Association between continuous renal replacement therapy and mortality after acute herbicide (glyphosate and/or glufosinate) intoxication: propensity score matching approach

Purpose@#We investigated the association between continuous renal replacement therapy (CRRT) and mortality after acute glyphosate or glufosinate intoxication. @*Methods@#The electronic medical records of patients with acute herbicide ingestion who were admitted to the regional emergency center of a metropolitan city in Korea from 3/1/2013 to 2/28/2022 were analyzed and reviewed retrospectively. The case group received CRRT, while the control group did not. In total, 96 patients experienced acute herbicide intoxication in the study period. Baseline characteristics were analyzed and compared between the two groups after propensity score matching. The outcome variable was mortality fitted by a Cox proportional hazard model. @*Results@#After full matching between cases of CRRT use and controls (patients who did not receive CRRT) using propensity scores, 96 patients (27 cases, 69 controls) were analyzed. Propensity matching yielded adequate balance (standardized mean differences <0.25) for all covariates. We fit a Cox proportional hazards model with survival as the outcome and CRRT as a factor, including the matching weights in the estimation. The estimated hazard ratio was 0.41 (95% confidence interval, 0.23–0.76; p=0.0044), indicating that CRRT reduced mortality. @*Conclusion@#In this propensity score-matched analysis, CRRT reduced mortality in patients who visited the hospital with acute glyphosate or glufosinate intoxication. In patients with acute herbicide poisoning with high severity calculated by the APACHE II (Acute Physiology and Chronic Health Evaluation II) score and SOFA (Sequential Organ Failure Assessment) score, CRRT should be actively considered to improve the survival rate.

Risk factors for post-contrast acute kidney injury in patients sequentially administered iodine- and gadolinium-based contrast media on the same visit to the emergency department: a retrospective study

This study compares the incidence of post-contrast acute kidney injury (PC-AKI) in patients who received a single administration of iodine-based contrast medium (ICM) with that in patients who received a sequential administration of ICM and gadolinium- based contrast agents (GBCA) in a single visit to an emergency department (ED) to determine the risk factors for PC-AKI. Methods: Patients who received one or more contrast media in the ED from 2016 to 2021 were included in this retrospective study. They were divided into the ICM alone and ICM + GBCA groups, and the incidence of PC-AKI was compared between the groups. The risk factors were assessed using a multivariable analysis after propensity score matching (PSM). Results: Overall, 6,318 patients were analyzed, of whom 139 were in the ICM + GBCA group. The incidence of PC-AKI was significantly higher in the ICM + GBCA group than in the ICM alone group (10.9% vs. 27.3%, p < 0.001). In the multivariable analysis, sequential administration was a risk factor for PC-AKI, and single administration was not (adjusted odds ratio [95% confidence interval] in the 1:1, 2:1, and 3:1 PSM cohorts: 2.38 [1.25–4.55], 2.13 [1.26–3.60], and 2.28 [1.39–3.72], respectively). In subgroup analyses of the ICM + GBCA group, osmolality (1.05 [1.01–1.10]) and estimated glomerular filtration rate (eGFR, 0.93 [0.88–0.98]) were associated with PC-AKI. Conclusion: Compared with a single administration of ICM alone, sequential administration of ICM and GBCA during a single ED visit might be a risk factor for PC-AKI. Osmolality and eGFR might be associated with PC-AKI after sequential administration.

A case of cardiac arrest after dermal exposure to 2.38% tetramethylammonium hydroxide

A 34-year-old man presented with an out-of-hospital cardiac arrest shortly after dermal exposure to tetramethylammonium hydroxide (TMAH). The patient was accidentally exposed to 2.38% TMAH despite the use of personal protective equipment and was referred to our emergency department one hour after the exposure. He was resuscitated using advanced cardiac life support and intensive care. However, he remained unconscious despite target temperature management. Second-degree chemical burns were found on 10% of his total body surface area. Brain magnetic resonance imaging showed severe anoxic-ischemic encephalopathy involving bilateral supratentorial grey matter. TMAH was detected in the patient’ s blood and urine. To the best of our knowledge, this is the first report of the identification of TMAH in the serum and urine after exposure to the agent. Previous cases of cardiac arrest reported were due to exposure to high concentrations of 25% TMAH. We postulate that even low concentrations of TMAH could be absorbed rapidly after dermal exposure and can have fatal consequences.

Adrenocorticotropic hormone and β-endorphin concentration as a prognostic factor in patients with subarachnoid hemorrhage due to aneurysmal rupture

Objective@#Adrenocorticotropic hormone (ACTH) and β-endorphin are pituitary neuro-peptides released by acute stress. We determined why the prognosis of patients with subarachnoid hemorrhages (SAH) due to aneurysmal rupture is not always dependent on the Hunt–Hess grading system (HHS) and delta-National Institutes of Health Stroke Scale (NIHSS), while studying endogenous neuropeptides, including ACTH and β-endorphin. @*Methods@#We analyzed blood samples collected from patients with SAH (SAH group; n=37) and those with unruptured intracranial aneurysms (control group; n=37). Blood sampling was performed before any procedure or chemical agents administration. The results of ACTH and β-endorphin measurements were compared using the delta-NIHSS and HHS. The data were analyzed using descriptive statistics, independent samples t-tests, and Pearson’s correlations. @*Results@#Of the 18 patients with low-grade HHS, 13 had low delta-NIHSS and five showed high delta-NIHSS. Of the 19 patients with high-grade HHS, the delta-NIHSS was ≥14 in the other five patients. ACTH concentration was high (497.3 pg/mL) in five patients with high-grade HHS and high delta-NIHSS. β-endorphin concentration was high (159.7 pg/mL) in 13 patients with low-grade HHS and low delta-NIHSS. @*Conclusions@#High ACTH levels in patients with massive bleeding and poor neurological status suggests increasing ACTH secretion in response to bleeding stress, which may aggravate neurological status. Contrary to ACTH, high β-endorphin levels in patients with low-grade HHS implied the involvement of additional factors in predicting fair outcomes related to low delta-NIHSS. These results may provide insight into the varying prognostic potential of HHS in SAH patients.

The effect of periodontitis on recipient outcomes after kidney transplantation

Recent several reports have demonstrated that periodontitis is prevalent and adversely affects the survival in patients with chronic kidney disease (CKD) or end-stage kidney disease. However, its impact on transplant outcomes remains uncertain. Methods: This retrospective cohort study included 136 and 167 patients, respectively, who underwent living donor kidney transplantation (KT) at Seoul National University Hospital from July 2012 to August 2016 and Korea University Hospital from April 2008 to October 2018. We divided patients into three groups according to stages of periodontitis based on a new classification system. Results: Patients with severe periodontitis were older, had a higher prevalence of diabetes, a higher body mass index and C-reactive protein level, a lower cardiac output, and were more likely to be smokers, indicating its association with chronic systemic inflammation. After KT, stage IV periodontitis was independently associated with a lower incidence of acute T cell-mediated rejection, suggesting the possible effect of periodontitis on immune function. However, 1-year and 3-year estimated glomerular filtration rates were not different. Among the KT recipients followed up more than 3 years, new-onset cardiovascular disease occurred in nine patients, and coronary artery disease occurred more frequently in patients with stage IV periodontitis. However, diabetes was the independent predictor of new-onset coronary artery disease in multivariate logistic regression analysis. Conclusion: Our findings showed that periodontitis might be an important player in determining posttransplant outcomes in recipients. Further interventional trials to test whether treating periodontitis could modify transplant outcome are needed.

Serial blood and urine measurement of drugs in a patient with acute intoxication of tramadol and zolpidem resulting in QT prolongation: a case report

We reported a case of acute intoxication by tramadol and zolpidem, resulting in QT prolongation in a patient. A 38-year-old male patient presented to the emergency department (ED) because of poisoning from 3 g of tramadol and 50 mg of zolpidem 4 hours before. During supportive treatment, he developed QT prolongation without clinical manifestations. He was discharged 5 days after admission without any sequelae. We measured the blood and urine concentrations of tramadol and zolpidem at various time points, which revealed a blood tramadol concentration-dependent change in QT intervals and an increased blood tramadol concentration at 8 hours after the ED visit. Tramadol and zolpidem were metabolized by the same enzyme, cytochrome P450 3A4. Therefore, competitive inhibition may increase drug toxicity. In addition, the blood concentration of tramadol may increase and result in QT prolongation even after appropriate initial treatment.

Bench-Top Comparison of Three Different Types of Stents Used for Treatment of Intracranial Atherosclerotic Stenosis / 신경중재치료의학

Purpose@#Four key bench-top tests, including trackability, conformability, wall-apposition, and bending stiffness, were performed to understand the mechanical characteristics in 3 different types of stents applicable for treatment of intracranial atherosclerotic stenosis: Balloon-expandable D+Storm, Pro-Kinetic Energy, and self-expandable Wingspan stents. @*Materials and Methods@#Trackability was assessed by measuring the tracking forces of each stent with its delivery systems. Conformability and wall apposition were quantified and analyzed using curved vessel models. A 3-point bending test was employed to evaluate bending stiffness. @*Results@#D+Storm showed the lowest tracking forces while the conformability of the Wingspan stent was superior to that of the tested stents. Pro-Kinetic Energy and D+Storm had better wall apposition in curved vessels than the Wingspan stent. Bending stiffness of the Wingspan stent was notably lower, whereas no significant differences were found between D+Storm and Energy. Pro-Kinetic Energy and D+Storm not only indicated lower gap ratios between the struts and the vessel wall but also maintained good wall apposition even in the curved model. @*Conclusion@#These bench-top measurements may provide clinicians with useful information in regard to selecting suitable stents for treatment of intracranial atherosclerotic stenosis.

Characteristics of the pneumonia patients transferred from long-term care hospitals:retrospective study of one regional emergency medical center

Objective@#This study investigated the characteristics of elderly pneumonia patients transferred from long-term care hospitals(LTCH). @*Methods@#The initial emergency department (ED) data of patients, who were transferred from other hospitals and over 65years old and hospitalized from 2014 to 2018 for pneumonia management through the ED, were extracted from the electronicmedical records. The differences in the initial status and prognosis between the LTCH group and non-LTCH groupwere compared, and the initial ED variables that affect the in-hospital mortality of the LTCH group were investigated. @*Results@#The total number of patients was 1,032; 423 (41.0 %) were included in the LTCH group. Compared to the non-LTCH group, the following severity indices, some laboratory data, and mortality were worse in the LTCH group: systemicinflammatory reaction syndrome (SIRS) criteria ≥2 (65.0% vs. 56.7%, P=0.008), quick Sequential Organ FailureAssessment score ≥2 (48.2% vs. 20.4%, P<0.001), CURB-65 (Confusion, Urea nitrogen, Respiration rate, Blood pressure,Age≥65 years) criteria ≥3 (51.8% vs. 29.2%, P<0.001), pneumonia severity index (PSI) class ≥4 (86.5% vs.61.2%, P<0.001), modified early warning score ≥5 (38.8% vs. 18.4%, P<0.001), serum albumin (median [IQR], 2.6 [2.2-2.9] g/dL vs. 2.8 [2.4-3.2] g/dL; P<0.001), blood urea nitrogen/albumin (B/A) ratio (median [IQR], 8.0 [5.0-12.8] vs. 6.6[4.4-10.4]; P<0.001), and in-hospital mortality (26.0% vs. 15.9%, P<0.001). Multivariate regression analysis revealed thealbumin grade, B/A ratio grade, PSI class, and SIRS criteria to independently affect the in-hospital mortality of the LTCHgroup. @*Conclusion@#The LTCH group had poorer initial severity indices and higher in-hospital mortality than the non-LTCHgroup. In addition, the albumin grade, B/A ratio grade, could be used for the severity index of pneumonia patients transferredfrom the LTCH.

Evaluation of pneumonia management effectiveness associated withinternal medicine management changes in the emergency department:a retrospective cohort study using a historically controlled group

Objective@#In Korea, many hospitals have recently changed the process of internal medicine management in the emergencydepartment (ED) because of reduced manpower, raising concerns regarding the decreased quality of medicalcare. The process of medical management in the ED was streamlined to resolve the reduced manpower. Thus, this studycompared the pneumonia treatment effectiveness before and after the process changes. @*Methods@#This study included patients who were diagnosed with pneumonia in the ED and hospitalized from January2014 to December 2016. They were divided into two groups based on before and after the changes. The disease severity,management adequacy, and prognosis were compared using the initial quick sequential organ failure assessmentscore (qSOFA), systemic inflammatory response syndrome criteria (SIRS), CURB-65 score, door-to-antibiotic time(DAT), length of stay (LOS), hospitalization period (HP), and in-hospital mortality, were collected retrospectively from themedical records. @*Results@#The qSOFA, SIRS, and CURB-65 scores did not differ between the two groups. The median (interquartilerange) DAT, LOS, and HP were reduced after the process changes: DAT (160.0 minutes [111.0-230.0] vs. 120.0 minutes[74.0-175.0], P<0.001), LOS (7.6 hours [4.8-15.8] vs. 4.7 hours [3.2-6.8], P<0.001), and HP (9.0 days [6.0-16.0] vs. 8.0days [5.0-15.0], P=0.011). On the other hand, the in-hospital mortality was similar in the two groups (14.1% vs. 11.2%,P=0.162). @*Conclusion@#The DAT, LOS, and HP decreased after the process changes, but the in-hospital mortality did not worsen.This shows that pneumonia management in the ED was not compromised, but rather improved, after the changes.

Endovascular Approach in Patients with Acute Complete Occlusion Due to Middle Cerebral Artery Dissection

Objective@#: Dissection of the middle cerebral artery (MCA) is less common than dissection of vessels in the vertebrobasilar system or carotid artery. Acute complete occlusion related to MCA dissection is extremely rare. We report an endovascular approach in patients with acute complete occlusion due to MCA dissection. @*Methods@#: We reviewed retrospectively the endovascular procedure and clinical results for acute-stroke patients who underwent recanalization from October 2014 through December 2018. Initial imaging findings and the endovascular procedure were analyzed for patients with acute complete occlusion due to MCA dissection. @*Results@#: We undertook first-line aspiration thrombectomy using a Penumbra catheter in 294 patients with acute occlusion of the M1 segment. Of these patients, seven were confirmed to have acute complete occlusion due to MCA dissection. All patients had angiographic findings of an intimal flap at the proximal occlusion site of the MCA. One patient complained of severe headache during microcatheter passage through the occluded lesion and died due to massive bleeding caused by rupture of the false lumen. The remaining patients underwent initial contact aspiration thrombectomy without microcatheter passage. After aspiration thrombectomy, six patients had delayed flow through the MCA. One patient underwent stenting of the MCA because of progressive symptoms. @*Conclusion@#: An intimal flap at the proximal portion of an occluded MCA can suggest the possibility of MCA dissection. Contrast aspiration thrombectomy without microcatheter passage can reduce the risk of false lumen rupture in cases of MCA dissection.

Can Computed Tomographic Angiography Be Used to Predict Who Will Not Benefit from Endovascular Treatment in Patients with Acute Ischemic Stroke? The CTA-ABC Score

Objective@#: The objective of this study was to develop a score to predict patients with acute ischemic stroke (AIS) who will not benefit from endovascular treatment (EVT) using computed tomographic angiography (CTA) parameters. @*Methods@#: The CTA-ABC score was developed from 3 scales previously described in the literature: the Alberta Stroke Program Early CT Score (0–5 points, 3; 6–10 points, 0), the clot burden score (0–3 points, 1; 4–10 points, 0), and the leptomeningeal Collateral score (0–1 points, 2; 2–3 points, 0). We evaluated the predictive value of CTA parameters associated with symptomatic intracranial hemorrhage (sICH) or malignant middle cerebral artery infarction (MMCAI) after EVT and developed the score using logistic regression coefficients. The score was then validated. Performance of the score was tested with an area under the receiver operating characteristic curve (AUC-ROC). @*Results@#: The derivation cohort consisted of 115 and the validation cohort consisted of 40 AIS patients. The AUC-ROC was 0.97 (95% confidence interval [CI], 0.94–0.99; p<0.001) in the derivation cohort. The proportions of patients with sICH and/or MMCAI in the derivation cohort were 96%, 73%, 6%, and 0% for scores of 6, 5, 1, and 0 points, respectively. In the validation group, the proportions were similar (90%, 100%, 0%, and 0%, respectively) with an AUC-ROC of 0.96 (95% CI, 0.90–1.00; p<0.001). @*Conclusion@#: Our CTA-ABC score reliably assessed risk for sICH and/or MMCAI in patients with AIS who underwent EVT. It can support clinical decision-making, especially when the need for EVT is uncertain.

Changes in peak inspiratory flow rate and peak airway pressure with endotracheal tube size during chest compression / 世界急诊医学杂志（英文）

@#BACKGROUND: Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation (CPR). Airway management is usually performed using an endotracheal tube (ETT) during CPR. However, no study has assessed the effect of ETT size on the flow rate and airway pressure during CPR. METHODS: We measured changes in peak inspiratory flow rate (PIFR), peak airway pressure (Ppeak), and mean airway pressure (Pmean) according to changes in ETT size (internal diameter 6.0, 7.0, and 8.0 mm) and with or without CPR. A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator. Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device (LUCAS2, mode: active continuous, chest compression rate: 102±2/minute, chest compression depth 2–2.5 inches). RESULTS: The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT (6.0 vs. 8.0 mm): PIFR (32.1 L/min [30.5–35.3] vs. 28.9 L/min [27.5–30.8], P<0.001), Ppeak (48.84 cmH2O [27.46–52.11] vs. 27.45 cmH2O [22.53–52.57], P<0.001), and Pmean (18.34 cmH2O [14.61–21.66] vs.13.66 cmH2O [8.41–19.24], P<0.001). CONCLUSION: The changes in PIFR, Ppeak, and Pmean were related to the internal diameter of ETT, and these values tended to decrease with an increase in ETT size. Higher airway pressures were measured in the CPR group than in the no CPR group.

Initial Experience of ACE68 Reperfusion Catheter in Patients with Acute Ischemic Stroke Related to Internal Carotid Artery Occlusion

OBJECTIVE: Penumbra ACE68 reperfusion catheter is a new large bore aspiration catheter used for reperfusion of large vessel occlusion. The objective of this study was to investigate the efficacy of this catheter in comparison to that of previous Penumbra catheters in patients with acute ischemic stroke related to internal carotid artery (ICA) occlusion.METHODS: Data of all eligible patients who received endovascular treatment (EVT) for ICA occlusion using Penumbra aspiration catheters between January 2015 and December 2018 were retrospectively reviewed. After dividing into two groups according to use of penumbra ACE68, baseline characteristics of patients, successful recanalization rate, puncture to recanalization time, and switch to stent base technique rate were assessed. Successful recanalization was defined by a thrombolysis in cerebral infarction (TICI) score ≥2b and favorable functional outcome was defined according to modified Rankin scale (score, 0–2).RESULTS: ACE68 reperfusion catheter was used in 29 of 75 eligible patients (39%). The puncture to recanalization time was significantly shorter (26±18.2 minutes vs. 40±24.9 minutes, p=0.011) and the rate of switch to stent-based retrieval was significantly lower (3% vs. 20%, p=0.046) in ACE68 catheter group. Moreover, although not statistically significant, the successful recanalization rate was higher (83% vs. 76%, p=0.492) in ACE68 catheter group. Favorable functional outcome was observed in 48% of patients treated with ACE68 reperfusion catheter and in 30% of patients treated using other Penumbra systems (p=0.120). Baseline Alberta Stroke Program Early CT Scores ≥8 (odds ratio [OR], 9.74; 95% confidence interval [CI], 1.72–54.99; p=0.010) and successful recanalization (OR, 10.20; 95% CI, 1.13–92.46; p=0.039) were independent predictors of favorable outcome.CONCLUSION: EVT using ACE68 reperfusion catheter can be considered a first-line therapy in patients with acute ICA occlusion as it can achieve rapid recanalization and reduce the frequency of conversion to stent-retrieve therapy.

Patient-Specific Computational Fluid Dynamics in Ruptured Posterior Communicating Aneurysms Using Measured Non-Newtonian Viscosity : A Preliminary Study

OBJECTIVE: The objective of this study was to analyze patient-specific blood flow in ruptured aneurysms using obtained non-Newtonian viscosity and to observe associated hemodynamic features and morphological effects.METHODS: Five patients with acute subarachnoid hemorrhage caused by ruptured posterior communicating artery aneurysms were included in the study. Patients’ blood samples were measured immediately after enrollment. Computational fluid dynamics (CFD) was conducted to evaluate viscosity distributions and wall shear stress (WSS) distributions using a patient-specific geometric model and shear-thinning viscosity properties.RESULTS: Substantial viscosity change was found at the dome of the aneurysms studied when applying non-Newtonian blood viscosity measured at peak-systole and end-diastole. The maximal WSS of the non-Newtonian model on an aneurysm at peaksystole was approximately 16% lower compared to Newtonian fluid, and most of the hemodynamic features of Newtonian flow at the aneurysms were higher, except for minimal WSS value. However, the differences between the Newtonian and non-Newtonian flow were not statistically significant. Rupture point of an aneurysm showed low WSS regardless of Newtonian or non-Newtonian CFD analyses.CONCLUSION: By using measured non-Newtonian viscosity and geometry on patient-specific CFD analysis, morphologic differences in hemodynamic features, such as changes in whole blood viscosity and WSS, were observed. Therefore, measured non-Newtonian viscosity might be possibly useful to obtain patient-specific hemodynamic and morphologic result.

Initial Experience of ACE68 Reperfusion Catheter in Patients with Acute Ischemic Stroke Related to Internal Carotid Artery Occlusion

OBJECTIVE: Penumbra ACE68 reperfusion catheter is a new large bore aspiration catheter used for reperfusion of large vessel occlusion. The objective of this study was to investigate the efficacy of this catheter in comparison to that of previous Penumbra catheters in patients with acute ischemic stroke related to internal carotid artery (ICA) occlusion. METHODS: Data of all eligible patients who received endovascular treatment (EVT) for ICA occlusion using Penumbra aspiration catheters between January 2015 and December 2018 were retrospectively reviewed. After dividing into two groups according to use of penumbra ACE68, baseline characteristics of patients, successful recanalization rate, puncture to recanalization time, and switch to stent base technique rate were assessed. Successful recanalization was defined by a thrombolysis in cerebral infarction (TICI) score ≥2b and favorable functional outcome was defined according to modified Rankin scale (score, 0–2). RESULTS: ACE68 reperfusion catheter was used in 29 of 75 eligible patients (39%). The puncture to recanalization time was significantly shorter (26±18.2 minutes vs. 40±24.9 minutes, p=0.011) and the rate of switch to stent-based retrieval was significantly lower (3% vs. 20%, p=0.046) in ACE68 catheter group. Moreover, although not statistically significant, the successful recanalization rate was higher (83% vs. 76%, p=0.492) in ACE68 catheter group. Favorable functional outcome was observed in 48% of patients treated with ACE68 reperfusion catheter and in 30% of patients treated using other Penumbra systems (p=0.120). Baseline Alberta Stroke Program Early CT Scores ≥8 (odds ratio [OR], 9.74; 95% confidence interval [CI], 1.72–54.99; p=0.010) and successful recanalization (OR, 10.20; 95% CI, 1.13–92.46; p=0.039) were independent predictors of favorable outcome. CONCLUSION: EVT using ACE68 reperfusion catheter can be considered a first-line therapy in patients with acute ICA occlusion as it can achieve rapid recanalization and reduce the frequency of conversion to stent-retrieve therapy.

Patient-Specific Computational Fluid Dynamics in Ruptured Posterior Communicating Aneurysms Using Measured Non-Newtonian Viscosity : A Preliminary Study

OBJECTIVE: The objective of this study was to analyze patient-specific blood flow in ruptured aneurysms using obtained non-Newtonian viscosity and to observe associated hemodynamic features and morphological effects. METHODS: Five patients with acute subarachnoid hemorrhage caused by ruptured posterior communicating artery aneurysms were included in the study. Patients’ blood samples were measured immediately after enrollment. Computational fluid dynamics (CFD) was conducted to evaluate viscosity distributions and wall shear stress (WSS) distributions using a patient-specific geometric model and shear-thinning viscosity properties. RESULTS: Substantial viscosity change was found at the dome of the aneurysms studied when applying non-Newtonian blood viscosity measured at peak-systole and end-diastole. The maximal WSS of the non-Newtonian model on an aneurysm at peaksystole was approximately 16% lower compared to Newtonian fluid, and most of the hemodynamic features of Newtonian flow at the aneurysms were higher, except for minimal WSS value. However, the differences between the Newtonian and non-Newtonian flow were not statistically significant. Rupture point of an aneurysm showed low WSS regardless of Newtonian or non-Newtonian CFD analyses. CONCLUSION: By using measured non-Newtonian viscosity and geometry on patient-specific CFD analysis, morphologic differences in hemodynamic features, such as changes in whole blood viscosity and WSS, were observed. Therefore, measured non-Newtonian viscosity might be possibly useful to obtain patient-specific hemodynamic and morphologic result.

Effect of regional climatic conditions, air pollutants, and season on the occurrence and severity of injury in trauma patients

OBJECTIVE: We analyzed the association between regional weather and temporal changes on the daily occurrence of trauma emergencies and their severity. METHODS: In this cross-sectional prospective study, we investigated daily atmospheric patterns in trauma episodes in 1,344 patients in Cheongju city, South Korea, from January 2016 to December 2016 and analyzed the association of trauma occurrence and Injury Severity Scores (ISS) with weather conditions on a daily scale. RESULTS: The mean age of trauma patients was 53.0±23.8 years and average ISS was 9.0±2.0. Incidence of trauma was positively correlated with average temperature (r=0.512, P < 0.001) and atmospheric pressure (r=0.332, P=0.010) and negatively correlated with air pollutants (particulate matter less than 2.5 µm³ [PM2.5], r=−0.629, P < 0.001; particulate matter less than 10 µm³ [PM10], r=−0.679, P < 0.001). ISS was not significantly correlated with climate parameters and air pollutants, and variability was observed in the frequency and severity of trauma by time of day (highest occurrence, 16–20 pm; highest ISS, 4–8 am), day of the week (highest occurrence and highest ISS, Saturday), month of the year (highest occurrence, July; highest ISS, November), and season (highest incidence, summer; highest ISS, autumn). CONCLUSION: The study shows a positive relationship between trauma occurrence and specific weather conditions, such as atmospheric temperature and pressure. There was a negative relationship between concentrations of PM2.5 or PM10, and trauma occurrence. However, no correlation was observed between weather conditions or the concentrations of air pollutants and ISS. In addition, seasonal, circaseptan, and circadian variations exist in trauma occurrence and severity. Thus, we suggest that evaluation of a larger, population-based data set is needed to further investigate and confirm these relationships.

Wall Shear Stress and Flow Patterns in Unruptured and Ruptured Anterior Communicating Artery Aneurysms Using Computational Fluid Dynamics

OBJECTIVE: The goal of this study was to compare several parameters, including wall shear stress (WSS) and flow pattern, between unruptured and ruptured anterior communicating artery (ACoA) aneurysms using patient-specific aneurysm geometry.METHODS: In total, 18 unruptured and 24 ruptured aneurysms were analyzed using computational fluid dynamics (CFD) models. Minimal, average, and maximal wall shear stress were calculated based on CFD simulations. Aneurysm height, ostium diameter, aspect ratio, and area of aneurysm were measured. Aneurysms were classified according to flow complexity (simple or complex) and inflow jet (concentrated or diffused). Statistical analyses were performed to ascertain differences between the aneurysm groups.RESULTS: Average wall shear stress of the ruptured group was greater than that of the unruptured group (9.42% for aneurysm and 10.38% for ostium). The average area of ruptured aneurysms was 31.22% larger than unruptured aneurysms. Simple flow was observed in 14 of 18 (78%) unruptured aneurysms, while all ruptured aneurysms had complex flow (p < 0.001). Ruptured aneurysms were more likely to have a concentrated inflow jet (63%), while unruptured aneurysms predominantly had a diffused inflow jet (83%, p=0.004).CONCLUSION: Ruptured aneurysms tended to have a larger geometric size and greater WSS compared to unruptured aneurysms, but the difference was not statistically significant. Flow complexity and inflow jet were significantly different between unruptured and ruptured ACoA aneurysms.

Wall Shear Stress and Flow Patterns in Unruptured and Ruptured Anterior Communicating Artery Aneurysms Using Computational Fluid Dynamics

OBJECTIVE: The goal of this study was to compare several parameters, including wall shear stress (WSS) and flow pattern, between unruptured and ruptured anterior communicating artery (ACoA) aneurysms using patient-specific aneurysm geometry. METHODS: In total, 18 unruptured and 24 ruptured aneurysms were analyzed using computational fluid dynamics (CFD) models. Minimal, average, and maximal wall shear stress were calculated based on CFD simulations. Aneurysm height, ostium diameter, aspect ratio, and area of aneurysm were measured. Aneurysms were classified according to flow complexity (simple or complex) and inflow jet (concentrated or diffused). Statistical analyses were performed to ascertain differences between the aneurysm groups. RESULTS: Average wall shear stress of the ruptured group was greater than that of the unruptured group (9.42% for aneurysm and 10.38% for ostium). The average area of ruptured aneurysms was 31.22% larger than unruptured aneurysms. Simple flow was observed in 14 of 18 (78%) unruptured aneurysms, while all ruptured aneurysms had complex flow (p < 0.001). Ruptured aneurysms were more likely to have a concentrated inflow jet (63%), while unruptured aneurysms predominantly had a diffused inflow jet (83%, p=0.004). CONCLUSION: Ruptured aneurysms tended to have a larger geometric size and greater WSS compared to unruptured aneurysms, but the difference was not statistically significant. Flow complexity and inflow jet were significantly different between unruptured and ruptured ACoA aneurysms.

Histopathological and Neurobehavioral Characterization in Adult Mice Exposed to Traumatic Brain Injury

PURPOSE: Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Severity of the initial insult is one of the most significant factors affecting outcome following TBI. In order to investigate the mechanisms of cellular injury and develop novel therapeutic strategies for TBI, we designed a standardized animal TBI model and evaluated histological and functional outcomes according to the degree of impact severity. METHODS: Male adult C57Bl/6 mice underwent controlled cortical impact (CCI) at varying depths of deflection (1.0-2.0 mm). We performed hematoxylin and eosin staining at 7 days after recovery from TBI. Neurobehavioral characterization after TBI was analyzed by the Barnes maze test, passive avoidance test, open field test, rotarod test, tail suspension test, and light/dark test. RESULTS: We observed a graded injury response according to the degree of deflection depths tested (diameter, 3 mm; velocity, 3 m/s; and duration, 500 ms) compared to sham controls. In the Barnes maze test, the severe TBI (2 mm depth) group showed reduced spatial memory as compared with the sham and mild TBI (1 mm depth) groups at 7 days after TBI. There was a significant difference in the results of the open field test and light/dark test among the three groups. CONCLUSION: Our findings demonstrate that the graded injury responses following TBI resulted in differential histopathological and behavioral outcomes in a mouse experimental CCI model. Thus, a model of CCI with histologic/behavioral outcome analysis may offer a reliable and convenient design for preclinical TBI research involving mice.