Multiple learning points ECG

Sad outcome but great learning points all round from Dr Amal Mattu. Interesting concept about HIV being a cardiac risk factor - will add that to my list and watch out for it in the future for sure.




For more of his vids or older cases, go to www.ekg.umem.org

Parachuting loaded mice

Now who would have thought that panadol could kill snakes!?! No need for bags of sulphur then... kidding.

Here's a fantastic story from the chaps at Poison Review:

Parachuting loaded mice!

The danger of science denial

Something different but we all need a rallying call every now and then against the forces of ignorance.
This is a talk from TEDed - the education aspect of the superb TED talks series. He is not a doctor but he puts across his well thought out medical argument very well. The highlight for me was "Big Placebo".





Maybe one day we will have critical mass to get us to the next phase of planetary evolution. Meanwhile, educate away.

Now that's wicked...

It's not everyday one learns new things but I quickly learnt several new things all at once. Just by reading and listening to the fabulous recent podcast by emcrit.org boss Scott Weingart talking about Tacit Knowledge and Medical Podcasting.

"What the heck is Tacit Knowledge?" - I sure didn't know. A quick read on Wikipedia filled me in on that. Thank's Scott. That really defines the beauty of medical knowledge sharing on the level of podcasting and online media. This is exemplified by my recent encounter with a traumatic cardiac arrest from stab wounds. We quickly performed bilateral finger thoracotomies as part of the resuscitative efforts, though unfortunately the patient did not survive. Since it was a trauma code, I was asked later, "What the heck is a finger thoracostomy?". I sure didn't know before, but now I do.  Thanks again, Scott. 

Now what's really wicked... is of course wicked problems. What the heck is that? Not as evil or as far-fetched as the dark side of the moon you'd think. But they are tough problems so far as to solutions or even mere notion of thinking about it in the first place. Apparently, it takes a wicked problem to conceptualise and define a wicked problem.

From Wikipedia, wicked problems are also characterised by the following:
  1. The solution depends on how the problem is framed and vice-versa (i.e. the problem definition depends on the solution)
  2. Stakeholders have radically different world views and different frames for understanding the problem.
  3. The constraints that the problem is subject to and the resources needed to solve it change over time.
  4. The problem is never solved definitively.

What comes to mind immediately is the problem of  ED overcrowding and access block. Now that's super wicked... 



ECG OTW 25th Feb

Great ECG over at John Larkin's site.
Test yourself and against others.

De - telescoping

This is one of those rare life threatening emergencies in children in which diagnosis and management is time critical. Also, rarely, the treatment is not surgical and here is a great video by Prof Larry Mellick on air/barium insufflation of an intussusception for those who have never seen one.




More of his videos here.

Remember that:

  • most present in first 3 months of life
  • intermittent abdo pain is most common symptom
  • red currant jelly and vomiting with abdo pain is only 25% of time
  • examination while crying is of limited value
Ref: An Evidence-Based, Systematic Approach ToAcute, Unexplained,Excessive Crying In Infants. EMpractice.net

Gel > radiation

This should put some finality on the subject. Don't know why there are still some doubters but maybe its the lack of use from other specialities. As in most things, education will set your free!



So lap on the gel and reduce the rad exposure on your patients.
Thanks to SCANCRIT.COM for the update and image.

How to get "fed"

Modern information streams are a whole lot different from 20 or even 10 years ago. In my opinion, we've entered a new improved age of info dissemination. If you are a trainee or simply are busy, RSS feeds are for you. You don't want to be chasing around for info but let it come to you.
A lot of people (medical personnel) have been asking about "feeds" and such. Here's something I drew up to get you guys started:

RSS feeds
Have placed a permanent link on the side tab to the right as well.
As always, feel free to comment or suggest if you have better ways for my readers.

Bugs below

This is a great run down by Dr Rob Orman of ERCAST on infections and abscesses of the not so palatable kind.
An essential talk on a much ignored topic.
Also interesting the evidence on antibiotics near the end.

A-primer-on-butt-pus

The Line is Elegant, but NOT Fail Safe.

Assessing if a patient with acute paracetamol exposure with the Rumack-Matthew nomogram is probably one of the better prediction tool in medicine, but it is not fail safe. As this retrospective study remind us, it can sometime fail to predict late rise in serum paracetamol level crossing into toxic zone, especially when the paracetamol is in mixed formulation with other drugs. Even acute exposure to paracetamol alone sometimes show late rise.

So what are we to do??? Well, my best guess will be, if there is a large ingestion especially in mixed formulation, or when the serum level is really just below the line, we may want to check another level a few hours later.

As far as I know, there is no study to inform if this strategy will make a difference in patient outcome, so no one really knows. Maybe someone wiser have a better plan. Till we know, be mindful...

***
Dougherty PP, et al. Unexpected late rise in plasma acetaminophen concentrations with change in risk stratification in acute acetaminophen overdoses. J Emerg Med. 2012 Jul;43(1):58-63. Epub 2011 Jun 29.

http://www.ncbi.nlm.nih.gov/m/pubmed/21719230/

3 minute cardio

Got to credit this cardiologist for this really innovative teaching technique. Awesome moniker for an awesome idea.

3 minute cardio round

Also thanks to LITFL for introducing his site.

Spare the kids

A little reminder to not over expose our young ones to unnecessary radiation. if clinical presentation and signs point toward a foreign body, attempt proper visualisation says this study:

Additional views do not help.

Stroke, Thrombolysis, NIHSS .....

We've recently had a Great Thrombolysis Debate in our ED.

But would like to summarise (I've cut and pasted the rev bits) what I read in sev EM papers some time back on some controversial area together with the references below:

A.  Acute Stroke, Neuroimaging, and Thrombolysis

    MRI is at least equal in efficacy to CT for detection of ICH in the hyperacute stroke patient, and both appear to have very high sensitivity and specificity. MRI is superior to CT for demonstration of subacute and chronic hemorrhage and hemorrhagic transformation of an acute ischemic stroke.

    MR-DWI (diffusion weighted imaging MR) is far superior to unenhanced CT and routine MRI in the detection of acute ischemia, with very high sensitivity and specificity. For a patient within 3 hours of symptom onset, MRI can be used if it does not unduly delay the timely administration of IV tPA since a more definitive diagnosis will be obtained with MR-DWI and it is far more effective than CT for excluding some mimics of acute cerebral ischemia.

    For patients beyond 3 hours from onset of symptoms, either MR-DWI or CTA should be performed, especially if mechanical thrombectomy or intra-arterial thrombolytic therapy is contemplated.

    Frank hypointensity on CT, particularly if it involves more than one third of an MCA territory, is a strong contraindication to treatment with thrombolysis. Early signs of infarct on CT, regardless of their extent, are not a contraindication to treatment.

    Gradient-echo MR can detect microhemorrhage, both old and new, better than CT, indicating the presence of amyloid angiopathy, hypertension, small vascular malformations, and other vascular diseases. The presence of a small number of these microhemorrhages (< 5) does not contraindicate intravenous thrombolysis.

Reference: Latchaw RE,et al. Recommendations for imaging of acute ischemic stroke: a scientific statement from the American Heart Association Stroke 2009;40(11):3646-78.




B.  Stroke Thrombolysis: Unique Exclusion Criteria for the 3 - 4.5 Hour Window

Exclusion criteria unique to the 3 -4.5 hour window:

    Age > 80 years
    History of prior stroke AND diabetes
    Oral anticoagulant treatment prior to admission (even if INR <1.7)
    Severe stroke: NIHSS >25
    CT findings involving stroke > 1/3 of the MCA territory

References:
(1) Carpenter CR, et al. Thrombolytic Therapy for Acute Ischemic Stroke beyond Three Hours J Emerg Med 2010 Jun 23. [Epub ahead of print]
(2) Wahlgren N, et al. Thrombolysis with alteplase 3-4.5 h after acute ischaemic stroke (SITS-ISTR): an observational study Lancet 2008;372:1303–1309.
(3) Hacke W, et al. Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke N Engl J Med 2008;359:1317–1329.
(4) Massachusetts General Hospital Stroke Service Protocols: http://www2.massgeneral.org/stopstroke/PostIVtPA345window2.aspx

C.  Early CT Signs of Ischemic Stroke

The NINDS Study found a 31% sensitivity for early signs of ischemic stroke on noncontrast CT within 3 hours of symptom onset. The rate of detection increased to 82% at 6 hours (1).

Early signs of cerebral ischemia on CT:

    Hypoattenuation of brain tissue - with ischemia, cytotoxic edema develops resulting in increased brain water content. There is a loss of gray-white differentiation because of the increase in the relative water concentration within the ischemic tissues.

    With edema, swelling of the gyri produces sulcal effacement, which may lead to ventricular compression.

    Hyperdense MCA sign - a result of thrombus or embolus in the MCA.

    Obscuration of the lentiform nucleus (also called blurred basal ganglia) is seen in MCA infarction and is one of the most frequently seen signs.

    Insular Ribbon sign refers to hypodensity and swelling of the insular cortex (the center of the cerebral cortex deep between the temporal lobe and the frontal lobe).

The sooner these signs become evident, the more profound is the degree of ischemia (1,2). Typically, at 6-12 hours sufficient edema is recruited into the stroke area to produce significant regional hypodensity on CT; a large hypodense area present within 3 hours of reported symptom onset should prompt careful review regarding the time of stroke symptom onset.

There is controversy as to whether early signs of infarct on CT are a contraindication to thrombolysis. The presence of CT evidence of infarction early in presentation has been associated with poor outcome and increased propensity for hemorrhagic transformation after thrombolytics in some studies (3,4).  In the NINDS trial, there was no interaction between early infarction signs and tPA treatment for any clinical outcomes. Currently early signs of ischemia on CT are not generally considered to be a contraindication to use of tPA.  However, "frank hypointensity" on CT, particularly if it involves more than one third of an MCA territory, is a strong contraindication to treatment (1).

References:
(1 ) Latchaw et al.  Recommendations for imaging acute ischemic stroke:  A scientific statement from the American Heart Association  Stroke 2009;40:3646-78.
(2) Patel SC, et al. National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Lack of clinical significance of early ischemic changes on computed tomography in acute stroke JAMA. 2001;286: 2830–2838.
(3) von Kummer R, et al. Acute stroke: usefulness of early CT findings before thrombolytic therapy Radiology 1997;205(2):327-33.
(4) Dzialowski I, et al. Extent of early ischemic changes on computed tomography (CT) before thrombolysis: prognostic value of the Alberta Stroke Program Early CT Score in ECASS II Stroke 2006;37(4):973-8.

D.  Acute Stroke with NIHSS Score of 0

Physicians rely on the National Institutes of Health Stroke Scale (NIHSS) to evaluate patients with suspected acute stroke and to make decisions about acute treatment. The NIHSS correlates with infarct size, clinical severity, and long-term outcome. It is important to recognize, however, that ischemic stroke may cause symptoms that are not captured by the NIHSS scale.

The NIHSS scale is highly weighted toward deficits caused by anterior circulation strokes, whereas deficits caused by posterior circulation strokes receive fewer points (1-3). Within the anterior circulation, the scale underestimates the degree of right versus left hemisphere injury (1,4). It is possible that some patients with persistent symptoms on arrival to ED and an NIHSS score of 0 still have an infarct (1).

In a recent study, stroke patients with an NIHSS score of 0 most commonly presented with nausea, vomiting, and headache, all of which are associated with posterior circulation ischemia (1). Midline lesions of the cerebellum cause truncal ataxia, which is not part of the NIHSS. In addition, decreased visual acuity, Horner's syndrome, and memory impairments are neurologic deficits not captured by the NIHSS. Subtle limb weakness (4/5) in an upper motor neuron pattern (extensors of the arms or flexors of the legs) may not be observed on the motor component of the NIHSS.

These data reinforce that the NIHSS cannot replace history and a thorough neurologic exam to diagnose acute stroke and that the NIHSS alone cannot be used to rule out a stroke in patients with acute persistent symptoms.

References:
(1) Martin-Schild S, et al. Zero on the NIHSS Does Not Equal the Absence of Stroke Ann Emerg Med 2011 Jan;57(1):42-5.
(2) Libman RB, et al. Differences between anterior and posterior circulation stroke in TOAST Cerebrovasc Dis 2001;11:311-316.
(3) Sato S, et al. Baseline NIH stroke scale score predicting outcome in anterior and posterior circulation strokes Neurology 2008;70:2371-2377.
(4) Fink JN, et al. Is the association of National Institutes of Health Stroke Scale scores and acute magnetic resonance imaging stroke volume equal for patients with right- and left-hemisphere ischemic stroke? Stroke 2002;33:954-958.



The Case of the Mysterious Rash

A 58 year old Chinese Missionary without any chronic co-morbidity or drug allergies, presented to our ED with an intensely itchy rash to his feet and body after recent travel to Tanzania a week ago.
His vital signs were stable and there was no fever or constitutional upset.
Morphology of the rash on his foot, as per photograph shown below -




Q1. What is the diagnosis?
Q2. What is the causative agent?
Q3. What is the commonest presentation?
Q4. What is the management ?
Q5. How can it be prevented?

Toddler's and hobblers

Paeds Morsels has come up with another timely reminder that Toddler's #s are often sidelined with the dreaded "Strain" phrase.

Things too look out for in this great rundown include:

  • Up to 43% of them have normal films
  • Pain on dorsiflexion is a sensitive sign
  • Cast it if in doubt and all other possibilities excluded
  • Don't forget other causes of a limping child
  • Kids' bones are more fragile than their ligaments

So treat 'em good and treat 'em right!

tPA in wonderland

The last few years have been a whirlwind for lytics in stroke.

What started out as the promised land has morphed into a veritable amazon forest. Whilst most agree with the basics and principles of it but the results have been far from convincing. Throw in some "fudgy" trial results with drug company sponsors and there is no wonder you have a growing skeptical audience.

There are trials and studies abound in every country but I personally don't push the "snake venom" to patients who are older than 80. Most of my learned colleagues on this site and I think of reasons NOT to give tPA rather than to give. Our take:

  • Talk to your patients
  • Talk to your patients' families
  • They ned to to know NNH as well as NNT
  • Show them simple diagrams to understand the above sentence like this one

Here's a fantastic PREZI look into the history of the relevant research:

Drgdhs-adventures-in-wonderland

Teaching in the Toilet

Great intellectual things you can do in the toilet. Teach staff how to take blood sample properly. And it works!!

Testing the effects of educational toilet posters: a novel way of reducing haemolysis of blood samples within ED. Corkill, D. Australas Emerg Nurs J, 2012 vol. 15(1) pp. 31-6.

But you probably need to design your poster properly, and there is no information on where is most effective - behind the cubicle door, in front of the urinals, or on the mirror... go figure

Good ol' H2O

Its amazing that even water has to prove itself nowadays but the purists among you will like this one. According to this BMJ article about irrigating wounds, it asks "why use salty when tap does the job fine?"

Water is ok

Thanks to EM Lit of Note for highlighting this article

Should you really crank up the resp rate?

Here's an interesting argument which is researched and backed up by the folks at emeducation.

Hyperventilation in TBI?

Is it just a myth that has been compounded all along?
Just another example of "tradition" based medicine?
Certainly what we teach our residents is to target the CO2 to the lower limit of normal (ie 35mmHg).