20 Tweets 17 reads Nov 22, 2020
1/ 📢Hello #MedTwitter
We recently had an interesting case-based discussion @ASPNeph pathology webinar.
Here’s what I learned about💥Rhabdomyolysis💥(RM) and AKI!
Let's begin with a poll:
Which one of these is true about RM?
#tweetorial #NephTwitter
2/ Ans: All the above.
💥Rhabdomyolysis💥
The disintegration of skeletal muscle→ release of intracellular constituents (myoglobin, electrolytes & Uric acid) into ECF & circulation
3/Let’s review 💥pathophysiology💥:
📌Myoglobinemia→ intrarenal vasoconstriction→ direct and ischemic tubule injury
📌Myoglobinuria→ cast formation & tubular obstruction→ cast nephropathy
nejm.org
4/ 💥What are the causes of RM-
While the list is long, some common reasons include-
📌trauma
📌ischemia
📌drugs
📌toxins
📌metabolic disorders
📌infections (#COVID19, the new kid on the block)
5/ It is important to remember 💥medications💥.
Which of the following medications cause RM?
6/ All the above
💥Drugs like statins, anti-psychotics, antidepressants, particularly when used with drugs inhibiting CYP450 and CYP3A4 can lead to RM.
Here’s a quick review of drugs.
7/💥 Is AKI and CK levels related?!
The risk of AKI is low if CK level < 15,000 to 20,000 U/L
⚡️exceptions are⚡️
📌Sepsis
📌Dehydration
📌Acidosis
In these conditions, AKI is seen with CK levels as low as 5000 U/L
jamanetwork.com
8/💥 What are the initial complications of RM induced AKI?
#boardreview @RoshanPGeorgeMD
9/ Ans-Hypocalcemia
💥Complications💥 of RM
📌↓Ca: entry of Ca into ischemic muscle cells & precipitation of Ca-Phos
📌↑Ca (during recovery): mobilized from the muscles cell
📌↑K, Phos, Uric acid & Mg: released from damaged cells, ↓ clearance if AKI
📌HAGMA (if AKI present)
10/ 💥Diagnosis💥
📌📝History
📌UA: myoglobinuria → ➕heme (dipstick)
📌🔬microscopy: ➕myoglobin casts, ➖ RBC
📌🧪Labs: ↑creatinine, ↑CK & dyselectrolytemias
11/ 💥Biopsy is not usually necessary, but when performed shows-
⚡️myoglobin cast nephropathy⚡️
reddish globular casts in distal tubule with associated acute tubular injury (H&E stain)
ajkd.org
12/💥 Main treatment approach to prevent AKI is 🌊🥤Hydration💧💦
📌Isotonic fluids are preferred
📌hydrate to maintain a urine output of at least 200 mL/h
📌hydrate until CK level below 1000 U/L
13/💥 Is alkalinization of urine recommended?
Well, data is inconsistent and conflicting!
⚡️Alkalinisation⚡️ of urine →
📌↓cast formation by ↑excretion of myoglobin,
📌stabilizes myoglobin- Ferrin complex (↓oxidative damage)
📌↓renal vasoconstriction
📌↓risk of hyper K
14/ 💥RCTs are needed to determine if the addition of bicarbonate and mannitol therapy is of any benefit.
Here are some studies that looked into it-
15/ When is dialysis/ KRT recommended?
📌Resistant symptomatic hyperkalemia (>6.5 mEq/L) or rapidly rising serum K
📌Oliguria (<0.5 mL/Kg for 12 hours) or, anuria +/- volume overload
📌Resistant metabolic acidosis (pH<7.1)
17/ 💥What’s a better modality in removing myoglobin from circulation?
📌iHD- does not remove myoglobin
📌CRRT (CVVHF and CVVHDF)- super high-flux filters & high volumes of ultrafiltration (convection) can remove myoglobin
📌Plasmapheresis: not effective
karger.com
18/ 💥Newer therapies💥
📌Antioxidants (pentoxifylline, Vit E, & Vit C)→ possibly ↓tubular free radical injury
📌Acetaminophen- ↓free radical formation (Boutaud 2010)
📌Recently, complement activation was shown as🔑driver of AKI, with complement blocking as a potential Rx
19/ 💥Prognosis of AKI:
In ICU patients,
📌59% mortality when AKI is present
Versus
📌22% when no AKI.
nejm.org
20/ 💥Thank you for scrolling till the end!
That’s all for today, let's end with a quick poll.
At what point would you admit a patient with isolated RM for hydration?

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