Thread by @ClementLeeMD

1/14
Rapid Response Series, #4: Altered Mental Status

Congrats to all the new interns who started this past week! 🥳 I saved a fun topic for this milestone—something all doctors will see regardless of specialty: encephalopathy

#MedTwitter #TipsForNewDocs

2/14
This one is hard to tackle because it runs the whole gamut of diagnoses, from benign things like sleep inertia 😴 to life threatening conditions like osmotic demyelination syndrome.

However, I’ll try to supply some frameworks I find to be helpful.

3/14
In medicine, pretest probability is always useful.🧮 But it’s especially useful for AMS.

What’s the most common cause of AMS in young individuals presenting to the ED?

4/14

In those age <60, the #1 cause is actually intoxication or withdrawal.☠️

What's the most common cause of AMS in the elderly? 👴

5/14
In those age ≥60, the list is more varied: top 3 are cerebrovascular disease 🧠, organ failure, and infections 🦠

(PMID 25215076; caveat: study was in an ED in China)

6/14
We also know setting does matter—for example, in the ICU, the “ICU triad” (pain, agitation, delirium) should be considered. 🏥

In the geriatric wards, the prevalence of delirium is as high as 29% (PMID 23992774) 👵

7/14
With pretest in mind, we can now run through a mnemonic for AMS.

Many of them exist (“MOVE STUPID,” “MIST”), but I felt none of these encapsulated everything.

I use “CHIPOTLE Vitals,” which I feel captures everything. Also, I love burritos. 🌯 @ChipotleTweets

8/14
C- constipation
H- head/intracranial
I- infection
P- psych
O- organ failure
T- toxin/withdrawal
L- lytes
E- endo

Vitals- any VS abnormality, including pain (!)

This one reminds me that bowel/bladder sx 💩 may cause agitation in the elderly or those who can’t communicate.

9/14
Now sometimes we need to act before have answers. A senior resident once taught me to “DON’T” forget some easy interventions: Dextrose, O2, Naloxone, and Thiamine. 💉

These are low risk and may help quickly reverse some specific cases of AMS.

10/14
If you have more time, here is some guidance on workup.

H & P can diagnose 40% & 20% of causes, respectively (PMID 25215076)

For labs, both the APA and ACEP recommend CBC, BMP, and UA initially. The APA also recs LFTs and an ABG, but evidence for this is weaker. 🩸

11/14
I feel like this deserves its own Tweet: DO NOT SEND AN AMMONIA. 🙅🏻‍♂️ #TWDFNR

There is a short list of things that raise arterial ammonia levels, and testing should be based on suspicion of those specific (rare) diseases.

12/14
Notice that head CT was also not mentioned—this rarely (15% of the time) leads to a diagnosis, but if there are obvious focal neuro deficits or high-risk trauma, makes sense to obtain. 🩻

13/14
A last pearl I have is that screening for delirium can be very simple— in one study, a wrong answer to “what type of place is this?” had a +LR of 30, nearly pathognomonic for delirium. 🤨❓🏨

(PMID 26369992)

14/14
That’s all! What are some other pearls #MedTwitter and #NeuroTwitter have on tackling AMS?

@AaronLBerkowitz @rabihmgeha @caseyalbin @TimRowesays @BageLeMage

I’m a Twitter noob and messed up this thread 😂 but the next tweet is here: