The Combination of hemodilution and Deliberate hypotension, Physiology and clinical application

Abstract

The current risks of blood transfusion can be categorized as infections, reactions and Immune suppression. Several methods have been used to reduce blood loss and homologous transfusion during surgery.

It has been reported that controlled hypotension or normovolemic hemodilution was effective in reducing blood loss in total hip arthroplasty and it was suggested that their combination could be the best technique for avoiding homologous transfusion.

On the other hand ,the combination of acute normovolemic hemodilution and controlled hypotension may impair tissue oxygenation in the important organs due to reduction in oxygen carrying capacity and perfusion pressure.

Acute normovolemic hemodilution (ANHD), involves the preoperative removal of blood and replacement with colloid or crystalloid solutions to achieve a predetermined hematocrit (Bet) . At the lower resulting Hct, fewer red cells are lost for any given amount of intraoperative hemorrhage and some autologous cells and coagulation factors are available for postoperative transfusion.