Reference: Ramesh S, Ayyan SM, Rath DP, Sadanandan DM. Efficacy and safety of ultrasound-guided erector spinae plane block compared to sham procedure in adult patients with rib fractures presenting to the emergency department: A randomized controlled trial. AEM April 2024 Date: April 19, 2024 Guest Skeptic: Dr. Suchismita Datta. She is an Assistant Professor and Director of Research in the Department of Emergency Medicine at the NYU Grossman Long Island Hospital Campus. Case: You are doing great things and helping many patients during your shift in the emergency department (ED) when you hear a trauma alert being called overheard. You walk over to the trauma room, and you see a healthy-looking 52-year-old male complaining of chest trauma after being involved in a motor vehicle collision before arrival. His imaging shows mildly displaced rib fractures of ribs four through seven. He is stable but complaining of pain despite initial IV acetaminophen and ketorolac. You offer him some opioids which he says makes him throw up. He’s been texting with his daughter who is an emergency medicine ultrasound fellow, and she mentioned something about using the ultrasound to inject something to decrease his pain. Background: We have covered rib fractures once before on the Skeptics’ Guide to Emergency Medicine. This was on SGEM#324 looking at using spirometry to guide discharging older patients with rib fractures. The evidence was not robust enough back in 2021 to confidently use this potential tool. We know that rib fractures are associated with an increased risk of morbidity and mortality – specifically related to hypoventilation-related complications [1]. These risks are particularly higher in the elderly [2]. A clinical decision tool called the STUMBL score was derived and validated by Battle et al in 2014 [3]. It risks stratified older patients with blunt trauma. An attempt was made to externally validate this tool in New Zealand by Murkerji et al 2021 [4]. It did not perform as well which is not unusual for a clinical decision instrument [5]. Rib fractures can cause lung splinting and therefore, pain management is a very important part of the management of rib fractures. In addition to coming with a litany of undesired systemic side effects such as a depressed level of consciousness and decreased respiratory drive, opioid pain medications are also short-acting and require frequent redosing. With the 2014 CDC declaration that prescription drug overdose is one of the five top health threats, there has been a movement away from opioids as the mainstay of pain management for rib fractures [6]. There have been some studies that looked at the efficacy of alternative pain management strategies, but very few have looked at the efficacy or safety of ultrasound-guided erector spinae plane block.  Clinical Question: How effective and safe is an ultrasound-guided erector spinae plane block in patients with rib fractures? Reference: Ramesh S, Ayyan SM, Rath DP, Sadanandan DM. Efficacy and safety of ultrasound-guided erector spinae plane block compared to sham procedure in adult patients with rib fractures presenting to the emergency department: A randomized controlled trial. AEM April 2024 * Population: Adult patients with confirmed rib fractures and a numeric rating score (NRS) greater than 4, despite routine analgesia. * Exclusions: Allergies to specific medications, penetrating thoracic trauma, pregnancy,

Reference: Albers GW et al. TIMELESS Investigators. Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection. NEJM Feb 2024 Date: April 12, 2024 Guest Skeptic: Dr. Vasisht Srinivasan is an Emergency Medicine physician and neurointensivist at the University of Washington and Harborview Medical Center in Seattle, WA. He is an assistant professor in Emergency Medicine, Neurology, and Neurosurgery at the School of Medicine at the University of Washington. Case: A 70-year-old woman was brought into the emergency department by EMS after her family reported she was having trouble talking.  They noticed this earlier in the day and let her rest, but when she had trouble moving her right arm, they called 911.  Initial evaluation by medics revealed right hemiplegia, a right facial droop, left gaze deviation, and aphasia.  When she arrives in your ED, her family tells you she was last seen normal about 12 hours ago.  A code stroke is activated, and the initial CT head shows no signs of hemorrhage or early ischemic changes.  A CT angiogram shows a proximal middle cerebral artery occlusion.  CT perfusion showed a 10 mL core and 189 mL penumbra.  As you speak to your stroke team, the question of thrombolysis comes up, as her core is quite small, and the stroke may still be very early in its time course. Background: The question of thrombolysis for acute ischemic stroke dates back nearly 30 years to the initial NINDS trial published in 1995 [1].  Since that time, numerous studies and analyses have been undertaken to categorize the potential benefits and potential harms associated with thrombolysis in stroke [2-8]. We have discussed this issue multiple times on the SGEM including: * SGEM#29: Stroke Me, Stroke Me * SGEM#70: The Secret of NINDS * SGEM Xtra:Thrombolysis for Acute Stroke * SGEM Xtra: Walk of Life * SGEM#297: tPA Advocates Be Like – Never Gonna Give You Up With the pentad of thrombectomy trials published in 2015 [9-13] and the extension of the thrombectomy window in 2018 following the publication of DAWN [13] and DEFUSE-3 [15], the standard of care has now shifted to mechanical thrombectomy for large vessel occlusion, though thrombolysis is still used up to 4.5 hours from onset of symptoms. We have looked at the issue of EVT with or without thrombolytics on the SGEM a few times. * SGEM#137: A Foggy Day – Endovascular Treatment for Acute Ischemic Stroke * SGEM#292: With or Without You – Endovascular Treatment with or without tPA for Large Vessel Occlusions * SGEM#297: tPA Advocates Be Like – Never Gonna Give You Up * SGEM#333: Do you Gotta Be Starting Something – Like tPA before EVT? * SGEM#349: Can tPA Be A Bridge Over Trouble Waters ...

Reference:  Drysdale SB et al. Nirsevimab for Prevention of Hospitalizations due to RSV in Infants. N Engl J Med. 2023 Date: March 29, 2024 Guest Skeptic: Dr. Michael Cosimini is a pediatrician in Portland Oregon. He is the designer of Empiric Game, a medical editor and contributor to Pediatrics Reviews and Perspectives (PedsRAP) and the digital media editor at Academic Pediatrics. He is passionate about podcasting and serious games for medical education. Case: A 4-month-old twin girl is brought by her parents to the emergency department (ED) for respiratory distress. She has had congestion, a runny nose, and a cough for the past three days. Her parents think her breathing has been getting worse, and she is breathing faster. On your examination, you see that she is tachypneic with a respiratory rate of 66 breaths per minute. You also note subcostal retractions. Her oxygen saturation on room air is 86%. After nasal suctioning, she remains tachypneic, but her oxygen saturation remains under 90%. A viral swab comes back positive for respiratory syncytial virus (RSV). The decision is made to put her on supplemental oxygen via nasal cannula and admit her to the hospital for close observation. Her parents tell you, “She has a twin brother at home. We heard about this new vaccine for RSV. Does it work?” Background: RSV is a major cause of respiratory illness in young children. It is common in bronchiolitis which leads to symptoms like coughing, wheezing, and difficulty breathing. RSV is a major reason why infants are hospitalized for respiratory issues, especially during the fall and winter months when RSV infections are more prevalent.  It’s hard to think about RSV without recalling the quote “Don’t just do something, stand there!” Because there have been so many things that we’ve tried for bronchiolitis that really don’t seem to have had much effect including hypertonic saline (SGEM#157), high-flow nasal oxygen (SGEM#228), corticosteroids, bronchodilators, etc  (SGEM#167).  One thing that has also been tried but not covered on the SGEM is a “vaccine” for RSV.  Attempts at developing a vaccine against RSV go back decades. The first significant effort to develop an RSV vaccine occurred in the 1960s. A formalin-inactivated RSV vaccine (FI-RSV) was developed and tested in infants and young children. However, instead of protecting against RSV, the vaccine led to worsened infection in many children resulting in some being hospitalized and two deaths. This tragic outcome slowed the development of an RSV vaccine for years. Over the next three decades, researchers sought to understand the immune response to RSV infections and explore potential vaccine targets other than the inactivated virus. During the 2000s, advances in molecular biology, immunology, and vaccine technology rekindled scientists’ efforts in RSV vaccine development. Researchers began exploring various approaches, including protein subunit vaccines, vectored vaccines, live-attenuated vaccines, and mRNA vaccines. Over the last decade, several RSV vaccine candidates have entered clinical trials. These trials have included vaccines for infants, older children, and at-risk adults, such as the elderly and pregnant women (intending to provide passive immunity to newborns). While some RSV vaccine candidates have shown promise, the challenge has been to find a vaccine that is safe, effective, and can provide long-lasting immunity. In 2022 in the European Union and UK and 2023 in the US and Canada approved Nirsevimab to prevent RSV.

Reference: Harrison et al. Mortality in adolescents and young adults following a first presentation to the emergency department for alcohol. AEM March 2024. Date: March 27, 2024 Guest Skeptic: Dr. Kirsty Challen is a Consultant in Emergency Medicine at Lancashire Teaching Hospitals. Case: It’s a Friday evening at the end of the academic year in the Paediatric Emergency Department (ED) and you are with the parents of a 15-year-old girl who has been brought in acutely intoxicated from an unofficial “School’s Out” party. Although your patient has recovered and is now fit for discharge, her parents are very worried that this may mean she is at more risk in the future. Background: We know that alcohol is a major cause of mortality and morbidity across the world [1] and that ED attendance due to it is rising [2,3]. We also know that adults who attend ED with alcohol-related problems are at an increased risk of death in the following year [4]– in fact, we discussed exactly that in SGEM#313 where we agreed that increasing frequency of alcohol-associated ED visits was associated with increasing mortality. However, we haven’t previously looked at the effect of alcohol in this specific vulnerable age group. CLINICAL QUESTION: IS A FIRST ED PRESENTATION RELATED TO ALCOHOL ASSOCIATED WITH INCREASED MORTALITY IN ADOLESCENTS AND YOUNG ADULTS? Reference: Harrison et al. Mortality in adolescents and young adults following a first presentation to the emergency department for alcohol. AEM March 2024. * Population: Patients aged 12-29 with ≥1 ED visit in Ontario 2009-15. * Excluded: Patients not resident in Ontario, those who were not eligible for OHIP 2 years before and 3 years after, and those with an alcohol-related ED visit in the 2 years before study commencement. * Intervention: Any visit related to alcohol * Comparison: No visits related to alcohol * Outcomes: * Primary Outcome(s): Mortality at 1 year * Secondary Outcomes: Mortality at 3 years, cause of death, predictors of death. * Type of Study: Retrospective cohort study. This is an SGEM HOP and we are pleased to have the lead author Dr. Daniel Myran on the show. Dr. Myran is the Canada Research Chair, Social Accountability, University of Ottawa Investigator, Assistant Professor, Department of Family Medicine, University of Ottawa, Associate Scientist, Ottawa Hospital Research Institute with a Cross Appointed School of Epidemiology and Public Health, University of Ottawa Authors’ Conclusions: “Incident ED visits due to alcohol in adolescents and young adults are associated with a high risk of 1-year mortality, especially in young adults, those with concurrent mental health or substance use disorders, and those with a more severe initial presentation.” Quality Checklist for Observational Cohort Studies: * Did the study address a clearly focused issue? Yes * Did the authors use an appropriate method to answer their question? Yes * Was the cohort recruited in an acceptable way? Yes * Was the exposure accurately measured to minimize bias? Unsure * Was the outcome accurately measured to minimize bias? Yes * Have the authors identified all-important confounding factors? No * Was the follow-up of subjects complete enough? Yes * How precise are the results? The confidence intervals are well away from zero, so precise enough. * Do you believe the results? Yes * Can the results be applied to the local population? Yes and unsure * Do the results of this study fit with other available evidence?

Reference: Marx et al. Simple Aspiration versus Drainage for Complete Pneumothorax: A Randomized Noninferiority Trial. Am J Respir Crit Care Med. 2023 Date: March 22, 2024 Guest Skeptic: Dr. Richard Malthaner holds the prestigious position of Chair/Head of the Division of Thoracic Surgery and serves as the Director of the Thoracic Robotic Program at Western University’s Schulich School of Medicine and Dentistry. Dr. Malthaner currently serves as the Vice President of the Canadian Association of Thoracic Surgeons and is the founder of the Skeptik Thoracik Journal Club. Case: A 25-year-old female medical student presents with right chest pain and dyspnea.  Chest x-ray (CXR) shows a “complete pneumothorax.” Background: The first time we got together to discuss chest tubes was on SGEM#129. That episode had two questions. The first question was in a trauma patient, how clinically useful is a CXR after putting in the chest tube? The answer we came up with was to put the tube on the correct side, within the triangle of safety, and within the pleural space. Continue to obtain a CXR post chest tube knowing it will probably not change management. Be more concerned if the patient is doing poorly or the tube is not draining. The second question we tried to answer was does chest tube location matter? The answer is that the part of the location that matters in these situations is that the chest tube is safely placed on the correct side and in the pleural space. The next time were talking chest tubes was not in trauma patients but rather in patients with their first large spontaneous pneumothorax in SGEM#300. We only had one question asking if they all needed a chest tube. The bottom line for that episode was it’s reasonable to provide conservative management in a patient with large first-time spontaneous pneumothoraxes if you can ensure close follow-up. We have looked at other chest-related issues with other guest skeptics. SGEM#339 looked at the optimal anatomical location for needle decompression for tension pneumothorax with Dr. Rob Edmonds. That study did not support the claim that the second intercostal space-midclavicular line is thicker than the fourth/fifth intercostal space-anterior axial line. The most recent time we have explored something involving chest tubes was with guest skeptic Dr. Chris Root (SGEM#355). We wanted to know if the size of the chest tube matters in hemodynamically stable patients with traumatic hemothorax. That was a multicenter, non-inferior, unblinded, randomized, parallel assignment comparison trial that reported small percutaneous catheters were non-inferior to large open chest tubes for traumatic hemothorax.  Patients can present with a spontaneous pneumothorax. This is defined as air in the pleural space between the lung and the chest wall with no obvious precipitating factor. It can occur in existing lung disease (secondary spontaneous pneumothorax) or with no known underlying lung pathology (primary spontaneous pneumothorax). Chest tube drainage remains the reference first-line treatment of primary spontaneous pneumothorax, however, complications occur in 9–26% of such cases. A less invasive alternative approach is simple aspiration, which could be an option. The best way to manage a first primary spontaneous pneumothorax episode remains unclear. Clinical Question: Is simple aspiration non-inferior to chest tube drainage for first-line lung e...

Date: March 16, 2024 This is an SGEM Xtra episode. Yes, that is two back-to-back SGEM Xtra episodes. The critical appraisal that was lined up for this week’s episode got delayed due to some scheduling problems with clinical responsibilities. You can access all the slides for this episode from this LINK and see the presentation on YouTube. This episode is from a talk I gave a few years ago on social media for knowledge translation. How this technology could make the world a better place. I’ve come to recognize that many SGEMers are not very familiar with the best movie decade of all time, the 1980’s. Therefore, I created this talk using the Matrix as a more contemporary theme from the late 1990’s early 2000’s. The Matrix was a groundbreaking movie created by Lana and Lily Wachowski and released in 1999. It started a movie franchise blending science fiction and action in a visual masterpiece. The first movie introduces us to a dystopian future in which humanity is unknowingly trapped inside the Matrix, a simulated reality created by intelligent machines to distract humans while using their bodies as an energy source or batteries. Thomas Anderson (Mr. Anderson), a computer programmer by day and a hacker named Neo by night, discovers the truth about the Matrix. He is drawn into a rebellion against the machines, led by Morpheus and Trinity. Neo is believed to be “The One,” a prophesized hero destined to end the war between humans and machines. The film explores themes of reality, freedom, and control. Like Morpheus in The Matrix, “all I’m offering is the truth, nothing more”. “What if I told you”…Morpheus never says that in The Matrix. Yet “what if I told you” is one of the most well-known Memes. There are many quotes from movies that are wrong/misquoted. Here are three examples of movie misquotes. For a list of the top ten movie misquotes click on the LINK: * Play it again Sam (Casablanca 1942): That line is never said in the movie Casablanca. Humphrey Bogart actually says ”You played it for her, you can play it for me. If she can stand it, I can. Play it!”. * Luke, I am your father (Star Wars V The Empire Strikes Back 1980): The actual line by Darth Vader is “No, I am your father.” * If you build it, they will come (Field of Dreams 1989): James Earl Jones says“People will come, Ray.” Back to the lecture, Morpheus sitting in the chair wearing cool sunglasses and offering Neo the red and blue pill never said “What if I told you”. In the actual dialogue in the scene, Morpheus says: “Do you want to know what ‘it’ is?”. What it is for today’s lecture is the problem with knowledge translation and how it can be addressed with Social Media. Trinity tells Neo in The Matrix “It’s the question that drives us, Neo. It’s the question that brought you here. You know the question, just as I did. In the movie, the question was “What is the Matrix”? For this lecture, the question is “How long does it take for high-quality clinically relevant information to reach the patient? There are a few answers to the question of how long knowledge translation takes in medicine. One answer is from Dr. John Jackson who was a British Neurologist. He said,

Date: March 6, 2024 This is an SGEM Xtra created from a lecture I gave for the Rural Ontario Medical Program (ROMP) ICE Camp Retreat in Collingwood, Ontario last month. ROMP helps Ontario medical students & residents arrange core & elective rotations in rural Ontario. An old friend, Dr. Matt De Stefano invited me to give a lecture to the PGY-3 Emergency Medicine Residents. Matt said it could be a talk on anything so I decided to create a new presentation called “A Philosophy of Emergency Medicine” This lecture was inspired by the wonderful Professor Melanie Trecek-King. She is a science educator from the USA and has an amazing website called Thinking is Power. I bought a T-shirt from Melanie that says “Be curious, be skeptical and be humble”. Such great wisdom from an amazing science communicator. For the presentation at ROMP, I made a friendly amendment to Melanie’s three items substituting that last piece of advice “Be Humble” (which is very important) with “Be Teachable” for the audience of PGY3 Emergency Medicine Residents. If you are interested in seeing all the slides they can be downloaded from this LINK or you can watch the episode on YouTube. Be Curious: The lecture started not with a 1980s cultural reference but rather with a recent cultural reference from the TV show Ted Lasso. Be Curious, not judgmental. This was a great show for a variety of reasons and we are planning to do a special SGEM Xtra episode on how the lessons we learned from Ted Lasso made us better.  Be Skeptical: This is the second important part of my EM philosophy. Carl Sagan is arguably one of the most famous skeptics ever. He in part inspired this knowledge translation project called the Skeptics’ Guide to Emergency Medicine. Probably one of his most famous quotes was that “extraordinary claims require extraordinary evidence” Be Teachable: The third philosophical point I wanted to make about Emergency Medicine was to encourage you to Be Teachable. This does not just apply to when you are a resident but also when you become an attending physician. You will not always be right. Be Kind: One more super important thing that you should consider as part of your EM philosophy is to be kind. It is something I learned from Dr. Brian Goldman. Brian is the host of the amazing CBC show White Coat Black Art and has authored several great books. One of the best books he wrote was called The Power of Kindness – Why Empathy is Essential in Everyday Life. The SGEM will be back next episode doing a structured critical appraisal of a recent publication. Trying to cut the knowledge translation window down from over ten years to less than one year using the power of social media. So, patients get the best care, based on the best evidence. If you would like a copy of all the slides used in this presentation simply click on the LINK and you can see all the slides on YouTube. Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

Reference: Gibbons et al. The sonographic protocol for the emergent evaluation of aortic dissections (SPEED protocol): A multicenter, prospective, observational study. AEM February 2024. Date: February 28, 2024 Guest Skeptic: Dr. Neil Dasgupta is an emergency medicine physician and ED intensivist from Long Island, NY.  He is the Vice Chair of the Emergency Department at Nassau University Medical Center in East Meadow, NY, the safety net hospital for Nassau County. Case: A 59-year-old man walks into your community emergency department (ED) complaining of chest pain. It is described as a ripping sensation that radiates to his back. His vital signs are all normal and the ECG done at triage does not show an occlusive myocardial infarction. The chest x-ray is unremarkable, and his troponin is not elevated. You suspect an acute aortic dissection (AoD). However, your CT scanner is offline for two hours of scheduled maintenance. He will need to be transferred to the tertiary care center which is 35 minutes away by ground EMS if it is a dissection. Your Spidey senses are tingling, and you don’t want to wait for the CT scanner to be back online to make the diagnosis. Arrangements are made for him to be transferred stat to the tertiary hospital while he is still stable. You wonder if a quick POCUS examination looking for three sonographic findings while waiting for the paramedics could help determine the likelihood of this being an AoD. Background: We recently covered acute aortic syndrome (AAS) on SGEM#430. AAS has been called the lethal triad and includes aortic dissection (AD), intramural hematoma (IMH), and penetrating aortic ulcer [1]. It is a rare but deadly condition that can present in atypical ways leading to delays in diagnosis and an associated increase in mortality. This episode is going to focus on acute aortic dissection (AoD) which is classified into two major types according to the Stanford classification system: Type A and Type B. This system is based on the location of the tear and helps guide treatment strategies. Type A dissections Involves the ascending aorta and may extend into the descending aorta. It’s more common and more dangerous than Type B, as it can lead to serious complications like rupture into the pericardial space leading to cardiac tamponade, aortic valve insufficiency, or myocardial infarction. Symptoms may include more severe chest pain radiating to the back, loss of consciousness, or symptoms of stroke if the blood supply to the brain is affected. Type A AoDs generally require an emergent trip to the operating room as soon as they are identified to reduce the likelihood of a terrible outcome. Type B dissections occur in the descending aorta only, after it has passed the arteries that supply blood to the arms and head. They are less common than Type A and usually less immediately life-threatening, but still serious and potentially fatal if not treated properly. Symptoms can include sudden onset of pain in the back or abdomen, depending on the exact location and extent of the dissection. The pain is often described as tearing or ripping. Speed is important in making the diagnosis of an AoD due to the associated increase in mortality with delays [2,3]. We know from last week that clinical decision tools (CDTs) are not ready for prime time. This is consistent with the American College of Emergency Physicians (ACEP) which does not recommend the routine use of clinical decision rules in suspected cases of AoD [4].

Reference: Li, T., & Gal, D. (2023). Consumers prefer natural medicines more when treating psychological than physical conditions. Journal of Consumer Psychology 2023, Date: February 23, 2024 Guest Skeptic: Ethan Milne is a Marketing PhD student at the Ivey Business School (Western University). He researches how moral outrage and status-seeking personalities motivate social media aggression, and how retribution can motivate consumer donations. Case: A 20-year-old male presents to the emergency department with palpitations. After a good history, directed physical examination and appropriate investigations you suspect he is suffering from a major depressive disorder (MDD) with a comorbidity of anxiety.  He is not a threat to himself or others and wants assistance. You arrange for him to be followed up by his family physician to discuss possible treatment options which include medications. He expresses concern that taking a synthetic drug to treat his depression wouldn’t allow him to be his authentic self. Background: Major Depressive Disorder, commonly known as depression, is a significant mental health condition. Depression is a leading cause of disability worldwide and is a major contributor to the overall global burden of disease. It affects an estimated 5-10% of the population at any given time, with variations depending on demographic factors such as age and gender. It is generally more common in women than in men and can occur at any age, although it often first appears during late adolescence to mid-20s [1]. The National Institute of Health (NIH) estimates that around 8.3% (21.0 million) of US adults over 18 have experienced a major depressive episode in the last year. Various factors can increase the risk of developing MDD, including genetic predisposition, personal or family history of depression, major life changes, trauma, stress, and certain physical illnesses and medications. Depression has been reported to be most prevalent among young women aged 12-17 (29.2%) [2]. The current diagnostic criteria for MDD are outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5-TR). These criteria serve as a guideline for clinicians to diagnose depression. To be diagnosed with MDD, a person must experience at least one of the two symptoms for at least two weeks: * Depressed Mood: Most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad, empty, hopeless) or observation made by others (e.g., appears tearful). * Loss of Interest or Pleasure: Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day. The person must also have five or more of the following symptoms during the same 2-week period, and these symptoms represent a change from previous functioning. * Significant Weight Loss or Gain (or decrease or increase in appetite nearly every day) * Insomnia or Hypersomnia: Trouble sleeping or sleeping too much nearly every day. * Psychomotor Agitation or Retardation: Noticeable by others, not merely subjective feelings of restlessness or being slowed down. * Fatigue or Loss of Energy: Nearly every day. * Feelings of Worthlessness or Excessive or Inappropriate Guilt: Nearly every day, not merely self-reproach or guilt about being sick. * Diminished Ability to Think or Concentrate (or indecisiveness, nearly every day) * Recurrent Thoughts of Death: Recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.

Reference: McLatchie et al and DAShED investigators. Diagnosis of Acute Aortic Syndrome in the Emergency Department (DAShED) study: an observational cohort study of people attending the emergency department with symptoms consistent with acute aortic syndrome. EMJ Nov 2023. Date: February 11, 2024 Guest Skeptic: Nirdosh Ashok Kumar, Emergency Medicine Specialist – Aga Khan University Hospital, Karachi, Pakistan. Case: A 66-year-old female with a history of smoking, hypertension, and type-2 diabetes presents to the emergency department (ED) with syncope while walking her dog. She complains of retrosternal chest pain radiating to her jaw. She is bradycardic, hypotensive, and tachypneic. She is received in the resuscitation room. Monitors have been attached, and intravenous (IV) access has been achieved and IV analgesia has been given. The ECG shows sinus tachycardia with non-specific ST-T changes. The chest x-ray is unremarkable. However, she is still in severe pain. A post-graduate year 2 (PGY-2) resident asks you if it could be a ruptured abdominal aortic aneurysm, aortic dissection, or angina. Background: The diagnosis of acute aortic syndrome (AAS) is commonly delayed or missed in the ED. AAS has been referred to as the “lethal triad” that incorporates aortic dissection (AD), intramural hematoma (IMH), and penetrating aortic ulcer (PAU) [1].  It is a rare condition with a high mortality rate and can present in atypical ways. It affects approximately 4,000 people per year in the United Kingdom [2] and 43,000 to 47,000 people per year in the USA [3]. The annual incidence rate of AD ranges between 2.9 and 7.2 per 100,000. [4-8] The misdiagnosis rate is estimated to be between 16% and 38%6,[9-19] with a diagnostic delay of up to 24 hours for 25% of cases, and mortality follows a linear increase of 0.5% per hour in the first 48 hours. [20] A retrospective observational study from Canadian researcher, Dr. Robert Ohle was published in CJEM in 2023. This study found that between 2003 and 2018, there were 1,299 cases of AAS in Ontario, the largest province in the country. It reported an overall annual incidence rate of 0.61 per 100,000 people which is much lower than previously reported rates. The study also highlighted the significant mortality rate associated with AAS, with a one-year mortality rate decreasing from 47.4% to 29.1%, and ED mortality at 14.9%​​. [21] When looking specifically at atraumatic chest pain presentations to the ED, it is estimated the incidence of AAS is one in 980. [22] It can be like looking for a needle in a haystack of chest pain patients. The gold standard for diagnosing AAS is to perform a CT aorta angiogram (CTA). However, scanning everyone chest pain patient would have a very low diagnostic yield [23,24], expose many patients to unnecessary ionizing radiation and end up being very costly. It would be great if there was a validated clinical decision tool (CDT) to help clinicians be more selective in using CTA to diagnose AAS. Some CDTs have been devised and tested for diagnosing AAS. [25,26] The Aortic Dissection Detection Risk Score (ADD-RS) is one CDT that has been derived and tested. Four studies with methodologic limitations were included in an SRMA of the ADD-RS and published in AEM 2020. [27] The authors concluded that patients with an ADD-RS score of ≤ 1 with d-dimer < 500 ng/mL have high sensitivity for ruling out AASs. However, it is unclear if it is good enough for clinicians to use, better than clinical gestalt [28,29], and an impact analysis has not been done to determine if it would lead to fewer CTAs and d-dimers being performed. Clinical Questions: What are the characteristics of ED attendances with possible AAS, how effective are existing clinical decision tools (ADD-RS, Canadian Guideline, Sheffield, AORTAs) and the use of CTA in an undifferentiated cohort of...