How we’re different
When I was rotating on surgery as a medical student, our attending once asked of our small group what may be concerning in the differential for right upper quadrant abdominal pain. A very eager and a somewhat brash student blurted immediately: “Echinococcal cyst!” The attending replied, “Well, that’s true, but if Echinococcal cyst is the first thing you think of as a surgical consultant, you’re crazy!”
On the other hand, take a practicing internal medicine physician like my Dad. He formulates his differentials with a very different strategy, which is: what is the most likely? A chronic cough is bronchitis (even with hemoptysis), pneumonia, GERD or postnasal drip. Shoulder pain is, of course, a sprain, bursitis, or some referred cervical impingement. And so on.
Unfortunately, neither hunting for zebras (an unofficial US name for exciting but rare diagnoses) nor settling for the most common works for emergency medicine. In fact, that is how true diagnoses may get missed and patients may start dying.
Why we are different
The EM differential diagnosis is a pyramid tipped on its head. It is therefore different from how differentials are approached by many other specialties.
In EM, we first have to think of and rule out the most severe or threatening pathology. That’s a given. But our choices have to come from among the common killers, not Martian viruses or unheard of tumors from a medical encyclopedia.
Amoebic meningitis is exciting to encounter in your practice. But guess what? Your patient won’t have it. At the same time, for EM physicians things like pulmonary embolus, aneurysm of the abdominal aorta, subarachnoid hemorrhage and necrotizing fasciitis are everyday icons on our cognitive desktops. While less common than a common cold, these things are by no means rare.
Why it is difficult
In EM, one can rest assured that common pathology will present atypically and not quite like the textbook.
It may take years of practice to be able to persuade someone that you have done due diligence and your professional duty by excluding a whole lot of deadly things, while the exact diagnosis still remains elusive.
Secretly paranoid, openly confident and always nice
We are confident, but also afraid. We have to think of the worst yet possible scenario for any complaint, yet of course anticipate that the actual diagnosis will hopefully be something less severe and quite common – like a migraine. After all, after most CT scans and lumbar punctures, it is not a subarachnoid hemorrhage.
In EM, we are in this perpetual struggle with having to be professionally pessimistic and paranoid on the one hand, yet emotionally supportive and reassuring for the patient on the other. I always teach my students, even nursing trainees, that no one should be leaving an emergency department more scared or anxious than when they came in.
Your job as a rotating trainee in EM is to understand and learn this exact interplay.
Homework
For your attending, but more importantly for yourself and your patients, you have to be as concerned with sepsis from PID on a 16-year-old young woman with fever and abdominal pain as you are with appendicitis. The 86 year old grandmother with Afib but on no anti-coagulation, because she falls a lot is not just TIA or CVA prone. Her embolic clots may just as well be traveling downstream, causing that intermittent or out of proportion abdominal pain called mesenteric ischemia – for which you do not have a good lab test or imaging, by the way.
