

The Skeptics Guide to Emergency Medicine
Dr. Ken Milne
Meet ’em, greet ’em, treat ’em and street ’em
Episodes
Mentioned books

Feb 15, 2020 • 20min
SGEM#284: Might as Well Jump, but We would Recommend a Parachute
Date: February 11th, 2020
Reference: Yeh et al. Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial. BMJ 2018.
Guest Skeptic: Marcus Prescott is a nurse in Norway. He is also now a third-year medical student.
Case: A 32-year-old woman with no previous medical history calls you while a passenger on a crashing plane. She has been offered a parachute by the flight attendant but is unsure whether jumping from the plane is wise. You quickly scour the literature for evidence to inform her decision.
Background: The parachute– an umbrella term for devices to slow the motion of an object through an atmosphere by creating drag – was first deployed in China roughly 4,000 years age. The modern versions reached widespread use with the invention of heavier than air flight early last century.
Different variants of parachutes have been used both for recreational and safety purposes; in either case aiming to avoid death in people falling from heights presumed to be lethal. Despite the near universal application, a systematic review from 2003 (Smith and Pell, BMJ) found no RCTs of parachute intervention.
That systematic review published in the BMJ is a classic paper and part of their annual holiday edition. It stated that there was observational data showing parachutes failed at times to prevent morbidity and mortality. There are also case reports of free falls that did not result in 100% mortality.
The authors suggested taking evidence-based medicine advocates up in a plane for a double blinded randomized control trial. The intervention would be a parachute and the control arm would be a sham parachute (backpack). To make it more rigorous, anyone who survived the first jump would cross over into the other arm of the study and jump again. Only then would we have definitive evidence that a parachute was effective in preventing death and major trauma related to gravitational challenges.
After years of trying to organize a trial, researchers were finally able to recruit some volunteers to jump out of a plane with a parachute or backpack.
Clinical Question: Do parachutes reduce death or major injury when jumping from aircraft?
Reference: Yeh et al. Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial. BMJ 2018.
Population: Adults 18 years of age and older, seated on aircraft and deemed rational decision makers.
Intervention: Jumping from aircraft with parachute
Comparison: Jumping from aircraft with backpack
Outcome:
Primary Outcome: Composite of death and major traumatic injury (ISS>15) within five minutes of impact or at 30 days.
Secondary Outcomes: Health status and subgroup analysis based on type of aircraft or previous parachute use.
Authors’ Conclusions: “Parachute use did not significantly reduce death or major injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggestion cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exists in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice.”
Quality Checklist for Randomized Clinical Trials:
The study population included or focused on those in the emergency department. No
The patients were adequately randomized. Yes
The randomization process was concealed. Yes
The patients were analyzed in the groups to which they were randomized. Yes
The study patients were recruited consecutively (i.e. no selection bias). No
The patients in both groups were similar with respect to prognostic factors. Unsure
All participants (patients, clinicians, outcome assessors) were unaware of group allocation.

Feb 8, 2020 • 24min
SGEM#283: Can You Be Absolutely Right in Diagnosing a SAH Using a Clinical Decision Instrument?
Date: January 29th, 2020
Reference: Perry et al. Prospective Implementation of the Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule. Stroke 2019
Guest Skeptic: Dr. Rory Spiegel is an EM/CC doctor who splits his time in the Emergency Department and Critical Care department. He also has this amazing #FOAMed blog called EM Nerd.
Case: A 48-year-old male presents to your emergency department with a sudden onset headache, which started about one-hour prior to arrival. The headache is severe is quality and the patient does not have a history of similar headaches in the past. It is associated with nausea, vomiting and photophobia.
Background: Headaches are a common complaint presenting to the emergency department. Subarachnoid hemorrhage represents one of the most serious underlying causes of headaches and we have covered it a number of times on the SGEM:
SGEM#48: Thunderstruck – Subarachnoid Hemorrhage
SGEM#134: Listen, to what the British Doctors Say about LPs post CT for SAH
SGEM#140: CT Scans to Rule Out Subarachnoid Hemorrhages in A Non-Academic Setting
SGEM#201: It’s in the Way That You Use It – Ottawa SAH Tool
In patients who present neurologically intact making the diagnosis early is key to preventing subsequent more life-threatening bleeding. A number of controversies surround the diagnosis of SAH in the emergency department. Two of the more provocative are the use of the Ottawa SAH Rule and whether a lumbar puncture (LP) is required following a negative CT if the scan is performed within 6-hours of symptom onset.
The Ottawa SAH Rule (tool) was covered on SGEM#201. The bottom line from that study was that the clinical decision instrument needed external validation, a meaningful impact analysis performed and patient acceptability of incorporating this rule into a shared decision-making instrument before being widely adopted.
We were surprised that in their background/introduction material they did not include the excellent SRMA on this topic by Carpenter et al. AEM 2016.
Clinical Question: What is the clinical impact of the Ottawa SAH Rule and the 6-hour CT Rule compared to standard care when implemented in six emergency departments across Canada?
Reference: Perry et al. Prospective Implementation of the Ottawa Subarachnoid Hemorrhage Rule and 6-Hour Computed Tomography Rule. Stroke 2019
The senior author on this publication was the legend of emergency medicine, Dr. Ian Stiell from Ottawa.
Population: Neurologically intact adult presenting to the ED with a chief complaint of a nontraumatic, acute headache, or syncope associated with a headache.
Exclusions: Patients with any of the following:
3 or more previous similar headaches (ie, same intensity/character as their current headache) over a period of >6 months (eg, established migraines)
confirmed SAH before arrival at study ED
previously investigated with CT and LP for the same headache
papilledema
new focal neurological deficit
previous diagnosis of intracranial aneurysm or SAH
known brain neoplasm
cerebroventricular shunt
headache within 72 hours following a LP
headache described as gradual or peak intensity beyond 1 hour.
Intervention: Physicians were actively encouraged to use the Ottawa SAH Rule and the 6-hour-CT Ruleto determine when to undergoing diagnostic workups for SAH and when a CT alone with an appropriate workup. Clinicians had the option to override the proposed rules.
Comparison: The control phase was standard care. Clinicians were encouraged to not use any clinical decision instrument and make the decision to pursue diagnostic studies based on their own clinical discretion.
Outcome: The primary outcome was the clinical impact of the Ottawa SAH Rule and 6-hr CT Rule for making the diagnosis of a SAH compared to usual care. SAH was defined as:
Subarachnoid blood on CT
Xanthochromia in the cerebrospinal fluid

Jan 29, 2020 • 3min
SGEM#281ss: Balance of Prognostic Factors in Randomized Controlled Trials
Date: January 25th, 2020
SGEM#281: EM Docs Got an AmbuBag
Statistically Significant: Dan Lane
We want to make the SGEM even better and address some of the criticisms from the ClinEpi world about clinicians trying to do critical appraisal. In order to do that we now have a Dr. Dan Lane who has a PhD in Clinical Epidemiology. He will be commenting on each the SGEM episodes.
Dr. Dan Lane
On this episode of Statistically Significant we are going to discuss the importance of balance of prognostic factors in randomized controlled trials, using the PreVent trial as an example.
Characteristics that indicate when a patient more likely to have an outcome, what we call prognostic factors, need to be accounted for when assessing the effectiveness of a treatment. Without accounting for prognostic factors, the measures of treatment effect can be biased due to observed or unobserved factors amongst patients in each group. Consider if this same study had been conducted as a non-randomized design –clinicians may have decided to ventilate select patients between induction and intubation because they perceived them as more unstable prior to induction. These patients may also be at higher risk for hypoxia during this period for the same reasons the clinicians chose to ventilate them and therefore they would look worse when compared to patients not receiving ventilation if you did not account for these reasons – this is what epidemiologists call an indication bias.
The goal of randomization in clinical trials is to balance patient characteristics between the different groups being investigated in the study. By randomly assigning patients to groups, the sole indication for receiving the treatment is the randomization process. As long as there are enough patients randomized, all known and unknown prognostic factors will be mathematically balanced between the groups. Therefore when talking about the balance of prognostic factors as part of critical appraisal, the key point to realize is there are both known and unknown factors. Although in this study they found some statistical differences between measured prognostic factors at baseline, these are just the prognostic factors that happen to be reported by the investigators. If we trust their randomization process then we can assume that the overall risk of the primary outcome, which includes measured and unmeasured prognostic factors, is mathematically balanced between the groups.
One final point - the use of statistical hypothesis testing to compare prognostic factors is actually inappropriate here because by definition the null hypothesis that the two groups are the same is assumed to be true when the two groups are selected based on randomization. Therefore, any differences between the groups would be due to chance alone and considering them different would be a type 1 error.
Additional Reading:
Altman and Bland. Treatment allocation in controlled trials: why randomise? BMJ May 1999
Sander Greeland. Randomization, statistics, and causal inference. Epidemiology Nov 1990
Stephen Sean. Baseline Balance and Valid Statistical Analyses: Common Misunderstandings. Applied Clinical Trials. May 2005.
REMEMBER TO BE SKEPTICAL OF ANYTHING YOU LEARN, EVEN IF YOU HEARD IT ON THE SKEPTICS’ GUIDE TO EMERGENCY MEDICINE.

Jan 25, 2020 • 15min
SGEM#281: EM Docs Got an AmbuBag – The PreVent Trial
Date: January 9th, 2020
Reference: Casey et al. Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults. NEJM February 2019
Guest Skeptic: Andrew Merelman is a critical care paramedic and second year medical student at Rocky Vista University in Colorado. His primary interests are resuscitation, critical care, airway management, and point-of-care ultrasound.
Case: A 60-year-old male is in your emergency department with sepsis from pneumonia. He has worsening work of breathing and a decreasing level of consciousness. You decide based on his clinical presentation that he needs to be intubated. Due to his already poor oxygenation, you are concerned about him desaturating during intubation and wonder if there is anything you can do to help prevent it.
Background: Emergency medicine is often referred to as the ABC (Airway, Breathing and Circulation) specialty. We have covered airway a few times on the SGEM:
SGEM#75: Video Killed Direct Laryngoscopy?
SGEM#96: Machine Head – NIPPV for Out of Hospital Respiratory Distress
SGEM#247:Supraglottic Airways Gonna Save You for an OHCA?
SGEM#249: Ace in the Hole – Confirming Endotracheal Tube Placement with POCUS
SGEM#271: Bougie Wonderland for First Pass Success
Rapid Sequence Intubation (RSI) has been a mainstay of emergency airway management for years. However, there are aspects of the procedure that have been debated, one of which is how best to oxygenate the patient during the apneic period while not increasing rates of aspiration.
Clinical Question: Is bag-mask ventilation (BMV) performed during the apneic period of RSI (defined as the time between administration of RSI medications and intubation) in critically ill adults safe and effective?
Reference: Casey et al. Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults. NEJM February 2019
Population: Adults patients (older than 17 years of age) undergoing induction and tracheal intubation in the intensive care unit.
Exclusions: Patients who were pregnant, incarcerated, had immediate need for intubation or if the treating clinicians felt that ventilation was indicated or contraindicated between induction and laryngoscopy.
Intervention: Bag-mask ventilation (BMV) during the time between administration of sedation/paralysis and insertion of the laryngoscope into the mouth for intubation.
Comparison: Apnea with or without nasal cannula oxygen during the time between administration of sedation/paralysis and insertion of the laryngoscope into the mouth for intubation.
Outcome:
Primary Outcome: The lowest oxygen saturation observed during the interval between induction and two minutes after tracheal intubation.
Secondary Outcome: The incidence of severe hypoxemia (oxygen saturation of less than 80%).
Authors’ Conclusions: “Among critically ill adults undergoing tracheal intubation, patients receiving bag-mask ventilation had higher oxygen saturations and a lower incidence of severe hypoxemia than those receiving no ventilation.”
Quality Checklist for Randomized Clinical Trials:
The study population included or focused on those in the emergency department. No
The patients were adequately randomized. Yes
The randomization process was concealed. Yes
The patients were analyzed in the groups to which they were randomized. 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. No
All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No
All groups were treated equally except for the intervention. No
Follow-up was complete (i.e. at least 80% for both groups). Yes
All patient-important outcomes were considered. No
The treatment effect was large enough and precise enough to be clinically significant. Unsure
Key Results: They screened 667 patients and enrol...

Jan 22, 2020 • 10min
SGEM Xtra: It’s All About the Bayes, ‘Bout the Bayes, No Fisher
Guest Skeptic: Dr. Dan Lane has a Masters in Health Services Research at the University of Calgary, a Doctor of Philosophy in Clinical Epidemiology from the University of Toronto and is currently a medical student at the University of Calgary.
Dan is naturally a contrarian, he strives to understand first principles of conventions in medical research in order to identify and challenge poor practices that have become dogma. He is passionate about statistics and epidemiology and wants to share that passion by making these topics more practical and approachable for clinicians. Believing the key to proper interpretation of medical research does not begin with memorizing some arbitrary threshold for statistical significance, Dan hopes to contribute to the SGEM through sharing an understanding of what story the numbers are actually telling about the data. Dan has no funding whatsoever, and no associations with industry. He is currently a medical student at the University of Calgary.
Dan has some pet peeves when it comes to statistics there used and critical appraisals. We will do some more in depth SGEM Xtras on each of these issues.
Thomas Bayes
Absolute vs. Relative Estimates
Effect Estimates and Not P-Values
All Models are Wrong
Predication vs. Classification
Bayes No Frequentists
The purpose of this SGEM Xtra, beside to introduce a new SGEM faculty member, is also to announce we are adding a new segment to the SGEM. It is going to be called Statistically Significant.
We want to make the SGEM even better and address some of the criticisms from the ClinEpi world about clinicians trying to do critical appraisal. In order to do that we now have a Dr. Dan Lane PhD who will be commenting on each the SGEM episodes.
The first instalment of Statistically Significant segment will be on this weeks’ SGEMHOP looking at troponin testing in the elderly patients presenting with non-specific complaints (SGEM#280). Let me know what you think of this idea. We have a few more lined up and feedback is always appreciated. Send me an email TheSGEM@gmail.com
Statistically Significant #280: Sensitivity and Specificity
Despite their dogmatic use in the literature, sensitivity and specificity have a number of limitations that are rarely considered or addressed in diagnostic test studies.
Sensitivity and Specificity are crude metrics, meaning they only look at the effect of a single measure and a single outcome. As crude measures they fail to incorporate any other information into their estimates, including potential confounders for the relationship between the test result and the outcome.
In this particular study, age is part of the primary objective for the study (geriatric patients) but is also a confounder of the relationship between troponin level (which may increase with age) and acute coronary syndrome risk (also increases with age). When confounders like age are present, crude measures will be influenced based on the prevalence of confounders in each the groups – for example, if there were more older patients in the troponin positive group, the estimates for sensitivity may be inflated.
Another limitation of sensitivity and specificity is they require a test result be classified as positive or negative. This is problematic when the real measure is a continuous measure, such as troponin. In the current study the test was considered “positive” if the troponin level was above the 99th percentiles for that enzyme. But this arbitrarily treats patients above or below the 99th percentile as homogeneous groups, meaning the statistics consider everyone above the threshold to be the same, and everyone below the threshold to be the same.
Consider a patient with a troponin right below the threshold and another patient right above the threshold – surely these patients are almost identical in terms of their risk for having ACS. But by inserting an arbitrary break into the measure,

Jan 18, 2020 • 30min
SGEM#280: This Old Heart of Mine and Troponin Testing
Date: January 16th, 2020
Reference: Troponin Testing and Coronary Syndrome in Geriatric Patients With Nonspecific Complaints: Are We Overtesting? AEM January 2020
Guest Skeptics:
Dr. James VandenBerg: James has a master’s degree in clinical investigation from Washington University in St. Louis, and is currently the Chief Resident at Detroit Receiving Hospital.
Dr. Andrew Huang: Andy is the Chief Resident at Sinai-Grace Hospital.
Case: As the resident, you have just finished seeing a 78-year-old male who has been brought in by his family over the holidays. The triage nurse has put the reason for the visit as “multiple complaints”. Despite spending 30 minutes in the room, you still are not sure exactly why the patient is here.
Your attending says that if you take a good geriatric history that you can always determine what’s going on. However, 15 minutes later your attending leaves the room defeated. The patient’s complaints are just so nonspecific.
The attending ends up ordering the “geriatrogram” – ticking off every blood test on the form, including the troponin. You turn to the attending and ask, “do you really think this could be acute coronary syndrome (ACS)?”
Background: Patients 65 years and older account for about 15% of emergency department visits in the United States. Their presentations are often complicated as they present with nonspecific symptoms, and there is often obscuring co-morbid conditions, polypharmacy, and cognitive/functional impairment.
Nonspecific symptoms in the elderly usually yield a broad differential and there are no recommended diagnostic algorithms, leading to extensive testing. ACS is usually amongst this differential, as cardiovascular disease is a leading cause of morbidity and mortality in this population.
Additionally, the elderly population with ACS more commonly presents without chest pain compared to younger patients (up to 20% of elderly patients with MI present with “weakness” as part of their chief complaint). While cardiovascular disease is the leading cause of mortality and morbidity in the elderly, the frequency of ACS amongst this population presenting with nonspecific symptoms is unknown.
Clinical Question: What is the frequency of ACS in elderly patients presenting to the ED with nonspecific complaints, and what is the utility of troponin testing in this population?
Reference: Wang et al. Troponin Testing and Coronary Syndrome in Geriatric Patients With Nonspecific Complaints: Are We Overtesting? AEM January 2020
Population: Patients aged 65 years and older presenting to the emergency department with nonspecific chief complaints who underwent troponin testing. “Nonspecific” was designed a priori as including weak or weakness, dizzy or dizziness, fatigue, lethargy, altered mental status, light-headedness, medical problem, examination requested, failure to thrive, or “multiple complaints.”
Exclusions: If they had a focal chief complaint (ex. focal pain, injury complaint, shortness of breath, vomiting, diaphoresis, syncope, fever, cough, focal neurologic deficit)or fever of at least 38C at triage.
Investigation: Troponin testing
Comparison: None
Outcomes: There were multiple outcomes of interest:
The proportion of patients with nonspecific complaints who underwent troponin testing.
The proportion of such patients who had elevated troponin.
The proportion of patients with ACS at the index visit or within 30 days.
The utility of troponin testing to diagnose or exclude ACS.
The frequency of other causes of troponin elevation in this population.
Dr. Alfred Wang
This is a LIVE episode of an SGEMHOP which means we have the lead author on the show. Dr. Alfred Wang is an emergency medicine physician at Indiana University in Indianapolis, IN. With the help from a dedicated team of physician-peers and mentor, Dr. Wang was able to complete this research project.

Jan 11, 2020 • 33min
SGEM#279: Do You Really Want to Hurt Me and Use a Placebo Control for a Migraine Trial?
Date: January 10th, 2020
Reference: Dodick DW et al. Ubrogepant for the Treatment of Migraine. NEJM 2019
Guest Skeptic: Dr. Anand Swaminathan is an Assistant Professor of Emergency Medicine at St. Joseph’s Hospital in Paterson, NJ. He is also the managing editor of EM:RAP and associate editor at REBEL EM.
Case: A 23-year-old man with a history of migraines presents with two days of headache, nausea and photo-photophobia typical of his prior migraines. He’s tried a number of medications at home including ibuprofen, acetaminophen, aspirin and sumatriptan without any considerable improvement in symptoms. You start to offer him your standard medications like metoclopramide and haloperidol when he asks about a new drug he heard about called ubrogepant.
Background: Migraine headaches are a chronic neurologic disease characterized by throbbing, often unilateral headaches that are often associated with nausea, vomiting, photophobia and phonophobia. It is a common disease and can be severe enough to impede on people’s lives.
Headaches themselves are not only a common emergency department presentation but one that is filled with potential dangers. There are a number of causes of headache that are life and limb threatening – subarachnoid hemorrhage (SGEM#201), meningitis, encephalitis, cerebral venous thrombosis, vertebral artery dissection among other things but, most headaches are benign in nature.
There is an international classification system of headaches (IHS 2018). The current system classifies them into primary and secondary headaches. An important part of our job as emergency physicians is to differentiate the lethal headache from the benign headache.
Though we rarely make a de novo diagnose of migraines in the emergency department, many patients with migraines present to us for symptom management. The pathophysiology of migraines is both complicated and poorly understood but there are a number of potential treatments including NSAIDs, acetaminophen, aspirin, neuroleptics, triptans and even propofol.
More recently, calcitonin gene-related peptide antagonists (CGRPs) have emerged as a new potential treatment. The first big study that came out on these drugs was published in the NEJM in 2019 and was entitled Rimegepant, an Oral Calcitonin Gene-Related Peptide Receptor Antagonist for Migraine (Lipton et al).
Now, we have a second study published in the NEJM on a related drug, ubrogepant.
Clinical Question: Does ubrogepant increase the percentage of patients who were free from pain and absent of the most bothersome migraine-associated symptom at two hours from initial dose in comparison to placebo?
Reference: Dodick DW et al. Ubrogepant for the Treatment of Migraine. NEJM 2019
Population: Adult patients (18-75 years of age) with at least a one-year history of migraine with or without aura that met criteria from the International classification of headache disorders and had migraine onset before the age of 50. Patients had to have a history of migraines between 4-72 hours and a history of migraine attacks separated by at least 48 hours of freedom from headache. Additionally, they had to have suffered from two to eight migraines per month over the last three months.
Exclusions: Patients with 15 or more headaches/month on average in the previous six months. Hard to distinguish the type of headache. Use of acute migraine treatment on ten or more days in the previous three months. Participated in a trial involving CGRP. Had clinically significant cardiovascular or cerebrovascular disease. History of hepatitis in the last six months or laboratory findings of liver disease (elevated AST, AST, Bilirubin or low serum albumin).
Additional Exclusions from ClinicalTrials.gov
Has a history of migraine aura with diplopia or impairment of level of consciousness, hemiplegic migraine, or retinal migraine
Has a current diagnosis of new persistent daily headache,

Dec 28, 2019 • 28min
SGEM Xtra: Come Together, Right Now – Over Renal Colic
Date: December 16th, 2019
Reference: Moore et al. Imaging in Suspected Renal Colic: Systematic Review of the Literature and Multispecialty Consensus. Annals of EM, JU, and JACR 2019.
Dr. Chris Moore
Guest Skeptics: Dr. Christopher Moore is an Associate Professor of Emergency Medicine a Yale School of Medicine. He is also the Chief for the Section of Emergency Ultrasound and Director of the Emergency Ultrasound Fellowship.
Dr. Kevan Sternberg is an Associate Professor of Urology at the University of Vermont Medical Center.
This is an SGEM Xtra and is a result of a paper that was published in three journals (Annals of EM, Journal of Urology and Journal of the American College of Radiology). The paper was about what is the best diagnostic imaging modality for renal colic.
Renal Colic on the SGEM:
SGEM#4: Getting Unstoned
Kidney Stones
SGEM#32: Stone Me
SGEM#71: Like a Rolling Stone
SGEM#97: Hippy Hippy Shake – Ultrasound Vs. CT Scan for Diagnosing Renal Colic
SGEM#154: Here I Go Again, Kidney Stone
SGEM#202: Lidocaine for Renal Colic?
SGEM#220: Acupuncture Morphine for Renal Colic
SGEM#230: Tamsulosin – You’ve Lost that Loving Feeling – For Renal Colic
Dr. Kevan Sternberg
There are greater than two million annual emergency department (ED) visits for suspected renal colic in the United States, and computed tomography (CT) scanning is now performed for more than 90% of patients who receive a diagnosis of kidney stone.
Despite a significant increase in CT use for diagnosis during the last two decades, patient-centered outcomes such as admission and intervention do not appear to have been affected.
There was a trial published in 2014 comparing radiology department ultrasound, POCUS and CT for suspected nephrolithiasis (Smith-Bindman et al. NEJM 2014). We covered this on SGEM#97 with Dr. Tony Seupaul and Dr. Spencer Wright. The bottom line from that episode was bedside emergency department ultrasound is safe and has several advantages over CT for the diagnosis of kidney stones.
Despite this evidence, recent data suggest that ultrasonography is used for less than 7% of patients receiving a diagnosis of kidney stone, and CT use has continued to increase. Similarly, although reduced-radiation-dose CT is recommended for the evaluation of renal colic, it is used for less than 10% of patients with kidney stone.
What did you do in this study?
We sought out a nine-member panel with representation from three specialty societies: ACEP, the American College of Radiology, and the American Urological Association.
How did you decide who was on the panel?
All panel members were board-certified practicing academic physicians and were nominated according to previous work on specialty- specific guidelines.
Clinical Question: For patients presenting to the ED with pain suspected to be uncomplicated renal colic, what imaging should be pursued compared with standard noncontrast CT scanning to optimize patient-centered outcomes?
To answer the question, you did a systematic review of the literature using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines.
After reviewing and summarizing the literature for imaging modalities, we delineated specific clinical scenarios to illustrate decision making with respect to initial imaging. We came up with a total of 29 clinical vignettes representing a balance of possible permutations (age, sex, pregnancy status, likelihood of stone disease, and likelihood of acute alternative diagnosis).
How did you come up with consensus on the best diagnostic imaging strategy?
Consensus was sought with a modified Delphi process that included three rounds of anonymous voting, with two group discussions between rounds. All nine members of the group answered the vignettes in a blinded fashion.
What were the three imaging options?
For purposes of defining consensus,

Dec 21, 2019 • 32min
SGEM Xtra: NNT – WET or DRI
Date: December 17th, 2019
Reference: Reeves and Reynolds. The NNT-WET and NNT-DRI: (Mostly) Satirical New Metrics to Emphasize the Inherent Inefficiency of Clinical Practice. AEM Dec 2019.
Guest Skeptics: Dr. Mathew Reeves is a Professor and Interim Chair of the Department of Epidemiology and Biostatistics at the College of Human Medicine at MSU.
Dr. Joshua Reynolds is an Associate Professor of Emergency Medicine at the College of Human Medicine at MSU. Outside of his academic duties, he works clinically in the adult ED at Spectrum Health in Grand Rapids, Michigan, the tertiary care center for Western Michigan.
This is an SGEM Xtra and is a result of the December AEM publication suggesting new metrics to emphasize the inherent inefficiency of clinical practice. This (mostly) satirical article seems to be in the same theme of the annual BMJ holiday edition.
The BMJ has published some great studies in their holiday edition. We have covered two of them on the SGEM:
SGEM#6: Orthopedic Surgeons: Strong AND Smart!
SGEM#23: A Bump Up Ahead (Diagnosis of Appendicitis)
One of my other favourite BMJ holiday edition articles has been the classic parachute trial (Smith and Pell BMJ Dec 2003). Parachutes have been used for years to prevent orthopaedic, head and soft tissue injuries after a gravitational challenge (jumping out of planes). There was observational data that showed parachute use led to injury and there were case reports of people surviving falling/jumping out of a plane without a parachute or it opening properly. They could find no randomized controlled trials (RCT) to include in their systematic review and meta-analysis (SRMA).
The authors suggested taking evidence-based medicine (EBM) advocates up in a plane and have them randomized in a double-blinded fashion to a parachute or a sham (backpack). It would be a cross over trial. Those participants who survived the first jump would be randomized into the opposite group. Only then would there be definitive evidence for the efficacy of parachutes.
Since that SRMA published in 2003, there has been a randomized control trial conducted and published on the topic of parachutes. It was published last year in the 2018 BMJ holiday edition (Yeh et al BMJ Dec 2018). It will be covered as an SGEM Xtra in 2020.
NNT: Number Needed to Treat
Dr. Joshua Reynolds
The NNT stands for the Number Needed to Treat. It estimates the average number of patients who need to be treated to positively impact one person with therapeutic benefit. It was originally described in 1988 by Andreas Laupacis, an internist and clinical epidemiologist who was at McMaster University in Ontario at the time. (Laupacis A et al NEJM 1988).
How is the NNT Described Mathematically?
The "number needed to do anything" is the inverse of the absolute change in risk. So in this case, the number needed to treat is the inverse of the absolute risk reduction (ARR): NNT=1/ARR
An Example of Calculating the NNT
Let’s say that there is a new drug to treat a bad disease and it reduces mortality from 25% to 15%. The absolute risk reduction is 10%, so NNT is the inverse of 0.1 and the NNT would be 10. Likewise, if that same drug reduces mortality from 25% to 20%, then the absolute reduction is 5% and the NNT would be 20, or 1 divided by 0.05.
What is An Advantage To Using the NNT?
One advantage is that using a single number, NNT describes the absolute impact or effectiveness of a particular therapy. Interventions with lower NNT are considered more efficacious, since one must theoretically treat fewer patients to observe an effect.
Is the NNT Popular?
Yes, there is an entire Internet domain devoted to NNT (www.thennt.com) . This site extols the virtues of NNT to promote the most effective therapies while questioning those with insufficient benefit.
NNH: Number Needed to Harm
Dr.Mathew Reeves
When quantifying the harms associated with treatment,

Dec 14, 2019 • 29min
SGEM#278: Seen Your Video for Acute Otitis Media Discharge Instructions?
Date: December 13th, 2019
Reference: Belisle et al. Video discharge instructions for acute otitis media in children: a randomized controlled open-label trial. AEM December 2019
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.
Case: An 18-month-old, previously healthy female presents to the emergency department with 24 hours of fever. The past few days the parents note there has been some rhinorrhea and cough. She looks well, immunizations are up to date and her examination reveals right sided acute otitis media (AOM). When discussing discharge instructions for her AOM, you wonder whether having the parents watch a video will be more beneficial for the child’s symptoms, rather than giving the parents oral instructions with a paper handout.
Dr. Chris Bond
Background: AOM is the second most commonly diagnosed illness in children and the most common indication for antibiotic prescription [1-2]. There are significant costs associated with AOM and parents often bring their children to health care providers for evaluation of pain and fever [3-4]. More than one third of children experience pain, fever or both three to seven days following treatment, and nearly seventy-five percent of parents identify pain and disturbed sleep as the most important sources of AOM related burden [5-6].
There is significant parental uncertainty regarding treatment of AOM and less than 30% of US parents receive instructions on appropriate analgesia for their children [7-8]. Discharge instruction complexity and inadequate comprehension is associated with medication errors, suboptimal post-discharge care and unnecessary recidivism [9-12]. Medication errors can be reduced using standardized discharge instructions, and parents prefer these to verbal summaries [13-15].
Video discharge instructions have been shown to be preferred over paper instructions in many pediatric presentations, however no study has explored the effectiveness of video instructions for AOM [16-17].
Clinical Question: Are video discharge instructions superior to a paper handout with respect to the Acute Otitis Media – Symptom Severity Score (AOM-SOS)?
Reference: Belisle et al. Video discharge instructions for acute otitis media in children: a randomized controlled open-label trial. AEM December 2019
Population: Parents of children age 6 months to 17 years with a chief complaint of otalgia in the setting of URTI and where the treating physician was at least 50% certain of a clinical diagnosis if AOM. Diagnostic certainty was on a 100mm visual analog scale based on the physicians’ rate of color photos of AOM.
Excluded: Parents who were not the primary care provider, had poor English proficiency, lacked internet or telephone access, and whose children had: a pre-existing diagnosis of AOM (<72 hours old); other concomitant diagnoses (pneumonia, urinary tract infection, gastroenteritis, sinusitis, or any other condition requiring antibiotics and/or hospital admission); tympanostomy tubes; acute tympanic membrane perforation.
Intervention: Video discharge instructions
Comparison: Paper-based discharge instructions identical to the video discharge instructions
Outcome:
Primary Outcome: AOM Severity of Symptom (AOM-SOS) score on day three post-discharge.
Secondary Outcomes: Knowledge questionnaire scores, parental satisfaction with the intervention, number of days of missed school or daycare (child) and work (parent), proportion of children with at least one return visit to a healthcare provider, and proportion of children who received analgesia.
Dr. Naveen Poonai
This is an SGEMHOP episode which means we have the lead author on the show. Dr. Naveen Poonai is a Paediatric Emergency Medicine physician at the Children’s Hospital, London Health Sciences Centre,


