Thread by @aldorodrigo

1/
In this #tweetorial of #FluidWars

We will try to expose the physiological irrationality of Normal Saline (NS).
IV FLUIDS are ubiquitous. They’re the most common inpatient intervention. The most used solution in the world is Ab-Normal Saline.

#HospitalistRegion #Nephmadness

2/
IV fluids bypass the gut, sometimes overrule the kidney and reach into our precious body fluids. Mixing and changing their physical chemical properties alike the administered fluid.

Fluids should be considered drugs and prescribed for specific indications, doses, targets.

3/
A long time ago..
A junior doctor asks the attending:
What type of fluid would you choose on this patient, Saline or Ringer’s?
▪️A: I’ll take the usual, Saline.
Does it really matter? They are both crystalloids with salt, right?

4/
No. They are not the same.
There are balance and unbalance solutions.
The former resemble plasma electrolyte composition and the latter contain supraphysiological chloride levels.

5/
Here are the main reasons Saline is WRONG.
✔ Saline causes hyperchloremic acidosis in a dose-dependent manner.

Not only on sick people, a volume of 2000 ml of chloride-rich infusate may induce hyperchloremic metabolic acidosis in healthy volunteers
ncbi.nlm.nih.gov/pubmed/22580944

6/
Now we know, it causes Hyperchloremic acidosis in a dose dependent manner.
How does the ab-Normal Saline (NS) causes harm?

7/
✔ Saline causes harm in animals
Renal vasoconstriction
↓RBF, ↓GFR
Pro-inflammatory
Worsens AKI
✔Saline causes harms in HUMANS too, specifically in the kidneys
In a RCT crossover study of Saline vs PlasmaLyte. NS showed a ↓ renal blood flow and renal cortical perfusion.

8/
Chloride? Everybody loves Sodium.
Cl- has received less attention. It is the main anion in the ECF and vital for maintenance of serum electroneutrality, acid-base, fluid homeostasis, osmotic pressure and well function of the kidneys.
Cl- is the queen of electrolytes, period.

9/
Did you know that the average pH of commercial 0.9% saline is around 5.5? In fact, Hartmann’s pH is also around 5. In vitro acidity is irrelevant.
What is the main mechanism of that explain in vivo hyperchloremic acidosis by NS?
ncbi.nlm.nih.gov/pubmed/23630439

10/
Significant amounts of NS, dilutes HCO3 while CO2↑, also the normal relationship between Na+ and Cl- changes. Increasing Cl- more than Na+. Normally there is a gap of 40 meq/L. According to Stewart that`s what Strong Ion Difference (SIG) is. Finally causing a change in pH.

10/
What is the clinical translation of this effects?
There was this SIGNAL of bad outcomes with saline in comparison with plasma-lyte, on this large database of almost half a million surgical patients!
ncbi.nlm.nih.gov/pubmed/22470070

11/
If only there was a study that showed safety and feasibility of restricting chloride solutions in the hospital setting.
@NorazimMYunos, @BellomoRinaldo: Hold my 🍺!
A before and after pilot study between a liberal vs chloride restrictive strategy in the critical care setting.

12/
Restricting iv chloride solutions, not only was posible.. it seems was Beneficial..
✔ Less AKI and need for RRT in the restrictive chloride group.
But, other studies were needed...

/13
Then SALT-ED and SMART came along.
The balance crystalloid group in this robust trials resulted in ⬇ Major adverse kidney events (MAKE) a composite of death, RRT and persistent ⬆Cr.

14/ In summary:
👉IV fluids are drugs, with indications, doses, targets.
👉Stop de NS inertia, think twice
👉NS causes ⬆Cl-, ⬆H+ and is bad, specially for the kidneys
👉Choose SMARTly balanced solutions (RL, HT, PL)

15/
Balance solutions is the way to go with a few exceptions, such as: neurosurgical patients, hypochloremic metabolic alkalosis.

For the #NephMadness 2019 #HospitalistRegion
Lactated Ringer’s vs Normal Saline
Clear WIN for Ringer’s!

ajkdblog.org/2019/03/15/nep…
@NephMadness