase 3.
    Critical care medicine 05/2013; · 6.37 Impact Factor
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    ABSTRACT: OBJECTIVES: The aim of this study is to investigate whether glutamine (GLN) enhances heat shock protein-25 (Hsp-25) and heat shock protein-72 (Hsp-72) expressions and attenuates cerebral ischaemic injury in rat cardiac arrest model. METHODS: Rats survived from cardiac arrest model were randomly assigned to CPR+GLN group (0.75g/kg of alanyl-glutamine, n=6) or CPR group (same volume of 0.9% saline, n=6). Additional 6 rats were used for SHAM group. For the outcome measures, neurologic deficit score (NDS, 0-80) was checked at 24-hr and 72-hr after cardiac arrest. At 72-hr after cardiac arrest, rats were euthanized and the brain was harvested. Then, right hemisphere was used for cresyl-violet and TUNEL staining. Left hemisphere was used for Western blot analysis of phosphorylated heat shock factor-1 (p-HSF-1), Hsp-25, Hsp-72, and cleaved caspase-3. Kruskal-Wallis test and Mann-Whitney U post-hoc test with Bonferroni correction were used for the analysis. RESULTS: Resuscitation variables were not different between CPR and CPR+GLN. NDS in CPR+GLN was higher than that in CPR (p <0.017) and lower than that in SHAM (p <0.017) at both 24-hr and 72-hr. P-HSF-1, Hsp-25 and Hsp-72 expressions in CPR+GLN were significantly enhanced (p <0.017) than those in other groups. Cleaved caspase-3 expression in CPR was significantly higher (p <0.017) than in SHAM and CPR+GLN. Inschaemic and TUNEL-positive neurons were more frequently observed in CPR than in CPR+GLN. CONCLUSIONS: Glutamine attenuates cerebral ischaemic injury in cardiac arrest model of rats and this is associated with the enhancement of Hsp-25 and Hsp-72 expressions.
    Resuscitation 03/2013; · 4.10 Impact Factor
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    ABSTRACT: 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 to 500,000 residents), and rural areas (less than 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=4,172). 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.
    Resuscitation 01/2013; · 4.10 Impact Factor
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    ABSTRACT: AIM OF STUDY: The effects of therapeutic hypothermia (HT) during experimental sepsis may be influenced by disease severity. We experimentally investigated the effect of therapeutic HT on varying disease severity in a septic rat model. MATERIALS AND METHODS: An adult male Sprague-Dawley rat model of intra-abdominal sepsis was used. To modify the disease severity, we used two different models; a moderate severe sepsis model (MSSM) and a severe septic shock model (SSSM). All rats were randomized to a hypothermia group (HT, 30-32°C) or a normothermia group (NT, 36-38°C) 1h after sepsis induction in each model. HT was maintained for 4h and rewarming was conducted for 2h. Survival time was recorded for up to 12h in the SSSM group and 24h in the MSSM group. Acute lung and liver injury, cytokine, and malondialdehyde (MDA) levels were investigated 7h after sepsis induction. Hemodynamic profiles were also evaluated. RESULTS: In the SSSM, there were survival benefits and reduced acute lung and liver injury with therapeutic HT. Therapeutic HT was also associated with significantly reduced levels of plasma interleukin-6 and tissue malondialdehyde (MDA) levels in the liver and lung compared with the NT group in the SSSM. There was a tendency for the mean arterial pressure to be higher in the HT group compared to the NT group in the SSSM. In MSSM, however, there was no such beneficial effect. CONCLUSION: In this rat model of severe septic shock, therapeutic HT showed beneficial effects. In contrast, therapeutic HT did not show protective effect in the moderate sepsis model.
    Cytokine 09/2012; · 2.52 Impact Factor
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    ABSTRACT: Paraquat (PQ) causes lethal intoxication by inducing oxidant injury to the lung. Selenium is a cofactor for glutathione peroxidase (GPx), which is one of the major endogenous antioxidant enzymes. To determine whether selenium post-treatment activates GPx, decreases lung injury, and improves survival in PQ intoxicated rats. Male Spraque-Dawley rats were categorized into three groups: sham (n = 6), PQ (n = 12), and PQ + Se (n = 12). In the PQ and PQ + Se groups, 50 mg/kg of PQ was administered intraperitoneally. After 10 minutes, 60 μg/kg of Se (PQ + Se) or saline (PQ) was administered via the tail vein. Six rats per group were euthanized 6 hours or 24 hours later. Lung tissues were harvested for the measurement of GPx activity, reduced glutathione (GSH), glutathione disulfide (GSSG) and malondialdehyde (MDA) and for histological analysis. Using separated set of rats, survival of PQ (n = 10) and PQ + Se (n = 10) were observed for 72 hours. GPx activity in the PQ group at the 6-hour and 24-hour time points was lower than in the sham group (p < 0.006). GPx activity in the PQ + Se group at the 6-hour and 24-hour time points was higher than in the PQ group at the same time (p < 0.006). GPx activity in the PQ + Se group at 24 hours was higher than at 6-hour time point and also higher than in the sham group (p < 0.006). The GSH/GSSG ratio in the PQ + Se group at 24 hours was lower than that in the sham group (p < 0.006). MDA levels in the PQ group at 6 hours and 24 hours were higher than in the sham group (p < 0.006). MDA levels at 24 hours in the PQ + Se group was lower than in the PQ group (p < 0.006). Acute lung injury (ALI) scores in the PQ group at 6 hours and 24 hours were higher than in the sham group (p < 0.006). ALI scores at 24 hours in the PQ + Se group were lower than in the PQ group. Survival rates did not differ between PQ and PQ + Se (p = 0.869). Single dose of selenium post-treatment activates GPx and attenuates lipid peroxidation and lung injury early after paraquat intoxication, but does not improve 72 hours of survival.
    Clinical Toxicology 09/2012; 50(8):749-53. · 2.59 Impact Factor
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    ABSTRACT: 4F, apolipoprotein AI mimetic peptide, mimics anti-inflammatory properties of high-density lipoprotein (HDL). The aim of this study was to investigate whether 4F attenuates acute lung injury and improves survival in endotoxemic rats and to determine whether the therapeutic benefits of 4F are associated with the stimulation of sphingosine-1-phosphate receptor 1 (S1P1), the activation of Akt, the down-regulation of the nuclear factor-κB (NF-κB) pathway, and the suppression of cell adhesion molecules. To induce endotoxemia in rats, lipopolysaccharide (LPS, 10 mg/kg) was injected into a tail vein and 10 minutes later, vehicle or 4F (10 mg/kg) was administered intraperitoneally, respectively. We observed the survival of subjects for 72 hours. At 6-hour post-LPS, we killed animals and measured S1P1 expression, phosphorylated Akt/Akt ratio, cytoplasmic phosphorylated inhibitor κB-α/inhibitor κB-α ratio, nuclear NF-κB p65 expression and DNA-binding activity, endothelial leukocyte adhesion molecule-1 (E-selectin) and intercellular adhesion molecule-1 expression, myeloperoxidase activity, and histologic damages in lung tissues. We also measured serum HDL cholesterol level. 4F improved survival in endotoxemic rats. 4F restored LPS-induced diminution of serum HDL cholesterol level and increased lung S1P1 expression and phosphorylated Akt/Akt ratio in LPS-treated rats. Furthermore, 4F suppressed inhibitor κB-α degradation, NF-κB activation, E-selectin and intercellular adhesion molecule-1 expression, and myeloperoxidase activity, and attenuated histologic damages in lung tissues. 4F attenuated acute lung injury and improved survival in endotoxemic rats. The therapeutic benefits of 4F were found to be associated with the stimulation of S1P1, the activation of Akt, the down-regulation of the NF-κB pathway, and the suppression of cell adhesion molecules.
    The journal of trauma and acute care surgery. 06/2012; 72(6):1576-83.
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    ABSTRACT: AIM OF THE STUDY: N-acetylcysteine (NAC) has been investigated to attenuate organ injury in various experimental and clinical studies. However, results in hemorrhagic shock (HS) were controversial. We determined the effects of continuous administration of NAC on acute lung injury (ALI) and acute kidney injury (AKI) in HS model. METHODS: Twenty male Sprague-Dawley rats were used. Pressure controlled HS model defined by mean arterial pressure (MAP) 40±2mmHg for 90min followed by resuscitation and observation was used. Rats (n=10 per group) were randomized into 2 groups with NAC or dextrose. Intravenous NAC was given continuously from 15min after induction of HS to the end of observation period (2h). We measured serum IL-6, nitrite/nitrate concentration. NF-κB p65 DNA binding activity, expressions of cytoplasmic phosphorylated IκB-α (p-IκB-α) and IκB-α, malondialdehyde (MDA) and histopathological injury scores in lung and kidney were also evaluated. RESULTS: MAP did not show any difference during the study period. NAC decreased histopathologic scores in both lung and kidney. Lung and kidney MDA levels were significantly lower in the NAC group compared to control group. Serum nitrite/nitrate and IL-6 were also significantly lower in the NAC group. The levels of lung cytoplasmic p-IκB-α expression was mitigated by NAC, and NF-κB p65 DNA binding activity was also significantly decreased in the NAC group. CONCLUSIONS: Continuous infusion of NAC attenuated inflammatory response and acute lung and kidney injury after hemorrhagic shock in rats.
    Resuscitation 06/2012; · 4.10 Impact Factor
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    ABSTRACT: BACKGROUND: Therapeutic hypothermia has been proposed to protect organs in some diseases. However, the effect of therapeutic hypothermia on liver injury in sepsis is unknown. The aim of this study was to evaluate the effects of therapeutic hypothermia on liver injury in sepsis. METHODS: Male Sprague-Dawley rats underwent cecal ligation and incision (CLI). We randomly allocated rats into one of two groups 1 h after CLI: hypothermia (HT) and normothermia (NT). In the HT group, body temperature decreased to 32°C ± 0.5°C and was maintained 4 h, followed by rewarming to 37°C for 2 h. In the NT group, body temperature was maintained at 37°C ± 0.5°C throughout the experimental periods. At 7 h after CLI, we harvested blood and liver tissues and measured serum alanine aminotransferase and the histological liver injury score. We performed immunohistochemistry for cleaved caspase-3 and evaluated phosphorylation of Akt, GSK-3β and Bad with the Western blot assay. RESULTS: Serum alanine aminotransferase was significantly lower in the HT group than in the NT group (57.0 ± 6.0 IU/L versus 192.5 ± 92.5 IU/L; P = 0.028). The histological liver injury score was also significantly lower in the HT group than in the NT group (2.9 ± 0.5 versus 5.4 ± 0.6; P = 0.016). Phosphorylation of Akt, GSK-3β, and Bad was significantly increased in the HT group compared with the NT group (P < 0.001, P = 0.007, and P = 0.001, respectively). Hypothermia significantly mitigated expression of cleaved caspase-3 compared with the NT group (P = 0.032). CONCLUSIONS: Therapeutic hypothermia attenuated liver injury in a polymicrobial sepsis model of rats by enhancing the Akt signaling pathway and decreasing apoptosis.
    Journal of Surgical Research 06/2012; · 2.02 Impact Factor
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    ABSTRACT: Although emergency department (ED) crowding has been shown to be associated with delayed antibiotics treatment in community-acquired pneumonia (CAP) patients, association between ED crowding with mortality has not been investigated. We hypothesized emergency department crowding is associated with 28-day mortality in CAP patients. A retrospective observational study using prospective database was performed on CAP patients who visited a single, urban, tertiary care hospital ED between April 1, 2008 and September 30, 2009. Main outcomes were 28-day mortality and timeliness of antibiotic therapy (within 2, 4, 6, and 8 h of arrival). ED crowding was measured by Emergency Department Occupancy (EDO) rate. A multivariate logistic regression was performed to determine the association of 28-day mortality with EDO rate after adjusting for factors such as time-to-first-antibiotic-dose (TFAD), pneumonia severity index and laboratory markers. 477 cases were enrolled during the study period. 28-day mortality rate was 4.8%. EDO rate ranged from 37.2% to 162.8%, and median was 97.7% (IQR: 80.2%-116.3%). When categorized into tertiles by EDO rate, high crowding condition (EDO rate >109.3%) was significantly associated with a higher 28-day mortality (adjusted OR = 9.48, 95% CI 1.53-58.90). However, TFAD was not associated with 28-day mortality. ED crowding was not associated with delay of TFAD at various time intervals (2, 4, 6, and 8 h). ED crowding measured by EDO rate was associated with higher 28-day mortality in CAP patients after adjusting TFAD, pneumonia severity index (PSI), and laboratory markers, although there was no association between ED crowding and TFAD.
    The Journal of infection 03/2012; 64(3):268-75. · 4.13 Impact Factor
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    ABSTRACT: Post-resuscitation therapeutic hypothermia has been recommended because of its neuroprotective effects. However, a few studies have reported the effects of therapeutic hypothermia on the heart, especially in ventricular fibrillation cardiac arrest. The aim of this study was to determine whether therapeutic hypothermia attenuates post-resuscitation myocardial injury in a swine cardiac arrest model. A prospective animal study was performed in the university hospital animal research laboratory. Ventricular fibrillation cardiac arrest was induced in domestic pigs weighing 35-40 kg. After 6 min of no flow time, cardiopulmonary resuscitation was provided to pigs, and the restoration of spontaneous circulation (ROSC) was achieved. The subjects were randomly allocated to a normothermic (NT group, n=5) or hypothermic (HT group, n=5) group. In the HT group, therapeutic hypothermia (core temperature 32-34 °C) was maintained for 24h, and rewarming was performed over a period of 8 h. In the NT group, core temperature was maintained at 37 °C throughout the experiments. Sixty hours after ROSC, blood and myocardial tissues were harvested. Serum troponin I was not significantly different between the groups. However, myocardial histological damage was attenuated in the HT group. Myocardial ATP contents were higher in the HT group than in the NT group. Immunohistochemistry for apoptosis-related protein showed that survivin expression was higher in the HT group, and XAF1 and cleaved caspase-3 expressions were lower in the HT group than in the NT group. Therapeutic hypothermia attenuated histological myocardial injury in ventricular fibrillation cardiac arrest model of pigs while preserving more ATP and decreased apoptosis.
    Resuscitation 11/2011; 83(5):633-9. · 4.10 Impact Factor
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    ABSTRACT: Glucose control is important in the management of critically ill patients. However, strict glucose control requires a large amount of nursing resources, especially in overcrowded emergency departments (EDs). A continuous glucose monitoring system (CGMS) may be beneficial for glucose control in the ED. The objective of this study was to determine the test characteristics of CGMS in critically ill ED patients. A prospective observational study of critically ill ED patients was conducted. During a patient's visit to the ED, a CGMS sensor measured their interstitial fluid glucose levels continuously. Capillary glucose was measured every hour and used for glucose control and as a reference value. CGMS values were recorded in real time and compared with capillary glucose values. A total of 122 pairs of capillary and CGMS glucose values in 12 patients were analyzed. The correlation coefficient was 0.87, and Bland-Altman analysis showed that 117 pairs (95.9%) were within a 95% confidence interval. A Clarke Error Grid Analysis indicated an overall accuracy of 96.8% (Zones A and B). However, the mean absolute relative difference (MARD) was significantly higher in the hypoglycemic range than in a normo- or hyperglycemic range (p = 0.001). The sensitivity and positive predictive value of CGMS for detecting hypoglycemia were 33.3% and 16.7%, respectively. The CGMS specificity and negative predictive value were 95.8% and 98.3%, respectively. There was no linear correlation between MARD and body mass index, axillary temperature, inotrope score, and base deficit (all p-value >0.05). CGMS demonstrated good clinical accuracy by Clarke Error Grid Analysis. There also was high agreement between CGMS and capillary glucose levels. However, CGMS demonstrated only limited real-time hypoglycemia detection ability in critically ill ED patients.
    Journal of Emergency Medicine 10/2011; 43(2):251-7. · 1.33 Impact Factor
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    ABSTRACT: To construct a simple model to predict bacteremia in women with uncomplicated acute pyelonephritis (APN) for the judicious use of blood cultures. A prospective database including 735 women with uncomplicated APN at an academic urban emergency department was analyzed retrospectively. Independent risk factors were determined using multivariate logistic regression in two-thirds of patients. Cutoff values representing 10% and 30% of risk were selected for the stratification. This model was internally and externally validated using a remaining one-thirds of patients and 169 independent patients, respectively. Independent risk factors were as follows: age ≥65 years (odds ratio [OR]=5.18, 4 points), vomiting (OR=2.40, 2 points), heart rate >110 beats/min (OR=2.35, 2 points), segmented neutrophils >90% (OR=3.17, 3 points), and urine WBC ≥50/HPF (OR=4.27, 4 points). Patients were stratified as low (points <4), intermediate (points, 4-6), or high risk (7≤ points). The areas under receiver operating characteristics curves were 0.707 and 0.792 in internal and external validation cohorts, respectively. The model stratified internal and external validation cohort into low (8.5% and 5.7%), intermediate (16.5% and 14.8%), and high risk of bacteremia (42.0% and 56.4%). This model provides a useful tool to predict the risk of bacteremia, which can be helpful to decide whether to perform blood cultures and whether to admit the patient for the intravenous antibiotics in women with uncomplicated APN.
    The Journal of infection 06/2011; 63(2):124-30. · 4.13 Impact Factor
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    ABSTRACT: Abdominal contrast-enhanced computed tomography (A-CECT) is widely used in emergency departments despite the risk of contrast-induced nephropathy. We attempted to develop a risk stratification nomogram for nephropathy in patients receiving emergency A-CECT. Seven hundred fifty patients who received emergency A-CECT between August 2003 and January 2007, with available serum creatinine (SCr) measurements before and after A-CECT were included. Nephropathy was defined as either an absolute increase of 0.5 mg/dL or greater (44 μmol/L) or a relative increase of 25% or more in the SCr from baseline. A nomogram was developed based on multivariate logistic regression analysis using clinical variables available before A-CECT. The model was internally validated with a bootstrapping method, and performance was assessed by area under the receiver operating characteristics curve (AUC) and calibration curve. Nephropathy was observed in 34 of 750 patients. A nomogram was developed using age (odds ratio, 1.04 per 1-year increment) and baseline SCr (odds ratio, 2.51 per 1-mg/dL increment) as risk factors. Diagnostic accuracy of the model was fair by bias-corrected calibration plot. The AUC of the model was 0.794 (95% confidence interval, 0.734-0.854), and the AUC with bootstrapping samples of 200 repetitions was 0.794 (95% confidence interval, 0.737-0.851). The risk of nephropathy after emergency A-CECT can be individually predicted by internally validated nomogram using clinical variables available before the procedure.
    The American journal of emergency medicine 05/2011; 29(4):412-7. · 1.54 Impact Factor
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    ABSTRACT: The prognostic role of N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with community-acquired pneumonia (CAP) has not been evaluated. The aim of the present study was to investigate whether NT-proBNP level could predict mortality in hospitalised CAP patients. We performed a structured medical record review of all hospitalised CAP patients from May 2003 to October 2006, and classified patients into the 30-day survival and non-survival group. Data included demographic and clinical characteristics, and laboratory findings including NT-proBNP levels. The APACHE II scores, PSI (pneumonia severity index) and CURB65 (confusion, urea, respiratory rate, blood pressure and aged 65 or more) scores were calculated. Comparisons between survivors and non-survivors were made with χ(2), non-parametric tests and logistic regression and ROC analysis were used to compare the ability of NT-proBNP (adjusted for age, heart failure and creatinine), APACHE II, PSI and CURB65 to predict mortality. Of 502 patients, 61 (12.2%) died within 30 days. NT-proBNP levels were measured in 167 patients and were significantly higher in non-survivors compared to survivors (median 841.7 (IQR 267.1-3137.3) pg/ml vs 3658.0 (1863.0-7025.0) pg/ml, p=0.019). NT-proBNP was an independent predictor of mortality (adjusted OR 1.53; 95% CI 1.16 to 2.02, p=0.002). The AUC for NT-proBNP was 0.712 (95% CI, 0.613 to 0.812), which was comparable to those of PSI (0.749, p=0.531) and CURB65 (0.698, p=0.693), but inferior to that of APACHE II (0.831, p=0.037). Adding NT-proBNP to APACHE II, PSI and CURB65 did not significantly increase the AUCs, respectively. NT-proBNP level is an independent predictor of mortality in hospitalised CAP patients. The performance of NT-proBNP level is comparable to those of PSI and CURB65 in predicting mortality.
    Emergency Medicine Journal 02/2011; 28(2):122-7. · 1.65 Impact Factor
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    ABSTRACT: Paraquat intoxication induces acute lung injury and numerous fatalities have been reported. The mechanism of toxic effect of paraquat is oxidative injury and inflammation. Therapeutic hypothermia has been known to have antioxidant and anti-inflammatory effects. This study was designed to evaluate the effect of therapeutic hypothermia on paraquat intoxication. Male Sprague-Dawley rats were given 50 mg/kg of paraquat intraperitoneally and divided into the normothermia (36-38°C) group and the hypothermia (30-32°C) group after 1h of paraquat administration. The hypothermia group underwent 2 h of hypothermia followed by 2 h of rewarming. In the survival study, mortality was observed for 24 h after paraquat administration. An in the second experiment, lung tissues and plasma were harvested at 6 h after paraquat administration. The 12 h survival rate was significantly higher in the hypothermia group than in the normothermia group (100% vs. 50%, p<0.05), but survival rates for 24 h were not different. Acute lung injury score was lower in the hypothermia group than in the normothermia group (p<0.05). Thmalondialdehyde contents of lung tissues, plasma interleukin-6 and nitrite/nitrate concentrations were significantly decreased in the HT group compared to the NT group (p<0.05). Therapeutic hypothermia delayed early mortality and attenuated acute lung injury in paraquat intoxication.
    Resuscitation 01/2011; 82(4):487-91. · 4.10 Impact Factor
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    ABSTRACT: We hypothesized that when used in combination with cardiac troponins, heart-type fatty acid binding protein (H-FABP) would have greater diagnostic value than conventional markers for the early diagnosis of myocardial infarction (MI). Patients with typical chest pain at a single emergency department were consecutively enrolled. Initial blood samples were drawn for H-FABP, myoglobin, creatine kinase isoenzyme MB (CK-MB), and cardiac troponin-I (cTnI) measurements. MI was defined by serial cTnI measurements. To evaluate the adjunctive role of biochemical markers, we derived and compared logistic regression models predicting MI in terms of their discrimination (area under the receiver operating characteristics curve, AUC) and overall fit (Bayesian information criterion, BIC). Seventy-six of 170 patients were diagnosed as having MI. The AUC of cTnI, H-FABP, myoglobin, and CK-MB were 0.863, 0.827, 0.784, and 0.772, respectively. A logistic regression model using cTnI (P = 0.001) and H-FABP (P < 0.001) had the biggest AUC (0.900) and the best fit determined by BIC. Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of this model at 30% probability were 81.6%, 80.9%, 4.26, and 0.23, respectively. H-FABP has a better diagnostic value than both myoglobin and CK-MB as an adjunct to cTnI for the early diagnosis of MI.
    Journal of Korean medical science 01/2011; 26(1):47-52. · 0.84 Impact Factor
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    ABSTRACT: To examine whether niacin attenuates lung inflammation and improves survival during sepsis and to determine whether the beneficial effects of niacin are associated with downregulation of the nuclear factor (NF)-κB pathway. Prospective laboratory study. University laboratory. Male Sprague-Dawley rats (n = 119). To induce endotoxemia in rats, lipopolysaccharide (Escherichia coli, O26:B6) at a dosage of 10 mg/kg was injected into a tail vein and 10 mins later, vehicle, a low dose of niacin (360 mg/kg), or a high dose of niacin (1180 mg/kg) was administered once through an orogastric tube, respectively. We observed the survival of the subjects for 72 hrs. At 6 hrs postlipopolysaccharide, we euthanized animals and measured cytoplasmic phosphorylated inhibitor κB-α and inhibitor κB-α expressions, nuclear NF-κB p65 expression, NF-κB p65 DNA-binding activity, tumor necrosis factor-α, and interleukin-6 gene expressions and histologic damages in lung tissues. We also measured nicotinamide adenine dinucleotide, reduced nicotinamide adenine dinucleotide phosphate, reduced glutathione, and malondialdehyde levels in lung tissues. High dose of niacin suppressed NF-κB activation and proinflammatory cytokine gene expressions in lung tissues, reduced histologic lung damages, and improved survival in endotoxemic rats. Furthermore, it increased nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, and glutathione levels and decreased malondialdehyde level in lung tissues. High dose of niacin attenuated lung inflammation, reduced histologic lung damages, and improved survival during sepsis in rats. These therapeutic benefits were associated with downregulation of the NF-κB pathway.
    Critical care medicine 10/2010; 39(2):328-34. · 6.37 Impact Factor
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    ABSTRACT: 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. 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. 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. 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.
    Resuscitation 10/2010; 82(1):32-9. · 4.10 Impact Factor

Publication Stats

245 Citations
111.91 Total Impact Points

Institutions

  • 2006–2011
    • Seoul National University
      • • Department of Emergency Medicine
      • • Department of Biomedical Engineering
      Seoul, Seoul, South Korea
  • 2003–2010
    • Seoul National University Hospital
      • Department of Emergency Medicine
      Seoul, Seoul, South Korea
  • 2008–2009
    • Seoul National University Bundang Hospital
      • Department of Emergency Medicine
      Seoul, Seoul, South Korea