Does monitoring the microcirculation make a difference in sepsis? Outcome?

The main function of the microcirculation is to supply the tissues with oxygen-rich blood and nutrients in physiological and pathophysiological states. The expectation during resuscitation procedures is that correction of systemic hemodynamic variables (e.g., blood pressure, cardiac output) results in a parallel improvement of microcirculatory parameters (tissue perfusion and oxygenation). This expectation which occurs under normal physiology is known as hemodynamic coherence. This hemodynamic coherence however can be lost in certain disease states associated with critical illness. There is increasing evidence that loss of the hemodynamic coherence between macro- and microcirculation is associated with poor outcome, which raises the importance of microcirculatory imaging. Currently, several techniques exist for monitoring the microcirculation at the bedside. Hand-held microscopes applied to observe the sublingual microcirculation have provided important insights into its importance by enabling direct visualization of blood cells flowing within it. This chapter provides a general overview of direct microcirculatory monitoring techniques, highlighting their main working principles, advantages and limitations.