Communication Breakdown: Zebras, not Unicorns

In my last post I discussed the role of presentations in determining how a student is perceived by their evaluators.  Today I want to hone in on one particular part of the presentation:  the Differential Diagnosis.

The usual advice given to students on how to construct an "EM appropriate" differential is to go "worst first".  This means that the first diseases you discuss are those most likely to result in morbidity and mortality for the patient.  This is important in the ED as this is the place where all the sickest patients get funneled to.  In most out-patient settings acutely ill patients are a terrifying rarity.  In the ED they are the routine.  If you do not think of a life-threatening diagnosis, your chances of lucking into it are low.  "Worst first" is a safety net for us and our patients.

Every student has probably heard the truism, "When you hear hoof beats, think horses, not zebras."  The problem with this clever turn of phrase is that zebras are real.  If you have ever been to a zoo, or the Serengeti, you have seen them.  Positioned as we are, at the bottom of the medical pathology funnel, the ED is the Serengeti of medicine:  the place where zebras roam.  Or at least the zoo of medicine.

Not all uncommon diseases (zebras) are dangerous.  The uncommon and bad ones, like aortic dissection (~200 times less common than MI) are the ones we must be vigilant against and belong on our differentials when we "hear hoofbeats" (i.e. "chest pain").  Zebras that are not particularly dangerous do not need to appear on your differentials.

There are still diagnoses we should ignore, diseases that do not belong in an ED differential.  These are the ones that are neither common nor dangerous.  These are the ones we will only find in text books.  For EM, the truism should be changed to, "When you hear hoofbeats, do not think of Unicorns".

Once a student is able to reliably think of the dangerous zebras, the life threats, I encourage them to order their list by probability.  When first getting used to EM it is okay for your differential for a 25 year old man with pleuritic, reproducible chest pain and normal vitals to be "AMI, dissection, PE, pneumothorax, and espophageal rupture".  You have included the bad stuff.  But you have not given weight to prevalence of disease or your own clinical impression.  This is not what your supervisors are actually doing.

Instead, once you are reliably thinking of all the bad diagnoses, you can start presenting your differential the way the residents do.  Start with what you think the patient actually has, and why.  And that can be a common and less dangerous diagnosis.  You need to follow that "horse" with the less likely but more concerning differentials (the zebras), why you do not think the patient has them, and how far you want to go in tracking them down.   You can even tack a unicorn on at the end, so long as you do not want to actually pursue that mythical beast.

Happy hunting!

The Secret to Honors- Presentation Presentation Presentation

Now that Dr Kellogg has told why you need great communication, including presentations, here are some hints for how to be a rock star. Giving a superb presentation is a sure fire way to get honors in your EM clerkship. While it may seem each supervisor wants something different, there are some common features wanted by all. If you can master these basic aspects of the presentation and then tailor the finishing touches to your supervisor, you will succeed. 

Make sure to read The 3 Minute EM Presentation. It is a road map for success. 

First you must give an ordered, structured presentation: Don’t jump around or be too casual this is interpreted as lack of interest or knowledge.

Begin with the chief complaint - Set The Stage

“This is a 65yo male with h/o cad presenting with 1 hour of precordial chest pain.”

Follow with the history of present illness - Paint The Picture

Put the pieces you have gathered in the history together but make sure you have a reason for what you say.

Focus on the chief complaint, with the seven cardinal descriptors, followed by pertinent positives and negatives.

“The chest pain began 1 hr ago, while he was mowing the lawn, he describes it as a pressure over his central chest, radiating to the left jaw, associated with nausea, diaphoresis and shortness of breath. It increased with walking and decreased with rest and abated on arrival to the er. He had similar symptoms last year when he underwent catheterization with 2 stents.

He denies radiation to back, paraesthesia, pleuritic pain, change with position, or calf symptoms.”

Next you will review pertinent past medical history, medications, allergies, social history, and review of systems - Fill In The Background

Keep the focus on what relates to the chief complaint, not everything you learned.

“The patient has a history of hypertension, hyperlipidemia, CAD, Cath with stent x2 1 yr ago. He takes metoprolol last dose this morning, Aspirin 81mg last dose this am, and statin. He has NKDA. He does not smoke, drink alcohol or use cocaine, he does not use medications for erectile dysfunction.”

While you may know all about this patient’s h/o appendicitis at age 12 it does not relate to the complaint so leave it out.

Then relay the physical exam -

Again focus on what is important for the chief complaint. 

“vital signs stable, pt appears in no distress conversant, lungs CTAB, CV s1s2 RRR without m/g/h/t/ with full equal distal pulses no JVD, abd soft nd nt bs normoactive, ext no c/c/e symmetric calves”

Now you summarize the patient - Grab Your Audience 

This is your opportunity to pull your supervisor back in and show how you can interpret, assess, and plan. Your supervisor is likely being pulled in 5 different directions, you need to command their attention. 

“In summary this is a 65yo with h/o CAD presenting with exertional chest pain concerning for ACS.”

next move quickly to your differential and plan: Don’t get run over by your supervisor and never get the chance to show what you know and think.

“While ACS seems most likely we must consider dangerous causes of similar presentations including dissection, pulmonary emboli, esophageal rupture, and common mimickers of precordial chest pa in such as gerd, pneumonia, musculoskeletal pain and bronchitis.”

“My plan is to intervene with medication for pain, while supplying 02 as needed, and keep the patient on the cardiac monitor. To investigate his sx I would like an EKG, chest xray and laboratory studies to include cardiac enzymes.”

Remember to address: 

Interventions-what you do for the patient 

Investigations-what you do to investigate the chief complaint and differential

EM presentations are succinct, directed toward the chief complaint, focused on both dangerous and probable causes of the symptoms, and above all convey a clear picture of the patient and context for concern.  Remember to set the stage, paint the picture, fill in the background, and grab your audience. This is skill it takes concentration, practice and fortitude. Listen to the verbal and non-verbal feedback you are getting and tailor your presentation to your audience.