Tissue perfusion monitoring

Abstract

Over the past few years, the haemodynamic management of critically ill patients is moving from the stabilization of microcirculatory parameters (such as arterial pressure, heart rate, or cardiac output) to resaturation and maintenance of tissue perfusion parameters. This change of paradigm is necessary as we now know that normalization of microcirculatory parameters does not necessarily mean normal tissue perfusion. For that reason, in this edition we include a chapter dedicated to tissue perfusion monitoring. This includes discussion on mixed venous oxygen saturation (including physiology, equivalence of mixed venous oxygen saturation and central venous oxygen saturation, interpretation, and use as a therapeutic or prognostic target), pCO2 arterial-venous gap (physiology, interpretation, and use as therapeutic target), lactate concentration (metabolism of glucose to lactate, lactate and shock, parameters of tissue hypoperfusion and tissue hypoxia, persistent hyperlactataemia, and practical approach), and the videoscopy of microcirculation (describing a definition and physiological background, haemodynamic coherence, techniques and technologies, and clinical applications).