[Use and limitations of acute normovolemic hemodilution].

Acute normovolemic hemodilution was performed in 46 pts. before major surgical procedures 1800 ml of pt's blood were withdrawn and hct. lowered to 24.8% mean. The hct. after retransfusion averaged 31.8% while homologous blood could widely be avoided. 78% of pts tolerated a.n.h. well or sufficiently. During a.n.h. circulatory parameters remained constant while CO rose from 4.4 to 6.1 1/min. Shortly after a.n.h., in 13 cases slight, in 10 cases, however, severe side reactions occurred: rise in BP, HR and PAP, peripheral vasoconstriction with decrease of peripheral blood flow, unproportional increase of CO and ST-depression in ECG. As a reason of this centralisation reaction a sympathetic reaction and hypoxia are discussed.