All types of circulatory shock result in a severe hypotensive state at some stage in their development and virtually all involve an early splanchnic vascular hypoperfusion and a later impairment of cardiac function. One important and consistent feature of circulatory shock is a fundamental insufficiency of microcirculatory flow leading to inadequate perfusion of the somatic cells of many of the important organs of the body. If the cellular hypoxic insult can be limited by fluid therapy with colloids and crystalloids, then the incidence of systemic complications in the post-shock period will also be reduced.