generating a differential

[obiwan]

what does each letter stand for in the "VITAMIN D" mnemonic that you're supposed to go through when coming up with a differential?

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[jdh71]

what does each letter stand for in the "VITAMIN D" mnemonic that you're supposed to go through when coming up with a differential?

google is your friend

As an aside I've always hated the medicine insists on these silly differentials at the beginning. Seriously who makes a differential before knowing all of the information? "Abdominal pain . . . GO!" It's effing asinine, my history and exam are done before I ever think of anything resembling a "differential".

 

[BlackNDecker]

True, jdh71...but remember, knowing what to look for will dictate what you find on the physical exam. Further, having a differential in mind during the history can help focus your questions (and likewise minimize time spent going through the agonizing ROS).

 

[BlackNDecker]

Seriously who makes a differential before knowing all of the information? "Abdominal pain . . . GO!"

I believe this is precisely the rationale for listing/presenting the C.C. prior to the history.

 

[DragonWell]

what does each letter stand for in the "VITAMIN D" mnemonic that you're supposed to go through when coming up with a differential?

http://notmysecondopinion.blogspot.com/2006/10/differential-diagnosis.html

 

[jdh71]

True, jdh71...but remember, knowing what to look for will dictate what you find on the physical exam. Further, having a differential in mind during the history can help focus your questions (and likewise minimize time spent going through the agonizing ROS).

Um wut? I don't understand that at all. You let you patient talk, and that narrows the history. If you know how to do a thorough physical exam, you won't miss anything - there is nothing about the differential for "abdominal pain" before knowing anything else that will make me do a different exam. Putting together a differential before you have all your information is ******ed, and nothing more than useless mental masturbation. Maybe you guys have that kind of time at Mayo - a selling point for those look for "kick back"?

I know, I know!!!!1! Let's make a list of EVERYTHING that can cause abdominal pain (yeah!) - don't forget scorpion sting!!

Ok . . . you do that - in the meantime I'll be admitting the patient with a reasonable differential AFTER I've gotten a history and done an exam (also will probably have looked at the same garbage the ED always orders on EVERYONE).

 

[BlackNDecker]

ermmm....little wound up there, eh?

Putting together a differential before you have all your information is ******ed, and nothing more than useless mental masturbation.

Again...this is precisely the reason for the chief complaint. Knowing why a patient is presenting to continuity clinic allows me to quickly review the pertinent info in the (electronic) chart prior to entering the exam room. If you've never tried it, you should.... Sure, not every chief complaint requires brushing up on the literature...but many do.

If you know how to do a thorough physical exam, you won't miss anything - there is nothing about the differential for "abdominal pain" before knowing anything else that will make me do a different exam.

Ok sure...abdominal pain...no big whoop. The problem is when the patient presents with something beyond your knowledge base...quickly skimming UpToDate (or whatever you prefer) could help immensely.

I won't be so bold as to say I wouldn't miss anything...I've done some blinded studies working with residents routine cardiac auscultation vs. the phonocardiogram and you'd be surprised what people miss just on the cardiac exam alone.

 

[Captopril]

Don't challenge age-old knowledge and technique. You will inevitably come to the conclusion of fail.

Your history and exam methodology is dependent on your ability to make a DDx list...otherwise your kind of just shooting in the dark, hoping to fall upon the right Dx.

 

[DarthNeurology]

google is your friend

As an aside I've always hated the medicine insists on these silly differentials at the beginning. Seriously who makes a differential before knowing all of the information? "Abdominal pain . . . GO!" It's effing asinine, my history and exam are done before I ever think of anything resembling a "differential".

I agree with the above posters, after you get the chief complaint and have asked the patient why they have come to the ER etc . . . you should then ask more focused questions with a differential in mind, remember 80% of diagnosis are made from the history (I think even before the physical although maybe that includes the physical, most of the time the physical examination reveals what is expected although there are exceptions.)

For example, a patient has a chief complaint of "abdominal pain" that is sharp, 7/10, comes and goes every 30 minutes over the past day, has had pain like this before in the past. There are some very very specific questions you have to ask based on what it might be, such as, if the patient has coughed up any blood? Does food make the pain worse or is there a relation to food intake? Has the patient been able to keep down fluids, or food? If the patient starts then talking about throwing up bright red blood then he/she might have an ulcer which is actively bleeding and may need to be scoped. Any changes in their diet? Etc . . . What were the piror episodes of pain like? etc . . . Usually after the first 5 minutes I have a guess as to the top 3 diagnosis and what I think will need to be done, chief residents are even faster.

The physical exam is important, and often times critical, but in my experience rarely alters management, i.e. maybe 1-2 times out of ten does physical examination change anything. If somebody says abdominal pain as a chief complaint to me I immediately associate this with biliary colic, an ulcer, pancreatitis, appendicitis, constipation, mesenteric ischemia, colitis, etc . . . things fly through my head faster than I could ever type them. So, yes, in an elderly patient with a PMHx of atherosclerotic disease if the patient has abdominal pain after eating out of porportion to exam I would think about this after the first two sentences of the Chief Complaint and ask more questions to see if this could be cause.

In the end the physical examination should confirm you diagnostic impression and if it does not then maybe you need to ask different questions. Also, your physical examination should be focused on the organ systems of complaint, but also be guided by your differential, if you suspected appendicitis in a patient then you have to do some different examination techniques then if you are looking at someone who has coughed up bright red blood with abdominal pain. Same thing with CTs and imaging studies they should confirm your impression, if they don't then you need to reasses.

If someone says right lower quadrant pain in a teenage female then you should be able to come up with 7 possible DDx in 30 seconds to a minute. It is impossible to not do this and just do a PE with a thorough abdominal exam and THEN think up the DDx, invariably you will then have to go back to the patient and ask more questions and maybe even do the exam again.

 

[DarthNeurology]

True, jdh71...but remember, knowing what to look for will dictate what you find on the physical exam. Further, having a differential in mind during the history can help focus your questions (and likewise minimize time spent going through the agonizing ROS).

What I have been taught concerning the ROS is that it is always a fishing expedition just to see if there is anything that was missed in the history. For example, in an abdominal pain patient the GI part of the ROS will be "see HPI" in my H and P. But it pays to do the full ROS in terms of asking a couple questions about each system, such as if the patient with abdominal pain reported a 30 lbs. weight loss over the past month or so and a loss of appetite and fatigue then this would broaden my differential to include a more systemic process such as perhaps a GI malignancy. Sometimes ROS is a pain as some patients have small complaints in all organ sytems, but it serves well to eliminate possibilities and to pick up on an underlying problem so I generally wouldn't truncate the ROS even if I am 99% sure that the patient with heavy EtOH intake and past history of multiple admissions for pancreatitis is back with the same thing as the ROS helps gauges how they are doing elsewise.

 

[DarthNeurology]

Um wut? I don't understand that at all. You let you patient talk, and that narrows the history. If you know how to do a thorough physical exam, you won't miss anything - there is nothing about the differential for "abdominal pain" before knowing anything else that will make me do a different exam. Putting together a differential before you have all your information is ******ed, and nothing more than useless mental masturbation. Maybe you guys have that kind of time at Mayo - a selling point for those look for "kick back"?

I know, I know!!!!1! Let's make a list of EVERYTHING that can cause abdominal pain (yeah!) - don't forget scorpion sting!!

Ok . . . you do that - in the meantime I'll be admitting the patient with a reasonable differential AFTER I've gotten a history and done an exam (also will probably have looked at the same garbage the ED always orders on EVERYONE).

Sometimes a patient may have a history very compatible with pancreatitis, and physical examination may also be consistent with this, and in some areas of the country you would have to ask about scorpion bites so a specific CC can lead to some very specific questions.

 

[elwademd]

Sometimes a patient may have a history very compatible with pancreatitis, and physical examination may also be consistent with this, and in some areas of the country you would have to ask about scorpion bites so a specific CC can lead to some very specific questions.

its not all scorpion stings that cause pancreatitis. its a scorpion from south america (well, south america, and trinidad) : tityus trinitatis & tityus serrulatus. so, next time someone on rounds mentions a scorpion sting as a cause of pancreatitis, they should be gently reminded scorpions from south america or trinidad.

as far as generating a differential diagnosis, i think its different for the beginning medical student, than it is for a seasoned resident, than it is for an old wily attending.

for medical students, who are just beginning to learn about patient care, the differential should be broad. sort of a why this or why not that. once those principles are learned, from there it should start to be a practical differentail applied to the patient, as opposed to just naming everything and anything.

after all, gunshots and stab wounds can cause abdominal pain! but if there's no mention of getting shot or stabbed, and there are no wounds on the abdomen, it really should not be included.

 

[jdh71]

Sometimes a patient may have a history very compatible with pancreatitis, and physical examination may also be consistent with this, and in some areas of the country you would have to ask about scorpion bites so a specific CC can lead to some very specific questions.

I know, I know *gasp* "he's doing things differently!!!1!" - You see when you hear that I approach things differently you make a rather stupid mistake and assume a lot of things, because if you were to try it my way, you'd be "guessing". This is a personality and infomation categorization issue - I'm actually able to think outside the box because of the way I naturally approach problems. Please don't assume I'm doing thing a certain way. I cover all the bases, I merely do not have to start from a exhaustive DDx list - this used to cause all kinds of consternation by many attendings I've worked with, but at the end of the day, they have never been able to find fault with the end-point because I always get to the same end point.

To understand this you merely need to understand personality types, medicine is largely made up of ONE personality type, and therefore the entire system is set up around this one major type. It should then come as no surprise when a different personality type thinks differently about the approach. Where I went to medical school we were all personality tested prior to matriculating if we wished (optional), and I was told that I would run into this issue but that in the long run I would be fine.

And I am. I'm good at this - I still have a lot to learn and experience - but I'm really good at this.