Progressive Shock Low Cardiac Output decreases arterial pressure and reduces transport of nutrients to tissues Low Cardiac Output decreases arterial pressure and reduces transport of nutrients to tissues Blood pH then decreases because of lactic & carbonic acid buildup. Blood pH then decreases because of lactic & carbonic acid buildup. Waste products lead to blood agglutination. Smaller vessels may become blocked, further decreasing nutrient transport Waste products lead to blood agglutination. Smaller vessels may become blocked, further decreasing nutrient transport

HYPOVOLEMIA “Hemorrhagic Shock” “Hemorrhagic Shock” Diminished blood volume and cardiac output as a result of hemorrhage Diminished blood volume and cardiac output as a result of hemorrhage Commonly associated with major trauma and obstetrical situations Commonly associated with major trauma and obstetrical situations Affects the central nervous, cardiac, and renal systems Affects the central nervous, cardiac, and renal systems

Types of Hemorrhagic Shock

Effects of Hemorrhagic Shock

Dehydration and Shock – Form or Cause? Some texts refer to Dehydration as “a form of shock”, however the terms are not synonymous. Dehydration is the result of total body water loss Hypovolemic shock results from loss of blood volume and MAY result from dehydration as well as other alternate or contributing factors. Forms of Shock: Hypovolemic (inadequate blood volume) Hypovolemic (inadequate blood volume) Neurogenic (nervous system damage) Neurogenic (nervous system damage) Anaphylactic (allergic reaction) Anaphylactic (allergic reaction) Septic (infections/bacterial spread) Septic (infections/bacterial spread) Cardiogenic (heart problems) Cardiogenic (heart problems)

Dehydration is the result of losing water from the body faster than it can be moved from other locations within the body (interstitial spaces) or replaced through intake and absorption. Therefore, the rate of fluid loss is as important as the amount of fluid loss. Fluid Loss is primarily from Vascular spaces: Sweat glands move fluid from the blood to the skin Kidneys move fluid from the blood to the urine (highest contributor to fluid loss) Fluid may also be lost through breathing as well as vomiting or diarrhea (lost fluid originally from blood within gut walls). This fluid loss may CAUSE hypovolemic shock. Rapid and high fluid loss will cause shock (e.g. hemorrhage) Rapid and high fluid loss will cause shock (e.g. hemorrhage) Rapid and moderate fluid loss may lead to symptoms (e.g. fainting after whole blood donation, only 0.5-l); however may eventually be compensated for Rapid and moderate fluid loss may lead to symptoms (e.g. fainting after whole blood donation, only 0.5-l); however may eventually be compensated for Slow and high fluid loss will gradually increase symptoms until shock eventually occurs (see Chart). Slow and high fluid loss will gradually increase symptoms until shock eventually occurs (see Chart). Slow and moderate fluid loss may be compensated for by body without symptoms Slow and moderate fluid loss may be compensated for by body without symptoms

Fluid Loss and Shock Fluid Loss and Shock % Dehydration Examination Findings <5 History of fluid loss, but no findings on physical examination 5 Dry oral mucous membranes, but no panting or pathological tachycardia 7 Mild to moderate decreased skin turgor, dry oral mucous membranes, slight tachycardia, and normal pulse pressure 10 Moderate to marked degree of decreased skin turgor, dry oral mucous membranes, tachycardia, and decreased pulse pressure. 12 Marked loss of skin turgor, dry oral mucous membranes, and significant signs of shock FLUID AND ELECTROLYTE THERAPY ( Wayne E. Wingfield, MS, DVM