Both hemorrhage and severe burns can result in hypovolemia h

Both hemorrhage and severe burns can result in hypovolemia; however, the electrolyte imbalances are quite different. What are the fundamental differences between these two conditions? What alterations and manifestations would you expect with each?

Solution

Hypovolemia or oligemia is a state of decreased blood volume; or decrease in volume of blood plasma. It is thus loss of blood volume due to things such as bleeding or dehydration. It may result in multiple organ failure due to inadequate circulating volume and subsequent inadequate perfusion.

Critical burns often damage blood vessels and cause fluid loss, hypovolemia. In a burn injury, the systemic microcirculation loses its vessel wall integrity. Thus the proteins are lost in the inteistitium, which causes the intravascular colloid osmotic pressure to drop and allows fluid to escape from the circulatory system.There is a marked decrease in interstitial pressure due to the release of osmotically active particles. Therefore, a vaccum is created and fluid is sucked in the plasma space. There occurs increase in fluid flux into the interstitium due to sudden decrease in interstitial pressure and an increase in capillary permeability to protein. Therefore, there occurs a massive outpouring of fluids, electrolytes, and proteins into the interstitium. These changes cause loss of circulating plasma volume, hemoconcentration, edema formation, decreased urine and depressed cardiovascular acivity. Functional plasma volume in burn tissue can be restored only with expansion of the extracellular space.

Hemorrhagic shocks (both external and internal) due to deep cuts, injuries, trauma etc occurs when the body begins to shut down due to large amounts of blood loss. People suffering injuries that involve heavy bleeding may go into hemorrhagic shock, due to decreased blood plasma. Body needs to maintain a particular hemoglobin concentration with respect to plasma volume. Hypovolemia (blood volume decreases with no changes in hemoglobin concentration) occurs in rapidly bleeding individuals who do not receive intravenous fluids. In such cases hypovolemia is associated with substantial decreases in cardiac output and mixed venous oxygen tension. Aggressive fluid replacement may produce the condition of isovolemic anemia, which is characterized by adequate blood volume but decreased hemoglobin concentration and thus low oxygen carrying capacity. Slow and planned fluid replacement with appropriate colloids/saline improvises the condition.