Effekte stromafreier Hämoglobinlösungen auf die Mikrozirkulation im quergestreiften Rückenhautmuskel beim Hamster

Effects of stroma free hemoglobin solutions on microcirculation in the striated dorsal skin muscle of the hamster: Since ischemia and hypoxia lead to cellular necrosis by failure of microvascular perfusion, oxygen delivery to the tissue is crucial for survival of the organism. For decades there was pursuit of developing oxygen carrying blood substitutes, but the breakthrough of stroma free hemoglobin solutions has failed due to different issues such as nephrotoxicity, systemic activation of complement cascade, vasoconstriction and other side effects. To prove the in vivo safety and efficiency of the solutions available to date, quantitative analysis of the microcirculation is needed as a crucial parameter of tissue integrity. In the present study, the skin fold chamber model of the hamster was used to investigate the effects of bovine and human hemoglobin solutions on the microcirculation of the striated dorsal skin muscle by means of computer assisted microcirculation analysis. This was done under physiologic conditions by a hypervolemic infusion of appr. 10 % of the calculated blood volume, and by an isovolemic hemodilution to a hematocrit of appr. 25 %, respectively. For pathophysiologic conditions a hemorrhagic shock as a stress model was induced by non-fractioned withdrawal of half the calculated blood volume within a few minutes, and treated by volume substitution with the respective solutions. Our results demonstrate that the application of the investigated hemoglobin solutions under physiologic conditions does not impair the microcirculation. Under pathophysiologic conditions they lead to an improved recovery of blood flow as compared to common volume substitutes. However, the level of tissue perfusion provided by retransfusion of autologous blood was not achieved by treatment with the hemoglobin solutions. Nevertheless, a sufficient tissue oxygenation was warranted by the specific properties of the hemoglobin solutions. In clinical trials the studied hemoglobin solutions were effective in elective surgery with expected major blood loss but not in trauma patients. The development of an oxygen carrying blood substitute suitable for trauma patients is still being pursued.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Ludwig-Maximilians-Universität

Year

2003

Author dc:creator

• Botzlar, Andreas

Repository record source_url

https://edoc.ub.uni-muenchen.de/1542/

OAI identifier oai:identifier

oai:edoc.ub.uni-muenchen.de:1542