This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'A patient with burns die within 24 hours. What could be the most probable cause: \nSelect and explain. \nA. Circulatory shock, B. Physical burn injury to the airways above the larynx, C. Physical burn injury to the airways below the larynx, D. Circumferential burn', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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', 'role': 'assistant'}]