Fig. 1. Effect of progressive acute normovolemic hemodilution with hydroxyethyl starch (HES) 650/0.42 (n = 12) and HES 130/0.42 (n = 12) on plasma coagulation parameters (prothrombin time [PT; A ], activated partial thromboplastin time [aPTT; B ], functional activity of factor VIII [FVIII; C ], and functional activity of von Willebrand factor [vWF; D ]). PT, aPTT, FVIII activity, and vWF activity were determined before (baseline [BL]) and immediately after each step of acute normovolemic hemodilution (10, 20, 30, 40, and 50 ml · kg−1· body weight−1). Results are mean ± SD. Solution effect ( P sol) and dilution effect ( P dil) of HES 650/0.42 versus HES 130/0.42 as well as interaction between treatment and dilution ( P sol × dil) as determined by two-way analysis of variance for repeated measurements on one way (dilution).