Distributive Shock Overview
Distributive shock occurs as a result of excessive vasodilation and possibly increased capillary permeability (i.e. leaky blood vessels) which leads to an abnormal distribution of blood volume.
This abnormal distribution of the blood leads to inadequate oxygen and nutrient delivery to the tissues and organs of the body.
Distributive shock is similar to hypovolemic shock in that there is less blood volume in the arterial circulatory system to ensure adequate cardiac output. The difference is that the low blood volume associated with distributive shock is relative.
In other words, the volume of fluid is still in the body, but it is not in the right place to ensure adequate cardiac output. (should be in the arterial circulatory system). In contrast, hypovolemic shock the fluid is actually lost from the body.
There are 3 subtypes of distributive shock and the most common of these is septic shock. Two less common subtypes of distributive shock include neurogenic shock and anaphylactic shock.
The physiologic response of each type of distributive shock differs. Use the links below to learn about each type of distributive shock in more detail.
General Physiology of Distributive Shock
When massive vasodilation occurs as with early septic shock, this causes a reduction in systemic vascular resistance (SVR) and results in increased blood flow to the skin (venous system). This redistribution of fluids out of the arterial vascular space causes a pseudo-hypovolemia.
Even though the fluid volume remains in the body, it is in the wrong place. The decreased arterial fluid volume results in a decreased cardiac output which in turn results in a decrease in the oxygen supply and nutrient delivery to the tissues and organs of the body.
The three types of distributive shock have unique characteristics for recognition and management. In the links below each form of distributive shock is discussed in detail. Use the links below to gain a complete understanding of distributive shock.
If you have not already, you may want to review the following pages.