Johannes Enevoldsen
@johsenevoldsen.bsky.social
MD, PhD. Anaesthesiology trainee. Interested in health, statistics and scientific programming (R and Julia)
Pinned
The central venous pressure (CVP) waveform is the interaction between a fast cyclic effect of the heart and a slower cyclic effect of ventilation.
A steady CVP waveform can be visualized as a 3D plane.
🩺
(Old Twitter post)
A steady CVP waveform can be visualized as a 3D plane.
🩺
(Old Twitter post)
Reposted by Johannes Enevoldsen
I am on the job market and wanted to advertise myself here! 🤠
Looking for full-time or contracting roles!
Historically, my work spans population dynamics, healthcare informatics, robust adaptive controls, software engineering, and community engagement. 🧪
#STEMjobs #academicsky #publichealth
Looking for full-time or contracting roles!
Historically, my work spans population dynamics, healthcare informatics, robust adaptive controls, software engineering, and community engagement. 🧪
#STEMjobs #academicsky #publichealth
November 4, 2025 at 6:31 PM
I am on the job market and wanted to advertise myself here! 🤠
Looking for full-time or contracting roles!
Historically, my work spans population dynamics, healthcare informatics, robust adaptive controls, software engineering, and community engagement. 🧪
#STEMjobs #academicsky #publichealth
Looking for full-time or contracting roles!
Historically, my work spans population dynamics, healthcare informatics, robust adaptive controls, software engineering, and community engagement. 🧪
#STEMjobs #academicsky #publichealth
I don't understand the relationship between CO and ETCO2.
ETCO2 increases with rising CO, if ventilation and CO2 production is constant.
Is this just temporary?
We can't exhale more CO2 than we produce.
#anSky #medSky
@doctorhelgi.bsky.social
@load-dependent.bsky.social
@jm-l.bsky.social
ETCO2 increases with rising CO, if ventilation and CO2 production is constant.
Is this just temporary?
We can't exhale more CO2 than we produce.
#anSky #medSky
@doctorhelgi.bsky.social
@load-dependent.bsky.social
@jm-l.bsky.social
October 30, 2025 at 8:36 PM
I don't understand the relationship between CO and ETCO2.
ETCO2 increases with rising CO, if ventilation and CO2 production is constant.
Is this just temporary?
We can't exhale more CO2 than we produce.
#anSky #medSky
@doctorhelgi.bsky.social
@load-dependent.bsky.social
@jm-l.bsky.social
ETCO2 increases with rising CO, if ventilation and CO2 production is constant.
Is this just temporary?
We can't exhale more CO2 than we produce.
#anSky #medSky
@doctorhelgi.bsky.social
@load-dependent.bsky.social
@jm-l.bsky.social
Reposted by Johannes Enevoldsen
There's a puzzle I've found annoying so I thought I'd let you find it annoying too: kucharski.substack.com/p/why-the-tu...
October 15, 2025 at 7:52 PM
There's a puzzle I've found annoying so I thought I'd let you find it annoying too: kucharski.substack.com/p/why-the-tu...
Reposted by Johannes Enevoldsen
Small blog post on how to automate model building for mechanical systems using ModelingToolkit. #julialang
michielstock.github.io/posts/2025/p...
michielstock.github.io/posts/2025/p...
June 18, 2025 at 7:21 PM
Small blog post on how to automate model building for mechanical systems using ModelingToolkit. #julialang
michielstock.github.io/posts/2025/p...
michielstock.github.io/posts/2025/p...
Reposted by Johannes Enevoldsen
Thanks for the reminder @janemunday.bsky.social. Every summer, I repost this article DROWNING DOES NOT LOOK LIKE DROWNING. To date, I know of FOUR kids who were saved after someone who'd clicked on the link learnt how to spot actual drowning. Take time to read and pass on.
slate.com/technology/2...
slate.com/technology/2...
Drowning Doesn’t Look Like Drowning
Drowning is not the violent, splashing call for help that most people expect.
slate.com
June 19, 2025 at 4:22 PM
Thanks for the reminder @janemunday.bsky.social. Every summer, I repost this article DROWNING DOES NOT LOOK LIKE DROWNING. To date, I know of FOUR kids who were saved after someone who'd clicked on the link learnt how to spot actual drowning. Take time to read and pass on.
slate.com/technology/2...
slate.com/technology/2...
Reposted by Johannes Enevoldsen
Absolutely fascinating! We know the heart switches to lactate as energy substrate in shock, could there be a clinical benefit from lactate infusion in human cardiogenic shock? #emimcc #cccsky
Lactate infusion enhances cardiac output and peripheral perfusion in ischemic cardiogenic shock without affecting heart rate or systemic blood pressure, finds a study published in Critical Care.
#MedSky
#MedSky
Lactate infusion improves cardiac function in a porcine model of ischemic cardiogenic shock
Critical Care
bit.ly
June 13, 2025 at 2:22 PM
My cardiac arrhythmia simulation now also simulates how a reentrant loop can be terminated by increasing refractory time as suggested by @empoisonpharmd.bsky.social
Direct link to the updated part:
jenevoldsen.com/posts/excita...
Direct link to the updated part:
jenevoldsen.com/posts/excita...
May 26, 2025 at 3:46 AM
My cardiac arrhythmia simulation now also simulates how a reentrant loop can be terminated by increasing refractory time as suggested by @empoisonpharmd.bsky.social
Direct link to the updated part:
jenevoldsen.com/posts/excita...
Direct link to the updated part:
jenevoldsen.com/posts/excita...
Reposted by Johannes Enevoldsen
✨ It's new samwho visual essay o'clock! ✨
Reservoir sampling is one of my favourite algorithms. It allows you to sample from a set without knowing the size of that set.
I try to assume no prior knowledge, and use no scary math notation. Just beautiful visuals.
Let me know what you think! ❤️
Reservoir sampling is one of my favourite algorithms. It allows you to sample from a set without knowing the size of that set.
I try to assume no prior knowledge, and use no scary math notation. Just beautiful visuals.
Let me know what you think! ❤️
May 8, 2025 at 3:27 PM
✨ It's new samwho visual essay o'clock! ✨
Reservoir sampling is one of my favourite algorithms. It allows you to sample from a set without knowing the size of that set.
I try to assume no prior knowledge, and use no scary math notation. Just beautiful visuals.
Let me know what you think! ❤️
Reservoir sampling is one of my favourite algorithms. It allows you to sample from a set without knowing the size of that set.
I try to assume no prior knowledge, and use no scary math notation. Just beautiful visuals.
Let me know what you think! ❤️
Reposted by Johannes Enevoldsen
I just want to say I use this constantly at the bedside when dealing with patients who have arrythmias to explain how they propagate.
would LOVE LOVE a model where increasing refractory terminates reentrant rhythm so I can show how diltiazem terminates SVT.
such an amazing tool, thank you
would LOVE LOVE a model where increasing refractory terminates reentrant rhythm so I can show how diltiazem terminates SVT.
such an amazing tool, thank you
I wrote a short interactive article👆
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
April 29, 2025 at 6:33 PM
I just want to say I use this constantly at the bedside when dealing with patients who have arrythmias to explain how they propagate.
would LOVE LOVE a model where increasing refractory terminates reentrant rhythm so I can show how diltiazem terminates SVT.
such an amazing tool, thank you
would LOVE LOVE a model where increasing refractory terminates reentrant rhythm so I can show how diltiazem terminates SVT.
such an amazing tool, thank you
A 10-minute movie in a 6.3-second looping GIF.
Movie: Sprite Fright (#Blender open movie): studio.blender.org/projects/spr...
Code (#JuliaLang and @makie.org)
gist.github.com/JohannesNE/2...
Movie: Sprite Fright (#Blender open movie): studio.blender.org/projects/spr...
Code (#JuliaLang and @makie.org)
gist.github.com/JohannesNE/2...
April 8, 2025 at 10:09 AM
A 10-minute movie in a 6.3-second looping GIF.
Movie: Sprite Fright (#Blender open movie): studio.blender.org/projects/spr...
Code (#JuliaLang and @makie.org)
gist.github.com/JohannesNE/2...
Movie: Sprite Fright (#Blender open movie): studio.blender.org/projects/spr...
Code (#JuliaLang and @makie.org)
gist.github.com/JohannesNE/2...
Reposted by Johannes Enevoldsen
Fellow #JuliaLang enthusiasts in Europe, I've got 4 words for you.
JuliaCon Local Paris 2025
Yes, it's happening. Like the global @juliacon.bsky.social event, but with more croissants. Stay tuned!
JuliaCon Local Paris 2025
Yes, it's happening. Like the global @juliacon.bsky.social event, but with more croissants. Stay tuned!
JuliaCon Local Paris 2025
JuliaCon Local Paris 2025
juliacon.org
March 11, 2025 at 5:52 PM
Fellow #JuliaLang enthusiasts in Europe, I've got 4 words for you.
JuliaCon Local Paris 2025
Yes, it's happening. Like the global @juliacon.bsky.social event, but with more croissants. Stay tuned!
JuliaCon Local Paris 2025
Yes, it's happening. Like the global @juliacon.bsky.social event, but with more croissants. Stay tuned!
Where I could really see a place for LLMs in medicine right now, is not for decision-making, but for understanding a patient's medical records in a reasonable time.
- Find plans for this admission, that were never followed up upon.
- Give a short review of the pt's medical history.
...
- Find plans for this admission, that were never followed up upon.
- Give a short review of the pt's medical history.
...
For everyone thinking that we simply tell doctors they should *not* use LLMs for decision making and that they will listen to that, just look at these numbers:
"76% of respondents reported using general-purpose LLMs in clinical decision-making"
www.fiercehealthcare.com/special-repo...
"76% of respondents reported using general-purpose LLMs in clinical decision-making"
www.fiercehealthcare.com/special-repo...
Some doctors are using public AI chatbots like ChatGPT in clinical decisions. Is it safe?
Nineteen-year-old Lia was at a follow-up appointment at a boutique dermatology practice in New York City. She was interested in a prescription for hair growth. Since she was already on another medicat...
www.fiercehealthcare.com
February 25, 2025 at 9:00 AM
Where I could really see a place for LLMs in medicine right now, is not for decision-making, but for understanding a patient's medical records in a reasonable time.
- Find plans for this admission, that were never followed up upon.
- Give a short review of the pt's medical history.
...
- Find plans for this admission, that were never followed up upon.
- Give a short review of the pt's medical history.
...
Reposted by Johannes Enevoldsen
The Hypotension-Prediction Index--a convoluted way of predicting hypotension by...checking whether the MAP is low--fails once again. Shocker.
"HPI-guided hemodynamic therapy did not reduce the incidence of postoperative AKI or overall complications [vs] standard care."
"HPI-guided hemodynamic therapy did not reduce the incidence of postoperative AKI or overall complications [vs] standard care."
Hemodynamic Management guided by the Hypotension Prediction ... : Anesthesiology
erate-to-high-risk elective abdominal surgery patients.
Methods:
This multicenter randomized trial was conducted from October 2022 to February 2024 across 28 hospitals evaluating HPI-guided managem...
journals.lww.com
February 1, 2025 at 3:26 AM
The Hypotension-Prediction Index--a convoluted way of predicting hypotension by...checking whether the MAP is low--fails once again. Shocker.
"HPI-guided hemodynamic therapy did not reduce the incidence of postoperative AKI or overall complications [vs] standard care."
"HPI-guided hemodynamic therapy did not reduce the incidence of postoperative AKI or overall complications [vs] standard care."
I wrote a short interactive article👆
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
February 20, 2025 at 12:23 PM
I wrote a short interactive article👆
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
It uses simulations to demonstrate how different cardiac arrhythmias can develop.
Try it out! (It has defibrillators ⚡️)
jenevoldsen.com/posts/excitable-cells
#medsky #cardiosky #cccsky #emimcc
I'm writing an interactive article demonstrating how certain cardiac arrhythmias can develop.
Feedback is very welcome!
jenevoldsen.com/posts/excita...
#CardioSky #MedSky
@load-dependent.bsky.social @zentensivist.bsky.social @nickmark.bsky.social @kdpsingh.bsky.social
Feedback is very welcome!
jenevoldsen.com/posts/excita...
#CardioSky #MedSky
@load-dependent.bsky.social @zentensivist.bsky.social @nickmark.bsky.social @kdpsingh.bsky.social
Johannes Enevoldsen - Excitable cells (draft version)
A demonstration of how reentry tachyarrhythmias can develop in a system of excitable cells.
jenevoldsen.com
February 16, 2025 at 12:34 PM
I'm writing an interactive article demonstrating how certain cardiac arrhythmias can develop.
Feedback is very welcome!
jenevoldsen.com/posts/excita...
#CardioSky #MedSky
@load-dependent.bsky.social @zentensivist.bsky.social @nickmark.bsky.social @kdpsingh.bsky.social
Feedback is very welcome!
jenevoldsen.com/posts/excita...
#CardioSky #MedSky
@load-dependent.bsky.social @zentensivist.bsky.social @nickmark.bsky.social @kdpsingh.bsky.social
Reposted by Johannes Enevoldsen
It’s mostly nonsense anyways
Wait for the trials to come out
www.nephjc.com/news/landmar...
ajkdblog.org/2021/06/16/c...
Wait for the trials to come out
www.nephjc.com/news/landmar...
ajkdblog.org/2021/06/16/c...
Are Calcium-based Phosphate binders bad? A Rant/Commentary — NephJC
How strong is the evidence against calcium based PO4 binders? Swap breaks it down in his usual style
www.nephjc.com
January 9, 2025 at 5:10 PM
It’s mostly nonsense anyways
Wait for the trials to come out
www.nephjc.com/news/landmar...
ajkdblog.org/2021/06/16/c...
Wait for the trials to come out
www.nephjc.com/news/landmar...
ajkdblog.org/2021/06/16/c...
I recently had an equivalent experience with understanding calcium-phosphate disorder in CKD... 🫠
Today, for a brief moment, odds ratios made sense to me. I understood the odds, their ratios. It was beautiful, like catching smoke in the palm of my hand. But that moment is now gone. Like tears in rain. #StatsSky
January 9, 2025 at 4:29 PM
I recently had an equivalent experience with understanding calcium-phosphate disorder in CKD... 🫠
What do we think about adjusting p-values for safety outcomes for multiple testing, and then claiming no significant harm?
Is this common practice? Any papers commenting on the (in)appropriateness?
#statsSky
@stephensenn.bsky.social
@statsepi.bsky.social
@f2harrell.bsky.social
Is this common practice? Any papers commenting on the (in)appropriateness?
#statsSky
@stephensenn.bsky.social
@statsepi.bsky.social
@f2harrell.bsky.social
January 9, 2025 at 9:35 AM
What do we think about adjusting p-values for safety outcomes for multiple testing, and then claiming no significant harm?
Is this common practice? Any papers commenting on the (in)appropriateness?
#statsSky
@stephensenn.bsky.social
@statsepi.bsky.social
@f2harrell.bsky.social
Is this common practice? Any papers commenting on the (in)appropriateness?
#statsSky
@stephensenn.bsky.social
@statsepi.bsky.social
@f2harrell.bsky.social
Reposted by Johannes Enevoldsen
Which is why we need people who critically look at ML/chatgpt/AI
I love new toys, gadgets, technology, data trends
But I’m a scientist first and hope this will never change
I love new toys, gadgets, technology, data trends
But I’m a scientist first and hope this will never change
My position is, that HPI does not work due to a flaw in its development. I attempt to explain this flaw, as I believe, that if more people understood it, we would not still be having this discussion about HPI.
Based a paper with Simon Vistisen
journals.lww.com/ejanaesthesi...
Based a paper with Simon Vistisen
journals.lww.com/ejanaesthesi...
CON: The hypotension prediction index is not a validated... : European Journal of Anaesthesiology | EJA
ich may have been overstated. A selection bias may have forced the HPI algorithm to learn almost exclusively from MAP. This CON position paper describes the selection bias further and summarises the s...
journals.lww.com
November 28, 2024 at 1:04 PM
Which is why we need people who critically look at ML/chatgpt/AI
I love new toys, gadgets, technology, data trends
But I’m a scientist first and hope this will never change
I love new toys, gadgets, technology, data trends
But I’m a scientist first and hope this will never change
Reposted by Johannes Enevoldsen
1w cough and increasing dyspnea. Upon pickup by paramedics sat70%, hypotensive. ⬆️CRP/WBC. Pneumonia/septic shock assumed, abx and bolus fluids initiated, intubated in the ER. Hypotensive despite high dose pressor, #Echo follows #FOAMed #FOAMcc
November 3, 2024 at 10:45 PM
1w cough and increasing dyspnea. Upon pickup by paramedics sat70%, hypotensive. ⬆️CRP/WBC. Pneumonia/septic shock assumed, abx and bolus fluids initiated, intubated in the ER. Hypotensive despite high dose pressor, #Echo follows #FOAMed #FOAMcc
What prior do you use for SEED?
And for the love of the great Flying Spaghetti Monster DO NOT TUNE ON YOUR SEED. Just don't.
November 24, 2024 at 7:01 AM
What prior do you use for SEED?
Reposted by Johannes Enevoldsen
Check my starter pack and tell me who to add! Also contains the #pocus feed. go.bsky.app/EtZL9J6
November 23, 2024 at 8:12 PM
Check my starter pack and tell me who to add! Also contains the #pocus feed. go.bsky.app/EtZL9J6
This is something I've had to rediscover every time I've made graphics for a new project.
Great post.
Great post.
"I really like the overall look, but I'm finding it hard to tell the difference between the turquoise and the green - is it possible to redo all the graphs with a different colour?"
A happy reminder of the joy of setting up colours sensibly when creating dataviz with #rstats. Thank you past self!
A happy reminder of the joy of setting up colours sensibly when creating dataviz with #rstats. Thank you past self!
November 23, 2024 at 4:44 PM
This is something I've had to rediscover every time I've made graphics for a new project.
Great post.
Great post.
Reposted by Johannes Enevoldsen
Semi related - we went big on the pivotal like protocol in Ottawa
www.nephjc.com/news/pivotal
Our ESA requirements plummeted. Many patients have come off ESA completely.
I think that’s a good thing!
www.nephjc.com/news/pivotal
Our ESA requirements plummeted. Many patients have come off ESA completely.
I think that’s a good thing!
The ESA Empire Explodes — NephJC
Can PIVOTAL pivot us to pump more iron? It is indeed a pivot from the lazy, halycon days of the ESA era, now to the evil ESA empire crumbling under the strong iron attack. Join us to discuss!
www.nephjc.com
November 23, 2024 at 12:21 AM
Semi related - we went big on the pivotal like protocol in Ottawa
www.nephjc.com/news/pivotal
Our ESA requirements plummeted. Many patients have come off ESA completely.
I think that’s a good thing!
www.nephjc.com/news/pivotal
Our ESA requirements plummeted. Many patients have come off ESA completely.
I think that’s a good thing!