What changes are typically observed in hypovolemia?

In cases of hypovolemia, which generally refers to a reduced volume of blood in the body, there are specific physiological changes that occur. The correct observation of decreased systemic blood pressure is attributed to the reduced circulating blood volume, which directly affects the heart's ability to generate sufficient pressure during circulation.

When hypovolemia is present, cardiac output also decreases. This is due to the heart not receiving enough blood to pump, which compromises the overall blood flow to various organs and tissues. Because of this compromised volume, central venous pressure (CVP), which reflects the pressure in the thoracic vena cava and thus the volume of blood returning to the heart, also decreases.

Additionally, pulmonary artery wedge pressure (PAWP) is typically associated with left atrial pressure, which is influenced by left ventricular filling. In a hypovolemic state, the reduced blood volume leads to a decrease in PAWP as the heart receives diminished blood flow and volume to fill the left atrium.

Therefore, decreased systemic blood pressure, decreased pulmonary artery wedge pressure, and decreased central venous pressure accurately describe the hemodynamic changes typically observed in hypovolemia.