When you make a differential, and then take a history, the point is to ask specific questions to move certain differential diagnosis up or down your list. Most of the time differentials aren't taken off the list (just moved down), especially not as early on as the history. NOT UNTIL YOU HAVE DONE ALL OF THESE THINGS, can you certainly say, this is LESS LIKELY (you can never be 100% sure) doesn't have this disease. After the history is definitely too soon. This is how we were trained early on during my 1st and 2nd years of medical schools.
Word. This is how medicine is practiced on the wards where I trained. One patient had a negative AFB Sputum x 3, but still looked like TB and eventually we got a lung biopsy that showed AFB positive organisms. So, a diagnosis may become less likely,but it is still there on the imaignary list of everything the patient has.
You can't take a history and say you have "ruled out" or "ruled in" much of anything, granted the history and physical may make one more prominent, . . . in the case of bloody sputum, weight loss, fever, this could be cancer and that would need to evaluated and you still have to ask questions about smoking, you can't just say that you smell TB and therefore have ruled it in.
The only time I hear the term "rule out" was when a patient was admitted for MI. . . Honestly, I haven't seen in the charts or heard much anybody say we have "ruled in" something. More often people talk about a "working diagnosis" like let's treat presumptively for TB, but also consult hem/onc about the biopsy results etc . . . More often that you realize the presumptive or "working diagnosis" changes.
A good history and physical should explore the top 5-10 diagnosis, and also do a good ROS to give a broad picture, it is inappropriate to begin to "rule out" or "rule in" anything at that point just because you are basing these decision on gut decisions. In real life and especially on Step 2 CS the cases are/are made to be ambigious, i.e. they don't have to give the patient "TB" for Step 2 CS, but can make it one of the likely diagnosis, in addition to others.
Attendings/consultants on service just list the top diagnosis and workup or give the concrete diagnosis i.e. newly diagnosed hiv/aids with a cd4 of 11. . . Nobody ever writes in a chart about ruling something out because we all know the game can change.
People have different clinical training, and some being less rigorous than others. One patient I had on service a resident had said on rounds that "we've ruled out cellulitis" . . . , later we consulted ID who said, no, it was cellulitis and we started treating for that. An intern was confused and said "I thought we ruled out cellulitis" and everybody just sort of rolled their eyes. The intern basically demonstrated they don't understand how worthless the term is and also didn't understand that diagnosis change and you really can't definitively rule out anything.
Never assume anything is off the differential, and just because a resident or even attending says that we have "ruled out" something it really doesn't mean a hill of beans. For most diseases there is no definitive way to 95% be sure that the patient doesn't have the disease. This is a very important concept in medicine, ALL imaging/testing procedures have a false negative rate even if very small and you WILL get a patient who has a negative test result and you can't say you ruled out the disease as the symptoms still match etc . . . Superoxide may not have benefited from this training, but is is a very bad idea to start off internship/residency thinking that you can "rule out" something and don't have to consider that diagnosis, especially during the history and physical.
