Fluid Responsiveness is Not the Same as Fluid Benefit

Abstract

Fluid responsiveness has been a hot topic for some time.
Although with an easy conceptual definition (responding to
volume expansion by increasing cardiac output), its practical
assessment has been the subject of research, debate and
some controversy, for the past 15 to 20 years. The problem
is that fluid responsiveness is not the same as fluid benefit.
And we have been wasting time researching in ways to predict fluid responsiveness. I really do not want to know if the
patient is fluid responsive or not (are not we all?), but rather
if fluid expansion is beneficial or detrimental to that specific
patient, on that specific moment. We test patients in shock for
fluid responsiveness. If, whatever the method we use, we find
them to be responsive, we do intravenous fluids. We only stop
fluid loading/fluid expansion if one of two things happen: if the
patient is no longer in shock, or if the patient is no longer fluid responsive. We would never use a drug with proven harm,
especially if its benefit was insufficiently proven. Nevertheless
we continue to use fluids in scenarios in which their harm is
proven, but their benefit is not. We need a paradigm shift. We
need to stop looking for ways to predict fluid responsiveness.
We must search for ways to identify which patients benefit
from fluid expansion, fluid depletion or a neutral fluid strategy. New trials should prospectively compare well defined fluid
strategies (expansion, depletion or neutral) to be applied depending on a set of predetermined tests. Until then, we will
end up with the same question: will this specific patient, at this
specific moment, benefit from fluid expansion, fluid depletion
or a neutral fluid strategy?