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This Article Full Text Full Text (PDF) All Versions of this Article: 285/3/H1140    most recent 00285.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Contaldo, C. Articles by Erni, D. Search for Related Content PubMed PubMed Citation Articles by Contaldo, C. Articles by Erni, D.

Improved oxygenation in ischemic hamster flap tissue is correlated with increasing hemodilution with Hb vesicles and their O₂ affinity

¹Department of Orthopedic, Plastic and Hand Surgery, Inselspital University Hospital, 3010 Berne, Switzerland; and ²Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan

Submitted 1 April 2003 ; accepted in final form 5 May 2003

The aim of this study was to test the influence of oxygen affinity of Hb vesicles (HbVs) and level of blood exchange on the oxygenation in collateralized, ischemic, and hypoxic hamster flap tissue during normovolemic hemodilution. Microhemodynamics were investigated with intravital microscopy. Tissue PO₂ was measured with Clark-type microprobes. HbVs with a P₅₀ of 15 mmHg (HbV15) and 30 mmHg (HbV30) were suspended in 6% Dextran 70 (Dx70). The Hb concentration of the solutions was 7.5 g/dl. A stepwise replacement of 15%, 30%, and 50% of total blood volume was performed, which resulted in a gradual decrease in total Hb concentration. In the ischemic tissue, hemodilution led to an increase in microvascular blood flow to maximally 141–166% of baseline in all groups (median; P < 0.01 vs. baseline, not significant between groups). Oxygen tension was transiently raised to 121 ± 17% after the 30% blood exchange with Dx70 (P < 0.05), whereas it was increased after each step of hemodilution with HbV15-Dx70 and HbV30-Dx70, reaching 217 ± 67% (P < 0.01) and 164 ± 33% (P < 0.01 vs. baseline and other groups), respectively, after the 50% blood exchange. We conclude that despite a decrease in total Hb concentration, the oxygenation in the ischemic, hypoxic tissue could be improved with increasing blood exchange with HbV solutions. Furthermore, better oxygenation was obtained with the left-shifted HbVs.

blood substitutes; artificial red blood cells; microhemodynamics; hypoxia; collateral circulation