Significance and pathogenesis of septic shock.

Abstract

Septic shock is a state of inadequate tissue perfusion induced by microbial products and characterized by low blood pressure and biochemical signs of oxygen deficit. The reduced oxygen and nutrient transport to vital organs is caused by a generalized intravascular inflammatory response resulting in vasodilation. Septic shock evolves through different stages and is initially characterized by a hyperdynamic circulation, i.e., high cardiac output and after volume loading low peripheral resistance (Parillo 1993). Most patients dying of septic shock remain in this circulatory state to the end (Parillo 1993). In patients with overwhelming bacteremia caused by Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, and certain other bacteria the initial hyperdynamic circulation is gradually transformed into a hypodynamic circulation due to reduced cardiac performance. These patients die in a state of irreversible vasodilation combined with myocardial failure often with a terminal arrhythmia (Mercier et al. 1988; Brandtzaeg 1995).