In a patient with extensive burns covering 50% of the body, which physiologic abnormality is acutely life-threatening?

• A. Hyperthermia
• B. Polyuria
• C. Hypovolemia
• D. Infection

Answer: (C)

Massive burns disrupt the skin barrier and trigger a surge of capillary permeability, causing fluids and proteins to leak into the interstitial space (third-spacing). This leads to a rapid drop in intravascular volume, reduced venous return, and potential hypovolemic shock. In a patient with half of the body burned, this acute loss of circulating volume is the most immediate threat to life. The mainstay is rapid fluid resuscitation in the first 24 hours (often guided by formulas and urine output targets) to restore perfusion. While infection risk and other issues are significant in burn care, they are not the immediate life-threatening event in the initial resuscitation phase, and hyperthermia is typically managed but does not drive acute mortality as directly as hypovolemia does.