Organdysfunktion und gestörte Mikrozirkulation des septischen Patienten

Zusammenfassung

Experimentelle und klinische Untersuchungen zur Pathogenese der Sepsis konnten zweifelsfrei nachweisen, dass Störungen der Mikrozirkulation eine wesentliche Determinante in der Manifestation der Organdysfunktion bis hin zum Organversagen darstellen. Von besonderer Bedeutung für sowohl die Entwicklung, als auch Progredienz des multiplen Organversagens, sind die Persistenz nutritiver Perfusionsstörungen mit fokaler Minderperfusion und Hypoxie vitaler Organe sowie die Aktivierung zellulärer und humoraler Systeme mit Dysbalance der Hämostase. Weiterhin sind Veränderungen der Hämorheologie mit Abnahme der Blutzelldeformabilität, Vasomotordysfunktion mit Umverteilung des Blutflusses sowie mitochondriale Sauerstoffutilisations-Störungen für die Gewebeschädigung und den Funktionsverlust verantwortlich. Im Gegensatz zu indirekten Methoden zur Erfassung der Mikrozirkulation (Laser-Doppler-Flowmetrie, HbO₂-Spektroskopie und Kapnometrie) erlaubt das OPS (orthogonal polarization spectral)- und SDF (sidestream dark-field)-Imaging die direkte Visualisierung und quantitative Analyse mikrovaskulärer Netzwerke mit deren Perfusion und Leukozyten-Endothelzell-Interaktion. Erste Studien zeigen, dass die persistierende Minderperfusion der sublingualen Mukosa als einziger Parameter das Sepsis-bedingte Multiorganversagen mit Tod des Patienten hinreichend vorhersagt. Mit diesen nicht-invasiven bildgebenden Verfahren gilt es daher, in zukünftigen Untersuchungen den prädiktiven Wert von Mikrozirkulationsstörungen im Rahmen der Pathophysiologie von Sepsis und septischem Schock systematisch zu erarbeiten.

Abstract

There is a large body of evidence from both experimental and clinical studies that deteriorations of the microcirculation are major determinants for the manifestation of organ dysfunction and organ failure in sepsis. The persistence of nutritive perfusion failure with focal hypoperfusion and cellular hypoxia as well as the activation of cellular and humoral cascades are of outstanding importance for the development and progression of multiple organ failure. In addition, alterations in hemorheology with reduced blood cell deformability, vasomotor dysfunction and maldistribution of blood flow as well as deteriorations in mitochondrial oxygen utilisation contribute to tissue injury and loss of organ function. In contrast to indirect methods for assessment of the microcirculation (laser Doppler flowmetry, HbO₂-spectroscopy and capnometry), OPS (orthogonal polarization spectral)- and SDF (sidestream dark-field)-imaging allow for direct visualisation and quantitative analysis of microvascular networks, including nutritive perfusion and leukocyte-endothelial cell interaction. Recent studies using OPS-imaging could demonstrate that persistent microcirculatory hypoperfusion of the sublingual mucosa was proportionally related to the occurence and severity of multiple organ failure. Further studies using these newer imaging techniques are required to characterize the predictive value of microcirculatory alterations for the outcome in sepsis and septic shock.

Schlüsselwörter

Entzündung - Mikrozirkulation; - Perfusionsversagen - Hypoxie - bildgebende Verfahren

Key words

Inflammation - microcirculation - perfusion failure - hypoxia - imaging techniques

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