| PrefaceRecently, the blood supply can not meet with the development of surgery and trauma aid. Meanwhile, adverse effects associated with transfusion of homologous blood and blood include immunosuppression with enhanced cancer recurrence and postoperative infectious complication; the transmission of infectious diseases(hepatitis B and C, HIV); transfusion reaction etc.With the development of moden medicine, the clinical transfusion criteria is recognized and the traditionary opinion is challenged that patients whose Hb and Hct are separately less than 10 g per dl and 30 percent can not tolerate difficult surgery and anesthesia. Valeri's research showed that the potential dangers of transfusion deficiency are myocardial ischemia and homeostasis. If normal intravascular volume and tissue perfusion are maintained, there is no adverse effect on cardiovascular function until heavy anemia occurs. Kitchms' survey showed that the bottommost concentration of Hb is 70 g per L foranesthesia to those patients who refuse to accept or have no chance to get blood transfusion. In 1998, having discussed RBC transfusion treatment, NIH believed tha there is evedence that hemoglobin values of less than 100 g per L are torlerated during surgery.Because of the deficiency of blood supply, fear of allogeneic blood transfusion and recognition of transfusion criteria, blood conservation strategies to minimize allogeneic blood use become clinical important programe. Nowadays, usual blood conservation strategies of perioperation: (1) Preoperation autologous blood donation: Its deficiency is apparent, including the lower cost effectiveness, the expensive costs and a high discard rate of untransfused autologous blood. Spiess reported that during phlebotomy, hemodynamic changes had usually occurred with monitering. (2) Intraoperative blood salvage and autotransfusion: It can't reserve the functional platelet and coagulation factors. Severe blood contamination, Septemia, Cancer patients are not usually considered candidates for the transfusion of salvaged blood. BST is expensive. Therefore, its application is limited. (3) The more practiced Acute normovelemic hemodilution(ANH) today and the seldom reported Acute hypervolemic hemodilution(AHH): Using AHH, dilution lowering the hematocrit of blood is solely achieved by preoperative infusion of plasma expander without removal of autologous blood. With the same effect of hemodilution, AHH is easier, less time consuming and less expensivethan ANH. Possible contamination of the autologous blood units or accidental administration to the wrong patient, are avoided by this method. There is a report that it is possible to administer an appropriate volume of colloidal solution to induce AHH without any adverse hemodynamic effects by using isoflurane as a vasodilator. Mielke's experiment showed that the use of a starch solution for AHH did not result in excessively high arterial blood pressures, especially in the pulmonary circulation, and he could not find any signs of excessive intravascular volume after AHH. But the application of AHH is seldom reported, whose effects still need to be overall assessed, so it can be clinically introduced as a superior blood protective strategy.The hemorrage volume of thoracic operation is more, so it has relatively high clinical value to apply blood conservation of hitraoperation. Therefore, this test chose patients undergoing thoracic operation as research objects. Through monitoring the changes of hemodynamics, Hb, Hct, Pt, serum electrolyte (K+, Na+, Cl-), coagulation parameters (PT, KPTT, TT), we assessed the function and effect of acute hypervolemic hemodilution (AHH) increasing blood volume, maintaining hemodynamics and body internal environment homeostasis and coagulation function. ObjectiveTo assess the feasibility and effect of acute hypervolemichemodilution (AHH) increasing blood volume, maintaining hemodynamics, body intermal enviroment homeostasis and coagulation function. Me... |
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