This episode is a philosophical discussion about a personal interest of mine, surrounding physical diagnosis in the emergency department. I’ve found, and I’m sure many of you listening have too, that there is some contention around the relevance of the physical exam in the face of increasingly powerful diagnostic technologies. So it seemed to me that this contention could be especially poignant in the ED, in the face of constant pressure to get the right diagnosis in the shortest time. To get some perspective, I sat down with two experts in physical diagnosis, Dr. Sullivan and Dr. Cloutier who are both attendings here at OHSU. Dr. Sullivan is a hospitalist who many here at OHSU consider to be a pinnacle expert in physical diagnosis, and Dr. Cloutier is a very broadly qualified emergency medicine attending with a specialized expertise in diagnostic reasoning.
Summary of Key Points
Physical diagnosis is a low-technology diagnostic test. This differentiates it from the physical exam, which is generally used for screening. Screening is about testing a healthy population, whereas a diagnostic test is evaluating a sick person for disease.
Diagnostic reasoning is like being inside a tree. The trunk is the actual disease process and it’s very easy to get out on branches as you order more and more testing. You have to keep focused on the trunk if you want to find the unifying diagnosis.
Be very careful when ordering tertiary testing (contrast CTs, MRIs, specialty consulting, etc.). When you’re testing your testing, you need to stop and re-evaluate your line of reasoning.
Have a very well formed question for a consultant or a referral. Think about a specialist as tertiary diagnostic testing, and we as physicians need to guide the consultant the same way we guide other diagnostic testing.
The most important findings of physical diagnosis are often what Dr. Sullivan refers to as the “facies of disease,” meaning the subjective impression of an experienced clinician. Watching the patient, talking to them, taking the history all help to form this impression, and often lead experienced clinicians to their diagnosis. How to develop this skill? Repetition. Seeing lots of patients and learning what is characteristic of disease various diseases.
Respect your experienced nurses and patient’s family members. If your patient’s nurse has a bad feeling about something– just go with it.
Dr. Cloutier recommends emphasizing the neurological examination for aspiring emergency medicine students– even to the point of taking a neurology elective.
Dr. Sullivan recommends Steve McGee’s Evidence Based Physical Diagnosis for learning about likelihood ratios associated with physical exam findings.
Bayesian reasoning is a method of evaluating the probability of an outcome given multiple contributing factors. Dr. Cloutier’s example refers to a specific disease as the outcome, so he’s talking about a differential diagnosis, each with it’s own probability and contributing factors. According to Bayesian reasoning, the post-test probability of the 1st test creates the pre-test probability of the 2nd test.