[Hemodilution in vitro and parameters of hemostasis]

High molecular weight (approximately 60,000) dextran having been selected in a protocol of per-operative hemodilution, a prior study was undertaken in vitro in order to measure the variations in parameters of hemostasis. Factor of primary hemostasis, of plasma coagulation and fibrinolysis were thus evaluated in control blood samples, not diluted and diluted to 1/5 th by dextran or by a buffer solution. Statistical analysis was carried out using the t-test for pairs of variables. The following emerge from the results: 1 - an absence of difference with regard to the fibrinolytic activity of the plasma, but marked fragility of the fibrin clot in the presence of dextran; 2 - variations for plasma coagulation factors due to dilution; 3 - acceleration of the phase of polymerisation of fibrin monomeres and a decrease in platelet stickiness and aggregation due to dextran.