bluuebunny/crossref_metadata_2025 huggingface dataset:
MOF‐Derived Metal Oxide Composites for Advanced Electrochemical Energy Storage
Authors: Li Yan , Xu Yuxia , Yang Wenping , Shen Wanxin , Xue Huaiguo , Pang Huan
Published: May 2018

Over the past two decades, metal–organic frameworks (MOFs), a type of porous material, have aroused great interest as precursors or templates for the derivation of metal oxides and composites for the next generation of electrochemical energy storage applications owing to their high specific surface areas, controllable structures, and adjustable pore sizes. The electrode materials, which affect the performance in practical applications, are pivotal components of batteries and supercapacitors. Metal oxide composites derived from metal–organic frameworks possessing high reversible capacity and superior rate and cycle performance are excellent electrode materials. In this Review, potential applications for MOF‐derived metal oxide composites for lithium‐ion batteries, sodium‐ion batteries, lithium–oxygen batteries, and supercapacitors are studied and summarized. Finally, the challenges and opportunities for future research on MOF‐derived metal oxide composites are proposed on the basis of academic knowledge from the reported literature as well as from experimental experience.
Strategies toward High‐Performance Cathode Materials for Lithium–Oxygen Batteries
Authors: Wang Kai‐Xue , Zhu Qian‐Cheng , Chen Jie‐Sheng
Published: May 2018

Rechargeable aprotic lithium (Li)–O2 batteries with high theoretical energy densities are regarded as promising next‐generation energy storage devices and have attracted considerable interest recently. However, these batteries still suffer from many critical issues, such as low capacity, poor cycle life, and low round‐trip efficiency, rendering the practical application of these batteries rather sluggish. Cathode catalysts with high oxygen reduction reaction (ORR) and evolution reaction activities are of particular importance for addressing these issues and consequently promoting the application of Li–O2 batteries. Thus, the rational design and preparation of the catalysts with high ORR activity, good electronic conductivity, and decent chemical/electrochemical stability are still challenging. In this Review, the strategies are outlined including the rational selection of catalytic species, the introduction of a 3D porous structure, the formation of functional composites, and the heteroatom doping which succeeded in the design of high‐performance cathode catalysts for stable Li–O2 batteries. Perspectives on enhancing the overall electrochemical performance of Li–O2 batteries based on the optimization of the properties and reliability of each part of the battery are also made. This Review sheds some new light on the design of highly active cathode catalysts and the development of high‐performance lithium–O2 batteries.
Controlled Propulsion of Two‐Dimensional Microswimmers in a Precessing Magnetic Field
Authors: Tottori Soichiro , Nelson Bradley J.
Published: May 2018

Magnetically actuated micro‐/nanoswimmers can potentially be used in noninvasive biomedical applications, such as targeted drug delivery and micromanipulation. Herein, two‐dimensional (2D) rigid ferromagnetic microstructures are shown to be capable of propelling themselves in three dimensions at low Reynolds numbers in a precessing field. Importantly, the above propulsion relies neither on soft structure deformation nor on the geometrical chirality of swimmers, but is rather driven by the dynamic chirality generated by field precession, which allows an almost unconstrained choice of materials and fabrication methods. Therefore, the swimming performance is systematically investigated as a function of precession angle and geometric design. One disadvantage of the described propulsion method is that the fabricated 2D swimmers are achiral, which means that the forward/backward swimming direction cannot be controlled. However, it has been found that asymmetric 2D swimmers always propel themselves toward their longer arm, which implies that dynamic chirality can be constrained to be either right‐handed or left‐handed by permanent magnetization. Thus, the simplicity of fabrication and possibility of dynamic chirality control make the developed method ideal for applications and fundamental studies that require a large number of swimmers.
Effect of Microstructure Evolution on Micro/Nano‐Mechanical Property of Fe–Co–Ni Ternary Alloys Solidified under Microgravity Condition
Authors: Liu Wei , Chang Jian , Wang Haipeng
Published: May 2018

Rapid solidification of highly undercooled Fe–Co–Ni alloys is realized by drop tube technique. The microstructures of Fe–10%Co–10%Ni, Fe–15.6%Co–12%Ni, and Fe–10%Co–20%Ni alloys are all composed of single α(Fe) solid solution phase, which are confirmed by the results of XRD and DSC. With the decrease of droplet diameters, the cooling rate and undercooling increase, meanwhile, the microstructural characteristic of α(Fe) phase transforms from coarse dendrites to equiaxed grains. The size of coarse dendrites decreases to one tenth for the refined equiaxed grains. Employing the Vickers hardness and nano indenter techniques, the mechanical properties of α(Fe) dendrites are investigated. The average Vickers microhardness of α(Fe) phase is remarkably enhanced with the decrease of the grain size. Due to the more homogenous solute distribution in the dendrite trunks, the nanohardness presents a gentle fluctuation. Once the droplet diameter exceeds a critical value, the solutes concentrate at the grain boundaries. As a result, the closer the indenters to the grain boundary, the larger the nanohardness.
Combined Effect of Phosphorus Grain Boundary Segregation, Yield Strength, and Grain Size on Embrittlement of a Cr–Mo Low‐Alloy Steel
Authors: Zhao Yu , Song Shenhua
Published: May 2018

The dependence of fracture appearance transition temperature (FATT) on phosphorus grain boundary segregation, yield strength, and grain size is experimentally evaluated for a 2.25Cr–1Mo low‐alloy steel. Both the phosphorus boundary segregation and yield strength are directly correlated to the FATT of the steel. However, the prior austenite grain size is not directly linked to the FATT although it influences phosphorus boundary segregation and yield strength. The FATT exhibits linear relations to phosphorus segregation concentration and yield strength, but there is no synergistic effect between these two entities. Based on the measurements, an embrittlement equation is established, which is expressed as FATT(°C) = 0.25σs + 2.64CP–270, where σs is the yield strength in MPa and CP is the phosphorus boundary concentration in at%. The calculated FATTs have a good agreement with the measured ones.
Shaking table test and numerical simulation on a vertical hybrid structure under seismic excitation
Authors: Lu Zheng , Li Junzuo , Zhou Ying
Published: May 2018

A shaking table test of a 12‐story steel/reinforced concrete (S/RC) frame, which is composed of a 4‐story steel frame in the higher part, a 1‐story S/RC frame as a transition story in the middle part, and a 7‐story reinforced concrete (RC) frame in the lower part of the model, has been conducted, and its results are compared with those of a standard 12‐story RC frame to evaluate seismic performance of this S/RC frame. The numerical simulation on such hybrid frame structure has been performed and validated by the above experimental results. It is found that irregular lateral‐stiffness distribution along structural height will not only increase rotation at the joint of boundary between transition story and steel frame or concrete frame but also enlarge rotation at such joint and lead to more obvious rigid deformation in steel frame of S/RC frame, which will undoubtedly intensify bending failure. Meanwhile, acceleration response of the upper steel frame will reach its peak when characteristic site period is near the counterpart of the upper steel frame. Further, the maximum interstory drift under frequent earthquake excitation is at the lower substructure, namely, the RC frame, but this is not the case in rare earthquake situation. When it comes to determining damping ratio for vertical hybrid structure, a general method for engineering, which takes concrete and steel damping ratio for the whole structure analysis and then gets envelopes of these results for design, may yield conservative results. Meanwhile, such method may underestimate responses near the transition story.
Effect of a relatively long afternoon nap on autonomous nervous activity, sleep architecture, and subjective sleep quality
Authors: Jiang Fang , Kobayashi Takemi , Ichihashi Takurou , Nomura Shusaku
Published: May 2018

Post‐lunch sleepiness and deterioration in performance, or ‘post‐lunch dip’, is considered a part of the biological rhythm. A short nap is a promising countermeasure to the post‐lunch dip. Compared to the extensive studies on the effects of a short nap, there is limited research on the physiological impact of a relatively long nap such as 60 min or more in the afternoon. Forty‐three male university students with normal sleep–wake cycles were assigned to two groups: group 1 slept for 6 h from 0:00 to 6:00, and group 2 napped for 2 h from 13:15 to 15:15. There was no prominent difference in the subjective quality of sleep between the groups. This was supported by the lack of any significant difference in sleep efficiency and latency between the groups. Additionally, the heart rate after the afternoon nap was significantly higher than the baseline level before nap (overshoot), whereas the heart rate in the morning was the same as recorded the night before. The relatively long afternoon nap may be comparable with a night's sleep in terms of sleep quality, whereas it may enhance greater autonomic arousal after awakening than that in the morning. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Fetal blood‐gas values during fetoscopic myelomeningocele repair performed under carbon dioxide insufflation
Authors: Baschat A. A. , Ahn E. S. , Murphy J. , Miller J. L.
Published: May 2018

Fetoscopic myelomeningocele (MMC) repair is performed using intrauterine carbon dioxide (CO2) insufflation. Sheep experiments have shown that CO2 insufflation is associated with significant fetal acidemia; however, corresponding data for human pregnancy are not available. We performed umbilical venous cord blood sampling in three patients during fetoscopic MMC repair at 25 + 1, 25 + 3 and 24 + 0 weeks' gestation, respectively. Fetal venous pH at the beginning of CO2 insufflation was 7.36, 7.46 and 7.37, respectively in the three fetuses, and repeat values were 7.28, 7.35 and 7.36 after 181, 159 and 149 min, respectively. The partial pressure of oxygen and CO2 was maintained in the normal range during these times, and pH decrease was less in Patient 3 who received humidified CO2 insufflation. Our observations suggest that, in contrast to sheep experiments, CO2 insufflation during fetoscopic myelomeningocele repair does not cause acidemia in human fetuses. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
δ‐Open set clustering—A new topological clustering method
Authors: Wang Shuliang , Li Qi , Yuan Hanning , Li Deren , Geng Jing , Zhao Chuanfeng , Lei Yimeng , Liu Chuanlu , Liu Chengfei
Published: May 2018

Clustering is an unsupervised learning method widely used for identifying the inherent data structure and applied to various fields such as data mining, patter recognition, machine learning, and others. A new topological clustering method called δ‐open set clustering is proposed in this study. The key idea of this method is to determine δ‐open sets in data, for which each δ‐open set represents one specific category of data. It is shown that this method has robust performance even for complex data set. It can classify the complex type of data sets coming with diverse shapes, recognize noise and deal with data set of high dimensionality. This method is effective even when the distribution of data is unbalanced. In the clustering process, one requires a single input parameter, namely the value of δ. A face identification experiment on the Olivetti Face Database indicates that this method performs much more reliably than the peak clustering method. We also provide another improved δ‐open set clustering that makes δ‐open set clustering capable of handling clusters with extreme density difference.

This article is categorized under:

Technologies > Structure Discovery and Clustering

Algorithmic Development > Structure Discovery
Patients’ Views of Treatment‐Focused Genetic Testing (TFGT): Some Lessons for the Mainstreaming of BRCA1 and BRCA2 Testing
Authors: Wright Sarah , Porteous Mary , Stirling Diane , Lawton Julia , Young Oliver , Gourley Charlie , Hallowell Nina
Published: May 2018

This paper explores patients’ views and experiences of undergoing treatment‐focused BRCA1 and BRCA2 genetic testing (TFGT), either offered following triaging to clinical genetics (breast cancer) or as part of a mainstreamed care pathway in oncology (ovarian cancer). Drawing on 26 in‐depth interviews with patients with breast or ovarian cancer who had undergone TFGT, this retrospective study examines patients’ views of genetic testing at this point in their care pathway, focusing on issues, such as initial response to the offer of testing, motivations for undergoing testing, and views on care pathways. Patients were amenable to the incorporation of TFGT at an early stage in their cancer care irrespective of (any) prior anticipation of having a genetic test or family history. While patients were glad to have been offered TFGT as part of their care, some questioned the logic of the test's timing in relation to their cancer treatment. Crucially, patients appeared unable to disentangle the treatment role of TFGT from its preventative function for self and other family members, suggesting that some may undergo TFGT to obtain information for others rather than for self.
Luminosity in the stream of consciousness
Authors: Jenkins David
Published: May 2018

Williamson’s (Knowledge and its limits, Oxford University Press, Oxford, 2000, Chapter 4) “anti-luminosity” argument aims to establish that there are no significant luminousconditions. “Far from forming a cognitive home”, luminous conditions are mere “curiosities” (2000, p. 109). Even supposing Williamson’s argument succeeds in showing that there are no significant luminousstateshis conclusion has not thereby been established. When it comes to determining what is luminous, mentaleventsandprocessesare among the best candidates. It is events and processes, after all, which constitute the stream of consciousness. Judgment, for instance, is plausibly self-conscious. If I am judging then plausibly I must know that I am. Similarly, deliberation is plausibly self-conscious. To be deliberating about some matter I plausibly must know that I am.That one is judgingandthat one is deliberatingare thus plausibly luminous conditions. Furthermore, I argue, Williamson’s anti-luminosity argument fails to speak against this suggestion. This reveals that Williamson’s argument is more limited in scope than has been thought—something likely missed due to a misplaced focus on mental states in the luminosity debate as well as in epistemology and the philosophy of mind more generally. For all Williamson shows, there may be luminous events and processes of a sort apt to constitute a cognitive home. I conclude by considering how the anti-luminosity argument might be reinstated in the judgment case and argue that the natural way to do so fails.
LO38: Does spaced instructional design result in improved retention of pediatric resuscitation skills? A randomized education study
Authors: Patocka C. , Cheng A. , Sibbald M. , Duff J. , Lai A. , Lee-Nobbee P. , Levin H. , Varshney T. , Weber B. , Abedin T. , Bhanji F.
Published: May 2018

Introduction: Survival from cardiac arrest has been linked to the quality of resuscitation care. Unfortunately, healthcare providers frequently underperform in these critical scenarios, with a well-documented deterioration in skills weeks to months following advanced life support courses. Improving initial training and preventing decay in knowledge and skills are a priority in resuscitation education. The spacing effect has repeatedly been shown to have an impact on learning and retention. Despite its potential advantages, the spacing effect has seldom been applied to organized education training or complex motor skill learning where it has the potential to make a significant impact. The purpose of this study was to determine if a resuscitation course taught in a spaced format compared to the usual massed instruction results in improved retention of procedural skills. Methods: EMS providers (Paramedics and Emergency Medical Technicians (EMT)) were block randomized to receive a Pediatric Advanced Life Support (PALS) course in either a spaced format (four 210-minute weekly sessions) or a massed format (two sequential 7-hour days). Blinded observers used expert-developed 4-point global rating scales to assess video recordings of each learner performing various resuscitation skills before, after and 3-months following course completion. Primary outcomes were performance on infant bag-valve-mask ventilation (BVMV), intraosseous (IO) insertion, infant intubation, infant and adult chest compressions. Results: Forty-eight of 50 participants completed the study protocol (26 spaced and 22 massed). There was no significant difference between the two groups on testing before and immediately after the course. 3-months following course completion participants in the spaced cohort scored higher overall for BVMV (2.2 ± 0.13 versus 1.8 ± 0.14, p=0.012) without statistically significant difference in scores for IO insertion (3.0 ± 0.13 versus 2.7± 0.13, p= 0.052), intubation (2.7± 0.13 versus 2.5 ± 0.14, p=0.249), infant compressions (2.5± 0.28 versus 2.5± 0.31, p=0.831) and adult compressions (2.3± 0.24 versus 2.2± 0.26, p=0.728) Conclusion: Procedural skills taught in a spaced format result in at least as good learning as the traditional massed format; more complex skills taught in a spaced format may result in better long term retention when compared to traditional massed training as there was a clear difference in BVMV and trend toward a difference in IO insertion.
LO42: How I stay healthy in emergency medicine: a qualitative analysis of a blog-based survey of expert emergency physicians and their methods to maintain and improve their wellness
Authors: Chou J. , Poonja Z. , Innes M. , Lin M. , Chan T. M. , Azan B. , Thoma B.
Published: May 2018

Introduction: Emergency medicine (EM) is a demanding specialty with high rates of physician burnout. As emergency physicians, we must stay healthy to promote healthy living, optimize our ability to care for our patients, extend our careers, and be there for our families. While we all desire a healthy lifestyle, maintaining one in practice can be difficult. We sought to investigate the strategies emergency physician employ to maintain and improve health and wellness while mitigating the professions stressors. Methods: From April 2015 to July 2017, forty-three wellness champions from Canada, the USA, and Australia were identified using a snowball sampling technique. Each participant answered 5 introductory questions and 8 productivity questions pertaining to health and wellness. These were transcribed and loaded to a publicly accessible blog, ALiEM.com, as part of the Healthy in EM series. Two investigators reviewed the transcripts using inductive methods and a grounded theory approach to generate themes and subthemes using coding software, NVivo (Burlington, Massachusetts), until saturation was achieved. Consensus between investigators (JC, ZP) established the master code and audit trail. An external audit by investigators (TC, BT) not involved with the initial analysis was performed to ensure reliability. Results: Major themes including diet, sleep, exercise and social activities were coded and further subcategorized along with perspectives, habits, personal philosophies, and career diversity. These themes translated across both professional and personal aspects of participants lives. For example, the pre-shift and post-shift strategies often included some form of regimented activities-of-daily-living that required discipline to adhere to at work and home. Conclusion: Our findings show the importance of homeostasis in the professional and personal realm among expert emergency medicine physicians. Among healthy emergency physicians, diet, sleep, and exercise patterns intertwined with perspectives, habits, personal philosophies, and social activities contributed to maintenance of wellness.
LO44: Optimizing skill retention in radiograph interpretation: a multicentre randomized control trial
Authors: Boutis K. , Carrier B. , Stimec J. , Pecarcic M. , Willan A. , Pusic M.
Published: May 2018

Introduction: Simulation-based education systems have increased physician skill in radiograph interpretation. However, the degree of skill retention and the factors that influence it are relatively unknown. The main objective of this research was to determine the rate and quantity of skill decay in post-graduate trainee physicians who completed a simulation-based learning intervention of radiograph interpretation. The impact of testing and refresher education on skill decay was also examined. Methods: This was a prospective, multicenter, analysis-blinded, four arm randomized control trial conducted from November 2014 to June 2016. Study interventions were administered using an on-line learning and measurement platform. Pediatric and emergency medicine residents in the United States and Canada were eligible for study participation. Participants were randomized to one of four groups. All participants completed an 80-case deliberately practiced learning set of pediatric elbow radiographs followed by an immediate 20-case post-test. Following this, Group 1 had no testing until 12 months; Groups 2, 3, and 4 had testing (20 cases without feedback) every 2 months until 12 months, but Group 3 also had refresher education (20 cases with feedback) at six months while Group 4 had refresher education at two, six, and ten months. The main outcome measure was accuracy at 12 months, adjusted for immediate post-test score, days to completion of 12 month test, and time on case. Based on prior data, we assumed the smallest important difference between groups in learning decay is 10%, a between-participant/within-group standard deviation of 17%, a type I error probability of 5%, a power of 80% and adjusted for three tests with a Bonferroni correction. For the primary analysis of Group 1 versus 2, 3, 4, this resulted in a minimal total sample size of 56, with 14 participants per group. Results: We enrolled 106 participants that completed all study interventions. The sample sizes in Groups 1, 2, 3, and 4 were 42, 22, 22, and 20 respectively. Overall, accuracy increased by 11.8% (95% CI 9.8, 13.8) with the 80-case learning set and then decreased by 5.5% (95% CI 2.5, 8.5) at 12 months. The difference in learning decay in Group 1 vs. Groups 2, 3, 4 was -8.1% (95% CI 2.5, 13.5), p=0.005. For Group 2 vs. Group 3 and 4, it was +0.8% (95% CI -7.2, 7.3), p=0.8, and between Group 3 vs. Group 4 it was +0.8% (95% CI -7.3, 10.1), p=0.8. Conclusion: Skill decay was significantly reduced by testing with 20 cases every two months. Refresher education had no additional effect to testing on reducing learning decay.
LO45: Incidence of delayed intracranial hemorrhage following a mild traumatic brain injury in patients taking anticoagulants or anti-platelets therapies: systematic review and meta-analysis
Authors: Emond M. , Laguë A. , O’Brien T. , Mitra B. , Tardif P. , Le Sage N. , Astous M. D , Mercier E.
Published: May 2018

Introduction: Head injury is a common presentation to all emergency departments. Previous research has shown that such injuries may be complicated by delayed intracranial hemorrhage (D-ICH) after the initial scan is negative. Exposure to anticoagulant or anti-platelet medications (ACAP) may be a risk factor for D-ICH. We have conducted a systematic review and meta-analysis to determine the incidence of delayed traumatic intracranial hemorrhage in patients taking anticoagulants, anti-platelets or both. Methods: The literature search was conducted in March 2017 with an update in April 2017. Keyword and MeSH terms were used to search OVID Medline, Embase and the Cochrane database as well as grey literature sources. All cohort and experimental studies were eligible for selection. Inclusion criteria included pre-injury exposure to oral anticoagulant and / or anti-platelet medication and a negative initial CT scan of the brain (CT1). The primary outcome was delayed intracranial hemorrhage present on repeat CT scan (CT2) within 48 hours of the presentation. Only patients who were rescanned or observed minimally were included. Clinically significant D-ICH were those that required neurosurgery, caused death or necessitated a change in management strategy, such as admission. Results: Fifteen primary studies were ultimately identified, comprising a total of 3801 patients. Of this number, 2111 had a control CT scan. 39 cases of D-ICH were identified, with the incidence of D-ICH calculated to be 1.31% (95% CI [0.56, 2.27]). No more than 12 of these patients had a clinically significant D-ICH representing 0.09% (95% CI [0.00, 0.31]). 10 of them were on warfarin and two on aspirin. There were three deaths recorded and three patients needed neurosurgery. Conclusion: The relatively low incidence suggests that repeat CT should not be mandatory for patients without ICH on first CT. This is further supported by the negligibly low rate of clinically significant D-ICH. Evidence-based assessments should be utilised to indicate the appropriate discharge plan, with further research required to guide the balance between clinical observation and repeat CT.
LO46: Sex-based differences in concussion symptom reporting and self-reported outcomes in a general adult ED population
Authors: Gaudet L. A. , Eliyahu L. , Lowes J. , Beach J. , Mrazik M. , Cummings G. , Couperthwaite S. , Voaklander D. , Rowe B. H.
Published: May 2018

Introduction: Patients with concussion frequently present to the emergency department (ED). Studies of athletes and children indicate that concussion symptoms are often more severe and prolonged in females compared with males. To-date, study of sex-based concussion differences in general adult populations have been limited. This study examined sex-based differences in concussion outcomes. Methods: Adult (>17 years) patients presenting to one of three urban EDs in Edmonton, Alberta with Glasgow coma scale score 13 within 72 hours of a concussive event were recruited by on-site research assistants. Follow-up calls at 30 and 90 days post ED discharge captured extent of PCS using the Rivermead Post-Concussion questionnaire (RPQ), effect on daily living activities measured by the Rivermead Head Injury Questionnaire (RHIQ), and overall health-related quality of life using the 12-item Short Form Health Survey (SF-12). Dichotomous and categorical variables were compared using Fishers exact test; continuous variables were compared using t-tests or Mann-Whitney tests, as appropriate. Results: Overall, 130/250 enrolled patients were female. The median age was 35 years; men trended towards being younger (median=32 years; IQR: 23, 45) than women (median=40 years; IQR: 22, 52). Compared to women, more men were single (56% vs 38% (p=0.007) and employed (82% vs 71% (p=0.055). Men and women experienced different injury mechanisms (p=0.007) with more women reporting injury due to a fall (44% vs 26%), while more men were injured at work (16% vs 7%) or due to an assault (11% vs. 3%). Men had a higher return to ED rate (13% vs. 5%; p=0.015). Women had higher RPQ scores at baseline (p<0.001) and 30-day follow-up (p=0.001); this difference was not significant by 90 days (p=0.099). While women reported on the RHIQ at 30 days that their injury affected their usual activities significantly more than men (Median=5, IQR: 0, 11 vs. median=0.5, IQR: 0.5, 7; p=0.004), both groups had similar scores on the SF-12 physical composite and mental composite scales at all three measurement points. Conclusion: In a general ED concussion population, demographic differences exist between men and women. Based on self-reported and objective outcomes, womens usual activities may be more affected by concussion and PCS than men. Further analysis of these differences is required in order to identify different treatment options and ensure adequate care and treatment of injury.
LO47: Incidence of intracranial bleeding in anticoagulated emergency patients with minor head injury: a meta-analysis
Authors: de Wit K. , Minas H. , Arthur W. , Turcotte M. , Eventov M. , Mason S. , Nishijima D. , Li M. , Versmée G.
Published: May 2018

Introduction: The proportion of Canadians receiving anticoagulation medication is increasing. Falls in the elderly are the most common cause of minor head injury and an increasing proportion of these patients are prescribed anticoagulation. Emergency department (ED) guidelines advise performing a CT head scan for all anticoagulated head injured patients, but the risk of intracranial hemorrhage (ICH) after a minor head injury (patients who have a Glasgow comma score (GSC) of 15) is unclear. We conducted a systematic review and meta-analysis to determine the point incidence of ICH in anticoagulated ED patients presenting with a minor head injury. Methods: We systematically searched Pubmed, EMBASE, Cochrane database, DARE, google scholar and conference abstracts (May 2017). Experts were contacted. Meta-Analyses and Systematic Reviews of Observational Studies (MOOSE) guidelines were followed with two authors reviewing titles, four authors reviewing full text and four authors performing data extraction. We included all prospective studies recruiting consecutive anticoagulated ED patients presenting with a head injury. We obtained additional data from the authors of the included studies on the subset of GCS 15 patients. We performed a meta-analysis to estimate the point incidence of ICH among patients with a GCS score of 15 using a random effects model. Results: A total of five studies (and 4,080 GCS 15, anticoagulated patients) from the Netherlands, Italy, France, USA and UK were included in the analysis. One study contributed 2,871 patients. Direct oral anticoagulants were prescribed in only 60 (1.5%) patients. There was significant heterogeneity between studies with regards to mechanism of injury, CT scanning and follow up method (I2 =93%). The random effects pooled incidence of ICH was 8.9% (95% CI 5.0-13.8%). Conclusion: We found little data to reflect contemporary anticoagulant prescribing practice. Around 9% of warfarinized patients with a minor head injury develop ICH. Future studies should evaluate the safety of selective CT head scanning in this population.
LO50: Necrotizing soft tissue infection: diagnostic accuracy of physical examination, imaging and LRINEC score a systematic review and meta-analysis
Authors: Fernando S. M. , Tran A. , Cheng W. , Taljaard M. , Rochwerg B. , Kyeremanteng K. , Seely A. J.E. , Inaba K. , Perry J. J.
Published: May 2018

Introduction: Necrotizing soft tissue infection (NSTI), a potentially life-threatening diagnosis, is often not immediately recognized by clinicians. Delays in diagnosis are associated with increased morbidity and mortality. We sought to summarize and compare the accuracy of physical exam, imaging, and Laboratory Risk Indicator of Necrotizing Fasciitis (LRINEC) Score used to confirm suspected NSTI in adult patients with skin and soft tissue infections. Methods: We searched Medline, Embase and 4 other databases from inception through November 2017. We included only English studies (randomized controlled trials, cohort and case-control studies) that reported the diagnostic accuracy of testing or LRINEC Score. Outcome was NSTI confirmed by surgery or histopathology. Two reviewers independently screened studies and extracted data. We assessed risk of bias using the Quality Assessment of Diagnostic Accuracy Studies 2 criteria. Diagnostic accuracy summary estimates were obtained from the Hierarchical Summary Receiver Operating Characteristic model. Results: We included 21 studies (n=6,044) in the meta-analysis. Of physical exam signs, pooled sensitivity and specificity for fever (49.4% [95% CI: 41.4-57.5], 78.0% [95% CI: 52.2-92.0]), hemorrhagic bullae (30.8% [95% CI: 16.2-50.6], 94.2% [95% CI: 82.9-98.2]) and hypotension (20.8% [95% CI: 7.7-45.2], 97.9% [95% CI: 89.1-99.6]) were generated. Computed tomography (CT) had 88.5% [95% CI: 55.5-97.9] sensitivity and 93.3% [95% CI: 80.8-97.9] specificity, while plain radiography had 48.9% [95% CI: 24.9-73.4] sensitivity and 94.0% [95% CI: 63.8-99.3] specificity. Finally, LRINEC 6 (traditional threshold) had 67.5% [95% CI: 48.3-82.3] sensitivity and 86.7% [95% CI: 77.6-92.5] specificity, while a LRINEC 8 had 94.9% [95% CI: 89.4-97.6] specificity but 40.8% [95% CI: 28.6-54.2] sensitivity. Conclusion: The absence of any one physical exam feature (e.g. fever or hypotension) is not sufficient to rule-out NSTI. CT is superior to plain radiography. The LRINEC Score had poor sensitivity, suggesting that a low score is not sufficient to rule-out NSTI. For patients with suspected NSTI, further evaluation is warranted. While no single test is sensitive, patients with high-risk features should receive early surgical consultation for definitive diagnosis and management.
LO53: Intravenous cefazolin plus oral probenecid vs. oral cephalexin for the treatment of skin and soft tissue infections: a randomized controlled trial
Authors: Zed P. J. , Dalen D. , Fry A. , Campbell S. G. , Eppler J.
Published: May 2018

Introduction: Skin and soft tissue infections (SSTIs) are a common reason for presentation to an emergency department (ED). Although many patients with mild SSTI are managed with oral antibiotics, those with mild-moderate infections are often treated with parenteral antibiotics, managed in EDs as outpatients using once daily intravenous cefazolin combined with oral probenecid. The purpose of our study was to determine if cephalexin 500 mg orally four times daily was non-inferior to cefazolin 2 g intravenously daily plus probenecid 1 g orally daily in the management of uncomplicated mild-moderate SSTIs patients presenting to the ED.. Methods: This was a prospective, multi-center, double dummy-blind, randomized controlled non-inferiority trial conducted at two tertiary care teaching hospitals in Canada. Patients were enrolled if they presented to the ED with an uncomplicated SSTI, in a 1:1 fashion to oral cephalexin or intravenous cefazolin plus oral probenecid for up to 7 days. The primary outcome was failure of therapy at 72 hours. Clinical cure at 7 days, intravenous to oral step-down, admission to hospital and adverse events were also evaluated. Results: 206 patients were randomized with 104 patients in the cephalexin group and 102 in the cefazolin and probenecid group. The proportion of patients failing therapy at 72 hours was similar between the treatment groups (4.2% and 6.1%, risk difference 1.9%, 95% CI (-3.3% to 7.1%), p-value for non-inferiority=0.001). Clinical cure at seven days was not significantly different (100% and 97.7%, risk difference -2.3%, 95% CI (-4.9% to 0.3%), p-value for non-inferiority=0.008). Conclusion: Cephalexin at appropriate doses appears to be a safe and effective alternative to outpatient parenteral cefazolin and probenecid in the treatment of uncomplicated mild to moderate SSTIs who present to the ED.
LO56: External validation of a 1-hour rapid diagnostic algorithm for ruling out acute myocardial infarction in emergency department patients with chest pain using a high-sensitivity troponin-T assay
Authors: Andruchow J. E. , Boyne T. S. , Vatanpour S. , Wang D. , McRae A. D.
Published: May 2018

Introduction: Ruling out acute myocardial infarction (AMI) using serial troponin testing is central to the care of many emergency department (ED) patients with chest pain. While diagnostic strategies using conventional troponin assays require repeat sampling over many hours to avoid missed diagnoses, serial high-sensitivity troponin (hs-cTn) assays may be able to exclude AMI in most patients within 1 or 2 hours. However, many of the initial studies deriving and validating these rapid diagnostic algorithms had all hs-cTn samples analyzed in a central core lab likely representing optimal assay performance. This objective of this study is to validate a 1-hour rapid diagnostic algorithm to exclude AMI in ED chest pain patients using an hs-cTn assay in real world practice. Methods: This prospective cohort study was conducted at a single urban tertiary center and regional percutaneous coronary intervention site in Calgary, Alberta. Patients were eligible for enrolment if they presented to the ED with chest pain, were 25-years or older and required biomarker testing to rule out AMI at the discretion of the attending emergency physician. Patients were excluded if they had clear acute ischemic ECG changes, new arrhythmia or renal failure requiring hemodialysis. A high-sensitivity troponin result (Roche Elecsys hs-cTnT) was obtained in all patients at ED presentation and 1-hour later. The primary outcome was AMI on the index visit. Secondary outcomes included 30-day AMI and 30-day major adverse cardiac events (MACE - including AMI, revascularization or cardiac death). Electronic medical records were reviewed and telephone follow-up was obtained for all patients at 30-days to ensure relevant events were captured. Two physician adjudication (board-certified emergency physician and cardiologist) was obtained for all outcomes. The study was REB approved. Results: A total of 350 patients were enrolled from August 2014 September 2016 with 1-hour serial hs-cTnT results, of which 219 (62.6%) met the 1-hour rapid diagnostic algorithm low risk criteria (time 0h hs-cTnT <12ng/L and delta 1h <3ng/L). The sensitivity of the 1-hour low risk criteria for index AMI was 97.2% (95% CI 85.5%-99.9%) and for 30-day AMI was 97.3% (95% CI 85.8-99.9%). The sensitivity of the low risk criteria for 30-day MACE was lower 80.9% (95% CI 66.7-90.9%) but maintained a high negative predictive value, 95.9% (95% CI 92.3-98.1%). Conclusion: A 1-hour rapid diagnostic algorithm using an hs-cTnT assay was highly sensitive for AMI on the index visit and successfully identified patients at low risk of 30-day AMI; however, sensitivity for 30-day MACE was much lower. Of note, the 1-hour algorithm appears to be less sensitive for both AMI and 30-day MACE than a 2-hour algorithm validated in the same population.
LO62: Variability in triage performance for chest pain patients in two Canadian cities
Authors: Stackhouse S. , Innes G. , Grafstein E.
Published: May 2018

Introduction: CTAS triage acuity determinations are used to prioritize patients, describe illness acuity, and compare casemix across institutions. The latter functions assume reliable application in diverse settings, but no studies have evaluated this using actual triage data. Methods: This administrative database study included all patients with a triage complaint of chest pain (CP) in Vancouver (2012-16) and Calgary (2016). We stratified patients into high vs. non-high severity groups based on discharge diagnoses. High severity diagnoses included all patients with aortic pathology, ACS, shock or arrest states, as well as patients requiring admission because of pulmonary embolism, dysrhythmias, CHF, neurologic or respiratory conditions. We dichotomized patient triage assignments to high (CTAS 1,2) vs. low (3,4,5) acuity, then constructed 2x2 tables correlating CTAS acuity with disease severity. Main outcomes included the proportion of CP patients triaged to high acuity categories and CTAS sensitivity for high severity conditions. Results: We studied 97277 Vancouver and 18622 Calgary patients. Age (mean, 54.8 years), sex (53.5% male) and casemix distributions were similar between cities, although Calgary had more high severity conditions (15.0% v. 10.5%) and a higher admission rate (22.5% v. 21.4%). Calgary triage nurses placed more patients in high acuity triage categories (85.1% vs. 45.2%) and achieved higher sensitivity for severe illness (96.2% vs. 76.2%); however, they were less accurate (28.7% vs. 60.3%) and less specific (16.8% vs. 58.4%). The proportion of CP patients triaged into high acuity categories ranged from 79% to 87% across four Calgary hospitals and from 28% to 62% at five Vancouver hospitals. Conclusion: This study shows profoundly different triage categorization at different sites seeing similar patient populations. Triage nurses are taught to strive for high sensitivity, but there may be operational consequences if specificity drops too low and large numbers of non-severe patients are triaged into high acuity categories. It is not clear which approach is better but these data suggest CTAS should not be used to compare patient acuity or complexity across different hospitals or regions.
LO63: Decision fatigue in the emergency department: how does emergency physician decision making change over an eight-hour shift?
Authors: Zheng B. , Kwok E. S.H. , Taljaard M. , Nemnom M. , Stiell I. G.
Published: May 2018

Introduction: Decision fatigue is a well-characterized phenomenon that has rarely been studied in the medical field. Emergency department (ED) physicians make many clinical decisions every shift. In this study, we examined ED physician decisions in computed tomography (CT) ordering, consultations, and discharges over time in an eight-hour shift. Methods: We performed a cohort study of adult patients presenting to two EDs of an academic, tertiary care hospital over a two-year period using the hospital administrative database. Patients triaged to the Urgent Care (minor acuity) area of the ED were excluded. Patients were analyzed based on the hour of the shift that they were initially assessed by an ED physician. For each hour, we evaluated the proportion of patients who had CTs, consultations, discharges, consultations not resulting in admission, returns within 72 hours of discharge, and median ED length of stay (LOS). Patients under the care of more than one ED physician (i.e. handovers) were analyzed as the time seen by the initial physician. Statistical significance of outcomes over time was assessed using random effects logistic regression. Results: 87,752 patients were included in the study period. 42,146 patients (48.0%) received consultations, of which, 29,347 (69.6%) were admitted. 45,470 patients (51.8%) were discharged without consultation, of which, 4102 (9.0%) returned within 72 hours. The median ED LOS for all non-consulted discharged patients was 4.9 hours. There was a statistically significant decline in the hourly rates of CT head and CT abdomen ordering as the shift progressed. CT head ordering declined significantly from 15.8% in the first hour to 12.2% in the last hour (p<0.0001) while CT abdomen declined significantly from 9.6% to 7.6% (p<0.0001). There were no significant differences in the hourly rates of consultations, consultations not resulting in admission, discharges, discharges returning within 72 hours, or ED LOS. Conclusion: ED physician decisions about patient disposition did not change in relation to hours into the shift. Interestingly, the rates of CT head and CT abdomen declined as the shift progressed. The lower CT ordering rates do not seem to be associated with any differences in patient disposition or ED LOS. In this large patient sample, we did not find evidence of decision fatigue among ED physicians.
LO65: Safety and satisfaction of a new program redirecting low-acuity emergency department patients to medical clinic: a prospective cohort study
Authors: Morris J. , Daoust R. , Cournoyer A. , Marquis M. , Chauny J. , Messier A.
Published: May 2018

Introduction: Overcrowding in emergency departments (EDs) is a constant problem. One of the major factors contributing to this situation is the inappropriate ED use by patients with low-acuity problems. In order to reduce overuse, EDs have developed agreements with clinics to reorient low-acuity ambulatory patients toward them. These agreements often leave the burden of decision on the triage personnel as to which patients can be safely redirected. The aim of this study was to evaluate the safety of redirecting patients to nearby medical clinics and to evaluate their satisfaction with this program. Methods: In the ED of a tertiary care facility, a computer-based algorithm allowing triage personnel to reorient patients presenting with one of 52 medical complaints, was implemented in 2016. Our prospective cohort study was composed of reorientation admissible ED patients between March 2017 and August 2017. Patient safety was evaluated with patient follow-up phone interviews one week after their visit to the ED to identify the number of patients who needed to return to a medical facility after their reorientation. Patient satisfaction with the reorientation program was evaluated during the same follow-ups. Results: Of the 980 reoriented patients interviewed, only 57 (5.9%; 95% confidence interval [CI] 4.57.5) had to unexpectedly go back to a health care facility. None of these returns were for severe complications. Over 84% of the reoriented patients were satisfied with their reorientation and 89% say they would use this program again. Having a transportation problem was most common reason mentioned by patients for refusing to be reoriented. Conclusion: Reorientation to medical clinics using a new computer-based algorithm was safe and no case of urgent return was seen during the 6-month study period. In addition, patients who were reoriented to medical clinics were satisfied by their treatment experience.