We present a proof-of-concept for the adaptive mesh refinement method applied to atmospheric boundary-layer simulations. Such a method may form an attractive alternative to static grids for studies ...on atmospheric flows that have a high degree of scale separation in space and/or time. Examples include the diurnal cycle and a convective boundary layer capped by a strong inversion. For such cases, large-eddy simulations using regular grids often have to rely on a subgrid-scale closure for the most challenging regions in the spatial and/or temporal domain. Here we analyze a flow configuration that describes the growth and subsequent decay of a convective boundary layer using direct numerical simulation (DNS). We validate the obtained results and benchmark the performance of the adaptive solver against two runs using fixed regular grids. It appears that the adaptive-mesh algorithm is able to coarsen and refine the grid dynamically whilst maintaining an accurate solution. In particular, during the initial growth of the convective boundary layer a high resolution is required compared to the subsequent stage of decaying turbulence. More specifically, the number of grid cells varies by two orders of magnitude over the course of the simulation. For this specific DNS case, the adaptive solver was not yet more efficient than the more traditional solver that is dedicated to these types of flows. However, the overall analysis shows that the method has a clear potential for numerical investigations of the most challenging atmospheric cases.
Objetivo: adaptar el Simulation Effectiveness Tool - Modified (SET-M) al portugués y verificar los índices de validez y confiabilidad. Método: estudio metodológico. En esta etapa de la investigación ...se utilizó el ISPOR, Análisis Factorial Confirmatorio, correlación entre el instrumento adaptado/Escala de Design de la Simulación - Versión Estudiante/Evaluación Práctica Individual y confiabilidad (test-retest e índices de consistencia interna). Muestra de conveniencia con 435 estudiantes de licenciatura en Enfermería y del posgrado. Resultados: el Simulation Effectiveness Tool – Modified - Versión Brasileña obtuvo un puntaje promedio entre 2,36 a 2,94; el Análisis Factorial Confirmatorio mostró una carga factorial > 0,30 para 17 de los 19 ítems. El alpha de Cronbach osciló entre 0,729 y 0,874; El omega de McDonald fue 0,782. No hubo correlación entre Simulation Effectiveness Tool – Modified Versión Brasileña y el Design de la Simulación o la Evaluación Práctica Individual. Hubo una correlación positiva entre el Simulation Effectiveness Tool – Modified Versión Brasileña y la edad de los participantes. Los puntajes de los voluntarios en las simulaciones fueron significativamente más altos que las de los observadores en tres dominios. Conclusión: el SET-M Versión Brasileña, manteniendo los 19 ítems y cuatro dominios de la escala original, se puso a disposición para su uso en Brasil para evaluar la efectividad de la simulación, recomendándose estudios con diferentes muestras.
Objetivo: adaptar para a língua portuguesa o Simulation Effectiveness Tool - Modified (SET-M) e verificar índices de validade e confiabilidade. Método: estudo metodológico. Utilizou-se o ISPOR, ...Análise Fatorial Confirmatória, correlação entre o instrumento adaptado/Escala de Design da Simulação – Versão Estudante/Avaliação Prática Individual e confiabilidade (teste-reteste e índices de consistência interna). Amostra de conveniência com 435 estudantes da Graduação em Enfermagem e Pós-Graduação. Resultados: o Simulation Effectiveness Tool - Modified Versão Brasileira obteve média de escores entre 2,36 a 2,94. A Análise Fatorial Confirmatória mostrou carga fatoral > 0,30 para 17 dos 19 itens. O alfa de Cronbach variou entre 0,729 e 0,874. O ômega de McDonald foi 0,782. Não houve correlação entre Simulation Effectiveness Tool - Modified Versão Brasileira e o Design da Simulação ou a Avaliação Prática Individual. Houve correlação positiva entre o Simulation Effectiveness Tool - Modified Versão Brasileira e a idade dos participantes. Os escores dos voluntários nas simulações foram significativamente mais altos que os dos observadores em três domínios. Conclusão: o SET-M Versão Brasileira, mantendo os 19 itens e quatro domínios da escala original, ficou disponibilizado para ser usado no Brasil para avaliar a efetividade da simulação, recomendando-se estudos com amostras diferentes.
AudienceThis scenario was developed to educate emergency medicine (EM) interns but can be used to educate medical students and junior residents. IntroductionTorsade de Pointes (TdP) is a rare but ...potentially fatal arrythmia if not quickly diagnosed and properly treated. TdP is defined as a polymorphic ventricular tachycardia (VT) characterized by an oscillatory change in amplitude around an isoelectric line that is associated with a QTc prolongation on the electrocardiogram (ECG).1 It has been well described to predispose to ventricular fibrillation and arrhythmic death. QTc prolongation can be congenital or acquired. Between 1 in 2000 to 20,000 have the genetic mutation for QTc prolongation.1 Acquired QTc is most commonly drug related leading to electrolyte abnormalities. 2 Around 28% of cases of TdP are associated with hypokalemia and hypomagnesemia.2 Several European centers estimate 0.8 to 1.2 per million people per year are drug induced.1 Patients with TdP most commonly presents with syncope, palpitations, and dizziness.2 While 50% are asymptomatic, up to 10% of patients will present in cardiac arrest.1 It is imperative for EM physicians to be able to recognize TdP as it can quickly decompensate into a ventricular fibrillation and sudden death. These patients require management of electrolyte abnormalities, ventricular dysrhythmias, and cardiac death.2 This simulation case will demonstrate treatment strategies for TdP with electrolyte repletion, antiarrhythmics, and defibrillation. Educational ObjectivesBy the end of this simulation session, learners will be able to: 1) formulate appropriate work-up for altered mental status (AMS) 2) recognize hypokalemia and associated findings on ECG 3) address hypomagnesemia in a setting to hypokalemia 4) manage pulseless VT by following advanced cardiac life support (ACLS) 5) recognize and address TdP 6) provide care after return of spontaneous circulation (ROSC) 7) consult intensivist and admit to intensive care unit (ICU). Educational MethodsThis session was conducted using high-fidelity simulation, which was immediately followed by an in-depth debriefing session. Each session had three EM first-year residents and six observers. There was one simulation instructor running the session and one simulation technician who acted as a nurse. Research MethodsAfter the simulation and debriefing session was complete, an online survey was sent via surveymonkey.com to all the participants. The survey collected responses to the following questions: (1) was the case believable? (2) did the case have the right amount of complexity? (3) did the case help improve medical knowledge and patient care? (4) did the simulation environment gave a real-life experience? (5) did the debriefing session after simulation help improve knowledge? A Likert scale was used to collect the responses. ResultsThis case was performed once a year for 2 years in a row. There was a total of 19 respondents from both years. One hundred percent of them either agreed or strongly agreed that the case was beneficial in learning and in improving medical knowledge and patient care. All of them found the post-session debrief to be very helpful. Two of them felt neutral about the case being realistic. DiscussionThis high-fidelity simulation was a realistic way of educating learners on how to manage hypokalemia and hypomagnesemia leading to TdP. Cost-effectiveness varies depending on what is available at individual simulation laboratories. Learners are forced to start with a broad differential for the patient who presents with AMS. As they manage the case, the patient quickly decompensates into a fatal arrhythmia due to electrolyte abnormalities. Learners enforced their knowledge on leading ACLS, intubation skills, and treating TdP with electrical conversion and electrolyte repletion. TopicsHypokalemia, hypomagnesemia, torsades de pointes, altered mental status, medical simulation.
AudienceThe targeted audience for this simulation are emergency medicine providers, including residents as well as advanced practice providers, to properly educate on recognizing, diagnosing, and ...managing methemoglobinemia. IntroductionMethemoglobinemia is a blood disorder characterized by the presence of ferric form of hemoglobin in the blood. This form of hemoglobin can carry oxygen but is unable to release it effectively causing a range of symptoms including headache, dizziness, nausea, and cyanosis. It is rarely congenital and mostly caused by the exposure to oxidizing agents, such as local anesthetics and quinolones.1 Normally, oxygen can bind to hemoglobin while it is in the ferrous state (Fe2+). In cases of methemoglobinemia, the heme iron configuration is converted from ferrous (Fe2+) to ferric (Fe3+), making it unable to bind to oxygen. As a result, normal ferrous hemes experience an increased affinity for oxygen causing a leftward shift in the oxygen dissociation curve. This in turn causes functional anemia due to reduced oxygen carrying capacity.1 Methemoglobinemia can result from exposure to different medications as well as environmental factors and presents like other disease processes including chronic obstructive pulmonary disease exacerbations. Congenital methemoglobinemia due to cytochrome b5 reductase deficiency is very rare, but the actual incidence is not known. Increased frequency of disease has been found in Siberian Yakuts, Athabaskans, Eskimos, and Navajo.2 Although it is also an unusual occurrence, acquired methemoglobinemia is much more frequently encountered than the congenital form.1In a 10-year retrospective study looking at the incidence rate of topical anesthetic-induced methemoglobinemia, it was found that the overall prevalence was 0.035%. A major risk factor was hospitalization at the time of a procedure being performed. An increased risk was also seen with benzocaine-based anesthetics.3. Educational ObjectivesAt the end of this simulation case, participants should be able to: 1) recognize shortness of breath, cyanosis and respiratory distress, and the difference between all of them based on the clinical presentation 2) identify the underlying cause of the condition by conducting a thorough history and physical 3) know how to identify and treat methemoglobinemia by ordering necessary labs and interventions and understand the pathophysiology leading to methemoglobinemia 4) recognize patient's response to treatment and continue to reassess. Educational MethodsThis is a high-fidelity simulation case that allows participants to evaluate and treat methemoglobinemia in a safe environment. The case is followed by a debriefing and small group discussion to review patient care skills, medical knowledge, interpersonal communication, practice-based learning, and improvement. Research MethodsThe educational content and efficacy were evaluated by oral feedback and a debriefing session immediately after completion of the simulation. A 5-point Likert scale was sent out to participants pre-simulation and post-simulation. Questions on the survey included whether they felt confident in their ability to recognize methemoglobinemia, understood the physiology and causes of methemoglobinemia, and felt confident in their ability to treat methemoglobinemia. ResultsSixteen learners responded to the survey, consisting of EM residents and medical students. Post simulation, approximately 92% of EM residents answered agree or strongly agree in their ability to recognize and treat methemoglobinemia compared to pre-sim survey of about 62.5%. Post-simulation feedback also resulted in positive reception, and learners found it useful to run through an uncommonly seen case in the hospital. Results showed overall improvement in recognition and treatment of methemoglobinemia among residents and medical students. DiscussionThis simulation improved recognition of methemoglobinemia including signs and symptoms associated with it. Proper management and treatment options were included such as administration of methylene blue. Overall, this simulation was helpful in teaching EM residents how to recognize, manage, and treat methemoglobinemia. In addition, post-simulation debriefing allowed further discussion among residents, which they found valuable. TopicsMethemoglobinemia, shortness of breath, cyanosis, respiratory distress, anemia, methemoglobin, oxygen dissociation curve, emergency medicine simulation.
Aortic Dissection Presenting as a STEMI Yee, Jennifer; Kendle, Andrew P
Journal of education & teaching in emergency medicine,
07/2022, Volume:
7, Issue:
3
Journal Article
Peer reviewed
Open access
AudienceThis scenario was developed to educate emergency medicine residents on the presentation and management of a patient with a Stanford type A aortic dissection. IntroductionChest pain is one of ...the most common chief complaints seen in the emergency department with a deadly differential diagnosis list. A "can't miss" diagnosis, aortic dissection occurs when an intimal tear creates a false lumen in the aorta, with a variably reported incidence of approximately 2.5-5 per 100,000 person-years.1 This amounts to an estimated 8,000-16,000 cases per year in the United States with a mortality likely underestimated due to prehospital death ranging from 20-40% within 24 hours and 30-50% at 5 years.2,3,4 There is a reported increase in mortality by 1% for every hour the diagnosis is delayed, and half of diagnoses are made greater than 24 hours after presentation.5 The symptoms can range from chest pain to back pain, abdominal pain or extremity pain, to syncope or isolated neurologic deficits, even to shock or cardiac arrest.6 Aortic dissection is most commonly categorized into two groups: Stanford type A, involving the ascending aorta, and Stanford type B, involving only the descending aorta, and are generally managed surgically vs. medically respectively based on this paradigm.7,8 Stanford type A can be complicated by severe aortic regurgitation, pericardial tamponade or coronary artery occlusion mimicking ST-segment elevation myocardial infarction (STEMI). These potentials make it important to switch from heuristic to analytical thinking when developing a differential diagnosis.9 A high index of suspicion with early recognition and management is critical in this catastrophic disease state, especially given the propensity for complications and a wide variety of presentations. Educational ObjectivesAt the conclusion of the simulation session or during the debriefing session, learners will be able to: 1) Verbalize the anatomical differences and management of Stanford type A and type B aortic dissections, 2) Describe physical exam findings that may be found with ascending aortic dissections, 3) Describe the various clinical manifestations of the propagation of aortic dissections, 4) Discuss the management of aortic dissection, including treatment and disposition. Educational MethodsThis session was conducted using a simulation scenario with a high-fidelity manikin as the patient and confederate/actor in the nursing role, followed by a post-scenario debriefing session on the presentation, differential diagnosis, potential physical exam findings, and management of patients with aortic dissection. Debriefing methods may be left to the discretion of the educators, but the authors have utilized advocacy-inquiry techniques.10 This scenario may also be run as an oral board examination case. Research MethodsThe residents are provided an electronic survey at the completion of the debriefing session to anonymously rate different aspects of the simulation, as well as provide qualitative feedback on the scenario. This survey is specific to the local institution's simulation center. ResultsTwenty learners completed a feedback form. This session received all 6 and 7 scores (consistently effective/very good and extremely effective/outstanding, respectively) other than one isolated 5 score. The lowest average score was 6.5 for, "Before the simulation, the instructor set the stage for an engaging learning experience," and the highest average score was 6.84 for, "The instructor identified what I did well or poorly - and why." Feedback from the residents was overwhelmingly positive (available upon request). All groups initially gave aspirin upon identification of the STEMI and several gave heparin. Debriefing topics included STEMI mimics, physical exam findings for aortic dissection, imaging and laboratory workup for aortic dissection, blood pressure and heart rate goals and pharmacologic management, uncomplicated STEMI management, and Type I versus Type II decision-making. DiscussionThis is an easily reproducible method for reviewing management of patients with aortic dissection. There are multiple potential presentations and complications of aortic dissections to further customize the experience for learners' needs. While it was discussed during debriefing that heparin administration was unlikely to cause immediate cardiopulmonary arrest, this state was included to reflect downstream hemorrhagic complications that may occur in the setting of antiplatelet administration for acute aortic dissection. Facilitators may choose to omit the arrest at their discretion. TopicsMedical simulation, emergency medicine, aortic dissection, ST-elevation myocardial infarction, cardiovascular emergencies, hypertensive emergencies, STEMI mimics, vascular surgery, cardiothoracic surgery.
Cyanide Poisoning Doman, Ghadeer; Aoun, Jihad; Truscinski, Joshua ...
Journal of education & teaching in emergency medicine
7, Issue:
3
Journal Article
Peer reviewed
Open access
The goal of this simulation is to educate emergency medicine students, residents, attending physicians, and mid-level practitioners to recognize, diagnose, and manage acute cyanide toxicity.
Cyanide ...has an almond scent and is a naturally occurring compound. It is present within many different types of plants and fruits including apricots, apples, peaches, lima beans, and cassava plants but is harmless.1 The trace amounts of cyanide found within organic materials is of little concern because its high reactivity causes it to be metabolized rapidly and create other compounds. However, modern synthetic materials such as plastics, papers, textiles, and machinery can release a much greater concentration of hydrogen cyanide when exposed to high temperatures.1 As the use of contemporary nitrogen-containing synthetic polymers has expanded, the possibility of cyanide toxicity has become increasingly common and severe. Hydrogen cyanide is especially dangerous to humans because the gaseous form reacts quickly upon inhalation.2When cyanide enters the body via inhalation, it blocks the cells from utilizing oxygen by binding to the cytochrome oxidase in the mitochondria.2 The inability of the cell to use oxygen forces cells from aerobic metabolism into anaerobic metabolism. Anaerobic metabolism results in the production of lactic acid, which causes metabolic acidosis.3 The human body cannot sustain itself with the lack of oxygen and anaerobic metabolism for a prolonged period of time. Ultimately, the body will suffer cardiorespiratory arrest.1Symptoms of cyanide toxicity include headache, nausea, shortness of breath, and altered mental status.1 These are similar to those of carbon monoxide and carbon dioxide inhalation. However, symptoms of cyanide toxicity cannot be treated with supplemental oxygen as carbon monoxide and carbon dioxide are. Cyanide toxicity must be treated with an antidote - sodium thiosulfate, sodium nitrite, and hydroxocobalamin.4 Each of the antidotes works by binding with the highly reactive cyanide, neutralizing the compound, and converting it into a water-soluble product that will be cleared through renal excretion.4Fire victims often present to the emergency department critically ill. They will likely have obvious external thermal burns and traumatic injuries; however, it is important for emergency personnel to recognize the respiratory distress and metabolic derangements that are most likely occurring due to toxic gas inhalation. People who are trapped within a burning structure are exposed to carbon monoxide, carbon dioxide, and cyanide from the combustion of contents within the building. These toxic gasses will cause severe tissue hypoxia without significant vital sign changes.5 The respiratory distress and metabolic compromise will be acutely more fatal than the obvious external injuries and burns. The challenge in treating these patients is for the healthcare team to know the differential diagnoses, prioritize airway, breathing and circulation, and to empirically treat the patient as if they have a confirmed exposure.It is estimated that 35% of all fire victims have toxic levels of cyanide upon arrival to the emergency room.2 Acute cyanide toxicity can become fatal within minutes; however, a prompt diagnosis and treatment can be lifesaving. Unfortunately, due to the limited amount of time the human body can sustain anaerobic metabolism and tissue hypoxia, blood test results are not available in time to be clinically applicable.2 Rather, the emergency room personnel must begin treatment immediately upon recognizing that toxic smoke inhalation may have occurred.We understand the importance of knowing how to treat fire victims. Therefore, the goal of this simulation case is to expose the emergency providers to cyanide poisoning and educate emergency providers about the critical steps of how to approach, diagnose, and treat cyanide toxicity.
After the completion of this simulation, participants will have learned how to: 1) identify clues of smoke inhalation based on a physical examination; 2) identify smoke inhalation-induced airway compromise and perform definitive management; 3) create a differential diagnosis for victims of fire cyanide poisoning, carbon monoxide, and carbon dioxide; 4) appropriately treat cyanide poisoning; 5) demonstrate the importance of preemptively treating for cyanide poisoning; 6) perform an initial physical examination and identify physical marks suggesting the patient is a fire and smoke inhalation victim; and 7) familiarize themselves with the Cyanokit and treatment with hydroxocobalamin.
This is a high-fidelity simulation case in which participants work through a case of a patient who has been exposed to fire. The participants will be able to work hands-on to evaluate, diagnose, and treat cyanide poisoning in an emergency event. Afterwards, there will be a small group discussion and debriefing of the case in order to review patient care skills, interpersonal and communication skills, medical knowledge, and system-based practice.
The participants were instructed to complete a survey before and after the simulation case. A quality Likert Scale was used to assess the participants' comfort level of diagnosing, treating, and managing a patient with toxic smoke inhalation. A score of 1 represented a negative experience and 5 represented a very positive experience. The surveys were then reviewed by the research team to determine if the simulation case improved the participants' comfort level. The survey answers were compared collectively, as well as individually, and were analyzed between the pre-simulation and post-simulation results.
Our simulation involved 25 participants: 20 participants were emergency medicine resident physicians and 5 were 4th-year medical students. In the pre-simulation survey, participants reported a mean of 2.7 out of 5 when asked to rate their confidence in their ability to treat a smoke inhalation victim. The post-simulation survey showed a significant increase to a mean of 3.5 out of 5. Participants were also asked to evaluate the usefulness of the simulation: 15 participants rated the case as a 5, which represented "very useful," and the other 10 participants rated the case as a 4, which represented "useful." The mean value when asked to assess the simulation case's usefulness and applicability in emergency medicine was 4.6 out of 5.
This simulation allows providers to focus on victims of fire. Fire victims are often critically ill and require time sensitive treatment. This simulation gives providers a chance to review their knowledge and prepare them for real life cases. Based on the survey results, the simulation improved awareness and understanding of the symptoms of acute cyanide toxicity and improved the participant's ability to recognize, diagnose, and treat cyanide poisoning.
Cyanide toxicity, carbon monoxide toxicity, cyanide antidote, fire victim, intubation, airway intervention, oxygen treatment, history taking, lab testing ordering, symptom identification, interpretation of lab results, emergency medicine simulation.
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