Happy Memorial Day

What was Memorial Day previously named?

Decoration Day -

because of the practice of decorating soldier's graves with flowers

Paucis Verbis card: Dermatomal and Myotomal Maps

There are some things in life which I just can't memorize and dermatomal/myotomal maps are one of them. Weird cases of peripheral neurologic symptoms have presented to the ED in the setting of trauma and no trauma. So purely for selfish reasons, I'm making my own map to have on file.

This installment of the Paucis Verbis (In a Few Words) e-card series reviews Sensory and Motor Function Testing by Levels.

Easier access to Paucis Verbis cards

Thanks to several readers' suggestions, I have made the Paucis Verbis (In A Few Words) reference cards more easily accessible.

I just discovered that Blogger recently has enabled a new feature called Pages. This feature allows the blog to go from essentially a single-page site to a multi-page site. So as of today, if you look at the top bar of this website, you now will see that this blog is divided into 3 pages:


When you click on the Paucis Verbis Card page, each topic is hyperlinked so that you can find the cards faster. Alternatively, you can use the "Search This Blog" feature in the right column.

Thanks to Chris for initially cataloging these cards on his site (LifeInTheFastLane.com) and making me wonder why Blogger couldn't make a similar indexing page. Alas, I found the answer.

Trick of the trade: Endotracheal tube lubrication

Does your endotracheal tube get caught up on a swollen or floppy epiglottis during insertion?

Trick of the Trade: Endotracheal tube lubrication
Occasionally the endotracheal tube may become “caught up” along the epiglottis. Because it is difficult to predict when this may happen, pre-lubricate the endotracheal tube cuff and tip with a thin layer of water-soluble lubricant, such as K-Y jelly. This lubricant can also minimize the degree of surface trauma to the trachea and tracheal rings as the tube passes the vocal cords.

Work in progress: Videoconference talk at Stony Brook EM Residency

I am about to give videoconferencing another try Wednesday. My friend Dr. Taku Taira (Assistant Program Director at SUNY Stony Brook EM Residency Program) invited me to give a talk to his residents this week. I'm giving my "Tricks of the Trade in Emergency Medicine" lecture, which summarizes a list of my favorite practical tips in the ED.

As with any high-tech endeavor, preparation and backup plans are critical. Taku and I always assume that there will be a technical glitch and we have several backup options.

I recently came across a helpful list of do's and don'ts in videoconferencing by Dierdre Bonnycastle (Clinical Teaching Development Coordinator at the Univ of Saskatchewan's College of Medicine).

• Preplanning Stage
• On the Day of the Videoconference

The issues covered include:

• Slide font size and layout
• Pacing of the talk
• Attire (avoid whites and bright colors to improve camera focusing on you)
• Be wary of the audience and what they can see (use the mouse instead of a laser pointer)
• Have a "spotter" in the audience who will interrupt speaker if there are questions.

In my case where I am giving a talk from my laptop at home, I would also add at few more tips:

• Position the camera so that it is at eye level with the speaker. It seems a bit awkward having the speaker looking down towards the audience.
• Put a post-it note on the camera saying "LOOK HERE". Instead of looking at the slides, the speaker should really be looking directly at the green or red light from the camera. I find it distracting when the videoconference speaker is looking down and to the side all the time. I think psuedo-direct eye contact engages the audience more (even though I can't really see the audience).
• Don't wear eyeglasses. The light from the screen or other ambient lighting will likely reflect off of them causing a distracting glare on the screen.
  

Article review: Teaching clinical reasoning

How did you LEARN the skill of clinical reasoning in medicine? What strategies do you use to generate a differential diagnosis, come up with a leading diagnosis, interpret tests, and assess the pros and cons of treatment plans?

Even more complex, how would you TEACH the skill of clinical reasoning?

Adult learning theories state that clinical reasoning (or clinical cognition) comes from both book-knowledge and real experiences. Teaching complex reasoning skills requires a multimodal approach, which may include:

• Large group and small group lectures
• Hands-on workshops
• Computer-based instruction
• Simulation training
• Self-directed reading

This well-written article suggests that an integral part of this approach should involve case-based teaching using actual patient examples. Think about when you were a medical student. I personally learned tons just by listening to my attending verbalize his/her thought-process in managing actual patients. Patients almost never fit the classic pattern outlined in textbooks. This teaching approach attempts to transplant and expand this high-yield experience into the classroom setting.

The driving principle supporting this approach is that gaining expertise requires the learner to be active in learning. This contrasts the passive learning experienced in a traditional lecture setting. Thus, the faculty member should not transmit knowledge to the passive learner but rather serve as a facilitator of learner-driven discussions.

The keys to success in case-based teaching include:

1. Selecting and setting up a case appropriate for the learner audience. A case presentation for 2nd year medical students will not be the same as that for 2nd year residents.
   
2. Selecting a case which clearly illustrates some of the concrete concepts in clinical reasoning (see figure below from the article)
3. Training the faculty member to facilitate analytical thinking
4. Incorporating a "debriefing" session after the case to discuss potential cognitive errors or near-misses. This teaches "metacognition", or the method of looking introspectively at one's own thinking. What clues led to the right or wrong diagnosis? What would or could have been done differently in reaching the conclusions?
   

An interesting concept that the author proposed was to have the faculty member also "be in the dark" about the case. S/he would be a "coach" and manage the "patient" alongside the learners. A different person (not the faculty member) would disclose aliquots of information about the case upon request. Although this may make some faculty members uncomfortable for fear of being wrong or not knowing the answer to students' questions, facilitation is a critical skill for academic faculty to learn. It is an integral part of adult learning theories.


Reference
Kassirer, J. (2010). Teaching Clinical Reasoning: Case-Based and Coached Academic Medicine DOI: 10.1097/ACM.0b013e3181d5dd0d

May 17-21: Disconnected from the internet

Apologies for the lapse in blog postings this week. I'm off-line for a week to recharge and get new ideas for the blog. I also need to save up energy before a whole new army of new interns and residents descend upon our ED at San Francisco General Hospital. I may go into internet withdrawal, but I have a feeling that I will survive...

Will be back on May 24.

EM Lightbox: Kidney stones

As most ED providers know, the term “kidney stone” is often inaccurate. Symptomatic patients typically present with stones not in the kidney itself but stuck at nature’s bottlenecks, i.e. the pelvic brim, ureteropelvic junction (UPJ), or most commonly the ureterovesical junction (UVJ)

Controversy exists regarding the optimal evaluation of nephroureterolithiasis. A non-contrast CT is often employed to diagnose stones, their size, location and associated ureterohydronephrosis, as well as to rule out other causes of pain. Finding the stone is crucial to prognosis, as stones that have passed into the bladder are passed nearly 100% of the time. In contrast, more proximally impacted stones may take longer to pass or may cause obstruction, infection, or intractable pain necessitating intervention.

The modern diagnostic approach is a prone noncontrast CT. Prone scanning helps delineate impacted UVJ stones from those layering posteriorly in the bladder near the UVJ. Pictured above is an impacted left UVJ stone, just adjacent to the bladder.

Pitfalls in locating stones in the distal ureters and bladder include phleboliths in pelvic veins and calcified seminal vesicles (seen above - calcified structure on the patient's right just posterior to the bladder).

References
Vaswani K, El-dieb A, Vitellas K, Bennett W, Bova J. Ureterolithiasis: classic and atypical findings on unenhanced helical computed tomography. Emergency Radiology 2002; 9: 60– 66.

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This "EM Lightbox" case was authored by guest blogger, Dr. Eric Silman.

EM Lightbox: Lunate and perilunate dislocation

Lunate dislocation

Besides making frequent appearances on emergency medicine standardized exams, carpal dislocations, most commonly lunate and perilunate dislocations, present frequently to Emergency Departments. They are orthopedic emergencies and can be associated with significant complications.

Lunate dislocation (top image) occurs when the lunate is displaced and subluxed anteriorly. This often subluxes into the carpal tunnel causing an acute median neuropathy. It is seen as a “moon-“ or “saucer-shaped” bone flipped volarly, with the more distal capitate sliding proximally against the distal radius.

Perilunate dislocation

In a perilunate dislocation, the lunate-radius articulation is preserved and the capitate (as well as the entire distal carpal row with attached metacarpals) “jumps” dorsally “out of the saucer”.

Both of these carpal dissociations are often associated with scaphoid fracture and always portend significant ligamentous damage usually requiring operative repair.

Kienbock's disease

Another classic complication is Kienbock’s disease, or avascular necrosis of the lunate bone, which occurs with interruption of the bone’s tenuous blood supply, as in the scaphoid. Notice loss of bone density and height.

See prior post about normal wrist anatomy on xray.

References

Wheeless, C. “Perilunate dislocations.” Wheeless’ Textbook of Orthopaedics N.p., 30 Nov. 2008 Web. 17 Apr. 2010.

Voigt, C. Injury to the heel of the hand. Unfallchirurg. 2006; 109(4):313-22.

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This "EM Lightbox" case was authored by guest blogger, Dr. Eric Silman.

EM Lightbox: Hemothorax on CXR

Upright CXR

Supine CXR

A hemothorax, a collection of blood in the pleural space, is relatively common in blunt or penetrating thoracic trauma and is an acute indication for pleural drainage.

Trauma patients are commonly initially evaluated with a supine chest x-ray. In traditional upright films, pleural blood layers inferiorly, obscuring the costophrenic angle laterally and/or the hemidiaphragm more medially. The top CXR shows a left hemothorax. Most studies agree that it takes somewhere between 200-500mL of fluid to blunt a hemidiaphragm.

In contrast, supine films may conceal sizeable hemothoraces. In supine films (bottom CXR), blood layers posteriorly, which causes generalized haziness of the affected hemithorax. Often the ipsilateral costophrenic angle and hemidiaphragm edges are preserved. In fact, up to 1 liter of pleural blood may go undetected on plain films.

With CT as the gold standard, bedside ultrasonoraphy by emergency physicians has been shown to be comparable in sensitivity to an initial supine chest x ray. This may expedite diagnosis.

References
Ma OJ, Mateer JR. Trauma ultrasound examination versus chest radiography in the detection of hemothorax. Ann Emerg Med. March 1997;29:312-316.

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This "EM Lightbox" case was authored by guest blogger, Dr. Eric Silman.

EM Lightbox: Hyperdense MCA sign

Noncontrast CT of the brain is often used to evaluate patients with stroke-like symptoms, but is often normal or shows very subtle findings early in acute ischemic stroke.

One clue of acute ischemic stroke, shown above, is the "Hyperdense MCA Sign". The right Middle Cerebral Artery appears denser in its proximal course than the contralateral side. In this head CT, although it is not visualized in this CT slice, the contralateral MCA is normal in density.

The increased vessel attenuation on CT is thought to be due to thrombus within the MCA lumen. Studies have shown a high specificity but low sensitivity of this sign as well as poorer prognosis in patients who present with stroke and a hyperdense MCA sign. A false positive hyperdense MCA sign may be seen with increase hematocrit and vascular calcification.

References
Jha B, Kothari M. Pearls & Oysters: Hyperdense or pseudohyperdense MCA sign: A Damocles sword? Neurology 2009; 72: e116-e117.

Pettiti N. The hyperdense middle cerebral artery sign. Radiology 1998; 208:687–688.

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This "EM Lightbox" case was authored by guest blogger, Dr. Eric Silman.

EM Lightbox: ACL rupture

The X-ray above shows two of the most common plain films signs of ACL rupture:

• Avulsion of the lateral tibial plateau
• Avulsion of the anterior tibial spine

The lateral tibial plateau avulsion, or Segond Fragment, is seen in greater than 75% of ACL tears. It has been shown to result from varus stress on the knee with internal rotation of the tibia, causing avulsion of bone at the insertion of the lateral joint capsule. Avulsion of the anterior tibial spine results from excessive tension on the ACL is usually accompanies rupture.

In acute knee trauma with pain and swelling, it is often difficult for emergency physicians to perform ligamentous examinations. These plain film hints can aid in the early diagnosis and prompt follow-up of ACL injuries.

References
Stallenberg, B. Fracture of the posterior aspect of the lateral tibial plateau: radiographic sign of anterior cruciate ligament tear. Radiology. 1993 Jun; 187(3): 821-5.

Wheeless, C. “Evaluation of the ACL tear.” Wheeless’ Textbook of Orthopaedics N.p., 30 Nov. 2008 Web. 17 Apr. 2010.

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This "EM Lightbox" case was authored by guest blogger, Dr. Eric Silman.

Paucis Verbis card: Ottawa knee, ankle, and foot rules

Often times, I get called to triage to help decide whether a patient should be sent to Radiology for an initial x-ray after injuring their knee, ankle, and/or foot. After teaching one of the nurses about the Ottawa rules, she taped a list of these rules on the triage wall.

This installment of the Paucis Verbis (In a Few Words) e-card series reviews Ottawa Knee, Ankle, and Foot Rules.

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

[MS Word] [PDF]

See other Paucis Verbis cards.

Creating and delivering the stellar lecture

I recently re-read a book "Made to Stick" by Chip Heath and Dan Heath which discusses why some ideas stick and others are completely forgettable. The concepts discussed have helped me design lectures.

Here's something that I have incorporated into my talks: Memorable ideas share common attributes, which can be summarized by the acronym SUCCESs.

S imple

• This is always a good rule in presentations. This is the KISS concept - Keep It Simple, Stupid. You want to core down your speaking points without losing your message.
• Avoid information overload.
  

U nexpectedness

• For scientific presentations, it's hard to build surprise into your talk. So, I subtly aim to challenge what they know and potentially don't know.
• Start the talk by framing the problem. Find the knowledge gap and talk about why your teaching points are important.
• Several of my talks start with a case and ask the audience what they think the answers are. When I see audience members pointing fingers at the screen and hear soft discussions, I know that I've hook some. I share the answers to the case at the end of the talk.
  

C oncrete

• Speak using concrete terms and examples.
• Avoid fancy science-speak, if possible.
• Avoid abstractions.

C redible

• While citing references and lots of numbers can lend you credibility, beware of overwhelming data.
• When talking numbers, spend a little extra time to discuss and frame their importance.

E motional

• Try to evoke emotion from your audience. This can be done by displaying high-resolution, iconic images.
  
• Audience members remember ideas and concepts better if you build an emotional connection with them.
• Scientific presentations, however, may have a hard time evoking emotion. Regardless, this is important to keep in mind.

S tories

• People tend to remember stories more than a bullet-pointed list of facts.
• When possible, display a photo or tell story to illustrate your message.
• For instance, when talking about lunate dislocations, I display a somewhat funny image of two muscular orthopedists trying to perform a closed reduction in the ED. Message: Lunate dislocations usually fail closed reduction maneuvers and should instead go the the operating room for open-reduction and internal fixation.

Trick of the trade: Percuss the spine in low back pain

Many patients present to the Emergency Department for low back pain. Determining whether these patients have a red-flag diagnosis can be difficult. Red flag diagnoses include:

• Fracture
• Cauda equina syndrome/ spinal cord compression
• Spinal infection
• Vertebral malignancy

Almost all patients presenting with back pain, whether it be a muscle spasm or a spinal epidural abscess, will have back tenderness to some extent. So, how can you better differentiate benign from dangerous etiologies?

Trick of the trade: Spine percussion
Percussion is an easy physical exam technique that can be used to risk-stratify patients that you suspect may have serious back pathology. Classically, percussion of the thoracic and lumbar spine should trigger pain in patients with serious back pain pathology, such as vertebral malignancy or a spinal infection. Because bone conducts vibration extremely well, percussion irritates deep space pathology. In contrast, percussion should not exacerbate discogenic pain, back strain, or muscular spasm.

Technique
Position your finger over the spinous process, and percuss using your other hand. Repeat this for each vertebral level. With significant focal spine tenderness to percussion, the clinician should be more suspicious for worrisome pathology.

Poll: How do you recover from a night shift?

There are so many amazing things that we get to see and do as emergency physicians.

• We see sick, undifferentiated patients who need our help acutely.
• We have cool toys, such as ultrasounds.
• We get to do great procedures.
• We work on a shift-based schedule.
• We work in team-based fashion with fun nurses, technicians, and staff.
  

However, one major down side is that almost all of us work some night shifts.

Question for the readers:
Let's say you just finished your shift at 6 am. Your next shift is at 6 am the next day. How do you recover from your night shift?

For me, I try to work 3-4 night shifts in a row and then try to stay up as late as possible after the last shift. Usually, I pass out at 7 pm and wake up at 5 am the next day. I'm good to go.

Other options I've heard of include:

• use of medications such as ambien
• short nap mid-day after a night shift and then getting 6 hours of sleep at night
• incorporation of rigorous exercise after your night shift

I'm curious. What do you do?

Article review: Mentoring in EM

This article in the Canadian Journal of Emergency Medical Care reviews the EM literature on mentoring. The authors specifically do a great job summarizing practical tips.

What is a mentor?
It is a person who supports and guides a junior colleague (junior faculty member, residents, or medical student) in his/her professional development.

Many studies show that medical trainees value mentoring. Junior faculty, especially those in academics, also benefit from mentorship by senior faculty. Despite these known facts, less than 40% of medical students have mentors. Furthermore, 98% of academic physicians cite a lack of mentorship as a major factor hindering their career progress.

Types of mentorship

• Individual, one-on-one mentoring
• Group mentoring
• Distance mentoring

How to get started in a mentorship relationship

• Schedule 30 minutes for the first meeting
• Get acquainted, sharing backgrounds and interests
• Exchange contact information
• Discuss best mode for communication and available times
• View mentee's CV
• Define expectations of the mentee and mentor
• Identify the mentee's short and long-term goals
• Pick 3 areas to work on together
• Schedule regular meetings

Yeung M, Nuth J, & Stiell IG (2010). Mentoring in emergency medicine: the art and the evidence. CJEM : Canadian journal of emergency medical care = JCMU : journal canadien de soins medicaux d'urgence, 12 (2), 143-9 PMID: 20219162