Résumé
Objective To investigate the effects of different degrees of hemodilution with the artificial plasma substitutes most commonly used in clinical practice on coagulation in vitro. Methods Ten male ASA physical status I volunteers aged (28.8?1.6) yr and weighing (66?8) kg were enrolled. Venous blood samples obtained from each volunteer were diluted with 10% HES (200 000/0.4-0.55), 4 % succinylated gelatin (gelofusine GEL), 3.5 % polygeline (Haemaccel HAE) and lactated Ringer's solution (RL) by 33% [blood: diluent(B:D) =2:1], 50% (B:D=1:1) and 66% (B:D=1:2). Coagulation of the undiluted blood (control) and diluted blood was measured with sonoclot coagulation and platelet function analyzer (SCT) and by routine coagulation tests. The parameters measured included activated clotting time (ACT), clot rate, platelet function (PF), Hct, platelet count (Pit), plasma fibrinogen concentration (Fig) and activated partial thromboplastin time (APTT) . Results (1) At 33 % dilution ACT was significantly shortened in all the four groups as compared with control value; at 50 % dilution ACT was significantly shorter than the control in RL, HES and HAE groups; at 66 % dilution ACT was significantly prolonged in HES group. (2) Clot rate was significantly decreased at 33 % dilution only in HES group but was significantly decreased in all the four groups at 50 % and 66 % dilution. (3) PF decreased significantly only in GEL group at 33 % dilution but was significantly decreased in GEL and HES groups at 50 % and 66 % dilution. (4) With increasing dilution Hct, Pit and Fig gradually decreased and APTT was prolonged. Conclusion Coagulation changes are closely related to the degrees of dilution. At 33 % dilution, the three artificial plasma substitutes tested do not significantly affect hemostasis. At 50 % and 66 % dilution coagulation is badly impaired, but there are differences among the substitutes used for dilution. HAE impairs oagulation least as it contains higher calcium