1/ #UncleBob discussed BMP on #VMR - spend #5goodminutes 2 analyze. Pt ~80 & weighs ~55kg (recent 5 kg wt loss). Sarcopenia Pt has orthostasis (HR & BP).
Na 134 K 4.7 Cl 99 HCO3 23 BUN 22 cr 1.2 nl glucose
tweetorial later today
Can these labs help?
@kidney_boy
@uabimres
2/
Gregory (Scotland Yard detective): “Is there any other point to which you would wish to draw my attention?”
Holmes: “To the curious incident of the dog in the night-time.”
Gregory: “The dog did nothing in the night-time.”
Holmes: “That was the curious incident.”
3/
We have a patient with presumed simple intravascular volume contraction. Do the labs support that hypothesis?
The sodium is slightly low - volume contraction is definitely a potential cause of low sodium - if the patient is drinking fluids freely.
4/
If the problem is simply volume contraction - then we would expect a hypokalemic metabolic alkalosis. Volume contraction stimulates aldosterone and sodium reabsorption (to try to protect volume). We change the proximal tubular bicarb reabsorption threshold.
5/
But the patient has a high K, and a low normal bicarbonate. Note the normal anion gap and we are told u/a is normal so likely no ketones. The BUN is quite high for some with decreased intake. The creatinine is very high for a patient with a BMI of 55 and sarcopenia.
6/
So the labs look partly like routine volume contraction, but some things just don't fit. What else could give orthostasis?
Autonomic dysfunction can - but the appropriate pulse increased excludes the autonomic branch of the schema.
7/
Then we learn that volume does no resolve the orthostatic BP & HR. Things are not what they appeared. Slightly low sodium, slightly high K and relative hypotension make one consider adrenal insufficiency.
8/
I would have drawn a random cortisol at that point and given a dose of dexamethasone. The cortisol should be elevated given the BP and the tachycardia. If it is not elevated than a stimulation test will either support or exclude adrenal insufficiency.
9/
I choose dexamethasone because it is the only glucocorticoid that will not interfere with the measurements of the stim test.
In fact this patient did have adrenal insufficiency. I (and the wisdom of the chat) did not work through this analysis.
10/ We got there in a different way. On further reflection, the BMP which seemed rather unremarkable actually could have been a clue. Now that you know the diagnosis, the numbers make total sense.
@CPSolvers @DxRxEdu @rabihmgeha @3owllearning @MohitHarshMD @HannahRAbrams
Share this Scrolly Tale with your friends.
A Scrolly Tale is a new way to read Twitter threads with a more visually immersive experience.
Discover more beautiful Scrolly Tales like this.