Final answer:
The third complication during prolonged tourniquet application is hemoconcentration, an increase in the concentration of cells and solids in the blood due to a decrease in plasma volume caused by the pressure of the tourniquet.
Step-by-step explanation:
The third complication that can occur during the prolonged application of a tourniquet is hemoconcentration. Hemoconcentration refers to an increase in the concentration of cells and solids in the blood, often as a result of a decrease in plasma volume. Hemoconcentration refers to the increased concentration of red blood cells and other blood components due to decreased blood flow in the area where the tourniquet is applied. This can lead to the formation of blood clots, impaired oxygen delivery, and tissue damage. This can happen due to fluid being forced out of the blood vessels into the tissue as a result of the pressure applied from the tourniquet. If a tourniquet is applied for an excessive period, it can impede normal circulation, resulting in unnecessary oxygen deprivation and the accumulation of metabolic waste, which in turn can lead to tissue damage.