In this dissertation, 42 patients of the intensive care unit treated with severe sepsis / septic were followed in a prospective cohort study. Eleven of the patients received the IgGMA-immuno globuline drug Pentaglobin® according to clearly defined inclusion and exclusion criteria. Micro circulation of the oral mucosa was measured by side stream darkfield imaging on seven consecutive days. In addition, various clinical and laboratory-chemical parameters as well as the determination of intensive care unit scoring systems (APACHE-II-Score, SAPS-II and SOFA-Score) were assessed. Especially the sublingually measured MFI proved to be a suitable indicator for the sepsis induced impairment of the small vessel perfusion. No distinct results regarding the serial micro circulation alteration in dependence on a Pentaglobin® medication could be observed. In contrast to such a lacking indication of Pentaglobin® at sepsis, the central importance of the micro circulation both for diagnostic and for monitoring of sepsis could be confirmed.