Normovolemic hemodilution in head and neck surgery.

As the transfusion risks to which patients are exposed are gradually understood, every effort is being made to find both a valid and safe alternative to homologous blood transfusions. Bearing this in mind, the most sensible solution appears to be the practice of a self-donor procedure with normovolemic hemodilution prior to elective surgery. However, even repeated bloodlettings do not modify the oxygen delivery to tissues since, with a reduction in the hemoglobin content of the circulating blood, there is a corresponding increase in oxygen availability. Since the reduction of circulating erythrocytes brings with it a reduction in blood viscosity, there is in turn an improvement in the microcirculation. The generally better tissue oxygenation, the reduction of the blood's viscosity and the increased circulatory perfusion all also favor a prophylaxis against deep vein thrombosis. We have currently performed 72 surgical procedures for head and neck neoplasms that were undertaken at the Clinical ENT Division of Treviso Hospital precisely with the normovolemic hemodilution described above. The self-donor transfusion technique was adopted with the help of the hospital's transfusion service. We have analyzed the data relative to this method and have found that the normovolemic hemodilution represents the treatment of choice in surgery-induced stress, particularly since this approach allows a better tissue oxygenation.