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Date:  30 Septembre 2014

Sceptical Host: Dr. Marcel Emond. Le Dr Émond est médecin spécialiste en médecine d’urgence, il exerce à titre d’urgentologue à l’Hôpital de l’Enfant-Jésus du Centre hospitalier affilié universitaire de Québec. Détenteur d’une maîtrise en recherche clinique, il poursuit présentement des études doctorales dans ce domaine.

TITRE:  CT Angiography for Blunt Cerebrovascular Injury Detection in Trauma Patients

J’enregistre cette version francophone du SGEM lors du congrès QueBEEM qui s’est déroulé à Québec offert par l’équipe BEEM sur deux jours et qui est un congrès pour l’instant très intéressant. Il permet de réviser les articles des dernières années et de vous permettre de vous mettre à jour au niveau de la littérature de la médecine

CAS : un homme de 21 ans se présente dans un hôpital rural suite à un accident de ski-doo. À l’arrivée, il est évident que le patient présente des lésions au niveau de la tête et du cou. Les signes vitaux sont stables, son GCS est 7 sur 15. L’examen neuro-vasculaire des extrémités démontre qu’aucune extrémités n’ait atteinte. Toutefois, à la radiographie, il y a présence d’une fracture de C3 et C4. En périphérie, le pt est intubé est transféré vers un centre de traumatologie tertiaire. Vous travaillez en tant que responsable de la traumatologie à ce centre.

QUESTION: « Est-ce qu’un angio-CT des carotides pour la détection des lésions potentielles des carotides et vertébrales est nécessaire? »

INTRODUCTION : Cette question est souvent un dilemme que nous avons quand on travaille à l’urgence lorsqu’on prend en charge des patients avec des traumatismes. Les lésions traumatiques carotidiennes et vertébrales sont peu fréquentes, ça représente environ 1 % des patients admis pour des traumatismes majeurs. Toutefois, c’est souvent des présentations retardées et malheureusement, ça conduit  a beaucoup de mortalité et morbidité avec des lésions hémisphériques ischémiques.

En 2013, un article à été publié dans Annals of Surgery qui regardait l’utilité diagnostique de l’angio-CT carotidienne et vertébrale comparé à l’angiographie standard. Roberts et ses coll. ont publié un article dont le titre est : « Diagnostic accuracy of computed tomography angiography for blunt cerebrovascular injury detection in trauma patients: A systematic review and meta-analysis, Ann Surg. 2013; 257 (4): 621-32. PubMed ID: 23470509 »

* Population: 8 études de patients 16 ans et plus, qui ont eu un traumatisme contondant majeur et pour lesquels on suspectait une lésion carotidienne et vertébrale basée sur différents risques cliniques de la littérature (définition non-standardisé).  1426 patients américains

* Intervention: Angio-CT des carotides et des vertebrales


* Comparison: Angiographie par soustraction digitale (ASD)

* Outcome: Capacité diagnostique de l’angio-CT par rapport à l’ASD.

Authors’ Conclusions: “Existing evidence suggests that the diagnostic performance of CTA varies considerably across studies, likely due to an implicit variation in diagnostic threshold across trauma centers. Moreover, although CTA appears to lack sensitivity to adequately rule out BCVI, it may be useful to rule in BCVI among trauma patients with a high pretest probability of injury.”

Liste des critères de validité:

* Est-ce que la question posée était pertinente pour la clinique et établie sur des critères standards .  OUI Commentaire: L’Étalon est un test onéreux (angiographie ) peu disponible. Ça reste la meilleure mesure étalon.

* Est-ce que la recherche des études fut détaillée et complète? OUI

* Est-ce que la qualité des études intiales fut évaluée adéquatement? OUI

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Date:  September 30th, 2014 

Guest Skeptic: Dr. Marcel Emond. Associate professor, Laval University.  Emergency physician the level one trauma centre in Quebec City. Research Director of the Canadian Emergency Team Initiative (CETI).

Case: 21-year-old man loses control of his snowmobile and presents to a small rural hospital with a head and neck injury. His vital signs are stable. Glasgow Coma Scale=7. He is moving all extremities. There is a C3/4 fracture identified on xray. He is intubated at the rural hospital and transferred to you at the trauma centre.

Questions: Is CT angiography accurate for detecting blunt cerebrovascular injury?

Reference: Roberts et al. Diagnostic accuracy of computed tomography angiography for blunt cerebrovascular injury detection in trauma patients: A systematic review and meta-analysis, Ann Surg 2013

* Population: Systematic review of 8 studies enrolling patients >16 years after sustaining blunt trauma with suspected blunt cerebrovascular injury (BCVI) based on risk factors or clinical signs. N=1426 patients presenting to United States trauma centres.

* Intervention: CT angiography (CTA) of carotid and vertebral arteries


* Comparison: Digital subtraction angiography (DSA) of carotid and vertebral arteries

* Outcome: Summary diagnostic accuracy of CTA compared to DSA for blunt cerebrovascular injury.

Authors’ Conclusions: “Existing evidence suggests that the diagnostic performance of CTA varies considerably across studies, likely due to an implicit variation in diagnostic threshold across trauma centers. Moreover, although CTA appears to lack sensitivity to adequately rule out BCVI, it may be useful to rule in BCVI among trauma patients with a high pretest probability of injury.”

Quality Checklist for Systematic Review:

* The diagnostic question is clinically relevant with an established criterion standard. Yes
 Comment: Though invasive and labour intensive, digital subtraction angiography is currently the criterion standard for detection of cerebrovascular injury.

* The search for studies was detailed and exhaustive. Yes

* The methodological quality of primary studies were assessed for common forms of diagnostic research bias. Yes

* The assessments of studies were reproducible. Yes

* There was low heterogeneity for estimates of sensitivity or specificity. No

* The summary diagnostic accuracy is sufficiently precise to improve upon existing clinical decision making models. No

Key Results: Eight studies with a total 5704 carotid or vertebral arteries in 1426 trauma patients were included. Pool results for blunt cerebrovascular injury detection with CTA vs. digital subtraction angiography.

Sensitivity 66%, Specificity 97%, +LR 20 and -LR 0.35

* Primary Outcome:

* Sensitivity 66% (95% CI 49-79%)  I2 =80 (lots of heterogeneity)

* Specificity was 97% (95% CI 91-99%) I2=94

* +LR was 20 (95% CI 6.9-58.4) I2=88

* -LR was 0.35 (95% CI 0.22-0.56) I2=75

This was a well-performed SR/MA. However, most of the studies included had unclear blinding. There was also a problem with heterogeneity was in all the measures between studies. Sources of heterogeneity might include who was reading the CTA, CT modality (16 or fewer slices), or diagnostic threshold variability between studies.

This study discussed likelihood ratios for diagnostic value of the test. If you have a LR of 1 it means no effect. However, if you have a +LR of >10 it is highly diagnositic for ruling in the condition. If you have a –LR of <0.1 it is highly diagnostic of ruling out the condition.

This review shows diagnostic accuracy of CTA for blunt cerebrovascular injury varies across institutions.

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Date: October 1st, 2014 

Guest Skeptics: Dr. Erin Brennan and Dr. Stuart Douglas. Residents in Emergency Medicine at Queen’s University.

This is another SGEM Journal Club. It was recorded live in Kingston, Ontario at Queen’s University. Thank you to Dr. Heather Murray and all the staff and residents. I had a great time and you have a great program.

There have been two previous SGEM JCs. The first one was at McGill University in Montreal. This is where Dr. William Osler started journal club “for the purchase and distribution of periodicals to which he could ill afford to subscribe”. I am pretty sure Dr. Osler would have been a big fan of FOAMed. SGEM#50 asked whether vasopressin, epinephrine and corticosteroid (VSE) protocol for in-hospital cardiac arrest resuscitation improve survival with favorable neurological outcomes compared to epinephrine alone.

The second episode took place at the home of evidence based medicine, McMaster University. This is where my mentor Dr. Andrew Worster taught me that the answer to any EBM question is “it all depends”. SGEM#55 asked whether an departmental guideline on controlled substance prescriptions reduce opioid abuse?

Case: 74-year-old man is brought by EMS for altered level of consciousness. He lives alone, family hadn’t heard from him in several days so went to check, found him to be coughing and mildly confused. EMS vitals: HR 115, RR 24, BP 103/70, O2 89% on room air, 99% on non-re-breather mask, T 38.4C and blood glucose is normal. The patient is not intubation, wishes no CPR, but full medical management.

Past medical history includes: COPD, type 2 diabetes, hypercholesterolemia, hypertension and peripheral vascular disease. He is triaged to acute care bed, IV access obtained and bolus 0f 1 liter normal saline provided. ECG shows sinus tachycardia and portable CXR demonstrates right lower lobe infiltrate. Laboratory tests are drawn and sent.

You start Early Goal Directed Therapy (EGDT) by rapidly recognized this man is septic, provided IV fluids and appropriate IV antibiotics for pneumonia. Now you are starting to think about more fluids +/- vasopressors to increase his Mean Arterial Pressure (MAP).

Question: Does a MAP of 80-85mmHg decrease 28 day mortality as compared to a MAP of 65-70mmHg?

Background: Sepsis remains a major contributor to ED morbidity, carrying a short-term mortality of approximately 20% (ProCESS). With approximately 750,000 annual cases in the US, recognition and early treatment of severe sepsis and septic shock has become a pillar of Emergency Medicine.

Sepsis can be defined as a “clinical syndrome complicating severe infection characterized by inflammation remote from the site of infection.  Disregulation of the inflammatory response can lead to multiple organ dysfunction.”

There is a continuum of sepsis ranging from SIRS (Systemic Inflammatory Response Syndrome) to septic shock.

* SIRS – temperature <36 or >38’C, HR >90 RR >20 (or PaCO2 <32mmHg), WBC <4 or >12, or >10% immature forms

* Sepsis – 2/4 SIRS criteria + infection.

* Severe Sepsis – Sepsis + hypotension end organ failure

* Septic Shock – Sepsis and hypotension refractory to fluid treatment

Mean Arterial Pressure (MAP) is he average arterial pressure during a cardiac cycle, represents the perfusion pressure seen by the organs/tissues.  MAP = (CO x SVR) + CVP, or estimated by MAP = 2/3 Diastolic BP + 1/3 Systolic BP (inaccurate if tachycardic).

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Date: October 5th, 2014

Guest Skeptic: Dr. Chris Carpenter. Associate Professor, Emergency Medicine. Director, Evidence Based Medicine, Washington University. C0-Author of Evidence Based Emergency Care- Diagnostic, Testing and Clinical Decision Rules. @SAEMEBM

The goal of the SGEM continues to be to cut the knowledge translation window down from over ten years to less than…

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Date:  September 23rd, 2014 

Reference: Stiell IG et al. Association of the Ottawa Aggressive Protocol with Rapid Discharge of Emergency Department Patients with Recent-Onset Atrial Fibrillation or Flutter. CJEM 2010.

Guest Skeptic: Dr. Anand Swaninathan or Swami as his is better known. Swani is an assistant program director at NYU/Bellevue Hospital in the department…

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Date:  September 17th, 2014 

Guest Skeptic: Dr. Pal Ager-Wick is from Norway. Consultant at Legevakten in Drammen, which is a GP run ED handling most things except major trauma. Keen interest in everything evidence based especially ultrasound. Pal is bringing Matt and Mike from the Ultrasound podcast to Norway.

Case Scenario: 35 year old…

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Date:  August 26th, 2014 

Guest Skeptic: Dr. Chris Bond. Chris is a clinical lecturer and emergency physician at the University of Calgary, #FOAM blogger, dogma basher, wine and food supergeek. Chris has a blog called SOCMOB, is part of the REBEL-EM Alliance and did a blog entry on colchicine for pericarditis.

Case Scenario: 33…

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Date:  September 5th, 2014 

Guest Skeptic: Dr. Ryan Radecki is an Assistant Professor of Emergency Medicine – The University of Texas Medical School at Houston. He has an amazing blog called Emergency Medicine Literature of Note. It is billed as musings on publications and studies relevant to EM & otherwise. You can follow Ryan…

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Date:  August 18th, 2014 

As many of you know actor and comedian Robin Williams died last week. I am having difficulties processing the loss. There are feelings of anger, sadness and disbelief.

It is weird; a person I have only known through movies has had a profound effect on me.

Robin Williams made a…

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Date:  July 26th, 2014 

This is the 42nd podcast of for this year and the last for Season#2. Why only 42 episodes? Keeping with the hitchhiker’s Guide to the Galaxy 42 seems like the right number. But don’t panic, the SGEM will be back in the fall with new episodes.

The goal of the…