As a Nephrologist, why do I love vasopressin? Particularly when I see patients in the CCU?

My ode to vasopressin in a 🧵

#medtwitter #cardstwitter #nephtwitter @MedTweetorials Right off the bat let's acknowledge that the following trials show no mortality benefit in critically ill patients with vasopressin. But that's not the point - we only care about the kidneys right now because I'm a Nephrologist.

The conventional diuretic treatment of ascites in patients with cirrhosis is high doses of spironolactone w/furosemide (classic 100/40 ratio). This was also mentioned recently on @thecurbsiders. Where does this come from and is it true? A quick🧵. #MedTwitter #nephtwitter In 1981 Fogel et al compared 3 diuretic strategies in 90 patients w/cirrhosis

1.spironolactone + lasix prn
2.lasix alone
3.spironolactone + lasix

🔥Furosemide alone appeared to perform worst for weight loss though not statistically sig. Required sig up-titration and massive KCl

Diuretic management in decompensated heart failure has been stagnant for years but recently we have some new tools to help us out.

Let's review the Rise of the Proximal Tubule Inhibitors in preparation for the #nephjc discussion on ADVOR tonight.

#MedTwitter @MedTweetorials First, it's important to recognize how crucial adequate decongestion is.

👇study: pubmed.ncbi.nlm.nih.gov/29544928/ which assessed pts in the PROTECT trial showed lack of decongestion was a predictor of mortality and HF re-hospitalization

Another one by Metra: pubmed.ncbi.nlm.nih.gov/22167320/

Great case of hypokalemia presented by chief fellow @Laurenaring yesterday.

60 y/o woman with a h/o nasopharyngeal cancer, nephrology consulted for hypokalemia.

Sk 2.5, bicarb 30, normal kidney function. No diuretic use, denies vomiting or diarrhea. #nephtwitter #medtwitter She was on pembrolizumab, which is a/w tubulointerstitial disease and subsequent hypokalemia d/t an RTA, however this was just started 5 days ago and her urine was bland.

Next step? As Nephrologists we want to know urine composition. In this case I would want a Uk, UCr and UCl

Should you give albumin with loop diuretics to augment diuresis?

I've been asked this three different times today so a quick🧵of my thoughts

#nephtwitter #MedTwitter @MedTweetorials First, edema formation. Starting with Starling's forces that govern fluid exchange between the plasma and interstitial space

Net filtration=LpS x [(Pcap-Pif)-s(Picap-Piif)]

(Pcap/Picap = hydrostatic pressure plasma/interstitium and Pif/Piif = oncotic pressure)

Why are thiazides effective in augmenting natriuresis when added to loops?

We all know that exposure to loops➡️increase in NCC channels in the distal tubule

BUT there's more

Did you know that there's a mechanism for thiazide sensitive NaCl reabsorption in the collecting duct? Electroneutral NaCl absorption can also occur in the collecting duct through the parallel action of pendrin and NDCBE (Na-dependent Cl/HCO3 exchanger) which is upregulated by Ang II and mineralocorticoids (when Ang II present)

How does increasing dietary potassium improve blood pressure?

I’ve heard this, even recommended it. But how does this really work? Grab some prunes and follow along this Tuesday morning tweetorial.

#Nephtwitter #cardstwitter @MedTweetorials Let’s establish that potassium does appear to have an inverse relationship with BP

In a meta-analysis of 22 RCTs ⬆️ K+ intake⬇️BP by an average of 5.3/3.1 mmHg

💥greatest benefit seen in hypertensive patients who ⬆️potassium intake to 90-120mEq/d

👉pubmed.ncbi.nlm.nih.gov/23558164/

How much salt is not enough?

The most common dietary rec made by physicians is sodium restriction

But to what extent?

Is an overly sodium restricted diet harmful? Especially in HF?

🔥Grab a salted pretzel and read on
#medtweetorials #nephtwitter #cardiotwitter #MedTwitter What degree of sodium restriction to you recommend to your heart failure patients?

When was the last time you were paged about a serum Cl- level? Probably never.

Despite being the most abundant anion in the body, Cl- is under appreciated

🔥Here’s why it matters (esp in heart failure!)

#tweetorial #medtwitter #nephtwitter #cardiotwitter #NSMC There is evidence supporting the use of hypertonic saline in patients with decompensated heart failure

See excellent blog post by @aldorodrig
👉 renalfellow.org/2019/04/03/the…

Mechanistically it never made sense to me, until I realized I may be focusing on the wrong ion 🤷🏾‍♂️

Do you often check a FeNa when working up a patient with AKI?

In my experience it’s ordered reflexively

But is this a good idea? Is a FeNa actually useful?

Let’s find out #NSMCInternship #nephtwitter #tweetorial

Poll!
To differentiate between prerenal AKI and ATN you would In normal circumstances sodium excretion = dietary intake

🔥What goes in must come out = extracellular volume is maintained within a narrow range

⬇️Volume → ⬆️RAAS →⬇️sodium excretion
⬆️Volume → ⬆️ANP → ⬆️sodium excretion

🤷‍♂️So why not just use UNa as a surrogate?