I think one of the hardest things to do in healthcare, and one of the hardest things to teach, is the process of forming a diagnosis. We talk about pertinent positives and pertinent negatives (which in and of themselves can be confusing to students) and about horses and zebras, but overall, we still don’t really do a great job with this. Brandon Oto over at his blog, Critical Concepts, does a great job talking about the importance of making a diagnosis, that is, naming it. Not just saying that the patient has tachycardia, but venturing a guess as to why. And I think that’s a critically important first step. And a scary one. By venturing a guess, we open ourselves up to being wrong. But, that’s how we learn and grow and get better.
But how do we go about making a differential diagnosis list? Do we just take everything that fits the presenting complaint and then start testing? Well, that seems to be what a lot of providers do. We test and test and test some more. But, there is a big downside to testing and in fact, when we test not to confirm a diagnosis but to establish one, we may cause more harm than good (VOMIT).
Dr Andre Mansoor from OHSU is one of the best teachers of diagnostic reasoning and the process of forming a differential diagnosis that I’ve come across. I try to use his techniques and processes not only in my own practice, but in my teaching. I actually teach a course called Diagnostics and Clinical Reasoning at Georgetown University in the Acute Care Nurse Practitioner program. So, I’d like to recommend Dr Mansoor’s website, Physical Diagnosis as well as his book Frameworks for Internal Medicine. This is one of many good talks he gives covering these principles and is a great overview of what you’ll find on his website and in his book.