What is lost into burned and unburned tissues which can cause hypovolemic shock when burn size exceeds 20%?

When a burn injury exceeds 20% of the total body surface area, the body experiences significant fluid loss, primarily in the form of plasma. Plasma is the liquid component of blood that helps transport nutrients, hormones, and waste products throughout the body. In severe burns, it is the plasma that permeates damaged capillaries and tissues, leading to a condition known as hypovolemic shock. This occurs because the loss of plasma decreases the overall blood volume, impairing the circulation and delivery of oxygen to vital organs.

This loss of plasma involves both the burned tissues and the unburned surrounding areas. Consequently, the significant reduction in circulating volume can lead to shock if not adequately managed with fluid resuscitation. Recognizing the importance of plasma loss in the context of burn injuries is critical in trauma care and the initial treatment of burn victims.