What is intravascular hypovolemia?
Hypovolemia may be absolute (loss of intravascular volume), relative (increased venous capacitance), or combined such as is often seen in septic shock. Hypovolemia results in cardiovascular compromise primarily by the decrease in cardiac output (systemic blood flow) caused by the decrease in preload.
What are the types of hypovolemia?
Two types of hypovolemia are distinguished: Absolute and relative hypovolemia. Absolute hypovolemia is defined as a reduction in total circulating blood volume [1, 2], which may be related to blood loss (hemorrhage) or plasma loss (gastrointestinal, renal, cutaneous, extravasation into interstitial tissues).
What is the difference between hypovolemia and hypervolemia?
Hypervolemia (fluid overload) is a condition in which blood has excess fluid. The opposite of this condition is hypovolemia where blood has very little fluid volume.
Is hypovolemia intracellular or extracellular?
Hypovolemia, also known as volume depletion or volume contraction, is a state of abnormally low extracellular fluid in the body. This may be due to either a loss of both salt and water or a decrease in blood volume. Hypovolemia refers to the loss of extracellular fluid and should not be confused with dehydration.
What is intravascular volume depletion?
Volume depletion denotes reduction of effective circulating volume in the intravascular space, whereas dehydration denotes loss of free water in greater proportion than the loss of sodium.
What are the 4 different types of shock?
There are mainly four broad categories of shock: distributive, hypovolemic, cardiogenic, and obstructive. [1] The wide range of etiologies can contribute to each of these categories and are manifested by the final outcome of shock.
Why does afterload increase in hypovolemic shock?
Afterload pressures are increased in hypovolemic or cardiogenic shock due to vasoconstriction and following administration of alpha stimulants such as epinephrine, norepinephrine or dopamine in high doses (greater than 10 mcg/kg/min).
What is the difference between hypovolemia and dehydration?
HYPOVOLEMIA refers to any condition in which the extracellular fluid volume is reduced, and results in decreased tissue perfusion. It can be produced by either salt and water loss (e.g. with vomiting, diarrhea, diuretics, or 3rd spacing) OR by water loss alone, which is termed DEHYDRATION.
What causes of hypovolemia?
Sweating, excess urination, vomiting, or diarrhea can all cause rapid water loss. If the fluid is not adequately replaced through drinking water, a person can become dehydrated and eventually hypovolemic. Bleeding is the most common cause of hypovolemia.
How does vasodilation cause hypovolemia?
Vasodilation, particularly venodilation, is a primary cause of relative hypovolemia induced by anesthetic drugs. As with any hypovolemic state, relative hypovolemia may reduce venous return, CO, tissue oxygen delivery, and eventually arterial blood pressure, when compensatory mechanisms are inadequate or impaired.