Targeting the microcirculation in resuscitation of acutely unwell patients

The ultimate goals of hemodynamic therapy in acutely unwell patients are to restore effective tissue perfusion and oxygen delivery to maintain cellular metabolism. Optimization of systemic hemodynamics may improve the time course of microcirculatory dysfunction and eventually the patient's outcome. However, relationships between systemic hemodynamics and microcirculatory changes during resuscitation are complex and underperfused microcirculation may persist, despite restored macrohemodynamics. Thus, targeting the microcirculation is a logical goal to obtain an adequate resuscitation.

The impact of systemic interventions such as fluid resuscitation, vasopressor therapy, and transfusion has been evaluated on microcirculatory perfusion in septic-shock patients. It demonstrated inconstant improvement according to time-course evolution of the underlying pathology with interindividual variability. Thus, therapy targeting the microcirculation should be adapted to individual microcirculatory monitoring. Specific therapy with nitroglycerin did not promote microcirculation in septic shock but was associated with microcirculatory improvement in cardiogenic shock.

Microcirculatory hemodynamics have to be restored as soon as possible during the early phase of the management of acutely unwell patients. Future trials should test whether microcirculation-guided strategy could better improve organ dysfunction than global hemodynamic-guided strategy. An optimal resuscitation has to restore the systematic hemodynamics and make sure of the quality of the microcirculation.