Affiliations: Division of Hematology/Oncology, Department of Medicine, University of Magdeburg | Division of Angiology, Department of Internal Medicine, University of Frankfurt/Main | Department of Medicine, Wenckebach - Krankenhaus, University of Berlin
Abstract: It was the aim of the study to characterize the effects of normovolemic and hypervolemic hemodilution on the muscle pO2 in the tibialis anterior muscle of patients suffering from chronic arterial occlusive disease (stage IIb according to the Fontaine classification) with a pain-free walking distance below 100 m. To compare various Hct levels (ranging from 30% to 50%), normovolemic and hypervolemic hemodilution was performed either by subsequent withdrawal of whole blood and substitution with hydroxyethylstarch solution (200/0,5) or only by infusion of the same plasmaexpander. At rest, muscle pO2 readings obtained by a polarographic method (micro-pt-needle electrodes) indicated clearly an impaired oxygen supply as compared to age-matched elderly volunteers. At the extreme ends of hematocrit in this study (Hct 33.75% and Hct 50.60%) muscle pO2 was significantly decreased as compared to Hct ranging from 38,57% to 45,38%. After a standardized pedal-ergometric exercise test a significant increase of muscle pO2 (2α<0,005) was found at Hct 40%–42%. Comparing normovolemic and hypervolemic hemodilution, hypervolemia at Hct 40%–42% did not improve muscle pO2 values after the pedalergometric exercise test. The data indicate, that normovolemic hemodilution towards the lower normal range (Hct 40% - 42%) can indeed improve muscle pO2 after pedalergometric exercise test in patients with severe intermittent claudication and concomitant increased Hct (Hct > 45%), whereas hypervolemic hemodilution showed no increase of muscle pO2. Thus, normovolemic hemodilution should be the preferred hemodilution regimen in patients suffering from intermittent claudication.
