The Skeptics Guide to Emergency Medicine

Date: July 29th, 2021 Reference: Azizi et al. Optimal anatomical location for needle decompression for tension pneumothorax: A multicenter prospective cohort study. Injury 2021 Guest Skeptic: Dr. Robert Edmonds is an emergency physician in the Air Force in Ohio.  This is Bob’s 14th episode cohosting the SGEM. DISCLAIMER: THE VIEWS AND OPINIONS OF THIS PODCAST DO NOT REPRESENT THE UNITED STATES GOVERNMENT OR THE US AIR FORCE. Case: You are driving home from a busy shift and see a car collision occur right in front of you.  The driver is a restrained self-extricated male who lost control of his vehicle into a light post and the vehicle’s airbags deployed.  After safely pulling over and having a bystander call 911, you evaluate the patient.  He is speaking in full sentences without confusion, has a strong, rapid pulse, significant pain in his chest and is having a very hard time breathing.  As you wait for EMS to arrive, you quickly dash back to your car to retrieve your stethoscope and an angiocatheter you have in your glovebox.  You notice a marked difference between breath sounds on the left side and decide the patient needs treatment for a tension pneumothorax.  After obtaining consent from the patient, you debate whether to decompress at the second intercostal space in the midclavicular line as you originally learned, or in the fourth/fifth intercostal space midaxillary line as per the current ATLS guidelines. Background: The latest ATLS guidelines were published in 2018. We covered them on the SGEM Xtra with Dr. Neil Parry. There were several changes to the new guidelines but one of them was changing the location for needled decompression for adult patients. Needle thoracostomy is subject to several complications compared to a tube thoracostomy primarily due to the shorter length of the needle as well as the smaller lumen, so site selection has focused on finding a short distance and a site unlikely to kink or get dislodged. Dr. Richard Malthaner We have covered chest tube thorocostomy a couple of times on the SGEM with Dr. Richard (Thoracic) Malthaner. SGEM#129 looked at where to put the chest tube on trauma patients and if a post-procedure chest Xray (CXR) was required. The conclusion from that episode 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 other episode on chest tubes was SGEM#300. The clinical question was does everyone with a large first-time spontaneous pneumothorax need a chest tube? The answer from that episode was It is reasonable to provide conservative management (no chest tube) in a patient with large first-time spontaneous pneumothoraxes if you can ensure close follow-up. The changes in the ATLS guidelines were based in part on a small study (n=20) utilizing cadavers [1]. There were also studies using CT scans showing a preference for the fourth/fifth ICS AAL [2,3].  These studies were limited by heterogeneity (I2 83%-98%), possible publication bias, and not being randomized trials. These authors are adding to the literature by utilizing ultrasound on live patients. This could reduce some of the potential confounders in prior studies that were exclusively cadavers which may have differences in CWT due to post-mortem changes. The previous studies also focused on homogenous populations like military members and are therefore less generalizable to the general population. Additionally, by using ultrasound instead of CT, some of the confounders from arm placement during CT were reduced.  Clinical Question: Is the chest wall thickness at the second intercostal space in the midclavicular line not thicker than the fourth/fifth intercostal space anterior axillary line? Reference: Azizi et al. Optimal anatomical location for needle decompression for tension pneumothorax: A multicenter prospective cohort study. Injury 2021 Population: A convenience sample of all adults presenting to one of the eight participating hospitals over a two-week period. (June 11-23, 2019) Excluded: Patients with pre-existing thoracic deformities, patients who were seriously ill requiring continuous urgent care, and patients who were unable to provide consent Intervention: Chest wall thickness at the second intercostal space in the midclavicular line Comparison: Chest wall thickness at the fourth/fifth intercostal space anterior axillary line Outcome: Primary Outcome: Median CWT in ICS2-MCL and ICS 4/5 AAL Secondary Outcomes: BMI 25-30 CWT, BMI 30+ CWT, hypothetical failure rates of needle decompression Authors’ Conclusions: “In overweight- and obese subjects, the chest wall is thicker in ICS 4/5-AAL than in ICS2-MCL and theoretical chances of successful needle decompression of a tension pneumothorax are significantly higher in ICS2-MCL compared to ICS 4/5-AAL.” Quality Checklist for Observational Study: Did the study address a clearly focused issue? Yes Did the authors use an appropriate method to answer their question? Unsure Was the cohort recruited in an acceptable way? Unsure Was the exposure accurately measured to minimize bias? Yes Was the outcome accurately measured to minimize bias? Yes/Unsure Have the authors identified all-important confounding factors? No Was the follow up of subjects complete enough? Yes How precise are the results? Precise Do you believe the results? Yes Can the results be applied to the local population? Unsure Do the results of this study fit with other available evidence? No Results: There were 390 patients available for analysis in this study. Mean age was 51 years, 52% were male and the mean BMI was 25.5. Key Result – There was no statistical difference in mean chest wall thickness between the second ICS-MCL and the fourth/fifth ICS-AAL Primary Outcome: Median chest wall thickness (CWT) 26mm (IQR 21-32) ICS2-MCL vs 26mm (IQR 21-33) ICS 4/5 AAL (p<0.001) Secondary Outcomes: Median CWT BMI 25-30: Chest wall was thinner at ICS2-MCL 27mm vs ICS 4/5-AAL 29mm Median CWT BMI 30+: Chest wall was thinner at ICS 2-MCL 35 mm vs. ICS 4/5-AAL 39 mm Hypothetical Failure Rates of Needle Decompression 1. Convivence Sample - The authors state they used a convenience sample of patients presenting to the ED of eight hospitals during a two-week period June 11-23, 2019. The words “convenience” sample often refer to limited hours of enrollment (not nights/weekends and holidays usually). They did not explicitly state what they meant by convenience sample in the published manuscript. Selection bias could have been introduced using this methodology. 2. Angle of Attack - The authors mention the CWT and then use this to extrapolate the hypothetical rate of needle decompression failure for the two sites. This assumes the clinician performing the needle decompression enters the skin in a perpendicular approach and goes the shortest distance possible to the pleura. It is reasonable to suspect that the patient who is receiving needle decompression rather than a chest tube is further from definitive care or in a greater degree of extremis than a stable patient with a spontaneous pneumothorax who ambulated into the ED complaining of chest pain and difficulty breathing.  It’s likely that not all needles used for needle decompression are placed perfectly perpendicular to the site of choice, and it seems reasonable to conclude that there could be a significant difference in the actual angle of attack the needle takes when comparing the two sites.  This makes the authors’ hypothetical rate of ND failure based purely on CWT a little less definitive. 3. Site Selection – They evaluated the site previously recommended by ATLS (second ICS-MCL) but compared it to a different site than the new ATLS recommendation. These authors looked at fourth/fifth ICS-AAL instead of ATLS recommended fourth/fifth ICS-MAL). The Laan SRMA mentions how “…in our analysis of the CWT reported at different locations, we found that the mean CWT was smallest at ICS4/5-AAL, thicker at ICS4/5-MAL, and thickest at ICS2-MCL. Despite this observed tendency, the difference in CWT was not statistically significant (P=.08).” So, if the authors truly intended to support use of the second ICS-MCL over the more lateral and inferior sites, the better comparison would have been fourth/fifth ICS-MAL based on previous evidence. 4. Under Pressure - The authors used ultrasound to measure the CWT at both sites.  They state that the ultrasound probe was placed “without any compression” and exactly perpendicular to the chest wall.  Although every effort was likely made to reduce compression, these two sites do differ in how lateral they are, and it is possible that some compression of tissues did occur during measurement despite the best of efforts.  This challenges the accuracy of the measurements between the two sites. 5. Clinically Important – While this is an interesting study using POCUS to determine CWT and generate a hypothetical failure rate, a much better study would be a randomized trial. Randomize patients into getting the needle decompression at the second ICS-MCL or the fourth/fifth ICS-MAL as per the latest ATLS guidelines. The primary outcome could be successful decompression. If one site is superior to another then a further larger trial could be done looking at all-cause mortality as the primary outcome. Comment on Authors’ Conclusion Compared to SGEM Conclusion: We are hesitant to change practice based on a subgroup analysis and find insufficient evidence to reject the ATLS guidelines for needle thoracostomy placement site. This is recognizing that there is not strong data to support the ATLS guideline recommendation.

Date: July 24th, 2021 Guest Skeptic: Dr. Brain Goldman is an Emergency Medicine physician who works at Mount Sinai hospital in Toronto. He is the host of CBC radio show White Coat Black Art and the podcast The Dose. He is also the author of the bestselling books The Night Shift, Secret language of Doctors, and the Power of Kindness. This is a SGEM Xtra. Brain and I went on an away mission by shuttle craft to Ticonderoga, NY for the weekend. This was to join Mr. William Shatner to celebrate his 90th birthday. We took the opportunity during part of the road trip to record an SGEM episode about how Star Trek made us better physicians. Some of you may love this episode while others may not. William Shatner 90th Birthday Party Celebration Away Mission 2021 There were a number of challenges that needed to be overcome to make this epic trip happen. First, it was difficult to get VIP tickets to this sold out event hosted by James Cowley. James created the Star Trek: Original Series Set Tour. This is an amazing recreation of the sets from the original series. James is also an executive film producer, actor and famous Elvis impersonator. He graced us with a performance as Elvis as part of the birthday celebration weekend (link to video). After obtaining a couple of VIP tickets to the event, the next concern was: what colour of shirt to wear? There is the gold command tunic worn by Captain James T. Kirk, the blue science/medical tunic worn by Mr. Spock and Dr. McCoy, or the infamous red shirt. Please note that the red shirt characters were not statistically more likely die. Another challenge was traveling to the USA. The border restrictions were supposed to have been eased on July 21st to allow crossing by ground. However, it was announced on July 20th that the restrictions would remain in place until August 9th. People were allowed to cross by air if fully vaccinated and had negative COVID19 test within three days of departure. This allowed us to fly over the border, rent a car and drive to Ticonderoga. The final challenge was what to get Mr. Shatner for his 90th birthday. I called the Stratford Festival a few months before the event and asked for their assistance. They kindly searched their archives for the three seasons he was part of the company (1954-1956). There were no pictures that featured him on stage because he was not a famous actor at the time. They did find two photos of Mr. Shatner receiving the Festival’s Guthrie Award from Governor General Vincent Massey in 1956. There were also some newspaper clippings describing how Mr. Christopher Plummer was admitted to hospital for a kidney stone and his understudy, William Shatner, took over the lead role in Henry the V. The Stratford Festival Archivist did find one amazing photo of Mr. Shanter from 1954. It is a picture of him sitting in a chair surrounded by a few other individuals checking out the masks for the 1954 production of Oedipus Rex. It looked like he was getting ready to sit in the captain's chair aboard the USS Enterprise NCC 1701. It's this photo that I had printed, framed and presented to him as a birthday present. He was very gracious and appreciative of receiving this special birthday gift. For those of you not familiar with Star Trek it started with a TV series that had 79 episodes and was broadcasted over three seasons from 1966-1969. It is a science fiction franchise created by Gene Roddenberry. Star Trek The Original Series (TOS) launched many other TV series and movies. This SGEM Xtra will discuss some of the lessons learned from Star Trek and how it has applied to our practice of emergency medicine. Brian and I had a wonderful away mission. Some of the highlights included the private tour of the Enterprise by Mr. Shatner. I had the chutzpah to ask a question of during the bridge chat about what Mr. Shatner learned from his time at the Stratford festival that he applied to his career in TV and movies. His answer was he learned excellence from the best directors and actors in the world. It was also wonderful to go on a couple of hikes with Brian around Ticonderoga and see the natural beauty of this historic town. It is located in New York state on the north end of Lake George and a southern portion of Lake Champlain. There is also fort in Ticonderoga build by the French in the 18th century that played an important role during the American revolution. Mr. Daren Dochterman Another super experience was meeting the talented Mr. Daren Dochterman. He is a set designer who has worked on many movies. Daren won an award for his work on the visual effects for the movie Star Trek: The Motion Picture Director's Cut. He informed us that the Director's Cut is being remastered for 4K release and he is part of the team. Daren also co-hosts the best Star Trek podcast called the Inglorious Treksperts with Mark A. Altman. After Brian and I met him and discussed our love of Star Trek TOS he made us honorary treksperts. Our private tour of the Star Trek TOS set was fantastic. Seeing everything from the transporter room, sick bay, engineering, and Captain Kirk's quarters. The biggest thrill was to sit in the command chair on the bridge of the Enterprise. It was a surreal moment to be in such a detailed replica and is very hard to describe. If you are a Star Trek fan I would highly suggest you make the trip to Ticonderoga and sit in the Captain's chair yourself. Star Trek and Evidence-Based Medicine Listeners to the SGEM know this knowledge translation project promotes evidence-based medicine (EBM). The definition we use for EBM is the one provided by Dr. David Sackett in the BMJ 1996. "Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients." There are three components to EBM that can be represented in a Venn diagram: Relevant Scientific Evidence - The literature should inform our care as clinicians but not necessarily dictate our care. Many people make the mistake of thinking that EBM is just about the scientific literature. This is not true. It is important to know about the relevant scientific information and how to critically appraise the evidence. Patients' Values/Preferences - We need to ask patients what they value and prefer. This may be different that what we as clinicians think and we should not assume to know. Each patient will be an expert at their own personal experience. They have agency and we can engage with them on using a shared decision model. Clinical Judgment - Often the available evidence will not be very strong or will not specifically apply to the individual patient we are caring for in the emergency department. Also the patient may not be able or want to participate in the decision. We need to use our good clinical judgement to apply the best evidence while honouring what patients prefer. This model of EBM can be illustrated by the three main characters of Star Trek TOS. Mr. Spock - He represents logical thinking and provides evidence to the situation. However, decisions are made in a context and do not reduce to just numbers, p-values, or confidence intervals around a point estimate of an observed effect size. The evidence can inform our care and guide our care but it should not dictate our care. Dr. McCoy (Bones) - He represents the patients in the EBM Venn diagram. Dr. McCoy advocates for humanity in Star Trek. He speaks passionately about the emotional aspect of challenging situations faced. Captain James T. Kirk - He represents the clinical judgment. Captain Kirk listens to the logic and evidence that Mr. Spock provides and to the emotional arguments made by Dr. McCoy. This dialog helps him make decisions. These are often life and death decisions based on incomplete information and is similar to what emergency physicians must do in the emergency department. Lessons Learned from Star Trek that Apply to Emergency Medicine Brian and I discussed a number of things we learned from Star Trek that we think informs our practice of emergency medicine and makes us better physicians. Listen to the SGEM podcast to hear the details of this discussion. This was recorded while we drove from our hotel in Burlington, Vermont to Ticonderoga, NY. Risk Is Our Business: We risk stratify patients all the time considering potential benefits vs potential harms. This has been discussed multiple times on the SGEM. SGEM#118: I Hope you Had a Negative D-dimer (ADJUST PE Study) SGEM#282: It’s All ‘bout that Bayes, ‘Bout that Bayes- No Trouble – In Diagnosing Pulmonary Embolism SGEM#212: Holding Back the Years – Risk Factors for Adverse Outcomes in Older Adults with Blunt Chest Trauma SGEM#252: Blue Monday- Screening Adult ED Patients for Risk of Future Suicidality SGEM#170: Don’t Go Breaking My Heart – Ottawa Heart Failure Risk Scale Anyone, Anytime, for Anything: The emergency department is the light in the house of medicine that is on to assess and treat anyone, at anytime for anything. This includes people with substance use disorder and mental illness. It should not matter a patients gender, age, or race. SGEM#313: Here Comes A Regular to the ED SGEM#280: This Old Heart of Mine and Troponin Testing SGEM#266: Old Man Take a Look at the Canadian CT Head Rule I’m a Lot Like You Were SGEM#248: She Works Hard for the Money – Time’s Up in Healthcare SGEM Xtra: I’m in a FIX State of Mind No Win Scenario: Every patient who presents to the emergency department is an opportunity. We can have a number needed to treat (NNT) of one to help. It all depends on how we define "win". Even if we do everything correctly patients will die. However, how we deal with death is also important. The NNT concept has been discussed on the SGEM. SGEM Xtra: NNT – WET or DRI

Date: July 14th, 2021 Reference: Pernica et al. Short-Course Antimicrobial Therapy for Pediatric Community-Acquired Pneumonia: The SAFER Randomized Clinical Trial. JAMA Pediatr. 2021. Guest Skeptic: Dr. Andrew (Andy) Tagg is an Emergency Physician with a special interest in education and lifelong learning. He is the co-founder of website lead of Don’t Forget the Bubbles (DFTB). When not drinking coffee and reading Batman comics he is playing with his children. Case: Six-year-old Morten comes into your emergency department (ED) with what looks like pneumonia.  He has been febrile with a temp of 39 degrees Celsius, he is mildly tachypneic but shows no real signs of respiratory distress and you can hear some crackles in the right mid-zone.  His chest X-ray (CXR) confirms your findings, but he is well enough to be treated as an outpatient. Background: It is hard to believe we have not covered the common condition of pediatric community acquired pneumonia (CAP) on the SGEM. Perhaps it is because there is limited evidence on this common condition. However, we have covered other pediatric infectious issues like: Honey for Cough SGEM#26 Fever Fear SGEM#95 Lumbar Punctures SGEM#296 Bronchiolitis SGEM#228 Invasive Bacterial Infection SGEM#334 We do have high-quality evidence that a CXR is not necessary to confirm the diagnosis of CAP in patients who are well enough to be managed as outpatients. There is also high-quality evidence that pre-school children do not routinely need antibiotics. This is because most  pneumonias in this age-group are caused by viral pathogens (Bradley et al 2011). Antibiotics are recommended for school age children diagnosed with CAP. However, how long should they be treated is an open question. The IDSA guidelines provide a strong recommendations based on moderate quality of evidence to guide our care. (Bradley et al 2011). Treatment courses of 10 days have been best studied, although shorter courses may be just as effective, particularly for more mild disease managed on an outpatient basis. (strong recommendation; moderate-quality evidence) There is an RCT reporting five days of amoxicillin (80mg/kg divided TID) was non-inferior to ten days for CAP in children six months to 59 months of age (Greenberg et al 2014). This was a relatively small study (n=115) from Israel. A short course (five days) has also been recommended by the American Thoracic Society and the IDSA for adults with CAP under certain conditions (Metlay et al 2019). We recommend that the duration of antibiotic therapy should be guided by a validated measure of clinical stability (resolution of vital sign abnormalities [heart rate, respiratory rate, blood pressure, oxygen saturation, and temperature], ability to eat, and normal mentation), and antibiotic therapy should be continued until the patient achieves stability and for no less than a total of 5 days (strong recommendation, moderate quality of evidence). Clinical Question: Is a five day course of antibiotic therapy non-inferior to a ten day course to achieve clinical cure for paediatric community-acquired pneumonia? Reference: Pernica et al. Short-Course Antimicrobial Therapy for Pediatric Community-Acquired Pneumonia: The SAFER Randomized Clinical Trial. JAMA Pediatr. 2021 Population: Children aged six months to ten years of age diagnosed with community acquired pneumonia (CAP) who are well enough to be treated as an outpatient. CAP was defined as fever (rectal, oral or axillary in 48 hours before presentation), tachypnea (based on age, accessory muscle use or auscultation findings), CXR, or primary diagnosis by the ED physician. Exclusions: Empyema or necrotizing pneumonia, preexisting pulmonary disease, congenital heart disease, history of aspiration, malignant neoplasm, immunodeficiency, kidney disfunction, on beta-lactam antibiotics for >24hrs at presentation, 5-days of beta-lactam <72hours before presentation, IV cephalosporin or azithromycin in the ED, suspected mononucleosis, prolonged admission in the previous two months, CAP diagnosed in the previous month, lung abscess in the previous six months or an allergy to penicillin allergy. Intervention: Five days of high-dose amoxicillin (90mg/kg/d divided TID) followed by five days of placebo Comparison: Ten days of high-dose amoxicillin (90mg/kg/d divided TID) Outcome: Primary Outcome: Clinical cure at 14-21 days Secondary Outcomes: Days off school/childcare, missed work days for carers, adverse reactions and adherence Authors’ Conclusions: “Short-course antibiotic therapy appeared to be comparable to standard care for the treatment of previously healthy children with CAP not requiring hospitalization. Clinical practice guidelines should consider recommending 5 days of amoxicillin for pediatric pneumonia management in accordance with antimicrobial stewardship principles.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Yes The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in in a per-protocol analysis for non-inferiority trials. Yes The study patients were recruited consecutively (i.e. no selection bias). Unsure The patients in both groups were similar with respect to prognostic factors. Yes All participants (patients, clinicians, outcome assessors) were unaware of group allocation. Yes All groups were treated equally except for the intervention. Yes Follow-up was complete (i.e. at least 80% for both groups). Yes All patient-important outcomes were considered. Yes The treatment effect was large enough and precise enough to be clinically significant. Unsure Results: They recruited a total of 281 children to be included in the trial with a median age of 2.6 years and 57% male. Key Result: A 5-day course of antibiotics was not non-inferior   to a 10-day course of antibiotics in children with CAP. Primary Outcome: Clinical cure at 14-21 days after enrollment Per-Protocol Analysis: 88.6% in the intervention group 90.8% in the control group. Risk difference −0.016 (97.5% Confidence Limit −0.087) and cannot claim non-inferiority Intention-to-Treat Analysis: 85.7% in the intervention group and 84.1% in the control group. Risk difference 0.023 (97.5% Confidence Limit −0.061) Secondary Outcomes: Caregivers were off work two days instead of three in the intervention group. All other secondary outcomes were the same. 1. Included Children: Of the 5,406 children diagnosed with pneumonia over the duration of the trial only 281 were randomized. There were 3,215 possible patients missed suggesting they were not recruited consecutively. Only 5% of all possible patients made it into the trial. Are these 281 children typical of the cohort of all cases of pneumonia or different? 2. Chest X-Ray (CXR): Do you really need a CXR to diagnose mild pneumonia? It is actively discouraged in our Australian guidelines and PIDS and the IDSA also recommend not doing it. Certainly, if you are worried about an alternative diagnosis such as inhaled foreign body but in mild pneumonia that you are going to send home? Around one-quarter did not have a formal radiologist report of pneumonia. They state in the publication: “It is suboptimal that some study participants were not believed to have radiographic findings consistent with pneumonia by the attending radiologist” We have talked about CXR before for diagnosing pneumonia in adults (SGEM#287 and SGEM#298). It is an imperfect gold standard (Copper Standard Bias). Even if the CXR is “positive" it does not mean a child has a bacterial pneumonia. Prescribing antibiotics to patient with a viral pneumonia is unlikely to have a patient-oriented outcome (POO). They did do nasopharageal swabs on some of the children and found no significant differences in clinical cure rates among those with respiratory viruses or M pneumoniae detected compared with those without. 3. Clinical Cure: Their definition of clinical cure included subjective criteria. This could have introduced uncertainty into the data. They did use a definition that was similar to that used in other studies of 5-day CAP therapy in children (Harris et al 1998) and adults (Dunbar et al 2003) Their specific definition was children meeting all three of the following criteria: significant improvement in dyspnoea and increased work of breathing, and no recorded tachypnoea, at the day 14-21 follow-up visit; no more than 1 fever spike (as defined above) as a result of bacterial respiratory illness from day 4 up to and including the day 14-21 follow-up visit; and lack of a requirement for additional antibacterials or admission to hospital because of persistent/progressive lower respiratory illness during the 2 weeks after enrollment. You can see that different physicians could have different interpretations on what a “significant improvement” looked like clinically and if the child required additional antibiotics or hospital admission. 4. Non-Inferiority: This was non-inferiority trial and they correctly performed a per-protocol analysis. The non-inferiority margin was based on several assumptions. Because the 1-sided 97.5% confidence limit of the point estimate of 7.5% was exceeded, a formal conclusion of non-inferiority could not be made. However, this is a statistical outcome and may not be a clinically important difference. Physicians will need to interpret the finding for themselves and think about how to apply the data. Both groups had about a 90% clinical cure rate with only a 1.6% absolute risk difference. Will crossing the one-sided statistical barrier by 1.2% (7.5% vs 8.7%) make a difference in clinically apply this data? 5.

Date: July 1st, 2021 Guest Skeptic #1: Dr. Chris Carpenter is Professor of Emergency Medicine at Washington University in St. Louis and a member of their Emergency Medicine Research Core. He is a member of the SAEM Board of Directors and the former Chair of the SAEM EBM Interest Group and ACEP Geriatric Section. He is Deputy Editor-in-Chief of Academic Emergency Medicine. He is also Associate Editor of Annals of Internal Medicine’s ACP Journal Club and the Journal of the American Geriatrics Society, and he serves on the American College of Emergency Physician’s (ACEP) Clinical Policy Committee. Dr. Carpenter also wrote the book on diagnostic testing and clinical decision rules. Reference: Musey et al. Guidelines for reasonable and appropriate care in the emergency department (GRACE): Recurrent, low-risk chest pain in the emergency department. AEM July 2021 This is an extra special SGEM. It is a combo of an SGEM Xtra and an SGEMHOP. The Society of Academic Emergency Medicine (SAEM) has decided to publish its own clinical practice guidelines (CPGs). They are called Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE). This episode will review the GRACE-1 guideline looking at low-risk recurrent chest pain. Because this is a new initiative by SAEM, I interviewed Dr. Chris Carpenter about these new GRACE guidelines. Dr. Chris Carpenter Listen to the SGEM podcast to hear him answer five background questions about these new CPGs. Who came up with the idea of doing CPGs? Why do we need more guidelines? Walk us through the GRACE process? Why pick recurrent, low-risk chest pain to be the first CPG? What do you hope to achieve with these CPGs Guest Skeptic #2: Dr. Suneel Upadhye is an Associate Professor of Emergency Medicine & Clinical Epidemiology at McMaster University. He is a founding member of the Best Evidence in Emergency Medicine (BEEM) program. Suneel is also the inaugural Research Lead for the EM Researchers of Niagara, which is a novel community-based EM research group within Niagara region, Canada. He is also a Guidelines Methodologist within CAEP and the SAEM GRACE groups. Case: You are seeing a patient who has returned to the emergency department (ED) with recurrent chest pain. It is their fourth visit in the last twelve months.  He has had his chest pain for approximately three to four hours now and is not classic for ischemic symptomatology.  His initial high-sensitivity (hs) troponin is negative, and his ECG is unremarkable.  In reviewing his records, you note that he has undergone significant cardiac testing in the recent past, which was unremarkable. This included a normal exercise stress test and CCTA 18 months ago.  You also note that he has an underlying anxiety disorder, which is being treated and followed by his family physician.   Background: This new SAEM GRACE initiative is committed to using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system, GRADE was pioneered at McMaster University, in creating rigorous, transparent, and trustworthy guidelines on common clinical problems for emergency medicine (EM) physicians that are not always directly studied in EM research activities. The steering group/panelists explored many different potential questions, and voted on the top eight, that were then reviewed in systematic fashion; evidence was rated using GRADE methods, and then final recommendations were made using the GRADE Evidence-to-Decision framework (Upadhye et al CJEM 2021 and Courtney and Lang AEM 2021).  The Methods team sought initial GRADE training, then shared that learned expertise with the question groups, many of whom were relative novices in guideline methodology. After two years, a comprehensive document is being published that answers the key diagnostic dilemmas in recurrent chest pain patients who have had recent normal cardiac investigations, to streamline testing and ED length of stay without risk of major adverse coronary events (MACE) at 30 days. Clinical Question: What are the recommendations for managing patients with recurrent, low-risk chest pain in the ED? Recurrent Chest Pain: Patients who have had a previous visit to an ED with chest pain that led to a diagnostic protocol for its evaluation that did not demonstrate evidence of acute coronary syndrome (ACS) or flow-limiting coronary stenosis.  This included two or more ED visits for chest pain in a 12-month period. Low-Risk: This was defined by HEART score <4 points (and other scores validated in the ED setting such as the HEART pathway or TIMI score) for disease-related poor outcomes within 30 days all of which require an electrocardiogram (ECG) for risk stratification. Expedited: This was considered a period of three to five days. There is no 100% guaranteed safety outcome for patients with low-risk chest pain with respect to 30-day MACE, but the “warranty” on negative high-sensitivity troponin test results (assay- and institution-dependent), either single or double tests “x” hours apart, should be reassuring to ED physicians to discharge such patients with reasonably expedited follow-up. This 30-day MACE risk is even lower when there is a negative CCTA result (ie. no coronary stenosis) in the preceding two years, or less than 50% obstructing stenosis on prior angiography in preceding five years.  Finally, in patients in whom depression/anxiety might be a driver of recurrent ED visits for low-risk chest pain, use of screening tools in the ED for mood disorder detection and subsequent referral for mental health supports may be warranted. Reference: Musey et al. Guidelines for reasonable and appropriate care in the emergency department (GRACE): Recurrent, low-risk chest pain in the emergency department. AEM July 2021 Authors’ Conclusions: “These guidelines outline and summarize the evidence and strength of GRACE recommendations regarding eight priority questions of interest to emergency clinicians, other healthcare professionals, patients, and policymakers with regard to the evaluation and management of patients with recurrent, low-risk chest pain seen in the ED. Direct evidence for the selected priority questions in this population is lacking, which highlights areas which will benefit from further robust prospective investigation in this specific population.” Quality Checklist for a Diagnostic Study: The study population included or focused on those in the emergency department? Yes An explicit and sensible process was used to identify, select and combine evidence? Yes The quality of the evidence was explicitly assessed using a validated instrument? Unsure An explicit and sensible process was used to the relative value of different outcomes? Unsure The guideline thoughtfully balances desirable and undesirable effects? Yes The guideline accounts for important recent developments? Yes The guidelines has been peer-reviewed and tested? Yes/No Practical, actionable and clinically important recommendations are made? Yes The guideline authors’ conflicts of interest are fully reported, transparent and unlikely to sway the recommendations of the guidelines? Yes GRACE-1 Recommendations: Here are the five nerdy questions I asked Suneel to help us better understand the GRACE-1 guidelines. Listen to his respond to each question on the SGEM podcast. The Panel: The panel was described as including geographically, ethnically, and gender diverse ED clinician. You also included a cardiologist. What I really liked is you had a patient representative and three methodologists. Can you discuss why you think having non-clinicians are important to have on the panel? Conflicts of Interest (COIs): These can introduce bias into CPGs. The Institute of Medicine published a document on improving CPGs and specifically addressed how to deal with COIs (Graham et al 2011). What COI were declared and how did your group manage these issues? Strength of Recommendations: Six out of the eight recommendations were based on low or very low levels of evidence. One recommendation had no evidence and only one had moderate evidence to support the recommendations. What are clinicians to do when there is a lack of good evidence to inform our management? Cost: You considered potential benefits and potential harms, but did you consider the cost of these recommendations. Actionable: It can take over ten years for high-quality, clinically relevant information to reach the patient bedside (Morris et al 2011). This is referred to as the knowledge translation (KT) gap. It is illustrated in the leaky pipe model that has seven leaks (Diner et al 2007). Will these recommendations be “actionable” in the ED setting? Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors’ conclusions. SGEM Bottom Line: It all depends. The strongest evidence from GRACE-1 is recommendation #6. There is moderate level of evidence that ACS can be excluded in adult patients with recurrent, low-risk chest pain using a single hs-troponin below a validated threshold without further diagnostic testing in patients who have a CCTA within the past two years showing no coronary stenosis. Case Resolution:  After discussing the likelihood of low-risk ACS in this patient’s recurrent chest pain, acknowledgement of some anxiety drivers for recurrent ED visits, and even lower risk of 30-day MACE given a normal exercise stress test and CCTA within the past two years, you both agree to discharge without further hs-troponin/other testing, and he will follow-up with his cardiologist within a few days. Dr. Suneel Upadhye Clinical Application: The application of this GRACE-1 clinical practice guideline depends on many factors. This includes: where you work, personal risk tolerance,

Date: July 1st, 2021 Guest Skeptic: Dr. Justin Morgenstern is an emergency physician and the creator of the #FOAMed project called First10EM.com. Reference: Dankiewicz et al: TTM2 Trial Investigators. Hypothermia versus Normothermia after Out-of-Hospital Cardiac Arrest. NEJM 2021 Case: A 58-year-old man collapsed in front of his family. When paramedics arrived, they found him to be in cardiac arrest, with ventricular fibrillation on the monitor. Paramedics managed to get return of spontaneous circulation after a single defibrillation, but the patient is still comatose on arrival. The charge nurse turns to you and asks: should I grab the ice packs? Background: Hypothermia has been a mainstay of post-arrest care after the publication of two trials in 2002 that both suggested a benefit. This trial by Bernard and colleagues randomized 77 patients with an initial cardiac rhythm of ventricular fibrillation who had achieved return of spontaneous circulation (ROSC) but were persistently comatose. The trial was not truly randomized, as the groups were based on the day of the month, and they also weren’t blinded. The results of this Australian trial seemed too good to be true. Hypothermia resulted in a large improvement in neurologic outcomes, defined as well enough to be sent home or to a rehab facility. It was 49% of the hypothermia group versus only 26% of the normothermia group. This gives a NNT of 4. The reported p value was borderline at 0.046, and when I re-calculate, it comes out as 0.06 (not statistically significant). The other trial was the Hypothermia After Cardiac Arrest (HACA), also published in NEJM 2002. They randomized 273 comatose adult patients out of 3,551 screened patients. These were witnessed OHCA who had a shockable rhythm, achieved ROSC, and had a short downtime. This trial used an air mattress to cool patients and was also not blinded. This second trial done in Europe also showed impressive results for favorable neurologic outcome. It was 55% in the hypothermia group vs 39% in the normothermia group (NNT 6). They also reported a 14% absolute decrease in mortality with therapeutic hypothermia post-OHCA. As a result of these two-small trials, hypothermia was widely adopted. However, there were many voices in the evidence-based medicine world that reminded us of the significant uncertainty that remained, and the weaknesses of these two trials. The SGEM covered a few  trials looking at therapeutic hypothermia for OCHA in the pre-hospital setting. The bottom line is there is not good evidence that therapeutic hypothermia is superior to usual care and cannot be recommended. SGEM#21: Ice, Ice, Baby (Hypothermia post Cardiac Arrest) SGEM#54: Baby It’s Cold Outside (Pre-Hospital Therapeutic Hypothermia in Out of Hospital Cardiac Arrest) SGEM#183: Don’t RINSE, Don’t Repeat Because of that uncertainty, a much larger, multi-center trial was run. This is the original Target Temperature Management (TTM) trial by Nielson et al NEJM 2013. As almost everyone knows, they compared two difference hypothermia targets, 33C and 36C. The result was no benefit for their primary outcome of mortality at the end of the trial and no benefit Cerebral Performance Category (CPC), modified Rankin Score (mRS) or mortality at 180 days. We did a structured critical appraisal of the TTM trial on SGEM#82. The bottom line was that the trial did not demonstrate a benefit of a targeted temperature of 33C vs. 36C for survival of OHCAs. But both groups in the TTM trial were hypothermic, so although it was the highest quality evidence available, it didn’t tell us whether hypothermia was any better than normothermia. Which is why the TTM2 trial was performed. Clinical Question: Does hypothermia result in improved survival after cardiac arrest as compared to controlled normothermia? Reference: Dankiewicz et al: TTM2 Trial Investigators. Hypothermia versus Normothermia after Out-of-Hospital Cardiac Arrest. NEJM 2021 Population: Comatose adult patients admitted to hospital after an OHCA, irrespective of initial rhythm. Intervention: Hypothermia with a target temperature of 33 degrees Celsius, maintained for 28 hours, and then slowly rewarmed by one degree every three hours. Comparison: Normothermia with an aim to maintain a temperature of 37.5C or less. Outcome: Primary Outcome: Death from any cause at six months Secondary Outcome: The main secondary outcome was a poor functional outcome at six months, defined as a score of four to six on the modified Rankin scale (mRS) Authors’ Conclusions: “In patients with coma after out-of-hospital cardiac arrest, targeted hypothermia did not lead to a lower incidence of death by 6 months than targeted normothermia.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Yes The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in the groups to which they were randomized (ITT analysis). Yes The study patients were recruited consecutively (i.e. no selection bias). Yes The patients in both groups were similar with respect to prognostic factors. Yes All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No All groups were treated equally except for the intervention. Unsure Follow-up was complete (i.e. at least 80% for both groups). Yes All patient-important outcomes were considered. Yes The treatment effect was large enough and precise enough to be clinically significant. No Results: They assessed 4,355 patients for eligibility in the trial and randomized 1,900. The mean age was 64 years and 80% were male. Most (91%) were bystander witnessed arrest, bystander CPR was performed in 80% of the arrests and three-quarters had shockable rhythms. Key Result: No statistical difference between hypothermia vs normothermia Primary Outcome: At six months, 50% of the hypothermia group and 48% of the normothermia group had died. This gives a relative risk (RR) of 1.04 (95% CI; 0.94 to 1.14); P=0.37 Secondary Outcomes: At six months, 55% of both groups had a poor functional outcome (mRS 4-6). RR 1.00 (95% CI; 0.92 to 1.09) Harms: Arrythmias resulting in hemodynamic compromise were more common in the hypothermia group (24% versus 16%, p<0.001) 1. Blinding: Keeping everyone perfectly blinded would have been very difficult to do in a hypothermia trial, so it makes sense that this is an open label study. However, the lack of blinding certainly increases the risk of bias, especially for more subjective outcomes like neurologic function. We are unsure which direction the bias would have been. Did the clinicians and researchers think that hypothermia was going to have a benefit or not? It would have been interesting to survey them before the trial to see what their thought of this treatment a priori.  2. Death: This outcome is not as objective as we sometimes think. When a study is unblinded, you generally want to see an objective outcome being used. Death is about as objective as it gets – you are either alive or dead. There generally isn’t much debate. However, in a modern ICU, we have a lot of control of when someone dies. If the doctors truly believed in hypothermia, they might have decided to keep people alive longer, to give them a better chance, biasing the results. These authors tried to account for that by ensuring that an independent, blinded physician performed a standard assessment for neuroprognostication on all patients. Although it is worth discussing, I don’t think bias is playing a hug role in the results we are seeing here. 3. Harms: Although I anticipate that many people will focus on the harm from arrythmias, I don’t think it was ultimately all that important. Arrythmias resulting in hemodynamic compromise certainly sound important, but ultimately that is a monitor-oriented outcome (MOO). The reason we care about arrythmias is that patients might die or have poor neurologic outcomes, and those patient-oriented outcomes (POOs) that are more important. In this trial the POOs were not different. So ultimately, I don’t think this is truly a harmful practice, but rather a neutral practice. 4. Control Group: Did they choose the best control group? Both groups in this trial had their temperature controlled to some extent, but was that necessary? Although it is a common hypothesis that avoiding fever is important in this patient population, there are no RCTs that demonstrate a benefit from fever control. This study still leaves us with the question of whether any temperature control is necessary. Adding a third group without any temperature control could have settled this issue once and for all. 5. Importance of Skepticism: This story arc around therapeutic hypothermia for OHCA is a great reminder of why we should be skeptical of any claim. The time to accept a claim is when there is sufficient evidence. There are many examples in medicine that show we can fall prey to intervention bias (Foy 2013). We can be overly optimistic about small studies that are nowhere close to scientifically definitive, and quickly crown borderline practices as “silver bullets” or “standard of care”. Think thrombolytics for acute ischemic stroke, TXA for just about anything, or cardiac stress testing. Science is a process that requires replication. Single studies rarely, if ever, define the “truth”. The overzealous adoption of medical practices can hurt our patients. Time and time again, we adopt medical interventions that are unproven. In many cases, the harms end up outweighing the benefits, but we only acknowledge this decades later, when replication studies are finally done.

Date: June 25th, 2021 Guest Skeptic: Dr. Chris Bond is an emergency medicine physician and assistant Professor at the University of Calgary. He is also an avid FOAM supporter/producer through various online outlets including TheSGEM. Reference: Chinnock et al. Self-obtained vaginal swabs are not inferior to provider-performed endocervical sampling for emergency department diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis. AEM June 2021 Case: A 31-year-old female presents to the emergency department with pelvic pain and vaginal discharge for the past 24 hours. She is afebrile, vital signs are normal and she is having a significant amount of pain. She says the pain is so severe that she cannot even imagine having a pelvic exam done right now for STI testing. Background: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) are the two most common sexually transmitted infections (STI) reported in the United States. Emergency departments (EDs) now diagnose an increasing percentage of NG/CT cases compared to STI clinics. (1,2) The standard of care for NG/CT diagnosis is nucleic acid amplification testing (NAAT), with the collection method being provider-performed endocervical sampling (PPES). PPES is uncomfortable for patients and has numerous other limitations, including the need for exam rooms, an available provider and often a female chaperone. These limitations can delay sample collection and can also add significant delay in a busy ED. The need for universal pelvic examination in the ED to perform STI testing has also come under increasing scrutiny. (3) Vaginal sample collection with self-obtained vaginal swabs (SOVS) was first developed and researched in non-ED settings based on these reasons and others. These studies demonstrated comparable sensitivity for NG/CT diagnosis when comparing SOVS to PPES, and high patient acceptability. (4-8) However, those studies were performed in a wide range of non-ED settings and were mostly asymptomatic screening rather than STI testing in an acute care environment. This study compares PPES with SOVS in an ED setting and explores patient’s acceptability or preference of SOVS versus PPES. Clinical Question: Do self-obtained swabs have noninferior sensitivity for the diagnosis of NG/CT compared to provider performed swabs in an ED setting using a rapid NAAT. Reference: Chinnock et al. Self-obtained vaginal swabs are not inferior to provider-performed endocervical sampling for emergency department diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis. AEM June 2021 Population: Female patients 18 years of age or older who were judged by the treating practitioner to need NG/CT testing Exclusions: Incarcerated any acute psychiatric condition precluded understanding instructions or giving informed consent, not English or Spanish proficient, or treated for NG/CT within the previous four weeks. Intervention: Self-obtained vaginal swab (SOVS) for NG/CT Comparison: Provider performed endocervical sampling swab for NG/CT Outcome: Primary Outcome: Noninferiority of SOVS sensitivity for NG/CT, with noninferiority being demonstrated if sensitivity was 90% or above. Secondary Outcomes: Kappa measurement of the SOVS and PPES, SOVS organism-specific sensitivity for NG and CT, acceptance rate of SOVS, rate of patients worried about doing SOVS correctly, and SOVS refusal rate. Dr. Brian Chinnock This is an SGEMHOP episode which means we have the lead author on the show. Dr Brian Chinnock is Professor in Department of Emergency Medicine at the UCSF-Fresno Medical Education Program, and Research Director. Authors’ Conclusions: “SOVS are noninferior to PPES in NG/CT diagnosis using a rapid NAAT in ED patients and surveys indicate high patient acceptability.” Quality Checklist for Observational Trials: 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? Yes Was the outcome accurately measured to minimize bias? Yes Have the authors identified all important confounding factors? Yes Was the follow up of subjects complete enough? Yes How precise are the results/is the estimate of risk? The results are precise with narrow confidence intervals Do you believe the results? Yes Can the results be applied to the local population? Yes Do the results of this study fit with other available evidence? Yes Results: The researchers found 750 patients eligible for inclusion in the study. The final cohort consisted of 515 patents with completed PPES and the SOVS results. The mean age was 30.7 years of age with 52% Hispanic ethnicity. The overall prevalence for either NG or CT or both was 17% (86/515). Of these patients with STIs, 34% (29/86) had infection with NG, 54% (47/86)) with CT, and 12% (10/87) with coinfection. Key Result: SOVS was non-inferior to PPES Primary Outcome: Noninferiority of SOVS sensitivity for NG/CT SOVS had a sensitivity of 95% (95% CI, 88% to 99%) for the detection of NG/CT when compared to PPES. Secondary Outcomes: Kappa was 93 (95% CI, 0.89 to 0.98), which is excellent. SOVS Sensitivity for NG and CT was 97% (95% CI = 87% to 100%) and 94% (95% CI = 84% to 99%) respectively 93% felt that collecting a self-sample is acceptable 28% who were concerned about doing SOVS incorrectl 26% refused SOVS due to reasons clearly related to the SOVS collection procedure (“uncomfortable performing SOVS,” “worried might do it incorrectly”, “prefers physician”) rather than the consent process. Here are the ten nerdy questions we asked Brian to help us better understand his study. Listen to his respond to each question on the SGEM podcast. 1. Selection Bias: Convenience sample (not overnight). Do you think that could have had an impact on your results? 2. Exclusions: Why were patients excluded if they had been treated for NG/CT in the previous 4 weeks? 3. Non-Inferiority: Why do a non-inferiority study design instead of a superiority design? 4. Endocervical Swabs: These were endocervical swabs used in the provide performed exam but would have been vaginal swabs if done by patients themselves. So, are endocervical swabs not actually required to be endocervical? 5. Power: The power was set based on the manufacturer’s reported sensitivity for PPES using the Cepheid Xpert assay of 99% for NG, 96% for CT and a presumed combination of 97%. Non-inferiority was set at 7% with an assumed prevalence of 14% based on the previous year’s data. This required a target of 571 patients or 615 if you only had a prevalence of 13%. You missed the overall target but did get at least 80 positive patients. Can you explain why you stopped enrollment, and do you think it would impact your study? 6. Aptima: Where I work, we use Aptima endovaginal swabs for STI testing, and I assume this would be even better for self-testing than swabs that require endocervical sampling. Are there other studies that support this hypothesis? 7. Best Swab Type: Is there a list of swab types that would be effective for SOVS vs. PPES? Yours is a 90-minute NAAT swab which is not used in many centers and the swabs used can vary by geographic location. 8. External Validity: In the limitations section, you mention the high proportion of Hispanic (52%) ethnicity as making the study potentially not generalizable to all ED settings. Can you explain why this would be? 9. Qualitative: Can you discuss the qualitative data as to reasons why patients declined to participate in the study and why some still preferred a provider performed exam to a self-obtained swab? 10 Anything Else: We like to have an open-ended question to allow the author to discuss something that we did not address in our nerdy questions. Is there anything else you would like to add about your study? Comment on Authors’ Conclusion Compared to SGEM Conclusion: We generally agree with the authors’ conclusions. SGEM Bottom Line: Consider the use of self-obtained vaginal swabs for STI testing and the necessity of performing a pelvic exam for patients presenting with clinical suspicion for NG/CT. Case Resolution: You provide your patient with analgesic for her pain and ask if she would prefer a self-obtained vaginal swab or for you to perform a pelvic exam to obtain a swab. She chooses to perform the swab herself, and you treat her empirically for an NG/CT. Dr. Chris Bond Clinical Application: This was an excellent study that supports the use of self-obtained vaginal swabs for STI testing in the ED and can reduce uncomfortable pelvic exams for patients. It is reasonable to offer this option to patients presenting to the ED who clinically require a swab for STI testing but there is no other need for a pelvic examination. What Do I Tell My Patient? I am concerned that you may have an STI. A vaginal swab should be done to test for this infection. Doing a vaginal swab by yourself is just as accurate as having me perform a pelvic exam. It will also be faster and probably less painful for you. I understand if you are uncomfortable doing it yourself. I am happy to do the exam and get the swab sample. It is your choice and both options are fine. Keener Kontest: Last weeks’ winner was Dr. Sebastian Nemetz from Offenbach, Germany. He knew Dr. Emil Siegle is the German physician is credited with the creation of pneumatic otoscopy? Listen to the podcast this week to hear the trivia question. Email your answer to TheSGEM@gmail.com with “keener” in the subject line. The first correct answer will receive a cool skeptical prize. SGEMHOP: Now it is your turn SGEMers. What do you think of this episode on the use of self-obtained vaginal swabs? Tweet your comments using #SGEMHOP.

Date: June 11th, 2021 Guest Skeptic: Dr. Dennis Ren is a paediatric emergency medicine fellow at Children’s National Hospital in Washington, DC. Reference: McLaren SH, et al. Invasive bacterial infections in afebrile infants diagnosed with acute otitis media. Pediatrics 2021 Case: You are working with a medical student at the emergency department when a 2-month-old boy is brought in by his parents for fussiness. They note that he has had upper respiratory symptoms for the past few days and fussier than usual. He has still continued to feed well and make wet diapers. He has not had any fever. Yesterday, they noticed that he seemed to be pulling at his right ear. On exam, he is afebrile, active, and alert. He cries and moves vigorously when you look into his ear. You see a bulging, red tympanic membrane. His left tympanic membrane is clear. The rest of his exam is unremarkable. You turn to the medical student and ask her what she would like to do for this patient. She replies that she thinks the patient has an acute otitis media (AOM) but given his age, she is also thinking about the possibility of an invasive bacterial infection (IBI) and would like to obtain some blood for labs and even consider a lumbar puncture for cerebral spinal fluid. How do you reply? Background: Acute Otitis media is the second most diagnosed illness in children and the most common indication for antibiotic prescription [1-2]. We have covered the of AOM twice on the SGEM: SGEM#132: One Balloon for Otitis Media with Effusion with Dr. Richard Lubell SGEM#278: Seen Your Video for Acute Otitis Media Discharge Instructions SGEMHOP with lead author Dr. Naveen Poonai? In 2013, the American Academy of Pediatrics (AAP) updated recommendations for the diagnosis and management of acute otitis media (AOM) for children older than 6 months. Unfortunately, there is limited guidance for patients younger than 6 months. The diagnosis of AOM becomes more complicated by the concern for concurrent invasive bacterial infections (IBI) in infants less than 3 months of age. Previous studies have demonstrated low prevalence of concurrent IBI in infants with AOM, but sample size has been small and included a mix of afebrile and febrile infants [3-4]. Additionally, the microbiology of pathogens causing AOM has shifted after the implementation of the pneumococcal conjugate vaccine with a higher proportion of patients having culture negative AOM [5]. This uncertainty has led to wide practice variation and controversy surrounding diagnostic testing (blood and cerebrospinal fluid testing), antibiotic administration (IV vs oral), and disposition (discharge vs admission) in infants with AOM. Clinical Question: What is the prevalence of invasive bacterial infections and adverse events in afebrile infants ≤ 90 days of age with acute otitis media? Reference: McLaren SH, et al. Invasive bacterial infections in afebrile infants diagnosed with acute otitis media. Pediatrics 2021 Population: Afebrile infants ≤ 90 days of age with clinically diagnosed acute otitis media across 33 pediatric emergency departments (29 USA, 2 Canadian and 2 Spanish EDs) from 2007 to 2017 Excluded: Temperature ≥38°C and <36°C in the ED or within 48 hours, antibiotic use (other than topical) within 48 hours of presentation, concurrent mastoiditis, evidence of focal bacterial infection, transferred to ED with previous diagnostic testing/antibiotics Intervention: Evaluation of invasive bacterial infections in blood or cerebrospinal fluid (CSF) Comparison: None Outcomes: Primary Outcome: Prevalence of IBI (bacterial meningitis and bacteremia) Secondary Outcomes: Variability in diagnostic testing for IBIincluding blood or cerebrospinal fluid (CSF), parenteral antibiotic administration, and hospitalization. Safety Outcome: AOM-associated adverse events Authors’ Conclusions: “Afebrile infants with clinician-diagnosed acute otitis media have a low prevalence of invasive bacterial infections and adverse events; therefore outpatient management without diagnostic testing may be reasonable.” Quality Checklist for Observational Study: 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? Unsure Was the exposure (diagnostic testing) accurately measured to minimize bias? Yes Was the outcome accurately measured to minimize bias? Unsure Have the authors identified all-important confounding factors? Unsure Was the follow up of subjects complete enough? Yes How precise are the results? Unsure Do you believe the results? Yes Can the results be applied to the local population? Unsure Do the results of this study fit with other available evidence? Yes Results: They screened 5,270 infants from 33 sites to establish a cohort of 1,637 who met inclusion/exclusion criteria. The median age was 68 days and 89% met the simplified American Academy of Pediatrics diagnostic criteria for AOM. Key Result: No infant with blood cultures had bacteremia and no infant was diagnosed with bacterial meningitis by CSF culture. Primary Outcome: Prevalence of Invasive Bacterial Infections 0/278 with blood cultures had bacteremia (95% CI 0%-1.4%) 0/102 with CSF cultures had bacterial meningitis (95% CI 0% to 3.6%) Two infants had adverse events in 30-day follow up and hospitalization history: Culture negative sepsis vs. severe dehydration from milk protein allergy Lymphadenitis (20 days after ED visit) after initial discharge on amoxicillin Secondary Outcomes: Diagnostic Testing, Antibiotic Administration, and Hospitalization Rates. One-fifth (21.7%, 355 of 1637) had ≥1 diagnostic test. One-third (34%, 34 of 100) of infants ≤28 days had a lumbar puncture. For infants with upper respiratory symptoms (n=1179), ~5% had a lumbar puncture, and 13.7% had blood cultures. ~10% received IV or IM antibiotic 90% received a prescription for oral antibiotic (most commonly amoxicillin followed by amoxicillin-clavulanate) 5% were discharged from the emergency department Almost half (47%) of infants 0-28 days were hospitalized 72-hour return rate was 63 (4.3%) of which 15 infants were hospitalized. Most common reason for hospitalization was bronchiolitis Older infants were less likely to have blood cultures, lumbar puncture, and hospitalization compared to younger infants. Ear discharge was significantly associated with diagnostic testing and hospitalization. 1. Diagnostic Uncertainty: The diagnosis of otitis media remains challenging. It is a clinical diagnosis and there is variability amongst clinicians. Here is the American Academy of Pediatrics (AAP) 2013 diagnostic criteria for AOM [6]. But even the AAP concedes that there is no gold standard for the diagnosis of AOM because it exists in a spectrum of findings as the disease process develops. This becomes challenging in a retrospective review as the diagnosis of AOM cannot be verified. The authors chose to use a simplified diagnostic criteria defined by presence of tympanic membrane erythema, bulging tympanic membrane, or otorrhea. Unfortunately, the presence of tympanic membrane erythema alone is not specific for AOM as it can be because the infant is crying. This may falsely increase the number of infants with AOM included in the analysis and underestimate the prevalence of IBI. Although, zero infants in the study had confirmed bacteremia or bacterial meningitis on cultures. 2. Primary Outcomes: They had two primary outcomes, prevalence of IBI (bacteremia and bacterial meningitis) and AOM-associated adverse events. We know from the movie Highlander…There can be only one! Primary outcome. I am uncertain that the two reported adverse events are truly associated with AOM. One patient who was initially discharged on amoxicillin presented 20 days later  with cervical lymphadenitis and perforated AOM. The other patient did grow Staphylococcus aureus from middle ear effusion and was hospitalized for culture-negative sepsis but was also thought to have a severe milk protein allergy. The authors note that this patient presented with severe illness during the index ED visit so was likely not going to be discharged home regardless. 3. Partial Verification Bias: There were several potential biases in this study that could have impacted the results. One was already mentioned in nerdy point number one that there is not a gold standard. This is called the imperfect gold standard bias or the copper standard bias. Another potential bias is partial verification bias. Not all infants in the study underwent the same testing for IBI. This can cause an underestimation of IBI. It is possible that some infants with bacteremia on whom blood cultures were not obtained were treated by oral antibiotics. The authors did try to perform follow up on patients within 30 days by reviewing medical records but acknowledge that this may not fully capture all patients with bacterial meningitis that was seen outside of the index ED or hospital system. 4. Selection Bias: As someone who works mainly in community hospitals, I’m concerned about selection bias. Are the infants who present to free-standing pediatric hospitals the same as those who present to community or rural EDs? Are those in large urban areas more likely or less likely to bring in a “fussy” infant? Are parents in the USA less likely to go to the ED because of co-pays, insurance status or other financial issues? It is unclear how any of these biases could alter the findings in this study. 5. Age: A last point to highlight is that there is a very low number of infants ≤28 days old (n=100, 6.1% of study population). This low number could be due to a variety of reasons.

Date: May 25th, 2021 Guest Skeptic: Dr. Garreth Debiegun is an emergency physician at Maine Medical Center in Portland, ME and clinical assistant professor with Tufts University School of Medicine. He also works at an urgent care and a rural critical access hospital. Garreth is interested in wilderness medicine and is the co-director of the wilderness medicine clerkship at Maine Med, and the medical director for Saddleback Ski Patrol and for Maine Region NSP. At work Garreth imagines himself as a student of evidence-based medicine trying to provide the best care based on the best evidence. References: Suzuki et al. Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial. JAMA 2021 Zi et al. Effect of Endovascular Treatment Alone vs Intravenous Alteplase Plus Endovascular Treatment on Functional Independence in Patients With Acute Ischemic Stroke: The DEVT Randomized Clinical Trial. JAMA 2021 Case: A 74-year-old woman presents to your emergency department with 1.5 hours of right-sided weakness, aphasia, and neglect. On rapid bedside assessment you calculate the National Institute of Health Stroke Score/Scale (NIHSS) of 11 and a Field Assessment for Stroke Triage for Emergency Destination (FAST-ED) score of 7; you suspect a large vessel occlusion (LVO) based on the high NIHSS and FAST-ED score >3. A non-contrast CT shows no evidence of intracranial hemorrhage. A CT angiogram plus CT perfusion demonstrate a clot in the left proximal middle cerebral artery (MCA) with a small infarcted area and a large penumbra. Based on your institution’s current guidelines, the patient is a candidate for endovascular therapy, but they are also within the current window for the administration of thrombolytics. You wonder if you gotta be starting something?  Specifically, you wonder if you should give the thrombolytics while waiting for your neurointerventional/endovascular team? Background: Management of acute ischemic stroke has been discussed on the SGEM ever since this knowledge translation project was launched in 2012. My position remains that there is uncertainty as to whether tPA provides a patient-oriented outcome and this was summarized in the downgrading of the NNT recommendation to “yellow” with Dr. Justin Morgenstern from First10EM. The world of stroke management has changed in the last few years the more robust evidence to support endovascular therapy (EVT) for large vessel occlusion (LVO) strokes. The tipping point came with the publication of MR. CLEAN in 2015. It was a multicenter, randomized, unblinded trial of patients with an LVO stroke in the anterior circulation treated in less than six hours after onset of symptoms. The primary outcome was good neurologic function defined as a modified Rankin Scale (mRS) score of 0-2 at 90 days. The trial included 500 patients and reported an absolute risk reduction of 14% (33% EVT vs 19% control) with a NNT of 7. Four other RCTs were stopped early due to the publication of MR. CLEAN.  All of these were published in the NEJM in the following six months. SWIFT PRIME (n=196) NNT of 4 EXTEND-IA (n=70) NNT of 2-5 depending on which outcome you picked REVASCAT (n=206) extended the window to eight hours NNT 6.5 ESCAPE (n=316) extended to 12 hours NNT 4 There are dangers with stopping trials early. Dr. Gordon Guyatt wrote in the BMJ that it can introduce bias towards efficacy. He said you should have a high level of skepticism regarding the findings of trials stopped early for benefit, particularly when those trials are relatively small, and replication is limited or absent. A systematic review and meta-analysis (SRMA) was published by Badhiwala, JH et al in JAMA 2015 looking at EVT for stroke. The first three RCTs reported no superiority. Then came MR. CLEAN and those four additional studies that were stopped early. The forest plot shows a point estimate that favors EVT and the 95% confidence interval does not cross the line of no statistical difference. We do need to be careful in not over interpreting this data because the bias of stopping trials early could have been compounded in the SRMA process. A couple more RCTs were published since the 2015 SRMA: DAWN 2018 (n=206) NNT 3 between 6-24 hours, stopped early DEFUSE 2018 (n=182) NNT 4 between 6-16 hours, stopped early Here is a lists all the studies and the number of patients enrolled/center/year put together by friend of the SGEM, Dr. Salim Rezaie (REBEL EM). The average was 4.6 patients/year from these stroke centres. While the NNT for EVT looks very impressive, it is suffering from denominator neglect. Once the patient is getting the intervention the NNT is in the single digits. However, how many possible stroke patients were screened, and code strokes were called to get the impressive NNTs of the EVT trials? Most of these trials didn’t tell us how many patients they screened to get the patients they registered.  Only one did – EXTEND-IA.  In that RCT, they screened ~7,800 patients, and registered 70. That’s 0.9%, or about 1/110, that were eligible for the treatment. The NNT in MR CLEAN, the largest and arguably the most methodologically sound of these trials, was 7.  If you must screen 110 patients to find one eligible, and need to treat 7 to benefit one, then about one out of every 770 patients having a potential stroke would benefit from this therapy. Therefore, we think the NNT provided by the RCTs suffer from denominator neglect. An NNT of 770 is not nearly as impressive as an NNT of 7. The agenda is in the numerator, but the devil is in the denominator. One major component of LVO management is the use of systemic thrombolytics in patients presenting within the current thrombolytic treatment window prior to endovascular intervention. However, it’s unclear if systemic thrombolytic administration results in better outcomes or if it simply exposes the patient to increased risks at a higher cost. There is a SRMA by Mistry et al published in Stroke 2017 on the issue of EVT +/- tPA. They included 13 studies (n=1,769) with three RCTs (which accounted for only 25% of patients) and ten observational studies (which accounted for the other 75% of the patients). They reported an NNT of 17 for good neurologic outcome (defined as mRS 0-2) with EVT + tPA compared to EVT alone. However, it was not statistically significant if you just looked at the RCT data. This is a problem of combining lower quality observational studies with higher-quality RCTs. We looked at a 2020 RCT by Yang P et al published in the NEJM on SGEM#292. This trial asked if EVT alone was non-inferior to EVT + tPA in stroke patients with LVOs presenting withing 4.5 hours of symptoms. The cohort consisted of 654 patients and the key results was EVT alone was not non-inferior to EVT plus tPA. Our SGEM bottom line was that there does not appear to be a role for systemic thrombolysis in acute ischemic stroke for appropriate patients when EVT is readily available. Two more trials have been published and that is what we are going to review today on the SGEM. Clinical Question: Does intravenous thrombolysis prior to mechanical thrombectomy increase the percentage of patients with LVO who achieve mRS of 0-2 (functional independence) at 90 days? Reference #1:  Suzuki et al. Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial. JAMA 2021 Population: Patients aged 18-85 evaluated at one of 23 stroke centers in Japan within 4.5 hours of onset, who were found to have: NIHSS ≥6, CTA or MRA proven ICA or M1 occlusion, minimal imaging changes of ischemic stroke. Patients had to be previously independent (mRS 0-2) and meet Japanese criteria for thrombolysis. Exclusions: Contraindication for contrast agent or EVT, contraindication for IVT, presence of severe renal disorder, pregnancy or possibility of pregnancy, unlikely to complete the study, such as due to progressive malignant tumor, judged incompatible with the study by the investigators Intervention: Mechanical thrombectomy of LVO without additional thrombolytics Comparison: Alteplase given at a dose of 0.6 mg/kg in addition to mechanical thrombectomy performed within 30 minutes of randomization Outcome: Primary Outcome: mRS evaluated by physical exam or phone interview at 90 days. Secondary Outcomes: Ordinal shift analysis of mRS, mRS 5-6, mRS 0-1, mRS 0-3, 90-day mortality, successful reperfusion, recanalization and adverse events (ICH) Authors’ Conclusions: “Among patients with acute large vessel occlusion, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Unsure The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in the groups to which they were treated (per-protocol analysis for non-inferiority trials). Yes The study patients were recruited consecutively (i.e. no selection bias). Unsure The patients in both groups were similar with respect to prognostic factors. Unsure All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No All groups were treated equally except for the intervention. Unsure Follow-up was complete (i.e. at least 80% for both groups). Yes All patient-important outcomes were considered. Yes

Date: May 28th, 2021 Guest Skeptics: Heather Logan is the executive Strategy lead for the Canadian Agency for Drug and Technologies in Health (CADTH). Dr. Wendy Levinson is the Chair of Choosing Wisely Canada (CWC) and a Professor of Medicine, University of Toronto This SGEM Xtra is based on document created by CADTH and presented at Choosing Wisely Canada National annual meeting May 13, 2021. The title of the report is Using Health Care Resources Wisely After the COVID-19 Pandemic: Recommendations to Reduce Low-Value Care. We have discussed Choosing Wisely before on SGEM Episodes: SGEM#15: Choosing Wisely SGEM Xtra: CAEP Choosing Wisely SGEM Xtra: Right, You’re Bloody Well Right, You’ve got the Bloody Right to Care Choosing Wisely Canada (CWC): Dr. Wendy Levinson It is the national voice for reducing unnecessary tests and treatments in health care. One of its important functions is to help clinicians and patients engage in conversations that lead to smart and effective care choices. Choosing Wisely Canada is led by a team of clinicians and staff based at St. Michael’s Hospital (Toronto), the University of Toronto, and in collaboration with the Canadian Medical Association. Choosing Wisely Canada mobilizes and supports clinicians and organizations committed to embedding campaign recommendations into practice. There are close to 350 documented quality improvement projects across the country that are building capacity for the spread and scale of Choosing Wisely. These efforts are underway in hospitals, long-term care homes, and primary care clinics. Many of these innovative projects, including their evidence-based tools and methods, have been packaged into easy to follow toolkits that are broadly circulated in order to encourage widespread adoption. This has allowed Choosing Wisely Canada to foster a network for those looking to implement campaign recommendations into practice. Canadian Agency for Drug and Technologies in Health (CADTH): Heather Logan It is an independent, not-for-profit agency funded by Canadian federal, provincial, and territorial governments (except Quebec) to provide credible, impartial advice and evidence-based information about the effectiveness of drugs and other health technologies to Canadian health care decision-makers. CADTH believes that credible, objective evidence should inform every important health care decision. When you want to know what the evidence says, ask CADTH. Created in 1989 by Canada’s federal, provincial, and territorial governments, CADTH was born from the idea that Canada needs a coordinated approach to assessing health technologies. The result was an organization that harnesses Canadian expertise from every region and produces evidence-informed solutions that benefit patients in jurisdictions across the country. South Huron Hospital Association (SHHA) is known as the "Little Hospital that Does". SHHA has been choosing wisely since 2012 selecting five items every three years. SHHA Choosing Wisely 2012 Influenza shots for staff with privileges SGEM#20 Use Ottawa ankle and knee rules SGEM#3 and SGEM#5 No routine use of antivirals for Bell’s Palsy SGEM#14 No routine use of antibiotics for simple cutaneous abscesses SGEM#13 No routine use of proton pump inhibitors for upper GI bleeds SGEM#16 SHHA Choosing Wisely 2015 Utilize Canadian CT head rules to guide our decisions on getting CT heads SGEM#106 Utilize Canadian C-Spine rules to guide our decisions on obtaining plain film c-spine imaging SGEM#232 Do not do annual physical exams on asymptomatic adults with no significant risk factors Do not screen women with Pap smears if under 21 years of age or over 69 years of age Do not order echo cardiograms routinely SHHA Choosing Wisely 2018 Only use supplemental Oxygen for STEMI patients that are hypoxic (saturations < 90%) SGEM#193 Use appropriate antibiotic selection for uncomplicated COPD exacerbation ie. Amoxicillin, Septra and Doxycycline Do not start IV unless you are 80% sure that you are actually going to use the IV SGEM#204 Treat Chronic Pain utilizing non-pharmacological means before prescribing an opioid medication Don’t place or leave in place a urinary catheter without reassessment Low-Value Care, Challenges of COVID19, High-Value Care and the Purpose of the CADTH Report Slides from the Choosing Wisely Presentation - May 13th, 2021 CADTH Four Step Approach Recommendations in Six Key Clinical Areas Primary care: Seven recommendations span primary care, including avoiding unnecessary rural transfers, annual exams, and screening and imaging tests Specialty care: Four recommendations address low-value procedures, including chronic dialysis, colonoscopy for constipation, cardiac imaging without high-risk markers, and knee MRIs End-of-life care: Three recommendations emphasize the importance of advance care planning conversations for patients with serious illness and access to palliative care Hospital care: Two recommendations address low-value routine investigations and pre-operative testing in hospital care Long-term care: One recommendation addresses unnecessary hospital transfers from long-term care Blood products: One recommendation addresses the overuse of red blood cells transfusion in hemodynamically stable critical care patients. Nineteen Recommendations for High-Value Care Hospital Care: Routine Investigations: Don't order routine investigations, including chest radiographs or blood tests, in critically ill patients except to answer a specific clinical question. Preoperative Testing: Don’t order baseline laboratory studies (complete blood count, coagulation testing, or serum biochemistry) for asymptomatic patients undergoing low-risk non-cardiac surgery End-of-Life Care: Advance Care Planning Conversations:  Don’t start or continue life-supporting interventions unless they are consistent with the patient’s values and realistic goals of care Don’t delay advance care planning conversations Palliative Care: Don’t delay palliative care for a patient with serious illness who has physical, psychological, social, or spiritual distress because they are pursuing disease-directed treatment Specialty or Outpatient Care: Nephrology: Don’t initiate chronic dialysis without ensuring a shared decision-making process between patients, their families, and their nephrology health care team Gastroenterology: Avoid performing a colonoscopy for constipation in those under the age of 50 years without a family history of colon cancer or alarm features Cardiology: Don’t perform stress cardiac imaging or advanced non-invasive imaging in the initial evaluation of patients without cardiac symptoms unless high-risk markers are present Orthopedics: Don’t order a knee MRI when weight-bearing X-rays demonstrate osteoarthritis and symptoms are suggestive of osteoarthritis as the MRI rarely adds useful information to guide diagnosis or treatment Long-Term Care: Transfer: Don’t send the frail resident of a nursing home to the hospital unless their urgent comfort and medical needs cannot be met in their care home Blood Products: Red Blood Cells Transfusion: Don’t routinely transfuse red blood cells in hemodynamically stable ICU patients with a hemoglobin concentration greater than 70 g/L (a threshold of 80 g/L may be considered for patients undergoing cardiac or orthopedic surgery and those with active cardiovascular disease) Oncology: Palliative: Don’t delay or avoid palliative care for a patient with metastatic cancer because they are pursuing disease-directed treatment Primary Care:  Rural Transfer: Don’t send a patient for a specialist visit that requires several hours of transport if the visit can be done virtually or by a local physician Annual Examinations: Don’t do annual physical exams on asymptomatic adults with no significant risk factors. Unnecessary Screening Tests: Don’t perform population-based screening for 25-OH-vitamin D deficiency. Unnecessary Imaging: Don’t order screening chest X-rays and ECGs for asymptomatic or low-risk outpatients Don’t do imaging for lower back pain unless red flags are present Don’t do imaging for uncomplicated headache unless red flags are present Don’t order a CT scan for uncomplicated acute rhinosinusitis The official CADTH report with all 19 recommendations and additional information  can be downloaded as a PDF. Key Messages from the CADTH Report Low-value tests, treatments, and procedures are an important health care quality problem in Canada and across the world because they provide little clinical benefit, may be harmful for patients, and waste limited resources. Due to the COVID-19 pandemic, health care systems face increased challenges of limited resources, reduced capacity, and a growing backlog of surgeries and other procedures. The pandemic has compelled health care professionals to make challenging decisions to prioritize health care services while coping with increased demand. As Canada emerges from the pandemic and health care systems rebuild and begin to address the backlog of delayed or cancelled services, there is an imperative to introduce lasting changes to reduce low-value care and ensure high-quality care is available to everyone. To help inform efforts for using health care resources wisely and to support decision-making, CADTH and Choosing Wisely Canada convened a 10-member multi-disciplinary panel of clinicians, patient representatives, and health policy experts to review areas of low-value care that can be reduced or limited. This panel reviewed, deliberated,

Date: May 20th, 2021 Guest Skeptic: Dr. Robert Edmonds is an emergency medicine physician in the Air Force in Dayton, Ohio, and a University of Missouri-Kansas City residency alumni from 2016. Reference: Jhunjhunwala et al. Reassessing the cardiac box: A comprehensive evaluation of the relationship between thoracic gunshot wounds and cardiac injury. Journal of Trauma and Acute Care Surgery. September 2017 DISCLAIMER: THE VIEWS AND OPINIONS OF THIS PODCAST DO NOT REPRESENT THE UNITED STATES GOVERNMENT OR THE US AIR FORCE. This SGEM episode was recored live for the Truman Medical Centers Multidisciplinary Trauma Conference. We did the session over zoom as an SGEM Journal Club. If you would like a copy of the slides from the presentation you can download them free open access at this LINK. Case: You receive a call on the Biocom for an incoming Type A trauma, three minutes out.  The patient is an adult male with a gunshot wound to the chest, and they’re combative with emergency medical services (EMS). Upon arrival in the emergency department (ED), the patient is incoherently speaking, has a pulse of 135 beats per minute, blood pressure of 85/50 mm Hg, and an obvious open wound in their left mid-axillary line at the level of the nipple. Background: Penetrating trauma is a major disease burden in the United States, and gunshot wounds cause 30,000 deaths annually [1] . As a country, penetrating trauma accounts for about 10% of all trauma cases [2] , but at some trauma centers it can reach much higher numbers. Here at the Truman Medical Center the average penetrating trauma for gunshot wounds alone represents ~19% of all traumas.  Naturally, patients with a direct cardiac injury from a gunshot wound (GSW) require prompt identification and management, so tools have sprung into existence to attempt to risk stratify patients at a higher risk of an underlying cardiac injury. One of the more common tools is the “cardiac box”. This three-dimensional area is at the highest risk of cardiac injury. The anatomical area is defined anteriorly as between the clavicle and xyphoid, and between the bilateral midclavicular lines. Per the authors, “The dogma of the cardiac box is largely based on small studies with primarily stab wounds. The underlying issue is that stab wounds are low kinetic energy and result from instruments with a fixed length. Thus, most stab wounds usually only result in a cardiac injury if the entrance is in very close proximity to the heart or there is a long weapon. Because these studies did include gunshots, the concept of the “box” was ultimately uniformly applied to all mechanisms. Injuries from high kinetic energy projectiles, however, can cause cardiac injury from entrance wounds to any area of the torso, especially the thorax.” Although it may be obvious to some that injury outside the cardiac box doesn’t rule out injury to the heart, the existence of such a tool colors our language and shifts the perceived risk in the clinician’s head.  According to a recent study in the Journal of Surgical Research [3] , 44% of all penetrating thoracic trauma patients presented to a non-trauma center (not a level 1 or level 2 ACS defined trauma center). For clinicians in these settings, use of the “cardiac box” nomenclature can have a significant impact on the perceived injuries when communicating with an on-call surgeon or when transferring the patient to another facility. If the injury is outside the cardiac box, it can be perceived as less concerning and may give the treating team a false sense of security. Clinical Question: Are the anatomic borders of the cardiac box adequate to predict cardiac injury from gunshot wounds? Reference: Jhunjhunwala et al. Reassessing the cardiac box: A comprehensive evaluation of the relationship between thoracic gunshot wounds and cardiac injury. Journal of Trauma and Acute Care Surgery. September 2017 Population: All patients in the Fulton County (Georgia) Medical Examiner’s autopsy registry who sustained a penetrating torso gunshot wound from January 2011 to December 2013. Excluded: Injuries above the clavicles and below the xyphoid Exposure: Wounds that were in the cardiac box- “defined as the two-dimensional plane covering the anterior surface of the thorax from the level of the clavicle to the tip of the xiphoid… and between the midclavicular lines (laterally).” The authors also included this same region projected onto the posterior thorax as well. Comparison: Patients with wounds outside the “cardiac box” Outcome: Primary Outcome: Cardiac injury Safety Outcome: None (this data all came from autopsy reports) Authors’ Conclusions: “For GSWs, the current cardiac box is inadequate to discriminate whether a gunshot wound will cause a cardiac injury. As expected, entrance wounds nearest to the heart are the most likely to result in cardiac injury, but, from a clinical standpoint, it is best to think outside the “box” for GSWs to the thorax.” Quality Checklist for Observational Study: Did the study address a clearly focused issue? Yes Did the authors use an appropriate method to answer their question? Yes/No Was the cohort recruited in an acceptable way? Yes Was the exposure accurately measured to minimize bias? Yes Was the outcome accurately measured to minimize bias? Yes Have the authors identified all-important confounding factors? Yes Was the follow up of subjects complete enough? Yes How precise are the results? Very Do you believe the results? Yes Can the results be applied to the local population? Unsure Do the results of this study fit with other available evidence? Yes Results: The authors identified 263 patients with 735 penetrating torso injuries over three years. They reported 620 (84%) of the injuries were from gunshot wounds (GSW) with a mean of 2.6 GSW/patient. After exclusions, 320 GSWs were included in the study. The mean age was 34% and 87% were male. Half of the patients were pronounced dead at the scene and 46% were dead on arrival. Key Results: The relative risk of having a cardiac injury from a GSW in the cardiac box is low and not statistically different from those outside the cardiac box. Primary Outcome: Cardiac Injury 80/257 (31%) in the box and (14/67) 21% outside the box RR = 0.96; p=0.82 We had a hard time confirming their numbers when we tried to calculate the RR. Also their percentage of GSW was 80% in the abstract and 84% in the result section. These discrepancies and issues made us less confident in the study. 1. Autopsy: The authors touch on the fact that their study was an autopsy study. This would exclude all the patients who suffered survivable trauma. In their patient demographics they list the frequency of dead at scene as 50% and dead-on arrival as 46% of all patients. This has huge implications as the patient population is massively different than the patients who survive long enough to enter the care of the hospital team. Although limiting the study to autopsy did provide opportunity to definitively examine for cardiac injury and to precisely evaluate for the location of wounds, the exclusion of patients with survivable injuries presents a challenge to the generalizability of the data.  It is unknown whether the sort of patient who survives long enough to receive care may have an injury pattern more consistent with the traditional cardiac box, and perhaps the tool performs better.  The authors mention that in their “experience with high volumes of penetrating cardiac injuries, these findings parallel clinical practice and experience,” but this is opinion rather than evidence. 2. Death Bias: This will expand on point #1. We often see survival bias but in this case the opposite is true. The bias is towards those who died. It is a form of selection bias. We do not know the injury pattern (inside or outside the cardiac box) for those patients who had GSWs, did not present to the hospital or presented to hospital and survived. 3. Power: The study doesn’t mention how they determined how many patients to enroll in the study. To adequately power a study to detect a difference between two groups, generally a calculation is performed beforehand (a priori) based on the estimated difference between the exposure group and the control group. The authors don’t comment on a power calculation and don’t mention their pre-trial expectation of a difference in cardiac injury based on anatomic location. Performing a power calculation a priori is based on two variables. One is setting the delta (difference) you assume there is between the two groups. In this case it would be cardiac injuries that are from penetrating injuries inside the cardiac box to those outside the cardiac box. The second is the confidence interval that is traditionally set at 95%. This can be one tailed (5%) or two-tailed (2.5%). Doing a power calculation after data has been collected would be wrong and potentially misleading. It is called observed power or post-hoc power. All it does is restate the p-value. Since observed power is a direct function of the p value it does not provide any additional useful information. Unfortunately, you will still see some journals request a post-hoc power calculation mistakenly thinking it will help them distinguish between “true negatives” from “false negatives”. In other word, to differentiate between the lack of observed effect is due to an ineffective treatment or the study shows no effect because it is too small. If you understand how that is not the case you can see how doing these post-hoc power calculations can be misleading, misinterpreted, and ultimately not helpful [4, 5]. 4. 2D vs. 3D: The authors used a two-dimensional definition of the cardiac box looking at the anterior and posterior surface of the thorax. However,