Acute normovolemic hemodilution.

Acute normovolemic hemodilution (AHN) is a well known but poorly used "blood saving" method. The authors, based on their own experience and on the "low hematocrit" physiology, present some concepts on AHN and a clinical experience to demonstrate the usefulness and affordability of this method. Consequently we offer several tools concerning both the realization of AHN and the safe use of such dilution, suggesting simple and exciting methods to determine if, when and how to apply this blood saving system.