[Hematocrit and coronary circulation: experimental data]

[Normovolemic hemodilution]

Transfusion of homologous blood to surgical patients is not without risks. Thus, strategies to prevent blood loss must be considered. This article deals with one of them: normovolaemic haemodilution together with its advantages, physiological consequences and technical aspects. In particular, it is important to follow certain inclusion criteria. The technique is safe, effective and relatively easy to implement. In the future, it could be used in non-surgical patients, when it is necessary to increase tissue perfusion.

[Programmed autologous transfusion in coronary surgery: experience with 106 patients]

Patients undergoing elective coronary bypass surgery can benefit from Preoperative Autologous Blood Donation (PAB), despite some opinions to the contrary, as a complement of intra-operative blood salvage techniques. We report herein 106 patients eligible for coronary bypass surgery included in our PAB program. We observed a very good tolerance owing to strict exclusion criteria, a close monitoring of vital signs, and as far as we are concerned, to the infusion of a macromolecular solution (Plasmion) in a 1:1 ratio, to maintain intra-vascular volume. We chose a volume replacement because the physiological adaptation to hypovolemia is altered by the beta-blocking and/or vasodilating agents which cannot be discontinued in patients with coronary heart disease. The changes in the hematological parameters are not different from those observed in other patients eligible for PAB. The postoperative hemoglobin level is satisfactory and compatible with a normal myocardial function inasmuch as the cardiopathy has been corrected. The efficiency of PAB is good since overall, 74% of the patients did not require homologous blood, this proportion rises to 84% for patients donating 3 or more units. Preoperative Autologous Blood Donation for patients with coronary heart disease implies a perfect coordination between the Blood Bank physicians and their colleagues from the Cardiology Department. Aside from its well known advantages, PAB allows a stimulation of erythropoiesis, a progressive normovolemic hemodilution perhaps beneficial to patients with coronary heart disease, and finally, a better psychological preparation to surgery.

[Original technic for preoperative hemodilution permitting deferred autologous transfusion (apropos of 106 cases)]

To carry out normovolemic haemodilution in the best security conditions we elaborate a new method of preoperative haemodilution. Collection of red cell concentrates and adequate compensation are made either in the blood bank or at the patient's bed side. There are two ways of proceeding: *manual plasmapheresis technic is used for the collection of less than 450 ml packed red cells; *collection of more than 450 ml packed red cells is carried out on a PCS Haemonetics cell separator. CPD autologous red cells concentrates prepared in that way can be stored to meet the patient's need during and after the operation. The patient is identified as donor and receiver as regards laboratory analysis and computer treatment as well. Information's transmission between blood bank hospital and clinics is secured with the same document. This method enables homologues transfusion save and completes autologous transfusion in 68% cases among 106 patients. It is to be noticed that none of the 98 haemodiluted patients suffered from thrombosis.