Hemodilution

This study will collect physiological measurements in healthy adult volunteers under controlled hypoxia and hemodilution conditions.

Intraoperative fluid therapy (IFT) is an integral part of anesthesia care during surgery. Its main indication is the optimization of oxygen supply to the tissues. For elective surgery that is not associated with higher blood loss and a long period of preoperative fasting, including fluids IFT is dosed to cover the basal daily need for fluids. However, it is not clear whether this fluid dose is optimal. Surgery is a stress factor that leads, among other things, to damage of the endothelial glycocalyx (EG). EG binds a significant amount of plasma, which is released during EG destruction and causes relative hemodilution. Isovolumic hemodilution is an established intraoperative procedure that serves to better control bleeding in procedures where bleeding is expected. However, partial hemodilution occurs even with standard IFT, and even when fluids are hardly given at all. Flow parameters in microcirculation have not yet been described depending on IFT conduction. The parameters of the microcirculation reflect its functioning, which will consequently affect the postoperative phase of the patient's moaning and clinical outcome.

In this trial, we proposed an individualized acute normovolemic hemodilution (ANH), and conduct a randomized controlled trial to testify the effect of individualized ANH on red cells requirement for non-cardiac surgeries with anticipating major blood loss in adults.