[Hemodilution, when and how -- in acute cerebral ischemia?].

Despite some criticism hemodilution is still the first choice therapy in stroke. The last trials have shown that not only the hematocrit had to be decreased but also the cardiac output had to be increased. The isovolemic hemodilution has the disadvantage that it does not carefully performed. This possible negative hemodynamic effect seems to be the reason for the unsatisfactory clinical outcome in some trials. Due to the disturbed autoregulation in the penumbra only the hypervolemic and not the isovolemic hemodilution is able to increase the cerebral blood flow in this area. The volume of hemodilution should be exactly adapted to the cardiac situation of the patients.