I thank Van der Linden and De Hert for their comments regarding our article. 1
I want to underline again that the aim of our work was not to demonstrate the efficacy per se of intraoperative acute normovolemic hemodilution (ANH) in adult open-heart surgery, but whether the introduction of low volume ANH in our standardized intraoperative blood-sparing protocol, constituted by the association of the infusion of tranexamic acid and the use of a cell-saving technique, could produce some additive advantage in terms of reduction of allogeneic transfusions. Furthermore, in the discussion of the article we justified our choice to perform low volume ANH with the intention to enroll also in the study patients with low body mass index and patients with relative low values of hemoglobin (12 g/dl).
The negative results of our study clinically confirm the theoretical conclusions of mathematical analysis on ANH, 2which state that only high volume ANH in presence of significant intraoperative bleeding significantly reduces the need for allogeneic transfusions. 3,4
Furthermore, our study may be considered an indirect demonstration of the efficacy of our intraoperative blood-sparing protocol to prevent excessive blood loss, rendering unnecessary the addition of low volume ANH in this type of patient.
I totally agree with the conclusions of Van der Linden and De Hert: each blood conservation strategy must be studied considering the patient's limitations, the type of surgical procedures, and the health care environment. Because my opinion is that the addition of an adequate amount of ANH to our actual effective blood conservation approach 5may determine, particularly in patients with an increased risk for excessive bleeding, further improvements to our research of a cardiovascular surgery with the minimum number of patients necessitating donor blood; at the moment, various studies considering high volume ANH are in progress at our institution.