The adrenergic coin: perfusion and metabolism

The pathologic state of shock is characterized by profound changes in tissue perfusion and metabolism. The main consequence of such pathophysiologic changes clearly affects the hierarchy of priority among the various organs, but which of these changes are adaptive or deleterious is still a question not completely answered. Therefore interfering with some of the main features of shock, such as low blood pressure, may have different consequences according to the flow redistribution and/or to the associated specific metabolic consequences. Vasopressor administration is one of the mainstay treatment approaches for various shock states. Catecholamines are the most widely used vasopressors in this context. In particular during septic shock there are various concepts about the use of adrenergic agents depending on the specific adrenoceptor profile of either endogenous and synthetic catecholamines [1]. The recommendations for the use of catecholamines consider primarily their efficacy in restoring or maintaining adequate systemic hemodynamics but also try to implement effects on regional blood flow and metabolism. Adrenergic agents may also be associated, however, with marked metabolic effects not necessarily linked to their hemodynamic effects [2].