Thread by @DTomacruzMD

Hi #medtwitter! We’re halfway through 2020(‼️), New month = new case with @TheSkeletonKG. A little rusty in the clinic, ready for a consult? 🤓 Join us as we figure out this patient’s #hypercalcemia. Let’s break it down with a #tweetorial. #NephTwitter

👉🏼renalfellow.org/2020/07/20/ske…

1/ 55 y/o F with no known comorbidities comes in for 3 months of on-and-off left flank pain and a recently treated UTI. Her labs:

2/ Because Nephrology is cool, you are excited to investigate 🕵🏻‍♀️🕵🏾‍♂️🕵️ her hypercalcemia. What's the next thing you order?

3/ That’s right, in her case we order ✅all of the above ✅
Back to her chief complaint, you first get a CT scan:

4/ What do you see? 🧐🧐🧐

5/ That’s an example of nephrocalcinosis--caused by CaPhos or CaOx deposition in the kidney. It's usually associated w/
⬆️calcium
⬆️phosphate
⬆️oxalate
In the urine 💦
More on this👇👇 pubmed.ncbi.nlm.nih.gov/25807034/

6/ 💥We also found an obstructing 1.4cm stone in the left distal ureter likely causing her flank pain

7/ Hold up, before you 📞the urologist for that stone, we need to go back to her calcium. When evaluating ⬆️Ca ☝🏻first evaluate if it is PTH or non-PTH mediated.
Her iPTH was ‼️1269 pg/mL‼️
📍Here is an algorithm we follow: doi.org/10.1053/j.ajkd…

8/ Following the algorithm let's take a look at the 24h urine lytes 🔍🔍Careful with those units and computations when dealing with Ca/Cr!
More on this here👉🏽doi.org/10.1111/j.1365…

9/ Phew! That’s a lot of labs. Time to put it together. 55y/o female + kidney stones + ⬆️calcemia + ⬆️calciuria. What’s our working diagnosis?

10/ That’s right! Classic case of Primary Hyperparathyroidism (PHPT) which is the most common case of outpatient hypercalcemia. Her parathyroid scintigraphy showed a hyperfunctioning parathyroid adenoma similar to the one seen here:

11/Quick review on PTH & Ca. How does PTH ⬆️serum Ca?? #endotwitter #nephtwitter
📌⬆️conversion of 25(OH)D ➡️1,25(OH)2D
📌⬆️calcitriol production:⬆️Ca absorption in gut
📌 stimulates Ca mobilization from bones🦴
📌⬆️ Ca resorption in TALH (passive) and DCT (active) in kidneys

12/ Nephrolithiasis is one of the complications of long standing PHPT. HYPERCALCIURIA is one of the major risk factors.
⬆️urinary calcium +
⬆️urinary phosphate ( + ⬇️urinary citrate seen in this patient)
= STONE FORMATION

More on stones 👉🏽ajkd.org/article/S0272-…

13/ Almost there!! Knowing her diagnosis, what would you do next in her management?

14/ We scheduled our patient for lap stone removal & parathyroidectomy. ✂️✂️ Indications for parathyroidectomy in PHPT include:

15/ Problem almost solved!👍 One last thing: what are some electrolytes to monitor when a patient undergoes parathyroidectomy? 📈📉

16/ It is impt to monitor for hungry bone syndrome ( ⬇️Ca ⬇️Phos ⬇️Mg) post op.
⬇️Ca occurs due rapid influx of Ca into the bone from ⬇️ PTH.
⬇️Phos ⬇️Mg can also occur.

Here's a more in-depth review:eje.bioscientifica.com/view/journals/….

Check out our patient’s electrolyte trends postop

17/ She was given a short course of Ca and Mg supplementation. iPTH levels ⬇️to normal after surgery and SCr decreased to 1.1mg/d with correction of calcium. Patient was discharged after!

18/ What did we learn??
✳️ It’s important to remember that successful parathyroidectomy in patients with renal involvement of PHPT
✅corrects hypercalcemia
⬇️risk of kidney stone recurrence
✋🏽prevents further decline ↘️↘️ in GFR

19/ Check out this amazing VA by @deniise_am and read our post on @RenalFellowNtwk
renalfellow.org/2020/07/20/ske… to learn more about calcium regulation and management of kidney stones!