Distributive shock

Distributive shock is defined by hypotension and generalized tissular hypoxia. This form of relative hypovolemia is the result of blood vessel dilation.^[1] Septic shock is the major cause^[2], but there are other examples as well.

Examples

Examples of this form of shock are:

• Septic shock - This is caused by an overwhelming infection leading to vasodilation, such as by Gram negative bacteria i.e. Escherichia coli which releases an endotoxin which produces adverse biochemical, immunological and occasionally neural mechanisms which are harmful to the body. Although tissues are being hyperperfused due to the massive vasodilation, the hypotensive state of the individual, paired with the massive inflammation found in septic shock, causes a reduction in tissular oxygen extraction (tissular hypoxia). Resultingly, [[SvO₂]] levels are very high.

Septic shock is treated by antibiotics, fluid replacement, and vasoconstrictors.

• Anaphylactic shock - Caused by a severe anaphylactic reaction to an allergen, antigen, drug or foreign protein causing the release of histamine which causes widespread vasodilation. Leading to hypotension and increase capillary permeability.
• Acute adrenal insufficiency is frequently the result of discontinuing corticosteroid treatment without tapering the dosage.
• Neurogenic shock. Neurogenic shock is the rarest form of shock. It is caused by trauma to the spinal cord resulting in the sudden loss of autonomic and motor reflexes below the injury level. Without stimulation by sympathetic nervous system the vessel walls relax uncontrolled, resulting in a sudden decrease in peripheral vascular resistance, leading to vasodilation and hypotension.

References

1. ^ "Shock: Heart and Blood Vessel Disorders: Merck Manual Home Edition". http://www.merck.com/mmhe/sec03/ch024/ch024a.html. 
2. ^ Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson. "Chapter 4". Robbins Basic Pathology: With STUDENT CONSULT Online Access (8th ed.). Philadelphia: Saunders. ISBN 1-4160-2973-7. 

External links

• Intensive Care Medicine by Irwin and Rippe
• The ICU Book by Marino
• Procedures and Techniques in Intensive Care Medicine by Irwin and Rippe