History and Physical Exam

[MD'05]

Does anyone know what a pertinent positive or a pertinent negative is? At a high level I understand the concept, but I am a second year -- how am I supposed to know which negatives are pertinent? I know about the pertinent's for MI (chest pain, diaphoresis, radiation, etc.), but what about the renal system that we haven't covered in pathophys yet? It seems like I could ask an unlimited number of questions.

I am using the Swartz Physical Diagnosis book, but I feel like I am missing something. I know this is a stupid question, but I am feeling very stupid right now.

Would someone be kind enough to point me in the right direction?

Thanks.

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[ckent]

pertinent refers to additional symptoms/tests that may point you into the direction of one disease or another. An example of this would be if you were working someone up for chest pain, some pertinent positives may be if the person has a familiy history of heart disease, diabetes, hyperlipidemia (these would suggest that the pt did have an MI). Some pertinent negatives would be if his first set of cardiac enzymes came back as negative, or if the chest pain was reproducible on palpation (these would suggest that the pt did not have an MI). You will learn what is "pertinent" as you progress in your training. The way that I figure it out (as a third yr) is by openning a text book, like Harrison's or Current, and turning to the section on whatever disease I think that my patient has. If the pt has signs or symptoms that the book lists as being present in that disease, then he has those pertinent positives. Whatever he does not have that is listed in my book can be reported as a pertinent negative. As for kidney diseases, an example of this would be if the pt has gross hematuria, this would be a pertinent positive (or negative if the pt didn't have this) for things like renal calculi or nephritic syndromes. If he has frothy urine or edema, this might be a pertinent positive for a nephrotic syndrome. Unless you are a very good med student, you probably won't be able to list all of the pertinent positives and negatives for most diseases off the top of your head until you get some practice with it during third yr so I wouldn't worry about it too much right now.

 

[souljah1]

In terms of history, thinking about these things will help you obtain pertinent positive/negative findings can:

Is the pt. volume depleted?
Is the pt. on any nephrotoxic drugs that could exacerbate renal hypofusion (i.e. NSAIDS and ACE Inhibitors)?
Is their an obstruction either due to malignancy, prostatic hypertrophy, stones, retroperitoneal fibrosis, bladder neck obstruction, crystallization of certain drugs (antiretrovirals often), etc?
Does the pt. have any preexisting renal insufficiency either due to HTN, diabetes mellitus, Lupus, etc?

Regarding the Physical/Labs:

Signs/symptoms of vol. depletion, BP alterations, prostate/bladder...what are your findings?

Are they making urine?
If oliguric, what is their FENa?
If they are making tons of urine, is it concentrated/positive for Glu/Kreb/AA?
Does their urinalysis result in + for casts, WBC, RBC, Glucose, Protein, etc?
Do they have flank pain?
If making urine, is it painful?
Do they have a fever?
Are they catabolic?
Are they on nephrotoxic drugs?
Did they have a prerenal condition that was exacerbated by CT or XR contrast?
What are their ADH levels in a hypovolemic/hypoperfused state?
etc...

my thinking is that answers to these questions can either be positive or negative findings depending on the differential you are considering.

Urinalysis can be very big in terms of narrowing down your differential. For instance, glomerulonephritis and interstitial nephritis shows up very differently upon urinalysis, with I.N. having WBCs, WBC casts, and +/- eosinophils, whereas Glomerulonephritis will most often have Red Cell casts. Urinalysis can also help you in determining the etiology of the renal impairment, i.e. looking at occult blood can help you determine presence of rhabdo.


We have just begun our renal block over here and I am trying to sort through all this stuff myself. I think any symptom/sign can be a positive or negative finding depending on the differential you are working with. If you are thinking Acute Tubular Necrosis, positive findings would include an isoosmotic urine and muddy brown granular casts...whereas a concentrated urine would indicate that the tubules were functioning properly so perhaps the impairment is prerenal, or if it is renal perhaps it is due to nephritis or something like that.

Hope this helps. I'm trying to figure it all out myself. Perhaps some brilliant third/fourth years can help us out on this. ?

 

[neilc]

as i understand it, it refers to the big issues that help rule in or out a diagnosis. these are the things that are important on a presentation or a write up to help demonstrate the line of thinking that led you to your conclusion.

it means to include the answers that are important, whether they were positive or negative.

this is an art that we will all get better and better at...early in our careers it will be hard to tell what is "pertinant", so we tend to have long presentations that leave out what the attendings really want to hear!

 

[MD'05]

ckent, souljah1, and neilc,

Thank you all for your answers! Now I get it!! You are right I won't know this stuff, but I can pick up a text and that's a start!!

We started interviewing hospitalized patients (with our preceptor watching closely) and of course it takes me forever just to pin down the CC, HPI, and PMH. When my preceptor reviewed my write up and said to include these pertinent */-'s, I was too scared to ask him what he meant. It seems like I don't know what I should and shouldn't know at this point. This transition period (between 2nd and 3rd year) is great, but frightening!!!

Thanks again!!

 

[Airborne]

A good H&P is a story that in the end leads to the most likely diagnosis. When someone presents with a symptom, a whole list is generated of possible causes - while it is easy to focus on only the positives, it is just as important to list the negatives that make the other diseases in your differential less likely.

Of course to do this, you first must generate a good differential diagnosis. Once this is established, the pertinent +/- come into place. For example, if someone has severe left sided flank pain, is it GI, Urinary, Reproductive, Pleuritic, Neurologic, etc, etc etc. Important perinent negatives would be a negative pregancy, lack of hematuria, etc and serve to focus the differential....

Airborne.