Abstract:
Goal directed fluid therapy (GDFT) implies the
flow-related parameters guided infusion of fluids. It requires
adherence to complex clinical algorithms and fluid protocols,
as well as simultaneous monitoring of several parameters and
evaluation of their fluid responsiveness or actual response to
fluid challenges. Automated clinical decision support systems
(ACDSS) are used to ease the task. However, they are based on
the flow-related (hemodynamic) parameters – arterial blood
pressure, cardiac output, etc. Meanwhile, infusions guided by
hemodynamic endpoints may lead to edema. A mini Volume
Loading Test (mVLT) may be helpful in detection of imminent
edema from changes in hemodilution during stepwise infusion
which is conventionally used for hemodynamic optimization.
We developed an ACDSS which is based on evaluation of both
hemodynamic and hemodilution parameters. It operates on the
basis of our unique algorithm which implies interchangeable
application of fluid loading, vasopressor injection and red cell
transfusion. This ACDSS is used in our PC-based command
centre of a prototype semi-closed loop (SCL) infusion system.
We developed a simulator – ‘Virtual Patient’ – on the basis of
our previous clinical records aiming to test a new controller, as
well as train the research team before starting a clinical trial.
In silico testing continued for 12 hours on five occasions.
Primary endpoint was the compliance of a controller with our
clinical algorithm and the stability of operation in a spectrum
of arterial hypotension and bleeding scenarios. The prototype
SCL infusion system was found ready for clinical validation.
