1/8 Let's review assessment of hypovolemia based on physical exam. (yes, I know #POCUS is SO valuable in making this assessment)

Which physical exam finding is most useful to detect hypovolemia in adults?

#MedTwitter #FOAMed #MedEd #MedStudentTwitter
2/8 According to a great review by Dr. McGee in JAMA Rational Clinical Exam "Is This Patient Hypovolemic" the answer is... sunken eyes!

jamanetwork.com/journals/jama/… Image
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. Image
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.

nejm.org/doi/full/10.10… Image
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.

researchgate.net/publication/29… Image
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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More from @SatyaPatelMD

19 Jul
1/9 Let’s say you are about to do a thyroid exam. Before the exam you do not suspect goiter (pre-test prob of 50%). How does the exam influence your probability? Let’s review some LRs from McGee!
#MedEd #FOAMed #MedTwitter #MedStudentTwitter #EndoTwitter @MedTweetorials
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)!
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).
Read 9 tweets
12 Jul
1/7 Spacers confused me, so I wanted to sort them out. Let’s start with a question - what type of inhalers can benefit from a spacer?

#MedTwitter #FOAMed #MedEd #MedStudentTwitter #PulmTwitter
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…
3/7 MDIs have various advantages and disadvantages, some of which can be mitigated by spacers.
Read 7 tweets
9 Jul
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?

#MedTwitter #FOAMed #MedEd
2/7 The answer is a ruler! Let’s look at the LRs.

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.

Graphic from McGee
Read 7 tweets
7 Jul
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

#MedTwitter #MedEd #EndoTwitter #FOAMed Image
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)
- 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
Read 4 tweets
23 May
1/ Had some fun today on rounds with these! The Rinne and Weber tests stress out a lot of folks, so let's tackle them today.

#MedTwitter #MedEd #EndNeurophobia @MedTweetorials
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).
Read 13 tweets
14 May
1/8 When might an FeUrea not be as useful as FeNa? Let's explore briefly!

#NephTwitter #MedEd #MedTwitter #Tweetorial #FOAMEd @MedTweetorials
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.
Read 8 tweets

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