First time on the wards as a senior resident this week, with @ShreyaTrivediMD as my attending (talk about pressure to impress)!
I'm prepping a talk to my interns on Acute Kidney Injury. Here is a tweetorial 🧵 on how I think about AKI. Take-home graphics at the end!😀 /1
I'm prepping a talk to my interns on Acute Kidney Injury. Here is a tweetorial 🧵 on how I think about AKI. Take-home graphics at the end!😀 /1
Let's start with definition. What is an acute kidney injury (AKI)? /2
Any of the above! @goKDIGO defines AKI as any one of those three criteria. Which means...
You can have an AKI with a "normal" creatinine. It all depends on your baseline! /3
You can have an AKI with a "normal" creatinine. It all depends on your baseline! /3
🚨Some caveats:
GFR can only be measured in steady state, so by definition you CANNOT determine GFR in the middle of an AKI 📈
💊 Some common drugs can impair creatinine secretion, mimicking an AKI without actual renal injury. Pip-Tazo, TMP-SMX are some examples.
/4
GFR can only be measured in steady state, so by definition you CANNOT determine GFR in the middle of an AKI 📈
💊 Some common drugs can impair creatinine secretion, mimicking an AKI without actual renal injury. Pip-Tazo, TMP-SMX are some examples.
/4
Okay but let's say your patient has a true AKI. First step: triage🏥
When is it an emergency❓
What are the big 5 indications for urgent dialysis ⁉️
/5
When is it an emergency❓
What are the big 5 indications for urgent dialysis ⁉️
/5
Think of the mnemonic A.E.I.O.U.
Any one of these should prompt a phone call to your neighborhood nephrologist👩⚕️(and perhaps preparation to place a central HD line) /6
Any one of these should prompt a phone call to your neighborhood nephrologist👩⚕️(and perhaps preparation to place a central HD line) /6
In someone more stable who doesn't meet those criteria, we have some more time to investigate potential causes of that AKI.
I was taught to group AKI into 3 buckets🪣
⬇️Pre-renal
⬇️Renal
⬇️Post-renal
/7
I was taught to group AKI into 3 buckets🪣
⬇️Pre-renal
⬇️Renal
⬇️Post-renal
/7
But what do those mean? Let's agree on some definitions and then walk through a case together!
🩸Pre-renal: poor circulating blood volume
🌊Renal: intrinsic nephron injury
🪨Post-renal: urinary obstruction (distal to kidneys)
/8
🩸Pre-renal: poor circulating blood volume
🌊Renal: intrinsic nephron injury
🪨Post-renal: urinary obstruction (distal to kidneys)
/8
The Case📜:
55yo man admitted with an AKI after 2 days of low grade fever, diarrhea and malaise🤒. Urine looks pretty concentrated. Cause?
55yo man admitted with an AKI after 2 days of low grade fever, diarrhea and malaise🤒. Urine looks pretty concentrated. Cause?
We often think of pre-renal in the hypovolemic patient...
But what if this 55yo patient also has a history of heart failure🫀+ had been staying at home eating takeout🍲 + had an elevated JVP on exam?
But what if this 55yo patient also has a history of heart failure🫀+ had been staying at home eating takeout🍲 + had an elevated JVP on exam?
Decompensated heart failure❤️🔥can cause AKI from vascular congestion 🚦 limiting circulating blood volume - it's still pre-renal!
And our kidneys respond the same way to HF as they would to hypovolemia: by concentrating urine (which is a helpful clue!) /10
And our kidneys respond the same way to HF as they would to hypovolemia: by concentrating urine (which is a helpful clue!) /10
Continuing with the case➡️You start IV diuretics and his heart failure exacerbation, including his AKI, resolves. 😃
But on hospital day 3, he becomes oliguric. Bladder is enlarged on ultrasound. He realizes he forgot to mention tamsulosin as a home med💊. What's going on? /11
But on hospital day 3, he becomes oliguric. Bladder is enlarged on ultrasound. He realizes he forgot to mention tamsulosin as a home med💊. What's going on? /11
A classic post-renal example! Urinary tract obstruction and pressure buildup causing upstream injury
🌊 Think about functional vs. structural causes
🚨 Do not be fooled by overflow incontinence. If you suspect obstruction, get the bladder/renal ultrasound.
/12
🌊 Think about functional vs. structural causes
🚨 Do not be fooled by overflow incontinence. If you suspect obstruction, get the bladder/renal ultrasound.
/12
Our patient recovers and follows up in clinic 2 weeks later. He shares he had a gout flare🔥after discharge, but this slowly improved with some ibuprofen💊.
But his creatinine has doubled and urine microscopy🔬is below (taken from @UpToDate) /13
But his creatinine has doubled and urine microscopy🔬is below (taken from @UpToDate) /13
You can probably guess this is a renal injury ie involving the nephron. But which part? 🧐
/14
/14
Here is where more specialized testing like urine microscopy can be super helpful.
Learn how to spin the urine or ask Nephro Bros like @themarcusfoo and @immaculatedensa to help you. /15
Learn how to spin the urine or ask Nephro Bros like @themarcusfoo and @immaculatedensa to help you. /15
He's diagnosed with acute interstitial nephritis (a topic for another day).
You stop the ibuprofen and his creatinine returns to baseline. You are inspired to become a nephrologist at @BID_NephFellows🥳Great job! /16
You stop the ibuprofen and his creatinine returns to baseline. You are inspired to become a nephrologist at @BID_NephFellows🥳Great job! /16
If you made it this far, I hope you enjoyed this virtual chalk talk. Credits to @jwilliamMD and @LaurenBurdine for feedback on my take-home graphics (scroll down to see)!
Got feedback for me? Send me a DM or drop it in the comments! /17
Got feedback for me? Send me a DM or drop it in the comments! /17
Finally, for med students looking for their dream program, plz consider @BIDMC_IM.
Come train with amazing co-residents like @nsrosenberg @DanielaarangoMD @caseyjkim @benjamin_osh @MargaretL16 @kandersonMD21 @SK_Sundararaman @AaronTroyMD
This is how we do it.
/18
Come train with amazing co-residents like @nsrosenberg @DanielaarangoMD @caseyjkim @benjamin_osh @MargaretL16 @kandersonMD21 @SK_Sundararaman @AaronTroyMD
This is how we do it.
/18
Take-home graphic (1 of 2) /19
Take-home graphic (2 of 2) /end
Loading suggestions...