What is anoxia?

• A. the absence of enough oxygen reaching the tissues
• B. total oxygen deprivation within tissues and organs
• C. an abnormally low concentration of oxygen in the blood
• D. an oxygen rich environment

Answer: (B)

Anoxia means a total absence of oxygen in the tissues. It is different from hypoxia, which is a reduced amount of oxygen, and from hypoxemia, which is low oxygen in the arterial blood. If tissues are anoxic, cellular respiration can’t proceed, ATP production stops, and cells can quickly become damaged or die if oxygen isn’t restored. In anesthesia and theatre nursing, this distinction matters because a patient can lose oxygen delivery or uptake due to airway problems, ventilation failure, or circulatory issues, leading to rapid tissue injury. The other descriptions describe partial oxygen deficiency or an oxygen-rich environment, which do not match the concept of complete oxygen deprivation.