"Physiology is the only polar star we have."
Luciano says it time and again—and he's absolutely right. So when it comes to fluid therapy, we need to begin by grounding ourselves in physiological principles.
I am Can Ince form The Netherlands and as a physiologist, that's my role—to focus on the mechanisms behind what we observe in the clinic. And I often find that clinicians are genuinely curious to hear from us: to understand which mechanisms are being affected, how they change in response to treatment, and why patients respond the way they do.
Let's ask the fundamental question:
Why are you giving fluids?
Is it to improve tissue oxygenation? Well, if there are no red blood cells, then there's no oxygen to carry—so that goal may not be met.
Is it to correct acid–base balance? Perhaps—that's likely what the person who asked me to speak about buffers had in mind.
Is it to restore or promote perfusion?
Or maybe it's all three.
This is why fluids are so central—and so controversial.
Everyone uses them. But there are many types of fluids, and there's often little consensus on which to use, when, how much, or when to stop. Add to that the negative side effects of fluid overload, and it's easy to see why this topic triggers strong emotions—especially among anesthesiologists and intensive care physicians.
Fluids are one of the most routinely administered treatments in critical care, yet also one of the least consistently applied. That's why events like this conference are so valuable: they create space for meaningful, evidence-based debate.
Here's a critical example:
When you administer large volumes of fluids, such as during cardiopulmonary bypass in cardiac surgery, you can end up diluting the blood so extensively that there's virtually no oxygen-carrying capacity left for a prolonged period. That's a dramatic physiological consequence, and it highlights why we must never treat fluids as neutral or benign. They are powerful interventions—and must be used with intention and precision.
So again, we come full circle:
Physiology remains our guiding star.
It must anchor every fluid decision we make.
