3/8 For a way to clinically interpret the LRs, let's turn our attention to Dr. McGee's book "Evidence-Based Physical Diagnosis." Although sunken eyes has the highest LR, notice how small the difference in increase in probability there is with each exam finding.
4/8 To understand why this is, it can be helpful to look at the Fagan nomogram used to calculate post-test probability based on LR.
5/8 So how do we use this thing? It requires you to have a sense of the pre-test probability (which you mark on the left side) and draw a line through the LR. Here's a great example that shows you how 2 different LRs influence post-test probability.
6/8 This (hopefully) helps visualize why you need quite a high LR or (rather low LR) to really influence your suspicion for something.
Remember that you cannot add the LRs of two findings and run it through the nomogram.
7/8 Last bit of info - if you decide to assess for skin turgor, you should do this in the subclavicular area, as elastin plays a large role in skin turgor in the extremities!
8/8 In summary:
⭐️Sunken eyes has the highest +LR for hypovolemia
⭐️Fagan nomograms show us that the LR needs to be really high or low to significantly change probability
⭐️Assess skin turgor in subclavicular area
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2/9 You may think “well that’s nice, but my thyroid exam technique is not the best.” Don’t worry, the Stanford 25 has got your back (including this clinical pearl)! stanfordmedicine25.stanford.edu/the25/thyroid.…
3/9 Now that you’ve identified a goiter, you will probably end up ordering some lab and imaging studies. But don’t leave the bedside just yet! Let’s first break down the differential for an enlarged thyroid (thanks again to the Stanford 25).
2/7 Metered dose inhaler (MDIs) are best used with a spacer! Pressurized devices were invented far earlier, but the technology was adapted to treat asthma in the form of an MDI in 1957 by Riker Labs. smithsonianmag.com/innovation/his…
1/7 Let’s go over the evidence-based physical exam for lower extremity deep vein thrombosis (LE DVT). In the spirit of quantifying clinical concern, here is a question - besides inspection (and #POCUS), which tool will help you the most?
Quick review of LRs:
- The (+) and (-) indicate the LR if a finding is present or absent, respectively
- The more the LR deviates from 1, the more useful it is
3/7 For this particular set of exam findings, it may be more helpful to see how much the LRs change your post-test probability (assuming a pre-test probability of 50%). The presence of absence of asymmetric calf swelling seems to be the most helpful.
1/4
Let's review the evidence-based physical exam for Cushing syndrome!
Quick review of LRs:
- The (+) and (-) indicate the LR if a finding is present or absent, respectively
- The more the LR deviates from 1, the more useful it is
2/4
Things that stand out to me
- "Buffalo hump" doesn't have a defined LRs despite being taught as a "classic" finding (occurs in 34-75% of patients)
- The presence of moon facies has a lower LR than I expected (1.6)
3/4 - The absence (or presence) of abdominal striae is not particularly helpful
- The presence of a thin skinfold (thickness on the back of the hand <1.8 mm in women of reproductive age) can be VERY telling
2/ What are the Weber and Rinne tests used to help identify?
3/ The answer is both! Remember that the most useful exams are hypothesis-driven so you need to do a history to begin suspecting if a patient has either type of hearing loss. This will help you generate a pre-test probability for disease (this will become relevant later).
2/8 First of all, a quick reminder that the utility of the FeNa and FeUrea in evaluation of AKI needs to be carefully considered before they are ordered (I'm a big fan of looking at UAs). journalofhospitalmedicine.com/jhospmed/artic…
3/8 You might see a table like the one below that can be used to (cautiously) interpret FENa and FEUrea.