[Hydroxyethyl starch as plasma substitute: experiments in isovolamic haemodilution (author's transl)].

Isovolaemic haemodilution to a hematocrit of 10% was achieved by stepwise exchange of blood against 6% hydroxyethyl starch (HES) in 11 splenectomized dogs. All animals survived the actuely performed extreme haemodilution; one animal died 5 days later due to massive bilateral pneumonia. Blood volume as determined by 51Cr-tagged red cells was unchanged at hematocrit 10%; 2 and 5 hours after reaching the minimum haematocrit, blood volume was reduced by 7 and 15% of control. At day 3 after dilution, blood volume was normal again. Thus under conditions of extreme isovolaemic haemodilution the volume effect of hydroxyethyl starch was found inferior to that of dextran 60. Haemodilution with HES was associated with a presistent augmentation of the serum concentration alpha-amylase.