HINTS Exam for Vertigo: Caveat Emptor


Hey all,

The March edition of Journal Club reviewed the HINTS exam for acute vestibular syndrome.  Much has been written/podcasted in the FOAM world about this controversial article, with the HINTS exam being touted as a godsend by some, while others recommend cautious use.  In addition to the usual critical appraisal of the article, journal club leaders Anthony Seto, Vanessa Potok and Andrew McRae also had us review the recommendations of 4 FOAM resources based on the HINTS article.  The FOAM recommendations were highly variable, to say the least. This post should be enlightening to many of us, and highlights the importance of actually reading articles yourself and critically appraising them, rather than implicitly taking advice based on the recommendations of a blog.

Article: HINTS to Diagnose Stroke in the Acute Vestibular Syndrome: Three-Step Bedside Oculomotor Examination More Sensitive Than Early MRI Diffusion-Weighted Imaging 

Jorge C. Kattah, Arun V. Talkad, David Z. Wang, Yu-Hsiang Hsieh, and David E. Newman-Toker. Stroke. 2009;40:3504-3510.


Image courtesy emjclub.com

Before getting into the nitty gritty, these are a few major reasons we should be cautious with use of the HINTS exam.

1)The definition of the acute vestibular syndrome (AVS) is continuous vertigo for > 24 hours. Ie: Not intermittent vertigo.  There is a very small subset of patients who actually have AVS, and in general we would likely have a higher index of suspicion for ominous causes in patients with continuous vertigo.  At journal club we agreed that many of us were applying this to patients with intermittent vertigo.  These patients were not included in the study.

2)This was done by a single neuro-ophthamologist using specialized equipment (Frenzl goggles) on a small number of patients (n=101) who were referred to a tertiary care stroke center from 25 community centres.  Most of us are not likely using Frenzl goggles in the ED, nor have we had specific training in this exam.  The study needs to be validated by EPs performing the exam in a typical group of patients presenting primarily to the ED.



Image courtesy takenotenigeria.com

Here are the FOAM blog views on this article.

Blogs: ALiEM, BoringEM, EM Nerd, EP Monthly

BlogKey MessagesLimitations and InaccuraciesIf you had a “blog-based” practice, how would reading this SINGLE blog affect how you practice?
ALiEM“HINTS seems just as good as diffusion weighted MRI to diagnose posterior stroke”. INFARCT is acronym to use to remember central features on HINTS exam (Impulse Normal, Fast-phase Alternating, Refixation on Cover Test) The paper’s key message is that HINTS is better than MRI for ruling out stroke, rather than “just as good” to “diagnose” Since HINTS is as good as MRI, I would just use HINTS.
BoringEM Notes evidence for HINTS “very strong”. ONLY use for persistent and continuous vertigo.Proceed with HINTS exam with caution, since we don’t expect the same high sensitivity and specificity when used by non-expert clinicians.Okay to use HINTS < 24h, since the study enrolled patients >1h. Does not go into critically appraising the paper to support the statement that evidence is “very strong” I would only use HINTS for persistent/continuous vertigo, but only with caution, since I am not an expert in the technique
EM Nerd Head impulse hard to do and may produce vertebral artery dissection. 2013 HINTS versus ABCD2 acts as validation set. However, ABCD2 was not designed to differentiate between central versus peripheral, so of course HINTS would perform better. Specialist does HINTS. Small sample size. Very select population.In high risk patient, HINTS would be used to rule out central cause and symptoms.

HINTS could aid decision making process for low risk patients to help identify a subtle presentation of central vertigo.

Until HINTS is examined in ED, performed by ED docs, and on our patients, cannot know if any benefit and if it will contribute to clinical decision making.
Inaccuracy: “Sensitivity of 96%” is not acceptable to safety r/o central cause. It was the specificity that was 96%. Sensitivity was 100%. I will be cautious about performing HINTS until it is studied as performed by emergency docs on a less high risk population.
EP Monthly The people performing HINTS in the study were well trained (neuroophthalmologist, neurologist).

HINTS only if continuous vertigo.
Overall, pro-HINTS I need to make sure the residents in my program get trained in HINTS. Only trained people should use HINTS, but if trained, we should all be using it



Now let’s critically appraise the article.


  • Prospective, cross-sectional study performed at single urban, academic hospital serving as regional stroke referral centre for 25 community hospitals

Patients were recruited from the emergency department (n=59), other institutions (n=37), admitted patients with cerebellar infarctions (n=4), and one outpatient (n=1). A total of 101 patients studied, collected over 9 years. 65% were men with mean age 62 (range 26 – 92 years old).

  • Single neuroophthalmologist did HINTS exam on patients
  • HINTS exam was performed between 1 hour to 9 days from symptom onset (mean 26 hours). 75% were examined within 24h of symptom onset.
  • All patients underwent neuroimaging generally after bedside HINTS. If they had imaging prior to HINTS, examiner was blinded to these results at time of assessment. 70% were imaged within 6h of symptom onset. 97% were imaged within 72h of symptom onset.
  • All patients (including those with suspected acute peripheral vestibulopathy) were admitted for observation and serial daily examinations
  • Stroke diagnosis: MRI with DWI (97%) or CT
  • Acute peripheral vestibulopathy diagnosis: absence of stroke in brainstem/cerebellum on MRI with DWI, lack of neurological signs on serial exam, and characteristic clinical course, +/- caloric testing
  • Eight patients with initial negative MRI later underwent repeat MRI for unexplained neurological signs suggesting brainstem localization


  • One neuroophthalmologist conducted HINTS exam
    • HI = Head Impulse
    • N = Nystagmus
    • TS = Test of Skew
  • “Benign” HINTS = abnormal “HI”, direction-fixed “N”, and absent “TS”
  • “Dangerous” HINTS = normal/untestable “HI” or direction-changing “N”, or present/untestable “TS”


  • Core features of acute vestibular syndrome (rapid onset of vertigo, N/V, and unsteady gait +/- nystagmus). Note that duration of symptoms was not important to be included in the study, some patients had ~ 1 hr of symptoms prior to HINTS exam.
  • At least 1 stroke risk factor
    • Smoking
    • Hypertension
    • Diabetes
    • Hyperlipidemia
    • Atrial fibrillation
    • Eclampsia
    • Hypercoagulable state
    • Recent cervical trauma
    • Prior stroke
    • Prior MI



  • History of recurrent vertigo +/- auditory symptoms


  1. Determine diagnostic accuracy of skew deviation for identifying stroke in acute vestibular syndrome: compare proportions with skew deviation in peripheral versus central cases
  2. Determine added value of skew deviation beyond h-HIT: stratify results by horizontal head impulse test findings
  3. Compare HINTS exam’s sensitivity and specificity for presence of stroke


  1. Skew present in 17% of the 101 studied subjects and was associated mainly with brainstem lesions
    1. Skew in 4% (n=1 of 25) with acute peripheral vestibulopathy, 4% (n=1 of 24) with pure cerebellar lesions and 30% (n=15 of 50) with brainstem lesion (chi-squared, P=0.003)
  2. Skew correctly predicted lateral pontine stroke in 2 out of the only 3 cases in which an abnormal horizontal head impulse test erroneously suggested peripheral localization (Table 3, below)
  3. Dangerous HINTS = 100% sensitive and 96% specific for central lesion (Table 4, below)


  1. Skew deviation is insensitive for central pathology but fairly specific for brainstem involvement for patients with acute vestibular syndrome
  2. Skew may help identify stroke when a positive head impulse test falsely suggests a peripheral lesion
  3. HINTS appears more sensitive (100% for HINTS) and specific (96% for HINTS) than MRI with DWI in detecting stroke in first 24-48 hours after symptom onset


  • Internal validity
  • Pros
    • An appropriate reference standard was used initially: neuroimaging
    • Cons:
    • Partially unmasked examiner: although masked to results of imaging, was not masked to patient’s clinical history, general neurological exam, or obvious oculomotor findings
    • Selective MRI follow-up scans: MRI follow-up was only obtained for selected cases based on evolution of new neurological signs or atypical subtle oculomotor signs, potentially leading to the misclassification of strokes and acute peripheral vestibulopathy, increasing apparent sensitivity
    • Observer bias in interpretation of eye findings may inflate HINTS sensitivity
    • Unclear whether radiologist was blinded to HINTS exam results
    • Unclear whether there may have been other eye exam components that would be useful for predicting stroke and a validation study would be required if the current study functions as just derivation data
    • Relatively small sample size (N=101)
  • External validity
    • Pros:
    • HINTS is not very time consuming to do, and it is free
    • HINTS may be useful for the right patient population, i.e. active symptoms to avoid labeling a normal head impulse test as “central” in normal patients
    • Acute vestibular syndrome in the literature is defined as >24 hours. The study enrolled patients between 1 hour to 9 days. It seems to suggest that HINTS can be used for patients presenting as early as 1 hour after symptom onset.
    • Cons:
    • Generalizability of exam technique: HINTS was performed by a neuroophthalmologist and not by emergency physicians
    • Single examiner: unsure if testing style can be replicated by others
    • Restricted enrollment to high-risk patients: unclear whether results can be extrapolated to lower-risk population. However, there were some younger patients in the mix (15 were less than 50 y.o. and 6 were less than 40 y.o.). It was not clear which patients of what age had which risk factors, and if those combinations would make one at “lower” or “higher” risk.

It may have been useful to stratify patients into ataxic versus non-ataxic, since we are more concerned about what to do about patients who have less obvious neurological findings.

UCalgary Journal Club Group

These points were discussed during Journal Club on March 19, 2015:

  • In a patient with acute vestibular syndrome, who had a normal CTA and reassuring HINTS, would you send them home? 43% would consult neurology first. 57% would send the patient home.
  • Would you incorporate HINTS as an additional part of your physical examination? Most people agreed they would consider incorporating the HINTS components as part of their examination and, in particular, examining for high-risk nystagmus and skew deviation. There appeared to be agreement that the head impulse test may be challenging to perform, and we may not have adequate inter-rater reliability with a single, experienced neuro-ophthalmologist.
  • If you do use HINTS, ensure you use it on the right patient population: i.e. someone who has active persistent vertigo (acute vestibular syndrome patient) and not an intermittent vertigo like BPPV.
  • You may consider downloading a slow-motion camera application on your mobile device in order to detect the subtle ocular symptoms. However, the safety and accuracy of this practice has not been rigorously evaluated. Evidence in support of slow-motion applications is anecdotal at best, and its use is not recommended without evidence of its utility.
  • It may be challenging to differentiate between a normal versus abnormal head-impulse test. Moreover, an abnormal head-impulse test, although should imply a peripheral cause, can still mean a central cause. Therefore, direction-changing nystagmus and present skew deviation may be elements of HINTS less challenging to interpret.
  • Although there are many limits to the generalizability of the HINTS exam, if it can be conducted on the right patient population using appropriate technique, it may add to your overall diagnostic evaluation for patients with acute vestibular syndrome. Consider reviewing the HINTS exam: http://empablogsite.com/2014/08/hints-exam/

There are many online resources and blogs that pertain to Emergency Medicine. Views may differ and there may often be limitations and inaccuracies. Remember to keep a critical mind when reading the online blogs and consult other resources as well as the primary source article.

Thanks again to Anthony Seto and Vanessa Potok for compiling this excellent summary.





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Novel Management of PEA Arrest (Calgary EM Journal Club)

ACLS management of PEA arrest is traditionally done using CPR, epinephrine and running through the H’s and T’s. Unfortunately, the H’s and T’s can be difficult to recall in a stressful situation, and furthermore, they do not approach cardiac arrest in a physiologic manner.

We recently reviewed the following paper that uses a novel approach to the management of PEA arrest.

Littmann et al. (2013) A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity. Medical Principles and Practice 2014.


The authors suggest a revision of the current approach to PEA arrest in order to streamline diagnosis and thus guide resuscitation.


The authors reviewed the current evidence around the ACLS guidelines.

Results/Proposed recommendations

Based on the literature review the authors felt cause-specific treatment of PEA arrest is more user friendly than the current ACLS teaching for a number of reasons.

  • The current ACLS teaching H’s and T’s of ACLS are cumbersome.
  • The current ACLS teaching is difficult to remember in code situation.
  • The proposed changes focus on more likely causes of PEA arrest.
  • The proposed changes provides a framework to work from.

As a result, the authors proposed the following algorithm to diagnose and manage the most common underlying etiologies of PEA arrest.



Photo courtesy Adelaide Emergency Physicians


The authors felt that their simplified and structured approach offered additional advantages over the current ACLS teachings in three main ways:

  1. Organized approach using EKG telemetry to differentiate between narrow complex (mechanical cause) vs. wide complex (Metabolic cause) PEA.
  1. The structured approach reduces the number of possible diagnosis for either wide or narrow QRS morphology.


Wide complex

A wide complex morphology in PEA arrest is likely to be hyperkalemia or sodium channel blocker toxicity.


Narrow complex

Whereas a narrow complex EKG are more likely to be due to PE, cardiac tamponade, tension pneumothorax or hyperinflation. In addition, with narrow complex morphology in PEA arrest, the use of ED ultrasound is likely to further identify the underlying cause.


  1. The algorithm provides specific treatment recommendations depending on the initial QRS morphology.
  1. Wide complex
    1. In the case of a wide complex (metabolic cause) PEA arrest the recommendations suggest IV calcium chloride and sodium bicarbonate depending if the clinical picture is hyperkalemia or sodium channel blockers overdose.
  1. Narrow complex
    1. In the case of narrow complex (mechanical cause) PEA arrest the recommendation suggest fluids wide open and using additional ultrasound to help determine if pericardiocentesis, needle decompression, thrombolysis or ventilator management is needed.

Critical Appraisal:


  • A comprehensive review of current ACLS PEA arrest guidelines
  • Common sense approach to PEA arrest


  • Recommendation only – not a study
  • No data to suggest improved outcomes etc.
  • Difficult to conduct future RCT to determine effect.


Journal Club Discussion:

There were a number of strengths and weaknesses that came out of the group discussion:


  • The recommendations were based on solid review of the current literature/guidelines and most liked the idea of a structured approach to PEA arrest.
  • The recommendations focused on the most likely causes of PEA arrest and removed ancillary causes that would appear obvious during assessment (eg. Hypothermia, hypoxia). The group agreed that this provided for a more manageable list to remember as well as a framework for treatment.
  • The addition of mechanical hyperinflation as a cause was uniformly agreed as a strong point of the recommendations.
  • The additional use of ultrasound was seen as a good step forward in helping to better identify underlying etiology of the PEA arrest.


  • The absence of trauma, hypokalemia, hypoglycemia, hypothermia, hypoxia and acidosis was a concern for some who felt that there can be subtle presentations that would go un-noticed.
  • Generalizable/Staff dependent – Requires ED physicians to be trained in use of ultrasound. (eg. rural areas etc.)


Overall, most journal club participants agreed that the framework was a good idea and helped with recall of important etiology; however, most did say that it would not substantially change their practice as they already use the current model without difficulty or use a modified version of the proposed recommendations.

For more reading on PEA, and whether it actually exists, check out the EDECMO podcast episode #13, here.





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Empiric antibiotics after cardiac arrest?

The July 2014 EM:RAP Paper Chase reviewed a paper claiming 38% of OHCA (Out of Hospital Cardiac Arrest) patients are bacteremic, and thus we should routinely give antibiotics to post-arrest patients.

We reviewed this paper at the Calgary Journal Club recently and unfortunately, the authors conclusions are more leap of faith than anything else.

This single center, prospective observational trial enrolled a convenience sample of 250 OHCA patients, 77 were excluded and 173 were analyzed.   Anaerobic and aerobic blood cultures were taken at the time of arrest.

65/173 (38%) of cultures were positive, and ED survival was lower in the bacteremic vs. non bacteremic group (25% vs. 40%, p<0.042).  Sounds great until you see there are no differences between groups for length of stay, overall and 28 day mortality (p>0.05).

When critically appraising the article, we find the following.

  • Pros:
    • Prospective, observational study that may become the pilot for further study into bacteremia and OHCA
  • Cons:
    • Single centered
    • Study was not designed to determine the infectious causality of cardiac arrest or factors influencing ROSC
    • Randomly drawn blood cultures, true prevalence of bacteremia is not known
  • Discussion Points – AKA Concerns
    • The results of this study were not generalizable to our population (or most) given that the study was conducted in an inner city hospital in Detroit with an 85% African American population.
    • The definition of bacteremia in the study:
      • It was unclear how many blood cultures were drawn in total
      • There was an unknown timeline of blood culture growth – with late cultures more likely representing a contaminant
      • Their definition led to a huge sensitivity but a low specificity
      • The species distribution heavily favoured skin flora. And some of those species are not pathologic invasive species (eg. S. epidermidis)
    • The question of whether the OHCA caused the bacteremia vs. the bacteremia causing the cardiac cannot be answered based on this paper. It is likely that a large proportion of the bacteremic patients were contaminants. It is also likely that sicker patients received more lines, another potential for skewing these patients towards bacteremia.
    • It was discussed that 69% of bacteremic patients vs only 30% of non-bacteremic OHCA ED survivors received empiric antibiotics. It was thought that this suggests that ED staff are able to identify something different about these patients from the presentation leading them to suspect sepsis. It would have been a nice question to ask the ED staff the question: “What was your working diagnosis?” to see if sepsis was suspected at a time after antibiotic administration.

To summarize, the study results dont’ support the author’s conclusions. The authors speculate on potential causation based on weak data. They cannot imply causation based on this study. We agree with the authors that more study is needed to determine temporal causation regarding bacteremia and cardiac arrest.

It was universally decided that this paper would not change our practice overall and that bacteremia in OHCA is an interesting idea, more investigation is needed. Also, we should really be vigilant for inciting infectious causes of OHCA and initiating antibiotics early when infection is suspected.



Coba et al. The Incidence and Significance of Bacteremia in Out of Hospital Cardiac Arrest. Resuscitation 2014.

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Pericarditis: Treatment and Diagnosis Pocket Card


Hi all,

This post contains a pocket card for the evidence based diagnosis and treatment of pericarditis as of 2014.  This came up after a recent U of C EM Journal Club in which the residents commented that there was just too much to remember with regard to the use of colchicine, it’s dosing, contraindications, etc. when treating pericarditis on shift.

You can take a look at my post reviewing the evidence on colchicine for pericarditis over at REBEL:EM, as well as the recent Calgary journal club review of Imazio’s ICAP paper, here.

This card will serve as a quick resource which you can put into your evernote or download onto your phone as a pdf file for on shift use.

Disclaimer: Everything here is evidence based, but the dosing of NSAID or ASA has not been compared/optimized in studies.  The listed dosing regimens are my own suggested ones, but feel free to modify as you see fit.


Screen shot 2015-01-17 at 4.43.50 PM

To download a PDF version of the pocket card,  click here.







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Pericarditis and Myocarditis (Calgary EM Journal Club)


The December journal club reviewed two papers, first up was Imazio’s paper investigating the benefits of treating pericarditis with colchicine.  You should definitely know this paper and be implementing it into practice. This is a must read.

The second paper was a retrospective review looking at the presenting symptoms and labwork abnormalities in pediatric myocarditis.

Paper #1

Imazio et al. A Randomized Trial of Colchicine for Acute Pericarditis NEJM 2013


  • Multicenter, double-blind randomized trail
  • 240 patients, 120 per study group


  • Colchicine at a dose of 0.5mg BID for 3 months for pts weighing > 70kg or 0.5 mg once daily for patients weighing <= 70 kg, vs placebo.
  • Each participant also took a tapering dose of conventional anti-inflammatory therapy with aspirin, Ibuprofen, or corticosteroid.
  • PPIs were also prescribed for GI prophylaxis


  • 18 years of age or older
  • First episode of pericarditis
  • Etiology either idiopathic, viral, after cardiac injury, or associated with connective tissues disease
  • Acute pericarditis was diagnosed with 2 of the following:
    • Typical chest pain (sharp and pleuritic, improved by sitting up and leaning forward), or pain radiating to trapezius ridge.
    • A pericardial friction rub
    • Suggestive changes on ECG (widespread ST segment elevation or PR depression)
    • New or worsening pericardial effusion


  • Tuberculous, neoplastic, or purulent pericarditis
  • Evidence of myopericarditis as indicated by elevation in serum troponin levels. This has become controversial with the new use of high sensitivity trops.
  • Severe liver disease or current aminotransferase levels of more than 1.5 times the upper limit of the normal range
  • Serum creatinine level of more than 221 umol/L
  • Skeletal myopathy or a serum CK level above upper limit of the normal range
  • Blood dyscrasia
  • Inflammatory bowel disease
  • Hypersensitivity to Colchicine or CI to it’s use
  • Current treatment with Colchicine
  • Life expectancy of < 18 months
  • Pregnant, lactating women, or women of childbearing potential who were not protected by contraception


Outcome measure(s):


  • Incessant or recurrent pericarditis


  • Symptom persistence at 72 hours
  • Remission within 1 week
  • Number of recurrences
  • The time to the first recurrence
  • Disease-related hospitalization
  • Cardiac tamponade
  • Constrictive pericarditis



  • Incessant or recurrent pericarditis occurred in 20 patients (16.7%) in the colchicine group, and 45 patients (37.5%) in the placebo group
  • Relative risk reduction in the colchicine group of 0.56; 95% CI
  • NNT to prevent on case of incessant or recurrent pericarditis was 4


  • Reduced frequency of symptom persistence at 72 hours (19.2% vs 40.0%, P=0.001)
  • Reduced number of recurrences per patient (0.21 vs 0.52, P=0.001)
  • Reduced rate of hospitalization related to pericarditis (5.0% vs 14.2%, P=0.02)
  • Improved rate of remission within 1 week (85% vs 58.3%, P< 0.001)
  • Prolonged time to first recurrence (24.7 weeks vs 17.7 weeks, P <0.001)
  • No significant difference in the incidence of adverse events (9.2% vs 8.3% for GI side effects)
  • Multivariable analysis showed independent risk factors for recurrence were the use of glucocorticoids (OR 4.17,95% CI, 1.28 to 13.53; P=0.02) and CRP elevation at presentation (OR 3.15; 95% CI, 1.05 to 9.49; P=0.04)


  • In patients with acute pericarditis, colchicine, when added to conventional anti-inflammatory therapy, significantly reduced the rate of incessant or recurrent pericarditis


Pros: This was a well designed, randomized, double-blind placebo controlled trial that was powered to find a clinically meaningful difference in a patient-centred outcome. The population studied was fairly representative of the patient population we will be seeing in the ED, and the follow-up interval was adequate, with excellent treatment adherence.

Cons: This study was not powered to detect differences in the more rare side effects that can be associated with colchicine, though it is not pragmatic to design such a trial. As there was no pre-planned subgroup analysis of patients who received the weight-adjusted lower dose versus those who received the conventional dose, and there is no evidence to suggest why a cut-off of 70kg was used, it is not accurate to state that low dose and conventional dose colchicine are equally efficacious, though it is biologically plausible and also supported by the results of the CORE and COPE trials.

Discussion Points: In light of the strong methodology of this trial, as well as multiple other favorable trials of colchicine in acute pericarditis (eg. CORP, COPE, recent Cochrane Review), using colchicine in first-episode, uncomplicated pericarditis patients will be considered by most staff. The trial used dosing regimens of 0.5-1.0mg daily based on patient weight; however, in Canada, colchicine is available as 0.6mg tablets, which would result in a 20% higher dose than that in the study. The clinical criteria used to define acute pericarditis in the trial are helpful to making the diagnosis of pericarditis in practice. Surprisingly, there was no increase in adverse GI side effects in the colchicine group.

Paper #2

Freedman et al. Pediatric Myocarditis: Emergency Department Clinical Findings and Diagnostic Evaluation Pediatrics 2007

OVERVIEW: This was a retrospective study aimed at describing the clinical presentations of pediatric patients with myocarditis– a very rare disease. This article was used to discuss how to critically appraise retrospective studies.


  • Retrospective chart review looking at patients from May 2000 to May 2006
  • Hospital for Sick Children in Toronto
  • 31 patients with Myocarditis (16 with biopsy proven/definite myocarditis, and 15 with probable myocarditis)
  • Charts were reviewed twice by single investigator, and two investigators independently classified patients exclusively into 1 of 5 presentations


  • 5 ED clinical presentations were defined:
    • Respiratory (rhinorrhea, cough, shortness of breath)
    • Gastrointestinal (nausea, vomiting, diarrhea, or abdominal pain)
    • Cardiac (chest pain or palpitations)
    • Hypoperfusion (lethargy, lightheadedness, dizziness, syncope, or seizure)
    • Kawasaki associated
  • CXR defined as abnormal and associated with myocarditis if cardiomegaly, pulmonary vascular congestion, or pleural effusion present
  • ECG defined as abnormal and associated with myocarditis if one of the following present: axis deviation, decreased ventricular voltages, ST segment or T wave abnormalities, atrial enlargement, ventricular enlargement, heart block, or an infarction pattern
  • Echocardiogram findings defined as consistent with myocarditis included increased ventricular end systolic or diastolic dimension, reduced shortening or ejection fractions, atrioventricular valve regurgitation, and regional wall motion abnormalities
  • Lab tests used age appropriate normal values were used (troponins were not used)


  • All patients < 18 yrs of age
  • Diagnosed at Hospital for Sick Children as having myocarditis between May 2000 and May 2006
  • Initial presentation was to an emergency department (either Hospital for Sick Children or transferred from another institution) or if the child underwent autopsy at Hospital for Sick Children and had a diagnosis of myocarditis
  • Initial presentation with myocarditis
  • Either having definite myocarditis (biopsy proven) or probable myocarditis (diagnosis assigned by pediatric cardiologist on basis of history, physical examination, and investigation results in the absence of an endomyocardial biopsy or in presence of negative biopsy results)


  • No ED visit
  • Patients who did not meet the definitions of definite or probably myocarditis
  • Inadequate documentation of initial presentation
  • Discharge diagnosis other than myocarditis


Outcome measure(s):


  • Relative frequency of ED presenting symptom complexes in children with myocarditis


  • Sensitivity of clinical exam findings, laboratory investigations, chest radiographs, ECGs, and echocardiograms in diagnosis myocarditis



  • The most common presenting symptoms at the time of ED presentation relate to the respiratory system
  • These are age related and patients > 10 years of age present predominantly with chest pain, and < 10 with respiratory symptoms. Overall more presented with respiratory symptoms


  • Sensitivity of clinical exam findings: most common physical exam feature was respiratory distress (68%), followed by tachycardia (18%)
  • Sensitivity of laboratory investigations: AST level is most sensitive marker for myocarditis with an elevated value in 85% (including 1 child who had normal ECG and CXR
  • Sensitivity of CXR: 55% sensitivity with cardiomegaly being most common abnormality (42%), followed by pulmonary venous congestion (32%)
  • Sensitivity of ECGs: 93% of cases, with ST or T wave abnormalities being the most common (67%), and Axis deviation second with 37%
    • 97% of children with either ECG or CXR done had an abnormality on one test
  • Sensitivity of echocardiograms: 87% had abnormalities consistent with myocarditis with myocardial dysfunction detected more frequently among those with definite myocarditis


  • Pediatric myocarditis presents primarily with respiratory and cardiac complaints
  • Maintain a high index of suspicion for myocarditis even in absence of clinical findings of CHF
  • When adequate clinical suspicion exists, screening tests should include CXR and ECGs
  • Evidence of elevated liver enzyme levels should raise additional concern regarding myocarditis in the appropriate clinical scenario


Pros: Given how rare the diagnosis of myocarditis is (0.5/10000), the retrospective design of this trial was very appropriate. Moreover, the authors strengthened the quality of their chart review and limited potential bias as best possible by clearly defining variables a priori, drawing on multiple databases for patients to include, describing how missing or conflicting variables were dealt with, and using a third reviewer to clarify discrepancies in coding of the primary outcome.

Cons: Given that the lab tests and other investigations in the study were not necessarily applied to the entire population, a true sensitivity cannot be calculated based on the results.

Discussion Points: This article was used as an example to discuss how retrospective studies can be methodologically strengthened. Troponins were not checked routinely in this patient population. Key clinical take-homes include: the overall very low incidence of myocarditis, the biphasic age distribution, and that young children tend to present with respiratory symptoms, while older children tend to present with cardiac symptoms.

Thanks to Anjali Pandya (PGY-3 FRCPC EM program) and Tasha Haiduk (CCFP-EM resident) as well as Shawn Dowling for the journal club appraisals.



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Problems with the Alvarado and Pediatric Appendicitis Scores (Calgary EM Journal Club)


In part 1 of this journal club, we reviewed the utility of a clinical decision rule for the inconclusive ultrasound in appendicitis.  Today we look at a meta-analysis of the Alvarado and Pediatric Appendicitis Score (PAS).

Onto the article.

Ann Emerg Med. 2014 Oct;64(4):365-372.e2. doi: 10.1016/j.annemergmed.2014.02.025. Epub 2014 Apr 14.

What are the most clinically useful cutoffs for the Alvarado and Pediatric Appendicitis Scores? A systematic review.

Ebell MH1Shinholser J2.


This systematic review included articles from a PubMed search and a search of reference lists of previous systematic reviews. Only prospective studies were included. Likelihood ratios were calculated for each of low, moderate and high-risk score groups for each score from the set of articles.

Total number of articles included for analysis: 26, with n = 3193 in adult studies and n = 4776 in pediatric studies.

The outcome measure was likelihood ratios calculated for various levels of Alvarado and PAS score cutoffs, deemed low (<4), moderate (5-7) and high-risk scores (>7) at various levels of pre-test probability for appendicitis.

The results of this systematic review found that in adults with a pre-test probability of >60%, and Alvarado score >7 suggests a very high likelihood (>85%) of appendicitis, while a pre-test probability of <50%, with an Alvarado score <4 suggests a very low likelihood of appendicitis (<3%).

In children with a pre-test probability of appendicitis >60%, an Alvarado score <4 suggests a very low likelihood of appendicitis (<3%), while a pre-test probability of >50% with an Alvarado score of >7 suggests a very high likelihood of appendicitis (>85%). The Pediatric Appendicitis Score was not as predictable at various pre-test probabilities for rule-out or rule-in of appendicitis.


Critical appraisal and journal club consensus:

The literature search in this systematic review was incomplete, searching only one database for full-text articles, whereas a more comprehensive strategy would have searched the grey literature (published abstracts, conference abstract presentations) and there should have been a more systematic approach to searching the reference lists of published reviews. Furthermore, there were many non-English articles included and there is risk of misinterpretation of results in all of these articles. Articles included had a high degree of heterogeneity of results and should not have been pooled for analysis.

While the overall objectives of the review aim to identify clinical score cutoffs that reliably predict important clinical outcomes (i.e. >85% likelihood of appendicitis and <3% likelihood appendicitis), their results may not be easily applied to ED patient care. The results are presented in an algorithm of estimation of pre-test probability combined with either Alvarado Score or Pediatric Appendicitis Score to lead to “rule-out” or “rule-in” decisions. Estimating pre-test probability is often not so straightforward in EM practice. Estimating pre-test probability is often not so straightforward in EM practice. Additionally, we are not simply “ruling-in” appendicitis at a >85% likelihood threshold and sending patients off to surgery, as the article suggests may be done, as this would result in an unacceptable 15% negative laparotomy rateThis study does not address imaging for appendicitis as an adjunct to clinical evaluation for appendicitis, as is the common practice in the ED.

Discussion at journal club emphasized that “pre-test probability” is a difficult to quantify value, and many clinicians will rely on clinical gestalt and components of the Alvarado (+/- Pediatric Appendicitis Score) when determining pre-test probability. It follows that if forming a pre-test probability of appendicitis based on components of the scoring systems, continuing on to use the same scoring system to reach a different post-test probability is not logical or clinically sound. Furthermore, the findings rely heavily on a structured clinical scoring system to “rule out” appendicitis, which is a clinical condition that can present atypically as often as it presents typically.

Thanks to Kathryn Crowder (CCFP-EM resident) and Shawn Dowling for this summary.




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