| IntruductionNumerous factors associated with cardiopulmonary bypass (CPB) contribute toward the changes that occur in platelet. These include physical factors (such as hypothermia and shear forces); exposure to artificial surfaces; the use of exogenous drugs; and the release of endogenous chemicals. CPB activates platelets with resultant structural and biochemical changes. Alterations in platelet count, clot formation, and the manner in which platelets interact with other cells is seen. CPB reduces platelets count, diminishes function of platelets, than cause excessive blood loss.Using homologous platelet products can reduce excessive blood loss postbypass, But potential complications of platelets are most commonly associated with alloimmunization to histocompatibility antigens. Transfusion-transmitted disease, bacterial contamination, nonhemolytic transfusion reaction, and graft-versus-host disease are only some of the complications related to platelet replacement from bank source. Beyond the potential hazard, there are also significant costs related to the donation and storage of these products.Preventing the processes that activate platelets or using methods to prevent theharmful effects of activation are important measures in reducing complications associated with CPB, reducing platelet shear; reducing surface activation; preventing platelet-related microembolism; using inhibitors of platelet activation,preventing exposure of platelets to cardiopulmonary bypass.Developed in 1968, the plateletpheresis techique allows selective collection of large quantities of platelets from a single donor. Single-donor homologous platelets infusions in cardiac surgical patients elevated the postoperarative platelet counts and reduced postoperative bleeding. This method reduces but also not eliminate the patient risk, as contrasted to autologous donations. In 1977, Harke and associates used introperative autologous plateletpheresis in 17 patients. They found that the postoperative platelet counts were higher, blood loss was reduced by 50%,and the introperative screem-filtration pressures were lower than in control patients. Other verified that with this technique, the platelet counts dropped less postoperativily, and levels of clotting factors VIII and XII were higher.Cohn and associates infused relatively small quantities of autologous platelet-rich plasma and found the need for HBTs did not decrease significantly. They suggested that additional studies be done using large-volume transfusions of platelet-rich plasma to evaluate the technique. More recently, Giordano and associates used 500ml of platelet-rich plasma in a study of a much larger group of patients. They reported a 50% reduction in HBTs. Furthermore , they found the use of autologous platelets.however these past reports are not randomized and rely heavily on the comparisons of homologous blood products used, such comparisons are important but may depend on sometimes inconsistent indications for transfusion.We study the effects of blood loss by autotransfusion of intraoperation platelet-rich plasmapheresis at congenital heart disease (after CPB). 20% of the patient'splasma volume has been collected before heparinization and the start of CPB, and later reinfused after termination of CPB and return to normol activated clotting time. MethodsFrom July, 1997 to May, 2001 we randomly selected 16 patients with congenital heart disease, prospectively randomized into two groups: the experimental groups (n=8) collecting 20%or more of the total estimated circulating platelets platelet-rich plasmapheresis by Haemonetics model V50 , reinfusing after CPB. And the control groups (n=8) not collecting, to observing blood loss from chest tube (lh,12h,24h) and blood transfusion, and fluid requirements postoperatively , determine hemoglobin (HB), hematocrit (HCT), platelet count, fibrinogen(FBG), PT, prothrombin time(%). After operation every patients are in normal range of HB, HCT, platelet count, PT, FBG, prothrombin time (%).All pati...
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