Nephrologist @UPMC l Professor of Medicine @PittDeptofMed l Fellowship PD @Pittrenal | Tweets/retweets are my own #Hyponatremia
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May 1, 2023 • 25 tweets • 6 min read
1/A former fellow sent me a text this afternoon “Hello. Covering service. Patient presented with PNa of 111 with pre renal azotemia. Bicarb 6. Currently on bicarb gtt and volume resuscitation. PNa 12 h later is 126. ICU doc says latest evidence says no risk of ODS per NEJM.”
2/I believe misinterpreting the results of the paper by MacMillan et al could promote serious therapeutic misadventures evidence.nejm.org/doi/full/10.10…
Nov 30, 2022 • 5 tweets • 1 min read
1/How do kidneys excrete acid? Kidneys get rid of acid mainly via the excretion of NH4+ and titrable acids. But what would happen if the main way to get rid of acid would be via free H+ excretion?
2/Lowest urine pH is around 4.5, which corresponds to a H+ concentration of 31,623 nmol/L
Feb 6, 2022 • 11 tweets • 4 min read
1/ I find the over reliance on the Adrogue-Madias (AM) formula to predict SNa changes after infusion of a specific IV fluid astounding. #hyponatremia tweetorial
2/ First of all, AM and other formulas (eg. Free Water Deficit formula) are simple mathematical manipulations of the simplified Edelman equation
Jun 28, 2020 • 6 tweets • 2 min read
How to estimate the increase in plasma sodium with oral urea? #ureaforhyponatremia
A 50 y/o woman with SIADH has a weight=70kg, UOP=1L/day, plasma sodium (PNa)=125 mEq/L, and UOsm=500 mOsm/kg. Which of the following is the expected PNa one day after fluid restriction 1 L/day and urea 15 g BID? (assume baseline solute balance and insensible losses of 0.8 L/day)
Oct 21, 2019 • 5 tweets • 1 min read
1/How to easily estimate urine volume (V) in steady state conditions. Let’s start with remembering Fractional excretion of X which is by definition: (Excreted X)/(Filtered X).
2/ Now calculating fractional excretion of water (FEH20)= Excreted H20/Filtered H20. Excreted H20 is essentially the urine volume (V) and Filtered H20 is essentially the GFR. So now we FEH20 = V/GFR ... (1)
Aug 1, 2019 • 15 tweets • 6 min read
Time for another #tweetorial on fluid restriction in #hyponatremia from SIADH. Is there a way to predict which patients with SIADH will respond to fluid restriction?
1/It has been said that the first line therapy for SIADH is fluid restriction but 60-70% of patients with SIADH will not respond to fluid restriction alone and they require the addition of a drug (e.g., urea). How can we tell who will respond and who won’t?
