Total absence of oxygen at the tissue level is called?

• A. Orthopnea
• B. Hypoxemia
• C. Anoxia
• D. Antipyretic

Answer: (C)

Anoxia is the total absence of oxygen at the tissue level. This means oxygen delivery to cells is completely cut off, forcing cells to rely on anaerobic metabolism and leading to rapid cellular injury if not corrected. It’s more severe than hypoxia (insufficient oxygen to tissues) and hypoxemia (low oxygen in the blood). The other terms don’t fit: orthopnea is difficulty breathing when lying flat, and an antipyretic is a fever-reducing medication. In EMS terms, anoxia signals a life-threatening emergency requiring immediate airway, breathing, and circulation support.