Never in the history of medicine has so much been done, by so many, so incompetently, with so little consequence as in the treatment of severe hyponatremia. #Tweetorial 1/10
You shouldn't correct hyponatremia too fast. The speed limit is 8 mmol/L per day. We are terrible at it. In George et al, 41% of 1,490 pts were corrected faster than 8 mEq/L. Look at the poor slobs at the left of the nomogram whose Na actually went down 🤪 2/10
Thankfully this incompetence is rarely punished. Of the 611 (41% of 1490) patients who over-corrected in the George trial, only 7 developed osmotic demyelination syndrome (ODS). Screw the sodium correction and you can get away with it 99% of the time. 3/10
I was invited to help a study looking at the incidence of ODS in hyponatremia using the GEMINI database which tracks internal medicine admissions in Toronto. It is amazing when someone you look up to DMs you asking to join them on an important study. Thanks @FralickMike 4/10
We tracked every case of hyponatremia (Na < 130) admitted to 5 academic hospitals in Toronto from 2010-2020.
22,858 cases. This is the biggest hyponatremia study ever. Even if you restrict the cohort to just sodiums < 120, it is nearly 2x George et al 5/10
The Canadians seem to do a better job of correcting the sodium, went too fast in only 18% of cases, 3632 patients. But hold on, a lot of these people had relatively mild hyponatremia. When you break it down by starting Na, Canadians look just as bad as the US at going slow 6/10
And what was the consequence of all that hyponatremia? All that rapid correction? 12 of osmotic demyelinating syndrome.
12 out of 22,858. 0.05%
If you divide by starting Na they found an incidence of:
0.3% with a Na < 120
0.015% with a Na > 120
**2.5% with a Na < 110**
7/10
The part of the manuscript you are looking for is the rates of ODS by rapid versus slow correction. Sorry. We couldn't publish this due to the ethical guardrails placed on this trial. And the statisticians wouldn’t whisper it in my ear because they know me. Bummer. 8/10
So what can we take from this paper? ODS is rare; Canadians are just at bad correcting the sodium slowly as the guys in Pittsburgh; and the rate of ODS really rises as the initial sodium level goes does down, from a trivial 0.015% at levels > 120 to 2.5% with sodiums < 110. 9/10
The begining of my medical career was dominated by HIV
Start med school in 91. Magic Johnson announces he is HIV+
MS3 med students do blood draws on HIV+ patients (phlebotomy refuses)
MS4 lost my first patient, advanced dementia HIV
Graduated in '95, peak HIV, 50k US deaths
The whole clincal world was HIV, but you would go to the textbooks and they would still be calling HIV HLTV3. It was bonkers. It was in this envirnoment that UpToDate crushed Harrisons.
Then during residency HAART emerges and the whole thing melts away in a matter of years. All that knowledge about opportunistic infections becomes less a critical part of IM and selective ID knowledge.
Next up at the Belgian Society of Nephrology. Ian MacDougall talking iron.
Patients with CKD have decreased intake and increased iron loss.
Dialysis patient red cell lifespan is 60 rather than 120 days. But iron is reprocessed. This is not a source of iron loss. Non-CKD patient lose 1 mg of iron a day.
So we had our first renal physiology text book session of the year and we came across this paragraph in chapter one of Koeppen and Stanton's Renal Physiology #Tweetorial
The addition of hypertonic saline will increase the size of the extracellular compartment through the IV infusion of fluid and through the movement of water from the intracellular (ICC) to the extracellular compartment (ECC).
But the book does not calculate how much fluid leaves the ICC. This is calculable. Here is how:
Assumptions:
• TBW is 42 liters,
• 2/3rds ICC (28L), 1/3rd ECC (14L)
• Starting Osm is 280
• Starting Na is 140
We are giving 1 liter of 3% NaCl which has a Na of 513 mEq/L
Writing some acid-base questions. What do tyou think of this one?
Following multiple trauma, your patient has a surgical drain which everyone is pretty sure is in a pancreatic pseudocyst. It is draining 100-400 ml a day. Labs:
"Yet Aβ still dominates research and drug development. NIH spent about $1.6 billion on projects that mention amyloids in this fiscal year, about half its overall Alzheimer’s funding."
"She and others in the lab often ran experiments and produced Western blots, Larson says, but in their papers together, Lesné prepared all the images for publication." 🤦🏽♂️