Mythbuster: Pediatric coin ingestion vs aspiration?

Is this coin in the esophagus or the trachea?

The classic teaching for the Boards exam is:

• Esophageal coins appear in the coronal plane, as shown above.
• Tracheal coins appear in the sagittal plane because of the cartilaginous tracheal rings.

Mythbuster: 
A case series of 8 pediatric patients were documented with coins positioned in a sagittal plane were actually in the esophagus! This data was collected over 15 years.

• Age range 3-17 years old
• Location of coin: 7/8 at level of aortic notch and 1/8 at distal esophagus 

The classic teaching likely still holds true most of the time (sagittal coin = tracheal foreign body), but don't rush to immediate judgment. Take a look at the lateral view, and see where the coin is located with respect to the trachea and airway. It may be more posterior, in which case, it's in the esophagus.

Thanks to Dr. Matt Anderson (Resident at Univ. of Wisconsin EM program) for the tip!


Reference

Schlesinger AE, Crowe JE. Sagittal orientation of ingested coins in the esophagus in children. AJR Am J Roentgenol. 2011 Mar;196(3):670-2. Pubmed .

Trick of the Trade: Safer guidewire disposal

Have you ever accidentally flicked a drop of blood while disposing a straight guidewire into a rectangular sharps bin? The bins just don't quite fit the wire easily. That's just an occupational exposure just waiting to happen to yourself.

Trick of the Trade:
Wrap guidewire around knuckles and dispose in reversed glove



Thanks to Dr. Rob Bryant (Utah Emergency Physicians) for the tip!

Tweet Pearls of the Week 9/14 to 9/21

Because a good tweet is a terrible thing to waste!

Paucis Verbis: Electrolytes and ECG changes

Image from Life in the Fast Lane

The electrocardiogram can pick up all sorts of electrolyte abnormalities. The most common abnormalities revolve around high and low levels of potassium and calcium. Magnesium derangements typically have nonspecific findings. How do you keep things straight? To make things more complicated, multiple electrolyte derangements can occur at the same time, making ECG interpretation challenging.

Thanks to Dr. Steve Field (Resident at Resurrection EM program) for the idea and card. Also take a look at Life In the Fast Lane's extensive review of ECG abnormalities and their causes.

Feel free to download this card and print on a 4'' x 6'' index card.

[MS Word] [PDF]

See other Paucis Verbis cards.

Reference
Diercks DB, Shumaik GM, Harrigan RA, Brady WJ, Chan TC. Electrocardiographic manifestations: electrolyte abnormalities. J Emerg Med. 2004 Aug;27(2):153-60. Pubmed .

Creating a personal learning environment

What is digital curation?

It is the selection, preservation, maintenance, collection and archiving of digital assets (1). Once you have curated the digital content you might want to share with others. There are different ways of sharing this content:

• Sending out the link
• Retweeting on Twitter
• “Like” on Facebook
• “1+” on Google+
• Many others

You might also want to share your reflection of digital content. This is where this guide might help you. A personalized learning network or environment (PLN or PLE) is created when you have curated digital information and shared your reflection with others.  You are collaborating when you interact with other people's posts, podcasts, or images.

Pick a topic or resource, such as an online blog, podcast, tweet, image, post on Facebook or Google+ that interests you. The source needs to be reputable and up to date. (Five criteria for evaluating Web pages).

Find an outlet. This is where you are going to write your reflection. These outlets may be set up as public (others can see your content) or private (only those with granted access can see your content). Some of these outlets may be set up where others can submit their comments for discussion. This feature may also be disabled if it is not desired. Here are a few social media outlets:

• Blogs
• Podcasts
• Websites
• Google Documents
• Twitter
• Storify

What’s your reflection?

• What do you know about the subject (topic)?
• What do they present in the online material?
• What does the primary literature say?
• How does it compare/contrast to you current knowledge?
• How will this change your current knowledge?
• Can this be applied to a different scenario?
• Do you see any future controversies?

The point is to gather information to enrich your background knowledge, write your reflection, and have a discussion with others about it. A perfect example of a Personalized Learning Network in action is by a medical student, Lauren Westafer (@LWestafer) from her blog "The Short Coat".

Become a content curator in three steps (2):

• Do it on a specific topic, so that you are seen as a trusted source or expert on that topic.
• Share only the best stuff.
• Do it continuously so that you are continuously providing up-to-date content.

Here's an excellent 4-minute video on the concept of Personalized Learning Network by Will Richardson(3):

Some educators might be a bit skeptical about the use of technology in education due to their unfamiliarity with this integration. These are 5 tips to help educators see how useful these tools can be. 

Five Things Every Teacher Should Know (4) 

1. Technology integration is about more than TOOLS

• Use technology to create a community  

2. Tech tools come and go, so focus on mastering the FUNCTIONALITY to support 21st century learning goals: the 4Cs.

• Critical thinking and problem solving
• Communication
• Collaboration
• Creativity and innovation

3. CYCLE: Search, save, share

• If you don’t know, know how to find it.  

4. Technology integration requires you to embrace LEARNING

• Be a sponge, don’t let the “expert” label throw you off.  

5. Roll with it

• Be flexible when using technology

Explore, gather some information, compare it to what you know, and share your experience with others. 

Some examples of digital curators in emergency medicine:

• www.lifeinthefastlane.com - “...Dedicated to providing online emergency medicine and critical care insights and education for everyone, everywhere...”
• emcrit.org - An EM/critical care doctor who via a podcast explores ways to improve patient care.
• prehospitalmed.com - A doctor from Australia who discusses the improvement of prehospital medicine via a podcast by expressing his opinions on podcasts, blogs, scientific literature.
• www.emlitofnote.com - “Musings on publications and studies relevant to emergency medicine.” A blog run by an emergency physician who explores and gives his opinion on primary literature.
• www.sinaiem.org - A website run by Mount Sinai Emergency Medicine Residency, they explore and give their impression on online content.
• www.emchatter.com - “A link directory to for all things emergency medicine on the web”
• The short coat a blog by a medical student who explores online information and writes her reflections online.

Javier Benítez, MD

References:
1. http://en.wikipedia.org/wiki/Digital_curation
2.Content Curation for Online Education
3. Personal Learning Environments And Personal Learning Networks Symposium
4. Five Things Every Teacher Should Know

 image source: http://www.scoop.it/t/content-curation-for-online-students

Hot off the press: Academic EM journal abstracts in Spanish

La revista Academic Emergency Medicine ha creado una nueva función en su página web en la cual todos los  resúmenes de los articulos seran traducidos al espanol. Felicidades a AEM por ser la primera revista americana en emergenciologia y unas de las primeras en medicina general por tomar en cuenta a la población de idioma español.

Muchas gracias a la gerente Sandra Arjona por darnos tan grata noticia.

http://onlinelibrary.wiley.com/doi/10.1111/acem.2012.19.issue-9/issuetoc

Trick of the Trade: A flexible pediatric ear curette

Image from univatty.blogspot.com

Having you had trouble seeing a pediatric patient's tympanic membrane because of impacted cerumen? Scared from that last time you used a rigid curette and caused bleeding in the ear canal? The parents   are worried that you hit the brain...

Trick of the Trade:
Make a customized, softer, flexible curette using a polyester-tipped applicator

The thin polyester-tipped applicators have a malleable and relatively soft handle. Fold the applicator in half and twist the apposing edges into a single curette instrument. You can shape the curette to adjust the angle to your patient's ear canal anatomy and adherent cerumen chunks.

Thanks to Dr. Aaron Kornblith (chief resident at UCSF-SFGH EM program).

Tweet Pearls of the Week 9/7 to 9/14

Because a good tweet is a terrible thing to waste 

Paucis Verbis: EMTALA rules in the transfer of ED patients

In U.S. academic emergency departments, decisions to accept patients is typically easy, because you have ready access to on-call physicians. When in doubt, accept transfer patients and sort things out later.

• What are the obligations for those transferring patients to other EDs? 
• What do the EMTALA (a.k.a. "anti-dumping") rules say?
• When can you transfer unstable patients?

As a general rule, the liability falls upon the transferring site and physician. So be sure that your patient won't decompensate in the ambulance during transfer. So, don't transfer that CP patient who is getting ruled-out for an MI or ACS no matter how good they look. Patients need to be stable for transfer.

Anyone with pearls to share?

Thanks to @EMurgentologist for tweeting me the idea!

Feel free to download this card and print on a 4'' x 6'' index card.

[MS Word] [PDF]

See other Paucis Verbis cards.

Reference:

• AMA Ethics Resource Center powerpoint slides
• EMTALA site FAQ

Mini-guide to Twitter: Why should I join?

What is Twitter? 

It’s a social network where people can send messages of a maximum of 140 characters in real time. It was created in 2006, and it has grown tremendously ever since. When it was first created the messages, called tweets, were about what people were doing in real time. Nowadays people, or "tweeple" as they are called on Twitter, are tweeting about any subject in the world. 

Here's is detailed guide on how to use Twitter by Albert Einstein College of Medicine. Slide 35 is a 7:47 minute video where Dr. Chretien, an internist, is interviewed about the use of social media. 

Twitter and Medical Education: Information and Inspiration 

from Albert Einstein College of Medicine

If used appropriately Twitter can be a powerful tool for education using a platform that is FREE and already used by a whole virtual community of educators and learners.

Advantages of following people on Twitter: 

• Quick and succinct
• Connect and network with people in the same or different field of expertise
• Initiate a discussion
• Explore another way of learning
• Stay up to date
• Increasing number of "live-tweeters" at EM conferences, who report succinct pearls from the sessions
• Can be accessed anytime and anywhere (asynchronous learning)
• Can come back to the pearls and review them (by favoriting tweets)
• Share other people's great tweets to those who follow you (by re-tweeting)
• No need to reveal patient information to learn
• You can just lurk and learn

Examples of ways people are using Twitter in education:

• Tweet images and ask for the diagnosis
• Tweet pearls as factoids or question-answer format, using text, images, or even video
• Tweet links to videos of procedures and lectures
• Reply to your tweets with a link to a reference, podcast, or video

Disadvantages of using Twitter: 

• Limited information because only allows 140 characters
• Need to learn the Twitter vocabulary
• Need to learn how to abbreviate but still get your message across
• Need internet connection
• Need to learn a new technology
• Risk of violating HIPAA 
• Can be distracting: https://vimeo.com/39784948

Because tweets are a coming from a single source, the information may be biased, not current, or frankly wrong. Furthermore, many people use their account for both personal and work-related tweets. So choose who you follow carefully!

Below is a starter list of people to follow on Twitter (in no particular order), who use it primarily for medical education related to EM. You can start slow and just follow a few people at first.

@M_Lin	http://academiclifeinem.blogspot.com/
@amalmattu	http://ekgumem.tumblr.com/
@EMEducation	http://betterinem.blogspot.com/
@kane_guthrie	http://lifeinthefastlane.com/
@RadiologySigns	http://radiologysigns.tumblr.com/
@CriticalCareNow	http://www.ultrarounds.com/
@embasic	http://embasic.org/
@EMManchester	http://www.stemlynsblog.org/
@RegionsTrauma	http://regionstraumapro.com/
@PharmERToxGuy	http://academiclifeinem.blogspot.com/
@I_C_N	http://www.intensivecarenetwork.com/
@keepingupwithem	http://keepingup.vanderbiltem.com/
@poisonreview	http://www.thepoisonreview.com/
@SonoSpot	http://www.sonospot.com/
@ultrasoundpod	http://ultrasoundpodcast.com/
@sandnsurf	http://lifeinthefastlane.com/
@emcrit	http://www.emcrit.org
@precordialthump	http://lifeinthefastlane.com/
@rfdsdoc	http://prehospitalmed.com/
@emlitofnote	http://www.emlitofnote.com/
@broomedocs	http://broomedocs.com/
@Radiopaedia	http://radiopaedia.org/
@BobStuntz	http://www.emrespodcast.tumblr.com/

See great comments from earlier survey-based post about "why Twitter?".

Javier Benítez, MD

Image sources:
https://twitter.com/images/resources/twitter-bird-blue-on-white.png

Ref:
https://twitter.com/about

Top 10 tweets about medical education

Have you seen Javier Benítez's recent Storify slideshows of great tweet pearls about Free Open Access Meducation (FOAM) in Emergency Medicine?

• Aug 24-Aug 31, 2012
• Aug 31-Sept 7, 2012

In similar fashion, here are my favorite 10 tweets in the recent Twitter world about medical education.

Tricks of the Trade: Calcium gel for hydrofluoric acid burns

From AccessMedicine.com

A 41 y/o m presents to your ED after an occupational exposure to 30% hydrofluoric acid (HF). The thumb and index finger of his right hand were affected. Upon visual examination, the site of exposure looks relatively benign but the patient is complaining of extreme pain. Beyond giving opioids, what can you do?

Topical calcium gluconate is the treatment for minor to moderate cutaneous burns from HF.

It would be really nice if there were a commercially available calcium gluconate gel available. Wait, there is! But it's pretty expensive and most hospitals won't stock it. Generic versions of 2.5% calcium gluconate gel are also hard to come by.

Trick of the Trade:
Make your own calcium gluconate gel.

What you'll need:

1. Calcium carbonate tablets (Tums^®), calcium gluconate powder, or solution
2. A water-soluble jelly (K-Y Jelly^® works great)

How to prepare: Mix any of the following with 5 ounces of K-Y Jelly^®:

• 10 g of calcium carbonate tablets, or
• 3.5 g calcium gluconate powder, or 
• 25 mL of calcium gluconate 10% solution

How to administer:

1. Thoroughly irrigate the area with water. 
2. Apply your concoction directly to the affected area. 
3. The best trick is to add the gel into a surgical glove and have the patient wear it for at least 30 minutes.

Don't expect your gel to look like one you could sell for profit. I'm a pharmacist with training in compounding and it still comes out pretty ugly (especially with Tums^®).

Other routes of calcium administration for topical burns include intradermal, intravenous, and intraarterial. An IV Bier block technique using 25 mL of 2.5% calcium gluconate has also showed some success.

Disposition

All patients with digital exposures should be observed over 4-6 hours. The pain usually recurs and you may need to reapply the gel (or maybe even try an alternative therapy). Make sure your patient has good discharge instructions and has access to specialized followup and wound care.



References

Anderson WJ, Anderson JR. Hydrofluoric acid burns of the hand: mechanism of injury and treatment. J Hand Surg. 1988;13:52-7. [PMID: 3351229]

Chick LR, Borah G. Calcium carbonate gel therapy for hydrofluoric acid burns of the hand. Plastic Reconstr Surg. 1990;86:935-9. [PMID: 2236319]

Bracken WM, Cuppage F, McLaury RL, et al. Comparative effectiveness of topical treatments for hydrofluoric acid burns. J Occup Med. 1985;27:733-9. [PMID: 4067676]

Upfal M, Doyle C. Medical management of hydrofluoric acid exposure. J Occup Med. 1990;32:726-31. [PMID: 2401930]

Burkhart KK, Brent J, Kirk MA, et al. Comparison of topical magnesium and calcium treatment for dermal hydrofluoric acid burns. Ann Emerg Med. 1994;24:9-13. [PMID: 8010555]

Kirkpatrick JJ, Burd DAR. An algorithmic approach to the treatment of hydrofluoric acid burns. Burns. 1995;21:495-9. [PMID: 8540974]

Su M. Chapter 105. Hydrofluoric Acid and Fluorides. In: Su M, ed. Goldfrank's Toxicologic Emergencies. 9th ed. New York: McGraw-Hill; 2011.

Tweet Pearls of the Week 8/31 to 9/7/12

Because a good tweet is a terrible thing to waste!

Diagnostic tests: Asking the right questions

You have picked up the next chart and have drawn your differential diagnosis based on the patient's demographic, chief complaint, and vital signs.

Pattern Recognition vs Probabilistic Diagnostic Reasoning2:

Pattern Recognition See it and recognize disorder ⇓ Compare post-test probability with threshold (usually pattern recognition implies near 100% and so above threshold)

Probabilistic Diagnostic Reasoning Clinical assessment generates pretest probability ⇓ New information generates post-test probability (may be iterative) ⇓ Compare post-test probability with threshold

You can approach diagnosing diseases by using either of these two patterns or a combination of both. Keep in mind these two methods can also complement each other. Pattern recognition is more of an intuitive approach, often referred to as System 1 thinking. It is much faster, heuristic. Probabilistic diagnostic reasoning may be referred as System 2 thinking, meaning it’s slower, but more analytical and systematic.

After you draw your differential diagnosis and before seeing the patient, you have a pretest probability of the diagnosis that ails the patient. After you obtain a focused history and physical exam, you have gathered information that will help you draw a more accurate post-test probability and narrow your differential diagnosis. The essence of being a doctor does not lie on the tests, therapies, signs, or symptoms, but on how you use them. Every sign and every symptom represents a diagnostic test.

Understanding statistical terms helps us interpret diagnostic test results.

Sensitivity:

• SnOUT: If a test has a high sensitivity and the elicited test is negative, you have essentially ruled OUT the disease.  
• How accurately the test picks up patients WITH disease

Specificity:

• SpIN: If a test has a high specificity and the test is positive, you have essentially ruled IN the disease. 
• How accurately the test picks up patients WITHOUT disease 

As you can see there are limitations when applying sensitivity and specificity on patients since we don't know if the have the disease or not. Predictive values have their limitations as well, these change with prevalence. Therefore, a test used to detect disease in a population with high prevalence would not be adequate in a population with low prevalence. Keep in mind that tests should not be used to replace your clinical judgement.

Prevalence:

• This is your pretest probability, used before you go into the room to see the patient. 

Likelihood Ratio (LR):

• Compares results of patients with disease vs patients without disease
• More accurate than sensitivity and specificity
• Helps you derive the post-test probability
• Takes sensitivity and specificity into account simultaneously 
• When LR >1 it means the probability of disease increases 
• When LR <1 it means the probability of disease decreases 
• When LR = 1, the probability of disease is unchanged 
• Before ordering a test, eliciting a symptom, or finding a sign, ask yourself: How will the absence or presence of this factor change my post-test probability? 
• Use the Fagan Nomogram to determine post-test probability.

Does the post-test probability drawn after your assessment change your threshold?
When the post-test probability falls between test threshold and treatment threshold, further investigation needs to be done. If it lies above the testing threshold it is encouraged to treat, but if it falls below the testing threshold, it is encouraged to pursue a different diagnosis.

Diagnostic and Test Threshold 7

There are three aspects that determine test and treatment thresholds:2

1. Properties of the test
2. The disease prognosis
3. The nature of the treatment

Changing testing thresholds

If	Then
Test: safe and less expensive Disease: worse prognosis Treatment: safe and effective	The LOWER the test threshold
Test: not as safe, more expensive Disease: benign Treatment: not safe or effective	The HIGHER the test threshold

Changing treatment thresholds 

If	Then
Test: safe and less expensive Disease: benign prognosis Treatment: expensive and major adverse effects	The HIGHER the treatment threshold The characteristics require a higher diagnostic certainty so that we cause less harm from this treatment.
Test: less safe, more invasive than the treatment Disease: worse prognosis Treatment: safer than the test	The LOWER the treatment threshold The treatment may be more preferable than the test.

Four Lessons of Diagnostic Testing as per David Newman 4

1. All tests are imperfect 
2. Context trumps results 
3. All tests have a threshold 
4. Likelihood ratios have it all

These four axioms are important to keep in mind when navigating the diagnostic and therapeutic process in medicine. If used appropriately, these four axioms can help us avoid harming patients.



References:
1. The Rational Physical Examination: Systematic reviews of the diagnostic properties of the history and the physical examination.

2. Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice, 2nd Edition

3. NNT Website by David Newman that looks into the number-needed-to-treat of different therapies and also the website contains a scale where likelihood ratios can be manipulated to calculate post-test probabilities.

4. SMART EM: by David Newman podcast on diagnostic tests

5. A universal model of diagnostic reasoning. Croskerry, P; Academic Medicine; 2009 Aug;84(8):1022-8.

6. A life at risk: a website with lots of LR on signs, symptoms, tests

7. Hayden SR, Brown MD. Likelihood ratio: A powerful tool for incorporating the results of a diagnostic test into clinical decisionmaking. Ann Emerg Med. 1999. May;33(5):575-80.

8. Anthony K. Akobeng. Understanding diagnostic tests 2: likelihood ratios, pre- and post-test probabilities and their use in clinical practice. Acta Paediatrica; 2007 Apr;96(4):487-91. Epub 2007 Feb 14.

9. Paucis Verbis from Academic Life in Emergency Medicine: multiple cards with likelihood ratios, pre- and post-test probabilities

10. mdcalc: Bayesian, sensitivities, specificities, probabilities: if you know the prevalence, sensitivity, and specificity of a disease mdcalc has a calculator to obtain the likelihood ratios, and the predictive values.

11. Center for Evidence Based Medicine. Interactive Nomogram January 2009