Ans. B: Physical burn injury to the airways above the larynx Inflammatory and circulatory changes in burn patient produce a net flow of water, solutes and proteins from the intravascular to extravascular space. This flow occurs over the first 36 hours after the injury. As the burn size approaches 10-15% of the total body surface area (TBSA), the loss of intravascular fluid can cause a level of circulatory shock Once burned, the linings of nose, mouth, tongue, palate and larynx will sta to swell. After a few hours, they may sta interfere with the larynx and may completely block the airway, if action is not taken to secure an airway Physical burn injury to the airways below the larynx is a rare injury Circumferential burns may compromise circulation to a limb