[Shock--what are the basics?]

Shock, derived from the French "choc", is defined as a syndrome precipitated by a systemic derangement in perfusion leading to widespread cellular hypoxia and vital organ dysfunction. There is an apparently mismatch of oxygen delivery and oxygen uptake on the cellular level. Shock is associated with significant morbidity and mortality. Therefore, rational therapy should rely on the allocation to one of the four primary circulatory defects: cardiogenic, obstructive, distributive and hypovolemic shock. Compensatory mechanisms such as activation of the sympathoadrenal axis and neurohumoral mechanisms act to preserve cardiac output and perfusion of the vital organ systems. Lactate acidosis serves as a marker of critical hypoperfusion. Persistent hypoperfusion und ischemia induce a systemic inflammatory response syndrome which may lead to multiple organ dysfunction or even multiple organ failure.