Wards Survival Series: Developing your Assessment & Differential Diagnosis

By Walter Wiggins

One of the major skills you’ll be expected to develop over the course of your 3rd year of medical school is the ability to formulate an assessment and differential diagnosis (DDx).

During the first couple of months, no one will expect much from your assessment and DDx. If you miss the actual diagnosis or include some obscure things on your DDx that aren’t really plausible or likely for the diagnosis, don’t worry…you’ll get better with practice. Just focus on basic techniques for developing an initial DDx, then prioritize your prime suspects by what is most likely given the patient’s demographics, history, and presentation.

Remember: atypical presentations of common things are way more common than typical (or atypical) presentations of uncommon things.

What we’ll talk in this post is the basic-level (think “bunny slope,” if you’re a skier) presentation. For more advanced presentation techniques, look for posts later this month from Luke and Fady about “reverse presentations.”

The main component of a good assessment is a summary statement. This is similar to what you’ve been taught to do with your introductory statement for the beginning of your presentation. However, the summary statement will require that you pull in a few key points from the details of your H&P and really try to paint a picture of what you think is going on.

1. Restate the patient demographics, pertinent medical/surgical history, and chief complaint.
   1. Mr. Smith is a 56 yo Black man with a history of hypertension, hyperlipidemia, and type 2 diabetes mellitus who presents to the clinic complaining of increasing dyspnea on exertion over the last 6 months.
2. Incorporate details from the HPI and ROS.
   1. Mr. Smith is a 56 yo Black man with a h/o HTN, HLD, DM2 who presents to clinic c/o increasing DOE over the last 6 months associated with paroxysmal nocturnal dyspnea, 4-pillow orthopnea, and bilateral pedal edema.
3. Now throw in the salient points from your PE.
   1. Mr. Smith is a 56 yo Black man with a h/o HTN, HLD, DM2 who presents to clinic c/o increasing DOE over the last 6 mos a/w PND & 4-pillow orthopnea, who demonstrates bibasilar crackles, elevated jugular venous pressure to 6 cm, and bilateral 2+ pitting edema to the mid-calf on exam.
4. Finally, give your thoughts about what is most concerning on your DDx.
   1. Mr. Smith is a 56 yo Black man with a h/o HTN, HLD, DM2 who presents to clinic c/o increasing DOE over the last 6 mos a/w PND & 4-pillow orthopnea, who demonstrates bibasilar crackles, elevated JVP to 6 cm, and bilateral 2+ pitting edema to the mid-calf on exam, concerning for new-onset congestive heart failure. DDx includes cor pulmonale secondary to COPD.

Once you have a good summary statement put together, the rest of your assessment should be easy. Simply list the problems that are being addressed in that particular clinic visit or actively treated during that particular hospitalization, starting with the one(s) you’re most concerned about.

After that, you can incorporate your plan for workup and management of those problems…but we’ll talk about that another day.