Rising #MedTwitter #MedX interns, here are my favorite approaches for acute inpatient medicine issues! 🚨

1) Hypoxemia, by @ClementLeeMD 🫁

Ditch the alveolar gas equation (sorry @PulmPEEPs) & use this practical approach.

https://x.com/ClementLeeMD/status/1531682388593545216

✍️ Dr. Lee's approach is summarized by @MatthewHoMD here, with Dx/Rx considerations by @Sophia_Hayes_MD.

https://x.com/MatthewHoMD/status/1531746062712549376

🩸 Paraprotein Evaluation 🩸

SPEP, SIFE, SFLC, UPEP, UIFE.

What do these abbreviations mean & how does one arrive to the land of paraproteinemias?

Here is a tweetorial for the internist diagnostician, in collaboration with @cullen_lilley! 🗻 The path to paraprotein evaluation may or may not begin with the observation of a "protein gap," meaning a (roughly) 4 g/dL difference between the serum Total protein & Albumin.

"Auto-antibody Craze" DDx 🔥

A short list of 🦓 diagnoses tied together by a rare, confusing disease signature.

Here's a super brief tweetorial. Signature ✍️

- Variable auto-antibody positivity → polyclonal hypergammaglobulinemia & autoimmune disease

- B-symptoms +/- LAD

What do I mean by variable auto-antibody positivity? Just take a look at these labs 👇

🫠 Approach to Hypotension 🫠

Recent ICU shifts = newfound appreciation for this clinical dilemma.

The traditional breakdown of hypotension/shock is very classic: my schema aims to sub-divide this framework & cover some new buckets.

Read on! 🧵 First, recall BP is a product of Cardiac Output * Systemic Vascular Resistance.

When assessing hypotension, cardiogenic etiologies should come to mind first because a markedly abnormal Heart Rate derangement may provide an up-front answer.

Think extremes:

- HR < 30

- HR > 150

🫀 Approach to HFpEF Dx 🫀

I loved creating this one-pager because my understanding of how to clinch this Dx shifted enormously throughout my intern year.

Turns out, "no diastolic dysfunction" on TTE doesn't = no HFpEF.

Let's go through the pathophys & see how this assists Dx. The pathophys of HFpEF first involves diastolic dysfunction.

(This may or may not be visualized on TTE; more on this in a second.)

With an expected ↑ LV-EDP during exercise (+/- at rest), LA pressure then ↑.

This will, chronically, lead to LA enlargement.

✨ TMA Schema 2.0 ✨

- Trigger: anemia + thrombocytopenia → (+) hemolysis & (–) DAT testing → (+) schistocytes on smear! 🔫

- Note 1: not all MAHA (non-immune hemolysis 2/2 RBC fragmentation) is caused by a TMA, but nearly all TMAs cause MAHA & thrombocytopenia 📚 📚 Note 2: unless concurrent blood disorder, coags = normal!

- More on the Hemolytic Anemia journey 🚶‍♀️ here:

https://twitter.com/MatthewHoMD/status/1497016074608463873?s=20&t=EHwjQiqwMhfQhgwkDqyXqQ

- More on the TMA journey 🚶‍♀️ here:

https://twitter.com/MatthewHoMD/status/1482538015222382592?s=20&t=EHwjQiqwMhfQhgwkDqyXqQ

Very pleased to close out 2022 with the opportunity to share important clinical lessons from a case just published in @BrownHospMed:

"Unilateral Pneumonitis and Hydropneumothorax Following Pembrolizumab" 🫁 💊

Case report available here: bhm.scholasticahq.com/article/39747-… Many thanks to @YaleIMed's Drs. Harriet Kluger & @PeterKahnMD for both their active involvement in this case & their support of this write-up.

Additionally, thankful to have had @yalepathology's Dr. Christine Minerowicz provide invaluable input on the pathology of this case.

💀 Pulmonary Infarction 💀

Is that focal chest consolidation a pneumonia? 🤔

Let's talk about a pneumonia mimicker that can be *very* easily missed if you've never seen it before 🎭 Pulmonary Infarction is the result of a simple series of events:

🩸 Pulmonary artery obstruction

↓

🩸 Alveolar hemorrhage & edema

☠️ If fluid not absorbed, RBC lysis & hemosiderin release leads to lung necrosis! ☠️

😵‍💫 Approach to Dizziness! 😵‍💫

4 big buckets:

- Pre-syncope
- Vertigo
- Imbalance/Dysequilibrium
- Psychiatric

This approach is very much a bird's eye view approach that should assist in history/data acquisition. I'll also cover a tricky don't-miss Dx. Dizziness 2/2 Pre-syncope:

🔴 History: "lightheadedness"

🔴 Pre-syncope DDx is stratified by the classic approach to syncope (orthostatic hypotension, reflex, cardiac)

Let's touch more on orthostatic hypotension, as this is not an endpoint Dx.

✨ Approach to Infiltrative Diseases 2.0 ✨

- After reading original 🧵 linked in this specific tweet, see new 🧵 below for beautified one-pager & illness scripts!

https://twitter.com/ASanchez_PS/status/1521863656350396417

Updated Lymphoma review:

https://twitter.com/ASanchez_PS/status/1574065624652730368?s=20&t=ySOlF-VD3N7k7RwJiOrnYA

🟤 Approach to Acute Hepatocellular Injury 🟤

The DDx of ↑ AST & ALT out of proportion to ↑ in cholestatic labs is easy for most.

BUT! I think some can't-miss conditions are frequently left out by early learners.

Here's a diagnostic approach that'll prioritize those causes. Acute hepatocellular injury = 3 P's.

- Plumbing (Biliary & Vascular)
- Pregnancy
- Parenchyma

🍺 EtOH-associated Hepatitis 🍺

- A diagnosis that considers careful consideration of history & entire clinical presentation.

- If fever, must consider occult infection prior to steroids.

- All should be offered an addiction medicine consultation (@DrMelissaWeimer). Maddrey discriminant function calculator here: mdcalc.com/calc/56/maddre…

Courtesy of @grahamwalker's wonderful site

How I teach students & interns on rounds without 📜 & ✒️:

1) "You'll get an email summary at end of the day. Feel free to not take notes!"

2) Verbal teaching 5-10 minutes

3) Send durable educational resource vs. new, free-form bulleted teaching via email! I usually do both! 💭 Tips 💭:

1) Save & keep your resources organized!

I use @msonenote & @GlassHealthHQ & @appleicloud for collecting/organizing notes that ultimately get sent to my learners:

🦀 Approach to Lymphomas 🦀

Re-sharing this updated framework with some increased organization, new references, & more specific terminology.

Let's take this ride again! 🔬 Previously, a lymphoid neoplasm of the marrow/blood = leukemia, solid lymph node (LN) neoplasm = lymphoma

🔬 However, many "lymphomas" can evolve into "leukemia," & vice-versa

🔬 Now, the WHO classifies lymphoid neoplasms based on cell of origin

https://twitter.com/matthew_mei/status/1518691577983496192?s=20&t=9mVBZMlcxa14UcfqJWmlng

🟡 DDx of AKI 🟡

AKI is a proximal diagnosis requiring a final etiological explanation.

In other words, when encountering AKI, one must ask, "why?"

Here's a one-pager organized by AKI's etiological buckets, which encourage the pursuit of an endpoint diagnosis! This framework inspired by:

1) @JFBirnbaum @HollandKaplan @PrathitKulkarni

More on "endpoint diagnoses" (authors above) here: pubmed.ncbi.nlm.nih.gov/35942949/

2) My lack of a one-pager capturing *all* etiological buckets of AKI

💥 Monoclonal Gammopathies of Clinical Significance! 💥

Everyone knows MGUS.

Monoclonal proteins are simply blameless protein markers until clonal B-cells progress to Myeloma, Waldenstrom's, or another disorder, right?

...It turns out, not quite!

Let's explore! First, some review. Where does monoclonal protein come from?

- Clonal B-cells 👉 Monoclonal protein secretion

- Such protein is also called "M-protein" or "Paraprotein"

Ref: @cullen_lilley

🪟 Pulmonary Alveolar Proteinosis (PAP) 🪟

- Rare cause of insidious-onset dyspnea on exertion
- On DDx of Crazy Paving on chest CT
- Due to 👇 production/clearance of surfactant What is Crazy Paving?

🪟 Ground glass opacification (GGO) w/ superimposed thickening of interlobular septa & intralobular interstitium

🪟 See below for anatomy of the secondary pulmonary lobule!

🪟 Graphics by @LandsbergManual

💥 Approach to Elevated Tryptase 💥

A patient without a history suspicious for anaphylaxis or angioedema presents with an elevated serum tryptase.

How do we interpret this uncommonly sent lab test? 🐉 Tryptase (along with histamine) is the most abundant & best characterized preformed granule released by mast cells.

🐉 Mast cells release tryptase (among other molecules) upon stimulation by:

- Allergens
- Drugs
- Toxins
- Physical stimuli
- Infections

Playing around w/ @AndreMansoor's polyneuropathy framework! Time-course of neuropathic symptoms provides clue toward Axonal vs. Demyelinating disease (labeled in framework above):

🕑 WEEKS-MONTHS = axonal etiology

🕑 CHRONIC = demyelinating etiology

✨ Approach to Infiltrative Diseases! ✨

This framework was inspired by @Gurpreet2015's recent Clinical Problem Solving Grand Rounds for @UCSFDOM. Many teaching points on this DDx also passed down by the @CPSolvers.

First, what are the Infiltrative Diseases? On a quick search, I couldn't find a universal, clear-cut definition for the Infiltrative Diseases, but these diseases all have something in common:

Cellular vs. Molecular infiltration of tissue

👇

(Multi)organ dysfunction

Framing lymphomas for clinical reasoning: a Herculean task given long list of diseases in our world of molecular biology.

Here's my first attempt at a summary:

1/11 Word on Classification:
🔬 Previously, a lymphoid neoplasm of the marrow/blood = leukemia, solid lymph node (LN) neoplasm = lymphoma
🔬 However, any "lymphoma" can evolve into a "leukemia," & vice-versa
🔬 Now, the WHO classifies lymphoid neoplasms based on cell of origin!

2/11