Nick Mark MD Profile picture
Intensivist, pulmonologist | Husband, Dad² | made @OnePagerICU | passionate about MedEd & innovation in medicine #ML/#AI |
Ross Grayson, MPH, CIH Profile picture Bharat Balan, MD, MS Profile picture Graham Nichol Profile picture Anoop Singh Ranhotra Profile picture Johnny Profile picture 14 subscribed
May 28 7 tweets 5 min read
Pulmonary teaching case: you are called to the bedside of a 60yo man who was admitted for pneumonia a week ago. You were called because “he coughed and now his chest is PULSATING!”

This is what you see at the site of a previously removed chest drain:

What’s the diagnosis?
1/… This is Empyema necessitans (EN):

EN is a rare complication of an infected pleural effusion where purulent fluid “escapes” the pleura and erodes into the chest wall, causing an extrapleural fluid collection that communicates with the pleural space.

From @Radiopaedia:
May 25 7 tweets 3 min read
Interesting RCT in @NEJM about platelet transfusions prior to CVC placement in people w/ thrombocytopenia (Plt 10-50k):
- higher rate of grade 2-4 bleeding w/o Plt transfusion: 11.9% vs 4.9%
- difference driven by much more bleeding w/ subclavian lines…
1/ Image This trial enrolled n=338 hospitalized people in 🇳🇱 with platelets between 10-50k, INR <1.5 (changed to 3.0). 57% were heme/onc patients & 43% were ICU patients.

Median Plt count was 30k

Most were getting a CVC for chemoTx. (Most weren’t exactly your “typical” ICU patient.)
2/ ImageImage
May 24 6 tweets 4 min read
ATS’ Leadership are in a Kobiyashi Maru situation with #ConferenceGate
- one one hand, they signed a terrible contract and stand to lose a ton of money if they pull out of Orlando
- the other hand, they risk having no one show up & alienating most of their members
1/ People are angry. Seeing how many green ribbons there are at ATS, it’s dawning on ATS’ leadership that they screwed up big time.

They wonder: Will these people boycott Orlando 3 times in the next decade? Will they keep paying dues? Is this an existential threat to the org?
May 14 10 tweets 4 min read
You've probably heard that Bicarbonate has to turn into CO2 to raise the pH. “Don’t give bicarb if you can’t increase ventilation.”

But how much CO2 is there in an amp of sodium bicarbonate?

A bicarb 🧵
1/ Image Sodium bicarbonate raises the pH by binding H+ ions and turning into CO2 and water.

For my fellow 🧪 nerds, I’ll write:

HCO3 (aq) + H+ (aq) --> CO2 (g) + H2O (l)

2/ Image
May 13 7 tweets 4 min read
Real shitty explanation by @atscommunity about where they plan to hold future conferences.

TL/DR: On one hand they had to consider safety & inclusion, on the other hand ATS’ sterling “reputation in the meetings industry.” They prioritized the latter.… ImageImage I’m disappointed that they have prioritized profit over the concerns of members.

Frankly, I would have been willing to pay higher dues, higher conference fees, legal fees, etc if the financial concerns had been raised transparently.

Instead they decided unilaterally.
Apr 15 5 tweets 3 min read
Here’s a fun medical puzzle: what does this antidote (Sugammadex) have in common with this cleaning product (Febreze)?

1/ ImageImage The answer is the chemical structures for both are cyclodextrins!

Sugammadex Febreze ImageImage
Apr 13 9 tweets 3 min read
This is an important & thought provoking meta-analysis about the potential harms of propofol.

I think this should (& almost certainly will) inspire important future studies.

But it won’t change my practice in the ICU quite yet. Here’s a 🧵 about why.
1/ First, this finding was driven by OR mortality, particularly in cardiac surgery patients.

ICU mortality was non-significant. (p=0.5). Additionally this is an unadjusted p-value, so if we correct for multiple comparisons it’s even more insignificant.

2/ Image
Apr 2 12 tweets 7 min read
Much has been made of the declining life expectancy in the US.

The reality is regional. Think of the US as two countries:

Some blue counties with increasing life-expectancy better than 🇯🇵 (84) & many red counties with plummeting life expectancy worse than 🇷🇺 (71).
1/ Compare the narrow variation between prefectures in Japan (range 82-84) with the wide variation among US states (range 71-81).



Mar 12 14 tweets 8 min read
The usual anti-vax suspects are talking about a paper “proving masks raise CO2 to harmful levels.”

Well I read it and it’s a bunch of non clinical wackos who used the wrong equipment to accidentally measure end tidal CO2.

A debunking 🧵

1/ Before we get to the paper with it’s very flawed methods & conclusions, let’s talk about the authors.
Mar 3 7 tweets 2 min read
In 2021, Stella Immanuel wrote over 69,000 prescriptions for hydroxychloroquine & almost 32,000 prescriptions for ivermectin.

This continued in 2022, with 30,996 prescriptions for hydroxychloroquine & 16,085 for ivermectin.

Why don’t medical boards act?… To put this another way 69k / 365 = 189 Rx per day

Even if she worked 12 hours every day, that’s 14 Rx per hour. Or one every 4 minutes.

There is simply no way she could have taken a history, reviewed medications/allergies & adequately counseled about the risks/benefits.

Feb 26 4 tweets 2 min read
Like all quacks, the FLCCC’s claims about their miracle cures get ever bigger with time.

Now, despite a glut of negative RCTs in COVID, they claim that ivermectin cures influenza & RSV.

Anything to keep the snake oil gravy train running.… Fact check: Marik was fired (he claims he resigned) from EVMS in late 2021. With no institution willing to hire him, he was *unable* to renew his university limited license. His license to practice medicine expired in 2022.

Feb 25 25 tweets 14 min read
Here’s a critical care puzzle & illustrates some important cardiopulmonary physiology:

These two pictures were taken just an hour apart. What intervention was done in between that changed the respiratory pattern? (Red box)

Multiple choice & answers in the 🧵.

1/ ImageImage The intervention was:

Dec 21, 2022 9 tweets 5 min read
A man comes to the ICU after uncomplicated cardiac surgery. He is hypertensive and a nicardipine infusion is started. 10 minutes later he becomes hypoxemic. A chest radiograph is obtained.

What happened?

1/ Image Here's some followup: an intervention was performed & hypoxemia resolved. These two CXR are taken 15 minutes apart.

What was done?


Pre: Post: ImageImage
Dec 11, 2022 20 tweets 9 min read
Here's a physiology case that *everyone* who touches a ventilator needs to understand:

A 60 yo woman is intubated for hypoxemia from multifocal pneumonia.
She has a SpO2 of 89% on PEEP +12 and 100% FiO2.
PEEP is increased to +16 & her SpO2 drops to 80%!

What happened?

1/ Before we get into the answer, let's make it interesting with some multiple choice.

Which mechanism(s) could cause worsening hypoxemia with increasing PEEP?

Dec 6, 2022 12 tweets 6 min read
Important ICU teaching case:
A woman with AL amyloidosis presents with hemorrhagic shock from a GI bleed. HR 130, BP 80s/40s, Hb 4.5. She’s been receiving CyBorD-Dara chemotherapy up until 1 month ago.

What crucial fact do you need to remember when ordering blood transfusions? The answer is that daratumumab (an anti-CD38 monoclonal) interferes with antibody screening & crossmatch!

In order to understand *why* this occurs we need to step back and review how blood is tested for compatibility.

Buckle up for a🧵! Let’s get our Coombs on, indirectly.
2/ ImageImage
Dec 6, 2022 4 tweets 3 min read
This is incremental.

During my undergrad @BrownUniversity I remember when researchers did this in *humans*: A man with quadriplegia controlled a computer or robotic limb using a brain-machine interface. It was on the cover of @Nature. That was in 2006.… More hilarious is in a “groundbreaking paper” ostensibly written by Elon & published in the Journal of Internet Medical Research, they claim it’s “plausible a person may someday control a digital mouse” w/ this technology.

Ignoring the fact that it was accomplished >15 yrs ago!
Dec 3, 2022 5 tweets 3 min read
Here’s an ECG with a pathognomonic finding that everyone ought to know, especially at this time of year. Image Explanation: this is an example of Osborn Waves seen in a person whose core temp was 28°C.

Osborn waves are positive deflections that occur at the J point. They are seen in hypothermia (T usually <32C) and typically more pronounced at lower temperatures. ImageImage
Nov 19, 2022 11 tweets 6 min read
Here’s a fun ICU puzzle: what is causing this crazy spiking pattern on the ECG waveform of both an intra-aortic balloon pump & ICU monitor?

A #MedEd 🧵 on an important clinical artifact & the triboelectric effect that we’ll need to go back in time 2500 years to understand!

1/ ImageImage Before we get to the cool physics behind this important clinical artifact, what device could attached to the patient that’s causing these crazy spikes on the EKG?

Nov 13, 2022 7 tweets 5 min read
Thousands have made the jump from #MedTwitter to #MedMastodon!

One issue I’ve heard is “I can’t get the app to work” or “I can’t find the server”

Good news: there are many mobile apps to choose from. Personally I think Meta-text & Tooot are easier to setup.

Here’s how.🧵
1/ 1️⃣ Setup a #MedMastodon account:

The easiest way is just follow this invite

You should see something like this.👇

Choose a name (or “handle”), enter your email address, & makeup a (secure) password.

That’s it!

Nov 11, 2022 5 tweets 2 min read
Nomenclature question: what do you call it if someone has an elevated PaCO2?

Medically they are synonyms. Both terms - hyperCAPNia & hyperCARBia - *mean* the same thing: having an increased PaCO2.

But the difference is a really big deal if you are a linguist.

Nov 11, 2022 4 tweets 3 min read
Ok so #TwitterChaos is hilarious & as a bonus we’ll never need to see adds from these companies on Twitter again.

1/ Continued…