Andrius Macas
Abstract
Summary
Tissue hypoxia emerges as a result of inadequate tissue oxygenation due to disbalance between oxygen delivery and oxygen consumption, and is one of the key factors in development of organ dysfunction. Hemodynamic parameters, conventionally used to assess tissue and organ perfusion, may show normal values in early tissue hypoxia and cannot rule out pathologic changes. Venous oximetry closely reflects the balance between oxygen delivery and consumption, and may provide its intermittent or continuous monitoring peri- and postoperatively. Such monitoring enables early identification of tissue hypoxia and therefore early therapeutic interventions are possible. However, venous oximetry is complex and a detailed understanding of the physiologic principles is essential for its safe and effective use in clinical practice. The successful use of venous oximetry in goal-directed management of early sepsis has led to interest in the use of this parameter in surgical patients.
Our review article describes the physiology, pathophysiology, and measurement of mixed (SvO2) and central (ScvO2) venous oxygen saturation, and explores the findings of contemporary studies investigating the use of venous oximetry in surgery and its relation with postoperative outcome. Observational studies of surgical patients have shown that low ScvO2 values are associated with higher risk of postoperative complications. According to small interventional studies, central venous oxygen saturation can be used as a therapeutic goal in hemodynamic correction and may decrease the incidence of postoperative complications.
Keyword(s): Venous oximetry, ScvO2, goal-directed, major surgery, tissue hypoxia, surgical complications.
DOI: 10.5200/23
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