Septic Shock (SIRS)


Definition of Septic

The systemic inflammatory response syndrome is most common cause of distributing shock. This release of inflammatory mediators into circulation caused by bacteria, virus, fungus, or rechettsiae can be devastating. Left untreated, These organisms can cause a massive overwhelming infection called SIRS or systemic inflammatory response syndrome.

One of the major causes of the condition leading to septic shock is infection by gram negative organism. The cell walls contain endotoxins which trigger the release of inflammatory mediators which causes vasodilation and increase in capillary permeability leading to shock.

Gram positive organisms, may release endo toxins which trigger the body’s immune response leading to toxic shock syndrome.

There is an alteration in peripheral circulation when septic shock occurs. Massive dilation will occur as a result of the release of histamine, and endorphans, and prostaglandins. The vasodilation will result in a change in the distribution of blood volume. Increased blood will occur to the heart, brain, liver and adrenal glands. At the same time there’ll be a decrease in blood to the skin, lungs, kidneys and visera.

There is an increase in capillary permeability which causes fluid and protein to move from the intravascular compartment out into the tissues. This results in decrease circulating volumes, increase blood viscosity, hypoproteinemia, and interstitial edema.


Little Rock Critical Care Course, lecture notes, Little Rock AR, 1998.