Introducing a New Biomarker Named R2*-BOLD-MRI Parameter to Assess Treatment Response in Osteosarcoma.

BACKGROUND: While histologic response to neoadjuvant chemotherapy (NChT) is the major prognostic factor for osteosarcoma treatment, evaluating that response is difficult. PURPOSE: To evaluate the feasibility of the blood oxygen level-dependent (BOLD) technique to assess the response to NChT. STUDY TYPE: Prospective. POPULATION: Twelve patients with osteosarcoma undergoing NChT. FIELD STRENGTH/SEQUENCE: 3 T; T2*-weighted BOLD, dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) (b values of 0, 400, and 1400 seconds/mm2 ) sequences. ASSESSMENT: Examination was performed before treatment (first), after each cycle of treatment (second and third). At each time point, spin dephasing rates (R2*) from BOLD magnetic resonance imaging (MRI), parameters from DCE-MRI (volume transfer constant [Ktrans ], reflux rate [kep ], volume fraction of the extravascular extracellular matrix [ve ], and blood plasma volume [vp ]), and the apparent diffusion coefficient (ADC) from DW-MRI were measured. STATISTICAL TESTS: Wilcoxon's signed rank test, Spearman's correlation coefficient (ρ) were used. A P-value of <0.05 was considered statistically significant. RESULTS: The difference and relative difference of the R2* values between the first/third MRIs in the extraosseous portion were statistically significant. Only the differences in the kep values between the first/second and between the first/third MRIs in the extraosseous portion were significant. The differences in the ADCs in the extraosseous and osseous portions were not statistically significant (P = 0.151, P = 0.733 each in extraosseous portion and P = 0.569, P = 0.129 each in osseous portion). The relative difference in R2* values in the extraosseous portion between the first/third MRI (ρ = 0.706) was significantly better correlated with the pathologic grade than those of kep and ADC over the same period (ρ = 0.286 and ρ = -0.091, respectively). DATA CONCLUSION: The R2* from the BOLD MRI technique could be a useful biomarker for evaluating treatment response in osteosarcoma treated with NchT. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Yield of concurrent systemic biopsy during MRI-targeted biopsy according to Prostate Imaging Reporting and Data System version 2 in patients with suspected prostate cancer.

OBJECTIVES: To investigate the yield of concurrent systemic biopsy (SB) during MRI-targeted biopsy (MRTB) as Prostate Imaging Reporting and Data System (PI-RADS) version 2 (v2) interpretations in patients with suspected prostate cancer (PCa). METHODS: A total of 285 patients with suspected PCa underwent prebiopsy 3-T MRI, followed by MRI-transrectal ultrasound fusion targeted biopsy and concurrent standard SB for lesions with PI-RADS v2 scores 3-5. Detection rates and positive core rates of PCa and clinically significant cancer (CSC) were evaluated. RESULTS: In concurrent MRTB and SB, PCa and CSC detection rates were 18.9% and 9.4% for PI-RADS score 3, 45.9% and 32.4% for PI-RADS score 4, and 82.1% and 72.6% for PI-RADS score 5, respectively. Overall detection rate of CSCs (40.0%) for concurrent MRTB and SB was significantly higher than that of MRTB (34.4%, p = 0.004) or SB alone (27.7%, p < 0.001): an increase of 5.6% (16 patients) compared with MRTB alone. For patients with PI-RADS score 4 or 5, the CSC detection rate of concurrent MRTB and SB was 47.0%, an increase of 6.1% when compared with MRTB (40.9%) only (p < 0.001). Of the 110 patients with both MRTB- and SB-positive findings, 22 (20.0%) had the highest Gleason score in SB compared with that in MRTB. In 9.5% (27/285) patients including 12 patients with CSCs, only SB was positive, with negative MRTB. CONCLUSION: Concurrent SB with MRTB based on PI-RADS v2 can yield a higher CSC detection rate compared with MRTB alone in patients with suspected PCa. KEY POINTS: • Concurrent SB with MRTB yields an increase of 5.6% CSC detection compared with MRTB alone. • Of both MRTB- and SB-positive findings, 20.0% patients have upgraded Gleason score in SB. • In 18.4% patients, only SB was positive, with negative MRTB. Adding MRTB to SB is helpful for adequate risk stratification, reducing diagnostic uncertainty of PCa.

Chest Compression Fraction between Mechanical Compressions on a Reducible Stretcher and Manual Compressions on a Standard Stretcher during Transport in Out-of-Hospital Cardiac Arrests: The Ambulance Stretcher Innovation of Asian Cardiopulmonary Resuscitation (ASIA-CPR) Pilot Trial.

BACKGROUND: Cardiopulmonary resuscitation (CPR) with the use of mechanical devices is recommended during ambulance transport. However, the CPR quality en route and while in transfer to the emergency department (ED) for out-of-hospital cardiac arrests (OHCAs) remains uncertain. We developed a mechanical CPR device outfitted on a reducible stretcher (M-CPR) and compared with standard manual CPR on a standard stretcher (S-CPR) to evaluate CPR quality. METHODS: Adult OHCAs transported by five ambulances in a metropolitan area with a population of 3.5 million (many of whom lived in high-rise buildings) from September to October (before-phase) and November to December (after-phase) in 2015 were collected. The reducible stretcher was developed for use in a small elevator during the transfer from scene to ambulance, and the AutoPulse® (ZOLL Medical, Chelmsford, MA, USA) was used for M-CPR. Chest compression fraction (CCF) was measured by transthoracic impedance data using an X-series® cardiac monitor (ZOLL Medical) during time from attachment to patient to arrival to the ED. A comparison of CCF using a Wilcoxon signed-rank test evaluated the difference between the before- and after-phases. RESULTS: Of the eligible 49 OHCAs, 31 (21 in the before-phase and 10 in the after-phase) were analyzed, excluding patients for whom CCF was not measured, for whom M-CPR was not used, who had a return of spontaneous circulation in the field before transport, or who collapsed during transport. There were no differences in demographic data. Median total CCF (median, q1-q3) was significantly higher in the after-phase M-CPR group (85.2, 83.4-86.3) than in the before-phase S-CPR group (80.1, 68.0-85.2) (p = 0.03). CONCLUSION: Mechanical CPR on the reducible stretcher during the transport of OHCAs to the ED showed a much higher chest compression fraction than standard manual CPR.

Quality between mechanical compression on reducible stretcher versus manual compression on standard stretcher in small elevator.

OBJECTIVES: Manual cardiopulmonary resuscitation (CPR) during vertical transport in small elevators using standard stretcher for out-of-hospital cardiac arrest can raise concerns with diminishing quality. Mechanical CPR on a reducible stretcher (RS-CPR) that can be shortened in the length was tested to compare the CPR quality with manual CPR on a standard stretcher (SS-CPR). METHODS: A randomized crossover manikin simulation was designed. Three teams of emergency medical technicians were recruited to perform serial CPR simulations using two different protocols (RS-CPR and SS-CPR) according to a randomization; the first 6 minutes of manual CPR at the scene was identical for both scenarios and two different protocols during vertical transport in a small elevator followed on a basis of cross-over assignment. The LUCAS-2 Chest Compression System (Zolife AB, Lund, Sweden) was used for RS-CPR. CPR quality was measured using a resuscitation manikin (Resusci Anne QCPR, Laerdal Medical, Stavanger, Norway) in terms of no flow fraction, compression depth, and rate (median and IQR). RESULTS: A total of 42 simulations were analyzed. CPR quality did not differ significantly at the scene. No flow fraction (%) was significantly lower when the stretcher was moving in RS-CPR then SS-CPR (36.0 (33.8-38.7) vs 44.0 (36.8-54.4), P< .01). RS-CPR showed significantly better quality than SS-CPR; 93.2 (50.6-95.6) vs 14.8 (0-20.8) for adequate depth (P< 0.01), and 97.5 (96.6-98.2) vs 68.9(43.4-78.5) for adequate rate (P< .01). CONCLUSION: Mechanical CPR on a reducible stretcher during vertical transport showed significant improvement in CPR quality in terms of no-flow fraction, compression depth, and rate compared with manual CPR on a standard stretcher.

The scene time interval and basic life support termination of resuscitation rule in adult out-of-hospital cardiac arrest.

We validated the basic life support termination of resuscitation (BLS TOR) rule retrospectively using Out-of-Hospital Cardiac Arrest (OHCA) data of metropolitan emergency medical service (EMS) in Korea. We also tested it by investigating the scene time interval for supplementing the BLS TOR rule. OHCA database of Seoul (January 2011 to December 2012) was used, which is composed of ambulance data and hospital medical record review. EMS-treated OHCA and 19 yr or older victims were enrolled, after excluding cases occurred in the ambulance and with incomplete information. The primary and secondary outcomes were hospital mortality and poor neurologic outcome. After calculating the sensitivity (SS), specificity (SP), and the positive and negative predictive values (PPV and NPV), tested the rule according to the scene time interval group for sensitivity analysis. Of total 4,835 analyzed patients, 3,361 (69.5%) cases met all 3 criteria of the BLS TOR rule. Of these, 3,224 (95.9%) were dead at discharge (SS,73.5%; SP,69.6%; PPV,95.9%; NPV, 21.3%) and 3,342 (99.4%) showed poor neurologic outcome at discharge (SS, 75.2%; SP, 89.9%; PPV, 99.4%; NPV, 11.5%). The cut-off scene time intervals for 100% SS and PPV were more than 20 min for survival to discharge and more than 14 min for good neurological recovery. The BLS TOR rule showed relatively lower SS and PPV in OHCA data in Seoul, Korea.

Scientific framework for research on disaster and mass casualty incident in Korea: building consensus using Delphi method.

We aimed to determine the scientific framework for research on disaster and mass casualty incident (MCI) in Korea, especially Korean terminology, feasible definition, and epidemiologic indices. The two staged policy Delphi method was performed by instructors of National Disaster Life Support (NDLS®) with the constructed questionnaire containing items based on the literature review. The first-stage survey was conducted by 11 experts through two rounds of survey for making issue and option. The second-stage survey was conducted by 35 experts for making a generalized group based consensus. Experts were selected among instructors of National Disaster Life Support Course. Through two staged Delphi survey experts made consensus: 1) the Korean terminology "jaenan" with "disaster" and "dajung-sonsang-sago" with "MCI"; 2) the feasible definition of "disaster" as the events that have an effect on one or more municipal local government area (city-county-district) or results in ≥ 10 of death or ≥ 50 injured victims; 3) the feasible definition of MCI as the events that result in ≥ 6 casualties including death; 4) essential 31 epidemiologic indices. Experts could determine the scientific framework in Korea for research on disaster medicine, considering the distinct characteristics of Korea and current research trends.

Differentiation Between Invasive Adenocarcinoma and Focal Interstitial Fibrosis among Persistent Pulmonary Part-solid Nodules: With Emphasis on the CT Morphologic Analysis.

PURPOSE: Focal interstitial fibrosis (FIF) manifesting as a persistent part-solid nodule (PSN) has been mistakenly treated surgically due to similar imaging features to invasive adenocarcinoma (ADC). The purpose of this study was to observe predictive imaging features correlated with FIF through CT morphologic analysis. MATERIALS AND METHODS: From January 2009 to December 2020, 44 patients with surgically proven FIF in a single institution were enrolled and compared with 88 ADC patients through propensity score matching. Patient characteristics and CT morphologic analysis of persistent PSNs were used to identify predictive imaging features of FIF. Receiver operating characteristic (ROC) curve analysis was used to quantify the performance of imaging features. RESULTS: A total of 132 patients with 132 PSNs (44 FIF, 88 ADC; mean age, 67.7±7.58; 75 females) were involved in our analysis. Multivariable analysis demonstrated that preserved peritumoral vascular margin (preserved vascular margin), preserved secondary pulmonary lobule margin (preserved lobular margin), and lower coronal to axial ratio (C/A ratio; cutoff: 1.005) were significant independent predictors of FIF (P<0.05). ROC curve analysis to evaluate the predictive value of the logistic model based on the imaging features of FIF, and the AUC value was 0.881. CONCLUSION: CT imaging features of preserved vascular margin, preserved lobular margin, and lower C/A ratio (cutoff, <1.005) might be helpful imaging features in discriminating FIF over ADC among persistent PSN in clinical practice.

Incidence and mortality rates of disasters and mass casualty incidents in Korea: a population-based cross-sectional study, 2000-2009.

The objective of study was to evaluate the incidence and mortality rates of disasters and mass casualty incidents (MCIs) over the past 10 yr in the administrative system of Korea administrative system and to examine their relationship with population characteristics. This was a population-based cross-sectional study. We calculated the nationwide incidence, as well as the crude mortality and injury incidence rates, of disasters and MCIs. The data were collected from the administrative database of the National Emergency Management Agency (NEMA) and from provincial fire departments from January 2000 to December 2009. A total of 47,169 events were collected from the NEMA administrative database. Of these events, 115 and 3,079 cases were defined as disasters and MCIs that occurred in Korea, respectively. The incidence of technical disasters/MCIs was approximately 12.7 times greater than that of natural disasters/MCIs. Over the past 10 yr, the crude mortality rates for disasters and MCIs were 2.36 deaths per 100,000 persons and 6.78 deaths per 100,000 persons, respectively. The crude injury incidence rates for disasters and MCIs were 25.47 injuries per 100,000 persons and 152 injuries per 100,000 persons, respectively. The incidence and mortality of disasters/MCIs in Korea seem to be low compared to that of trend around the world.

The impact of deep learning reconstruction in low dose computed tomography on the evaluation of interstitial lung disease.

To evaluate the effect of the deep learning model reconstruction (DLM) method in terms of image quality and diagnostic agreement in low-dose computed tomography (LDCT) for interstitial lung disease (ILD), 193 patients who underwent LDCT for suspected ILD were retrospectively reviewed. Datasets were reconstructed using filtered back projection (FBP), adaptive statistical iterative reconstruction Veo (ASiR-V), and DLM. For image quality analysis, the signal, noise, signal-to-noise ratio (SNR), blind/referenceless image spatial quality evaluator (BRISQUE), and visual scoring were evaluated. Also, CT patterns of usual interstitial pneumonia (UIP) were classified according to the 2022 idiopathic pulmonary fibrosis (IPF) diagnostic criteria. The differences between CT images subjected to FBP, ASiR-V 30%, and DLM were evaluated. The image noise and BRISQUE scores of DLM images was lower and SNR was higher than that of the ASiR-V and FBP images (ASiR-V vs. DLM, p < 0.001 and FBP vs. DLR-M, p < 0.001, respectively). The agreement of the diagnostic categorization of IPF between the three reconstruction methods was almost perfect (κ = 0.992, CI 0.990-0.994). Image quality was improved with DLM compared to ASiR-V and FBP.

A Comparative Study of Thoracoscopic Left Atrial Appendage Clipping vs Stapled Resection.

BACKGROUND: The left atrial appendage (LAA) is the predominant site of thrombus formation in atrial fibrillation (AF), which is associated with ischemic stroke. This study comparatively evaluated the complete LAA closure rates between LAA clipping and stapled resections. METHODS: The study included 333 patients who underwent thoracoscopic operation with both preoperative and postoperative computed tomographic scans. Propensity score matching (4:1 ratio) was applied, matching 90 LAA clipping patients with 206 stapled resection patients. The primary end point was complete LAA closure, defined as a residual LAA depth of <1 cm on computed tomographic images obtained 1 year postoperatively. RESULTS: No 30-day death was observed. Complete LAA closure was achieved in 85.9% (286 of 333) of patients. After propensity score matching, the clipping group demonstrated a significantly higher complete LAA closure rate than the stapled resection group (95.6% vs 83.0%, P = .003). The residual LAA stump depth was also shorter in the clipping group compared with the stapled resection group (2.9 vs 5.3 mm, P = .001). Two patients with a residual LAA stump exhibited an association with ischemic stroke during follow-up. CONCLUSIONS: The clipping group demonstrated a higher rate of complete LAA closure compared with the stapled resection group. Close monitoring of patients with residual LAA stumps is essential. Further research with larger cohorts is needed to elucidate impact of the residual LAA stump on thromboembolic events.

Diagnostic accuracy of focused assessment with sonography for trauma (FAST) examinations performed by emergency medical technicians.

OBJECTIVE: We aimed to assess the diagnostic accuracy of focused assessment with sonography for trauma (FAST) examinations when used by emergency medical technicians (EMTs) to detect the presence of free abdominal fluid. METHODS: Six level 1 EMTs (similar to intermediate EMTs in the United States) who worked at a tertiary emergency department in Korea underwent an educational program consisting of two one-hour didactic lectures that included the principles of ultrasonography, the anatomy of the abdomen, and two hours of hands-on practice. After this educational session, the EMTs performed FAST examinations on a convenience sample of patients from July 1 to October 5, 2009. These patients also received an abdominal computed tomography (CT) scan regardless of their chief complaints. The CT findings served as the definitive standard and were interpreted routinely and independently by emergency radiologists who were blinded to the study protocol. In addition, the EMTs were blinded to the CT findings. A positive CT finding was defined as the presence of free fluid, as interpreted by the radiologist. The sensitivity, specificity, predictive values, and their 95% confidence intervals (CIs) were calculated. Informed consent was obtained from all participating patients. RESULTS: Among the 1,060 eligible patients with abdominal CT scans, 403 patients were asked to participate in the study, and 240 patients agreed. Of these 240 patients, 80 (33.3%) had results showing the presence of free fluid. Fourteen patients had a significant amount of peritoneal cavity fluid, 15 had a moderate amount of peritoneal cavity fluid, and 51 had a minimal amount of peritoneal cavity fluid. Compared with the CT findings, the diagnostic performance of the FAST examination had a sensitivity of 61.3% (95% CI, 50.3%-71.2%), specificity of 96.3% (95% CI, 92.1%-98.3%), positive predictive value of 89.1% (95% CI, 77.0%-95.4%), and negative predictive value of 83.2% (95% CI, 76.9%-88.2%). For a significant or moderate amount of peritoneal cavity fluid, the sensitivity was considerably higher (86.2%). CONCLUSION: EMTs in Korea showed a high diagnostic performance that was comparable to that of surgeons and physicians when detecting peritoneal cavity free fluid in a Korean emergency department setting. The validity of FAST examinations in prehospital care situations should be investigated further.

Characteristics and outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI: implications for management of cystic lesions.

BACKGROUND: Chest MRI is a useful diagnostic modality for the evaluation of anterior mediastinal lesions but the outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI are unclear. METHODS: In this multicenter retrospective study, patients who underwent contrast-enhanced chest MRI in two tertiary centers to assess anterior mediastinal cystic lesions were included after excluding overt solid tumors and thymic hyperplasia. Anterior mediastinal cystic lesions were classified into two categories: probable (simple) cyst or indeterminate lesion (complex cyst). Size and imaging features of lesions during follow-up were evaluated and clinical outcomes were assessed. RESULTS: A total of 204 patients (mean age, 59 ± 11 years; M:F = 111:93) were studied; 186 (91.2%) were classified as probable cysts and 18 (8.8%) as indeterminate lesions on MRI. Among patients with probable cysts and more than 2 years of follow-up, lesion size was unchanged in 39.6% (36/91), decreased in 16.5% (15/91), and fluctuated in 8.8% (8/91). All patients who underwent surgery were confirmed cysts. None developed mural nodules or irregular wall thickening, suspicious for malignancy during follow-up. In patients with indeterminate lesions, 16.7% (3/18) had pathologically confirmed thymoma and 44.4% (8/18) had proven cysts. Follow-up numbers and intervals after MRI in patients with probable cysts were variable among physicians and institutions in clinical practice (p < 0.05) but more than half were followed for up to 2 years in two centers. CONCLUSION: Diagnosing anterior mediastinal cysts using MRI is reliable. MRI-based management of anterior mediastinal lesions may reduce the number of unnecessary follow-ups and surgeries.

Incidence and risk factors for sternal osteomyelitis after median sternotomy.

Background: Sternal osteomyelitis (OM) after median sternotomy is the rarest form of deep sternal wound infections (DSWIs). A retrospective study was implemented to evaluate the incidence and potential risk factors of sternal OM after median sternotomy. Methods: We analyzed 3,410 consecutive patients who underwent cardiothoracic surgery via median sternotomy from January 2005 to December 2019 at our institution. A sternal OM and control group without any sign of wound infections after median sternotomy were selected. Comparisons of the variables between the two groups were performed using the Student's t-test and Fisher's exact tests. The association of potential risk factors with sternal OM was tested by logistic regression analysis. Results: A total of 16 patients (0.47%) had sternal OM after median sternotomy. None of the variables were different between the sternal OM patients and the control group including body mass index (BMI), diabetes mellitus (DM), hypertension (HTN), left ventricle (LV) function, transfusion, operation time, cardiopulmonary bypass (CPB) time and intensive care unit and ventilator days. By univariate analysis, none of the variables were associated with an increased risk of sternal OM. Conclusions: The incidence of sternal OM after median sternotomy in our institution was 0.47% and there was no correlation between the known risk factors of DSWI and sternal OM in our study.

CT findings of basaloid squamous cell carcinoma of the lung in 12 patients: A distinct category of squamous cell carcinoma in 2015 WHO classification of lung tumors.

ABSTRACT: Basaloid squamous cell carcinoma (SCC) is very rare subtype of SCC of the lung and it is important to distinguish basaloid to other subtypes of SCCs, since the prognosis of basaloid subtype is considered poorer than that of other non-basaloid subtypes of SCCs. Aim of this study was to assess computed tomography (CT) findings of basaloid SCC of the lung in 12 patients.From January 2016 to April 2021, 12 patients with surgically proven basaloid SCC of the lung were identified. CT findings were analyzed, and the imaging features were compared with histopathologic reports. Clinical and demographic features were also analyzed.Axial location of the tumor was central in 5 patients, while 7 was in peripheral. Of the 7 patients whose tumors were located in the peripheral, margin of the tumor were smooth (n  = 2), lobulated (n  = 2), or spiculated (n  = 3). After contrast injection, net enhancement value ranged from 15.8 to 71.8 HU (median, 36.4 HU). Endobronchial growth were seen in 5 patients and these patients accompanied obstructive pneumonia or atelectasis. Internal profuse necrosis, cavitation, or calcifications were not seen.On CT, basaloid squamous cell presents as solitary nodule or mass with moderate enhancement. Tumor was located either peripheral or central compartment of the lung and cavitation was absent.

Reappraising the clinical usability of consolidation-to-tumor ratio on CT in clinical stage IA lung cancer.

OBJECTIVES: Ground-glass opacity (GGO) on computed tomography is associated with prognosis in early-stage non-small cell lung cancer (NSCLC) patients. However, the stratification of the prognostic value of GGO is controversial. We aimed to evaluate clinicopathologic characteristics of early-stage NSCLC based on the consolidation-to-tumor ratio (CTR), conduct multi-pronged analysis, and stratify prognosis accordingly. METHODS: We retrospectively investigated 944 patients with clinical stage IA NSCLC, who underwent curative-intent lung resection between August 2018 and January 2020. The CTR was measured and used to categorize patients into six groups (1, 0%; 2, 0-25%; 3, 25-50%; 4, 50-75%; 5, 75-100%; and 6, 100%). RESULTS: Pathologic nodal upstaging was found in 1.8% (group 4), 9.0% (group 5), and 17.4% (group 6), respectively. The proportion of patients with a high grade of tumor-infiltrating lymphocytes tended to decrease as the CTR increased. In a subtype analysis of patients with adenocarcinoma, all of the patients with predominant micro-papillary patterns were in the CTR > 50% groups, and most of the patients with predominant solid patterns were in group 6 (47/50, 94%). The multivariate analysis demonstrated that CTR 75-100% (hazard ratio [HR], 3.85; 95% confidence interval [CI], 1.58-9.36) and CTR 100% (HR, 5.58; 95% CI, 2.45-12.72) were independent prognostic factors for DFS, regardless of tumor size. CONCLUSION: We demonstrated that the CTR could provide various noninvasive clinicopathological information. A CTR of more than 75% is the factor associated with a poor prognosis and should be considered when making therapeutic plans for patients with early-stage NSCLC.

The effects of a community-based disaster drill of simulating Disaster Medical Assistance Team (DMAT) on the knowledge and attitudes.

BACKGROUND: We evaluated the effects of community-based disaster drill of simulating disaster medical assistance team on the knowledge and the attitudes. METHODS: Eight hours disaster drills, including didactic lectures, table simulation, and outdoor field simulation, were developed for participants who were recruited from community health centers, emergency departments, fire stations, emergency medical technicians' academy, and emergency information center in the Seoul Metropolitan City area from 2006 to 2008. We surveyed on the knowledge and the attitude using designed questionnaire before and after drill. We compared changes using t-test and repeated measure ANOVA. RESULTS: In this study, 14 community-based drills were performed and 525 (79.4%) people responded to both pre- and post-drill survey. Of these, the doctor was the second common occupation (26.9%) after volunteer students (47.1%). Overall, knowledge and attitude score significantly increased from 3.9±1.0 to 4.3±0.9 (p<0.001) and from 21.4±3.4 to 22.4±3.2 (p<0.001), respectively. The difference among professional license groups between pre- and post-drill knowledge level was significant (p=0.03), while the difference among jobs for attitude between pre- and post-drill was not different (p=0.78). CONCLUSION: Disaster drills on the establishment and operation of DMAT may affect both knowledge and attitude of participants positively.

Comparison between dispatcher-assisted bystander CPR and self-led bystander CPR in out-of-hospital cardiac arrest (OHCA).

INTRODUCTION: Bystander cardiopulmonary resuscitation (CPR) is an important prognostic factor for outcome in out-of-hospital cardiac arrest (OHCA). The dispatcher-assisted (DA) bystander CPR program has increased the rate of bystander CPR by targeting bystanders with a lower level of CPR training. We evaluated the effects of dispatcher-assisted bystander CPR and self-led bystander CPR. METHODS: A retrospective analysis was performed using a nationwide OHCA database from 2014 to 2018. Adult EMS-treated OHCA patients with presumed cardiac origin were enrolled. OHCAs were classified into 3 groups according to the type of bystander CPR (DA bystander CPR vs. self-led bystander CPR vs. no bystander CPR) provided. The primary outcome was good neurologic recovery at hospital discharge. A multivariable logistic regression model was used to estimate the association between the type of bystander CPR and outcomes. RESULTS: A total of 91,557 eligible OHCA patients was enrolled in the final analysis. The proportion of patients with favorable neurologic outcomes was highest with self-led bystander CPR (9.0% for self-led bystander CPR, 5.2% for DA bystander CPR and 3.2% for no bystander CPR, p < 0.01). Self-led bystander CPR was associated with better neurological recovery than DA bystander CPR (aOR with 95% CI (DA-CPR as reference): 0.63 (0.58-0.69) for no bystander CPR, 1.28 (1.17-1.40) for self-led bystander CPR). CONCLUSION: Although DA CPR was associated with better neurologic outcomes than no bystander CPR, good neurologic outcomes were most strongly associated with self-led bystander CPR.

Association of Flow Rate of Prehospital Oxygen Administration and Clinical Outcomes in Severe Traumatic Brain Injury.

The goal of this study was to investigate the association of prehospital oxygen administration flow with clinical outcome in severe traumatic brain injury (TBI) patients. This was a cross-sectional observational study using an emergency medical services-assessed severe trauma database in South Korea. The sample included adult patients with severe blunt TBI without hypoxia who were treated by EMS providers in 2013 and 2015. Main exposure was prehospital oxygen administration flow rate (no oxygen, low-flow 1~5, mid-flow 6~14, high-flow 15 L/min). Primary outcome was in-hospital mortality. A total of 1842 patients with severe TBI were included. The number of patients with no oxygen, low-flow oxygen, mid-flow oxygen, high-flow oxygen was 244, 573, 607, and 418, respectively. Mortality of each group was 34.8%, 32.3%, 39.9%, and 41.1%, respectively. Compared with the no-oxygen group, adjusted odds (95% CI) for mortality in the low-, mid-, and high-flow oxygen groups were 0.86 (0.62-1.20), 1.15 (0.83-1.60), and 1.21 (0.83-1.73), respectively. In the interaction analysis, low-flow oxygen showed lower mortality when prehospital saturation was 94-98% (adjusted odds ratio (AOR): 0.80 (0.67-0.95)) and ≥99% (AOR: 0.69 (0.53-0.91)). High-flow oxygen showed higher mortality when prehospital oxygen saturation was ≥99% (AOR: 1.33 (1.01~1.74)). Prehospital low-flow oxygen administration was associated with lower in-hospital mortality compared with the no-oxygen group. High-flow administration showed higher mortality.

Botryoid Wilms Tumor in a Neonate Presenting with Fetal Hydronephrosis: A Case Report.

Botryoid Wilms tumor, a very rare variant of Wilms tumor, arises from the pelvocalyceal system, and its occurrence in the fetal or neonatal period has never been reported in the literature. Herein, we report an exceedingly rare and challenging case of botryoid Wilms tumor in a neonate who initially presented with fetal hydronephrosis. Postnatal ultrasonography revealed multiple lobulating hypoechoic masses with varying degrees of intralesional vascularity within the dilated pelvocalyceal system. To our knowedge, this is a case report of botryoid Wilms tumor of the youngest child in English literature.

Development of a modified trauma and injury severity score to predict disability in acute trauma patients.

OBJECTIVE: The Trauma and Injury Severity Score (TRISS) has been used to predict trauma patient mortality and to assess the quality of trauma care systems. The goal of this investigation was to develop a modified trauma-related injury severity score (termed the TRISS-D) for predicting disability in acute trauma patients. METHODS: We used data collected by emergency medical services and entered into the Korea Centers for Disease Control and Prevention severe trauma database. The TRISS-D was based on age category (0-14, 15-54, ≥55 years), the Revised Trauma Score, and the Injury Severity Score. The outcome measures were severe disability and worsening disability. Worsening disability was defined as a lower Glasgow Outcome Scale score at hospital discharge than before the traumatic incident. Two types of cases were examined: those with penetrating or blunt injuries (group 1) and those with severe head injuries (group 2). We assessed the discriminatory power of the TRISS-D by calculating the area under a receiver operating characteristic curve (AUROC). RESULTS: The database comprised 14,791 patients; overall, 3,757 (25%) had severe disability and 6,018 (41%) had worsening disability. For severe disability, the AUROC (95% confidence interval) for the TRISS-D was 0.948 (0.944-0.952) in group 1 and 0.950 (0.946-0.954) in group 2. The corresponding values for worsening disability were 0.810 (0.803-0.817) and 0.816 (0.809-0.823), respectively. CONCLUSION: The TRISS-D showed excellent discriminatory power for severe disability and very good discriminatory power for worsening disability.