Thread by @CPSolvers

1/ A quick glance at the foot of the bed unravels a rare answer to a common complaint... another #tweetorial to sharpen our #clinicalreasoning skills, #medtwitter! Try to solve this mystery case and see if you can... nail it!

2/ A 58 year-old man presented with gradual, progressive dyspnea. Two months ago he had no trouble ambulating, now he is limited to several blocks.

3/ Take a mental pause here to practice how you might approach “dyspnea”, and then listen to @BBroderickMD take us through it: bit.ly/32fCXXr

4/ Let’s take a second to review the definition of “base rate of disease.” This refers to the relative prevalence of a diagnosis in the context of clinical syndrome and often serves as the initial anchor for the DDx (e.g., MOST conjunctivitis is 2/2 viruses)

5/ The base rate for dyspnea favors cardiopulmonary diseases. This lets us zero in on the “CV” and “Pulm” categories in the schema above and use the subsequent information to rank which system is most likely at play.

6/ The patient did not have fevers, cough, chest pain, orthopnea, paroxysmal nocturnal dyspnea, or weight changes. Given those pertinent negatives, which of the following falls to the BOTTOM of the differential?

7/ No orthopnea, PND, and weight changes makes CHF the least likely of the options above. Everything else now RISES in probability, owing simply to the fact that a common diagnosis has been rendered unlikely.

8/ T37.2 C, BP132/82, HR92, RR20, O2 sat 98% 2L. Exam showed decreased BS in the R lung, dystrophic nails, and lower extremity non-pitting edema. A chest xray showed a moderate unilateral R sided pleural effusion. What is the next best step in establishing a diagnosis?

9/ Pleural fluid analysis using Light’s criteria is a great initial step in breaking down the causes of pleural effusions. @ArsalanMedEd walks us through this schema here:
bit.ly/2xEsdDU

10/ Thoracentesis yielded 1.6L of an exudative yellow milky fluid w/ a lymphocytic predominance. Given the milky consistency, what additional test would be the highest yield to send?

11/ Adenosine deaminase was normal. Bacterial and acid fast cultures were negative. His pleural fluid triglycerides returned elevated at 265mg/dL (nl < 50), strongly suggesting a chylothorax. @jackpenner walks through a chylothorax schema here: bit.ly/2XVZEkP

12/ Hold on a minute! If the take-away is that chylothoraces are a lymphatic issue… could this be in any way related to the patient’s lower extremity lymphedema?! Do you have a way to think about the causes of lymphedema? Here is @dminter89’s approach: bit.ly/2Mk5sNQ

13/ For another fascinating case of lymphedema, check out this case from @LisaSandersmd @nytimes Diagnosis Column: nyti.ms/2JZ9ABv

14/ It sounds a lot like this patient has a lymphatic drainage issue. Let’s circle back to the other abnormal exam finding… dystrophic nails. Was this finding signal or noise? What are some nail abnormalities commonly associated with systemic disease?

15/ Some of our favorite nail findings are listed below! What other nail findings would you add?
And check out this awesome review article for more on nail findings and systemic disease: aafp.org/afp/2004/0315/…

16/ Based on the constellation of nail dystrophy, lymphedema, & pulmonary manifestations, the patient was diagnosed with Yellow Nail Syndrome (YNS), and started on SQ octreotide & Vit E. bit.ly/2yaoON8

17/ Want these schemas in your pocket? Check out the CPSolvers app: bit.ly/2YqR50L

18/ Does the case sound familiar? For more on YNS and to hear the full case, check out Episode 33 with @ESilvermanMD! bit.ly/2OhuBLW