Fluids and Inotropes: Getting It “Just Right” in Critical Care

This week I was so happy to chair a CPD meeting with Medtalkz SA where Roger Dickerson presented an educational session on the use of fluids and inotropes in EM.

Here is a summary of the talk, the major learning points, and some reflections!

Hat tip to Prof Roger Dickerson for an awesome presentation and as always a positive learning experience!

In critical care, the toughest calls are rarely about whether to act...it’s about what to do, when, and how much.

Fluids and inotropes are at the centre of this challenge. Too often, we reach for these medications out of habit, tradition, or desperation, rather than with a clear, physiology-driven plan.

Let's get right into the info!

• Shock isn’t defined by blood pressure
• Stability isn’t defined by being “on inotropes"
• "More” is not always better

1. Rethinking Shock

Shock is circulatory failure with inadequate tissue oxygen delivery.

It isn’t just hypotension. Patients can be shocked while normotensive or even hypertensive.

The task isn’t to “chase the numbers” but to restore perfusion, balance oxygen supply, and support the failing system—whether it’s the pump (heart), the pipes (vasculature), or the fluid volume itself.

2. Inotropes: Not Just Last Resort

We’ve all heard colleagues mutter that “the patient is stable on inotropes.”

The truth is: a patient on inotropes is unstable by definition

Key takeaways:

• Adrenaline – cheap, predictable, widely available. Our pragmatic first-line.
• Noradrenaline – the gold standard for distributive (septic) shock, though access challenges persist in South Africa.
• Dobutamine – “cardiac-friendly” at low doses, but dose creep increases risk.
• Dopamine – largely fallen out of practice; little role in modern shock management.

Rule of thumb:

➡️ Start fast (titrate quickly to effect).

➡️ Wean slow (withdraw cautiously as stability returns).

And always correct reversible causes first—acidosis, hypovolemia, tamponade, PE, hypothermia. No inotrope can fix physiology we’re ignoring.

3. Fluids: Goldilocks Medicine

When it comes to fluids, we often live between a rock and a hard place:

• Too little → ongoing shock.
• Too much → ARDS, renal failure, coagulopathy.

Guiding principles:

• Replace what’s lost: blood for blood, plasma for plasma, fluid for fluid.
• Prefer balanced crystalloids (Ringer’s, Plasma-Lyte) over “normal” saline.
• Blood remains best in haemorrhage, but don’t delay bleeding control—filling the bath without plugging the drain is pointless.
• Beware colloids (starches, gelatins, dextrans) → coagulopathy, renal harm, allergy risk.

And above all:

Use tools like point-of-care ultrasound to guide fluid responsiveness. Blood pressure alone is a poor guide.

4. Fluids in DKA: A Special Case

Diabetic ketoacidosis (DKA) is different. These patients often need large volumes fast, and the fluid you choose can either help or harm.

• Balanced crystalloids (Ringer’s Lactate, Plasma-Lyte) are preferred.
• Avoid 0.9% saline for large volumes: it worsens hyperchloremic metabolic acidosis, making the ketoacidosis harder to reverse.
• Balanced crystalloids also contain potassium, which supports electrolyte balance during insulin therapy.
• Expect to give 3–6L in the first 24h, but reassess often.

Bottom Line for DKA: Replace aggressively but wisely. Balanced crystalloids protect against worsening acidosis and give your insulin therapy the best chance to succeed.

5. The Leadership Lesson

This isn’t just pharmacology, it’s leadership at the bedside.

When the room is tense and the team is waiting, how we choose matters. Are we:

• Explaining why we’re picking adrenaline, not just ordering it?
• Teaching juniors to titrate to perfusion, not pressure?
• Modelling restraint when the temptation is to “do more”?

The Goldilocks approach—not too little, not too much, just right—is as much about culture as it is about physiology.

Bottom Line

• Shock is not necesarily hypotension.
• Start the right drug for the right reason, not just the one closest to hand.
• Fluids: prefer balanced crystalloids, replace what’s lost, avoid overload.
• Inotropes: titrate fast, wean slow, and never forget to fix the cause.
• Use POCUS and physiology, not tradition or pressure targets, to guide care.
• In DKA: avoid saline overload—balanced crystalloids are safer and smarter.

💬 Your turn:

How does your team decide when to start an inotrope or what fluid to choose in DKA? Do you feel confident that everyone at the bedside understands the why—or are we still too often operating on habit?