Shock constitutes widespread hypoperfusion of tissues due to reduction in the blood volume or cardiac output, or redistribution of blood, resulting in an inadequate effective circulating volume. There is insufficient delivery of oxygen and nutrients to the cells and tissues and inadequate clearance of waste products. The cellular hypoxia results in anaerobic metabolism, resulting in increased lactic acid production. If the derangements are not corrected, death of the cells and patient occurs.
Cardiogenic shock is caused by failure of the heart due to intrinsic myocardial damage.
Hypovolemic or hemorrhagic shock is due to inadequate blood or plasma volume caused by hemorrhage, fluid loss from severe burns, or trauma. Septic shock can also be caused by gram-positive bacteria and occasionally fungi. Septic shock is the most important form of shock in veterinary medicine. LPS binds to receptors on leukocytes, endothelial cells, and other cell types. These mediators affect a large number of vital organ systems.