Shock in infants and children.

Shock is a descriptive term indicating generalized inadequancy of organ perfusion. In the critically ill patient, the common denominator is insufficient microcirculatory flow. All patients have excessive sympathetic tone with arteriolar and venular vasoconstriction. Two phases may be clinically recognized. Phase 1 is usually reversible and is characterized by ischemic hypoxia. Phase 2 is often irreversible and is characterized by stagnant hypoxia, cell disruption, autolysis, and diffuse intravascular coagulation. Although the presentation of shock may vary with age, one usually detects evidence of inadequate tissue perfusion, hypotension, and poor urine output. Treatment consists of early recognition, establishment and maintenance of intravascular volume, and cardiorespiratory assistance with mechanical ventilation and various inotropic and vasoactive drugs. Pediatric mortality remains high despite new and sophisticated treatment methods.