David Ramirez

Cardio-thoracic Anesthesiologist, App developer, Creator of iTIVA for intravenous drugs . Instagram:

[Dr. Chacón-Lozsán F .'. @franciscojlk]

🫀 Septic shock is not just about pressure. It’s about coupling.

We often treat septic shock with a familiar mindset:

➡️ Fluids
➡️ Vasopressors
➡️ Maybe inotropes

But we rarely ask the deeper question:

👉 Is the heart actually working efficiently with the arterial system?

⚙️ Enter: Ventriculo-arterial coupling (LVAC)

LVAC = Ea / Ees

• Ea → arterial load
• Ees → ventricular contractility

➡️ This ratio reflects how efficiently energy is transferred from the heart to the circulation

🧠 Why this matters

The cardiovascular system is not just a pump.

It is an energy transmission system.

From the pressure-volume perspective:

• Stroke work = useful energy
• Potential energy = wasted energy
• Total energy (PVA) ∝ myocardial O₂ consumption

👉 Efficiency depends on coupling, not just output.

📊 Key physiological insights

✔️ Optimal mechanical efficiency
→ LVAC ≈ 0.5

✔️ Maximal stroke work
→ LVAC ≈ 1

✔️ Septic shock
→ Often LVAC > 1 (uncoupling)

🚨 What happens in septic shock?

A complex mix:

• Vasodilation → ↓ Ea (sometimes)
• Myocardial dysfunction → ↓ Ees
• Microcirculatory chaos
• Variable preload

➡️ Result:

👉 Frequent ventriculo-arterial uncoupling

And here’s the key:

❗ Normal MAP ≠ optimal coupling
❗ Improved BP ≠ improved flow

💉 Therapeutic implications

Same MAP, different physiology:

🔵 Patient A
→ NE increases Ees > Ea
→ ↓ LVAC → ↑ SV (responder)

🔴 Patient B
→ NE increases Ea > Ees
→ ↑ LVAC → no SV improvement (non-responder)

🧬 Clinical reality check

Even more provocative:

• LVAC-guided resuscitation → faster lactate clearance
• BUT → no mortality benefit yet

And importantly:

👉 Optimizing coupling does NOT guarantee microcirculatory perfusion

🔥 Take-home message

We should move from:

❌ Pressure-driven resuscitation

To:

✅ Efficiency-driven hemodynamics

Because:

👉 The goal is not just to push blood
👉 The goal is to transfer energy effectively to tissues

📚 Caicedo Ruiz JD. et al. (2026)
Journal of Critical Care
https://t.co/1ZNMHqwBl4

[David Ramirez @deramirezmd]

@grok @Soter21 @carlosadams @ArturoErdely pero q significa esto? q puedo correrlo offline?

[David Ramirez @deramirezmd]

@NoahEpstein_ GEMINI

[British Journal of Anaesthesia @BJAJournals]

Is continuous noradrenaline infusion the answer to preventing post-induction #hypotension? Does better haemodynamic stability translate to improved outcomes? This new trial explores these key issues. https://t.co/uPuthM9sDL

[David Ramirez @deramirezmd]

@sheilaromero03 Por qué lo dices ?

[David Ramirez @deramirezmd]

@Const_SEMEN @DrShmuk @simtiva_app Those targets are recommended when using ketamine with other hypnotic like propofol or inhaled anesthetics

[David Ramirez @deramirezmd]

@DrShmuk @simtiva_app ITIVA already had this model 2 years ago, just that I misspelled, there is like Klamp, but it is Kamp

[David Sinclair @davidasinclair]

Longevity is built one good habit at a time. Here are 5 habits to start today: 🧵

[Daniel Shmukler @DrShmuk]

@DrSleep88 @Hrznsrd iTIVA app available on play Store and Apple Store. Allows for manual TCI with be ANY volumetric infusion pump. Cost $8/ year.

[Daniel Shmukler @DrShmuk]

Tips for TIVA: amazing what's possible these days. sedation for brain MRI needed but no compatible pumps or shielded equipment available... No problem! iTIVA app and bolus method for TCI to maintain appropriate sedation level for 60mns☺️ everybody happy

[Daniel Shmukler @DrShmuk]

Tips for TIVA: Eleveld Excitement edition. No pump at moment with newer models, no problem! 6 years old for 2 hours...iTiva again but TCI MODE... Nice DSA on monitor as well. Titrating hypnosis to EEG feedback.

[Fabian E. Torres  @fabiantorres784]

@DrShmuk eBIS simulating your case, excellent alternative to @iTIVA @deramirezmd

[David Ramirez @deramirezmd]

@ZJZAC2 HI, I am interested using your watermark technique to added to labels to verify authenticity

[SIVA Trainees @SIVATrainees]

Using TIVA? Use Flows of 6L

In the UK flows of 6L are best for the environment and to save money.
This was a nice poster / infographic presented at SIVA a few years ago.

Have you started making your infographics? There's not long left!

[Shaheed Rahman @Sir_SR]

@saraharuss Ouchy! Not happened recently but I’ve had this.

I’d suggest keeping the barrel of a 5ml syringe available (I know it’s a 2ml in the vid we did but 5 mls is the one to use)

https://t.co/pkjfkyRZCM

[Carlos A. Lanz M. @DrCarlosALanzM]

Propofol y dexmedetomidina para cirugia de escoliosis utilizando iTIVA #TIVA

[Carlos A. Lanz M. @DrCarlosALanzM]

iTIVA is my day by day tool

[David Ramirez @deramirezmd]

@nolittley @DrShmuk Yes, running the pump in ml/hr is the easiest way to update the infusion rate when using iTIVA, just check the syringe have the same concentration in the app. And in the app you can check the dose in milligram per kilogram