The Tale of the Low Chloride
Once there was 34 year old man who used marijuana and was 🤮nauseous, vomitting, and confused. The resident 📞calls and says, "All the electrolytes are abnormal!! Can you help?"
renalfellow.org/2019/12/16/ske…
@TheSkeletonKG #FOAMED #medtwitter #tweetorial
You say of course and see the patient. 🥼🩺His BP was 131/87 mmHg with a HR of 142 bpm. He was fatigued, but AOx3. Moist mucous membranes, normal skin turgor, and no LE edema.
💉Labs are shown and reveal a serum osmolality of 263 with ALL normal labs 3 months prior.
Loving Nephrology🤓, you ask, "What about the urine?!"
He is making urine with a urine Cl of < 20.
(💭Learn more about FeK and Urine K/Cr ratio with our previous case! renalfellow.org/2019/11/14/the… @hotsaltrocks )
In this case, which 🩸electrolyte abnormality the most concerning to be life threatening?☠️
I would worry about his hypokalemia!
Look at this #Uwave! #ECGplease
Our patient has a 🌟Cl depleted metabolic alkalosis based on labs and results from ⬇️HCl loss from gastric secretions.🤮
For more on the #pathophysiology, read our post! renalfellow.org/2019/12/16/ske…
Figure courtesy of @kidney_boy
🧐But notice something missing?
📌There's only 5-10% of K in gastric acid, so why the hypokalemia?
Source: ncbi.nlm.nih.gov/pubmed/14919895
Potassium is lost through the urine via 3⃣ mechanisms
1⃣Secondary hyperaldosteronism in response to hypovolemia and low distal sensing of UrCl
Source: cjasn.asnjournals.org/content/10/2/3…
2⃣Filtered bicarbonate exceeding the reabsorptive capacity of bicarbonate. This leads to increased sodium bicarbonate delivery to the distal tubule.
Source: jasn.asnjournals.org/content/17/9/2…
3⃣Hypochloremia opens voltage gated K channels in the collecting duct resulting in K efflux.
Source: ncbi.nlm.nih.gov/pubmed/21270092
But hypokalemia can maintain the alkalosis through activation of H/K ATPase and intracellular shifting.
For more alkalosis initiating (ie increase HCO3 concentration) and maintaining (ie poor HCO3 excretion) mechanisms, read the post! @renal_padawan
renalfellow.org/2019/12/16/ske…
With a total of 360 mEq of KCl, our patient's Na and K normalized per our correction goals of Na change of 6-8mEq/L/24 hours.
For more and a discussion of Cl salts and the influence correction of hypokalemia has on hyponatremia, read the post!
renalfellow.org/2019/12/16/ske…
For more about the case and a discussion of Cl salts and the influence correction of hypokalemia has on hyponatremia⚖️, read the post!
renalfellow.org/2019/12/16/ske…
ERRATA: GIF updated. Thanks @NephroMD
Key Points
⚡️Where did all the K go? Out the urine!
⚡️Alkalosis worsens hypokalemia, which can perpetuate the alkalosis...and worsen the hypokalemia...
⚡️Cl depletion needs Cl repletion
⚡️Repleting low K can rapidly correct low Na
@TheSkeletonKG @eljosemenap @SaynaNorouzi
@NephroMD Thanks, Dr. Rondon.
Share this Scrolly Tale with your friends.
A Scrolly Tale is a new way to read Twitter threads with a more visually immersive experience.
Discover more beautiful Scrolly Tales like this.